e-obs Stories & Publications
Discover a World of Wildlife Science
With over two decades of unwavering commitment to serving the needs of tagged animals and our valued customers, we’ve forged deep connections in the world of wildlife research. Our relentless passion drives us to continually elevate our products, expanding our portfolio to benefit you.
Proven Impact
Our products have played a pivotal role in countless studies, spanning a diverse array of remarkable creatures, from coconut crabs (Birgus latro) to majestic red kites (Milvus milvus) and agile cheetahs (Acinonyx jubatus). The e-obs community, fueled by our technology, consistently pushes the boundaries of wildlife science, resulting in a wealth of publications that testify to the excellence of our materials and the exceptional work of our users.
21.
Uiterwaal, Stella F; Deem, Sharon L; Braude, Stanton H; Dell, Anthony I; O’Shea, Megan; Palmer, Jamie; Parikh, Sara; Wise, August; Blake, Stephen
In: Journal of Mammalogy, pp. gyaf077, 2025, ISSN: 0022-2372, 1545-1542.
Abstract | Links | BibTeX | Tags:
@article{uiterwaal_space_2025,
title = {Space use and environmental drivers of Northern Raccoon ( textitProcyon lotor ) activity in an urban park: evidence for avoidance of road crossings},
author = {Stella F Uiterwaal and Sharon L Deem and Stanton H Braude and Anthony I Dell and Megan O’Shea and Jamie Palmer and Sara Parikh and August Wise and Stephen Blake},
editor = {John Scheibe},
url = {https://academic.oup.com/jmammal/advance-article/doi/10.1093/jmammal/gyaf077/8341051},
doi = {10.1093/jmammal/gyaf077},
issn = {0022-2372, 1545-1542},
year = {2025},
date = {2025-11-01},
urldate = {2025-12-02},
journal = {Journal of Mammalogy},
pages = {gyaf077},
abstract = {Abstract
Urban parks often integrate seminatural habitats with areas of intensive human use and infrastructure. Wildlife behavior in such environments is influenced by various factors including human impacts, environmental conditions, and temporal rhythms of species. In this study, we analyzed location and activity data from 10 raccoons (Procyon lotor) in Forest Park, a large urban park in St. Louis, Missouri, USA. We first present metrics on Northern Raccoon (hereafter, raccoon) movement and space use, and then explore how road crossings correlate with movement. Our findings indicate that raccoon steps cross fewer roads than simulated steps, indicating an avoidance of road crossings despite the association of roads with food resources from human activities. Additionally, we employed tri-axial accelerometers to investigate factors affecting raccoon activity patterns. Our analysis reveals distinct annual and daily activity cycles and increased activity during warmer temperatures. We also show that total nighttime activity is highest during longer nights, despite increased hourly activity during shorter nights. Our results highlight the influence of environmental factors on urban wildlife behavior and illustrate how urban settings shape space use and movement.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract
Urban parks often integrate seminatural habitats with areas of intensive human use and infrastructure. Wildlife behavior in such environments is influenced by various factors including human impacts, environmental conditions, and temporal rhythms of species. In this study, we analyzed location and activity data from 10 raccoons (Procyon lotor) in Forest Park, a large urban park in St. Louis, Missouri, USA. We first present metrics on Northern Raccoon (hereafter, raccoon) movement and space use, and then explore how road crossings correlate with movement. Our findings indicate that raccoon steps cross fewer roads than simulated steps, indicating an avoidance of road crossings despite the association of roads with food resources from human activities. Additionally, we employed tri-axial accelerometers to investigate factors affecting raccoon activity patterns. Our analysis reveals distinct annual and daily activity cycles and increased activity during warmer temperatures. We also show that total nighttime activity is highest during longer nights, despite increased hourly activity during shorter nights. Our results highlight the influence of environmental factors on urban wildlife behavior and illustrate how urban settings shape space use and movement.
Urban parks often integrate seminatural habitats with areas of intensive human use and infrastructure. Wildlife behavior in such environments is influenced by various factors including human impacts, environmental conditions, and temporal rhythms of species. In this study, we analyzed location and activity data from 10 raccoons (Procyon lotor) in Forest Park, a large urban park in St. Louis, Missouri, USA. We first present metrics on Northern Raccoon (hereafter, raccoon) movement and space use, and then explore how road crossings correlate with movement. Our findings indicate that raccoon steps cross fewer roads than simulated steps, indicating an avoidance of road crossings despite the association of roads with food resources from human activities. Additionally, we employed tri-axial accelerometers to investigate factors affecting raccoon activity patterns. Our analysis reveals distinct annual and daily activity cycles and increased activity during warmer temperatures. We also show that total nighttime activity is highest during longer nights, despite increased hourly activity during shorter nights. Our results highlight the influence of environmental factors on urban wildlife behavior and illustrate how urban settings shape space use and movement.
22.
Ulrey, Erin E; Goodman, Paige E; Watkins, Sara A; Bakner, Nicholas W; Kilgo, John C; Lavretsky, Philip; Bothwell, Helen M; Collier, Bret A; Chamberlain, Michael J
Genetic analysis provides insight into the mating system of textitMeleagris gallopavo (Wild Turkey) and reveals frequent extra-pair paternity Journal Article
In: Ornithology, pp. ukaf055, 2025, ISSN: 0004-8038, 2732-4613.
Abstract | Links | BibTeX | Tags: Meleagris gallopavo, Wild Turkey
@article{ulrey_genetic_2025,
title = {Genetic analysis provides insight into the mating system of textitMeleagris gallopavo (Wild Turkey) and reveals frequent extra-pair paternity},
author = {Erin E Ulrey and Paige E Goodman and Sara A Watkins and Nicholas W Bakner and John C Kilgo and Philip Lavretsky and Helen M Bothwell and Bret A Collier and Michael J Chamberlain},
url = {https://academic.oup.com/auk/advance-article/doi/10.1093/ornithology/ukaf055/8279657},
doi = {10.1093/ornithology/ukaf055},
issn = {0004-8038, 2732-4613},
year = {2025},
date = {2025-10-01},
urldate = {2025-10-13},
journal = {Ornithology},
pages = {ukaf055},
abstract = {Abstract
Lekking is a polygynous mating strategy where males gather on communal display grounds to attract females, who primarily visit these sites to mate. Females at leks are considered free to choose their mates, and only a few dominant males are expected to obtain most mating opportunities. Meleagris gallopavo (Wild Turkey) is a widely distributed, ground-nesting, uniparental galliform that exhibits a polygynous mating strategy, but aspects of the species’ mating system are poorly understood. Our objective was to describe the mating system for M. g. sylvestris (Eastern Wild Turkey) using DNA extracted from eggshell membranes obtained from hatched clutches. We identified 307 offspring across 34 nests, assigned parentage, and examined sibling relationships among offspring. Our findings revealed that 19 (56%) nests had a single mother and father, whereas we detected multiple paternity in 15 (44%) nests. Additionally, we found that intraspecific nest parasitism occurred in 2.94% of nests, and we observed quasi-parasitism in only one nest containing an egg from an additional mother, indicating that parasitism is not a common alternative reproductive strategy represented in successful M. g. sylvestris nests. We observed that occurrences of multiple paternity were comparable to rates reported in other lekking species and suggest that multiple mating by females is an important alternative reproductive strategy for wild turkeys. Number of offspring sired by individual males increased with an increasing number of mates, and 6 males were responsible for 28% of all offspring, indicating a few males are most likely obtaining most mating opportunities. Our findings offer new insights into sexual selection and mating strategies of M. gallopavo.},
keywords = {Meleagris gallopavo, Wild Turkey},
pubstate = {published},
tppubtype = {article}
}
Abstract
Lekking is a polygynous mating strategy where males gather on communal display grounds to attract females, who primarily visit these sites to mate. Females at leks are considered free to choose their mates, and only a few dominant males are expected to obtain most mating opportunities. Meleagris gallopavo (Wild Turkey) is a widely distributed, ground-nesting, uniparental galliform that exhibits a polygynous mating strategy, but aspects of the species’ mating system are poorly understood. Our objective was to describe the mating system for M. g. sylvestris (Eastern Wild Turkey) using DNA extracted from eggshell membranes obtained from hatched clutches. We identified 307 offspring across 34 nests, assigned parentage, and examined sibling relationships among offspring. Our findings revealed that 19 (56%) nests had a single mother and father, whereas we detected multiple paternity in 15 (44%) nests. Additionally, we found that intraspecific nest parasitism occurred in 2.94% of nests, and we observed quasi-parasitism in only one nest containing an egg from an additional mother, indicating that parasitism is not a common alternative reproductive strategy represented in successful M. g. sylvestris nests. We observed that occurrences of multiple paternity were comparable to rates reported in other lekking species and suggest that multiple mating by females is an important alternative reproductive strategy for wild turkeys. Number of offspring sired by individual males increased with an increasing number of mates, and 6 males were responsible for 28% of all offspring, indicating a few males are most likely obtaining most mating opportunities. Our findings offer new insights into sexual selection and mating strategies of M. gallopavo.
Lekking is a polygynous mating strategy where males gather on communal display grounds to attract females, who primarily visit these sites to mate. Females at leks are considered free to choose their mates, and only a few dominant males are expected to obtain most mating opportunities. Meleagris gallopavo (Wild Turkey) is a widely distributed, ground-nesting, uniparental galliform that exhibits a polygynous mating strategy, but aspects of the species’ mating system are poorly understood. Our objective was to describe the mating system for M. g. sylvestris (Eastern Wild Turkey) using DNA extracted from eggshell membranes obtained from hatched clutches. We identified 307 offspring across 34 nests, assigned parentage, and examined sibling relationships among offspring. Our findings revealed that 19 (56%) nests had a single mother and father, whereas we detected multiple paternity in 15 (44%) nests. Additionally, we found that intraspecific nest parasitism occurred in 2.94% of nests, and we observed quasi-parasitism in only one nest containing an egg from an additional mother, indicating that parasitism is not a common alternative reproductive strategy represented in successful M. g. sylvestris nests. We observed that occurrences of multiple paternity were comparable to rates reported in other lekking species and suggest that multiple mating by females is an important alternative reproductive strategy for wild turkeys. Number of offspring sired by individual males increased with an increasing number of mates, and 6 males were responsible for 28% of all offspring, indicating a few males are most likely obtaining most mating opportunities. Our findings offer new insights into sexual selection and mating strategies of M. gallopavo.
23.
Berry, Paul; Dammhahn, Melanie; Hauptfleisch, Morgan; Hering, Robert; Blaum, Niels
Environmental cues and individuality shape diel and seasonal antelope behaviour in African drylands Journal Article
In: Movement Ecology, vol. 13, no. 1, pp. 77, 2025, ISSN: 2051-3933.
Abstract | Links | BibTeX | Tags: African, Antelope, Antidorcas marsupialis, common eland (Taurotragus oryx), greater kudu (Tragelaphus strepsiceros), springbok, Ungulate
@article{berry_environmental_2025,
title = {Environmental cues and individuality shape diel and seasonal antelope behaviour in African drylands},
author = {Paul Berry and Melanie Dammhahn and Morgan Hauptfleisch and Robert Hering and Niels Blaum},
url = {https://movementecologyjournal.biomedcentral.com/articles/10.1186/s40462-025-00604-y},
doi = {10.1186/s40462-025-00604-y},
issn = {2051-3933},
year = {2025},
date = {2025-10-01},
urldate = {2025-11-04},
journal = {Movement Ecology},
volume = {13},
number = {1},
pages = {77},
abstract = {Abstract
Large herbivores play a central role in dryland ecosystems, influencing vegetation dynamics, nutrient cycling, and trophic interactions. While they are adapted to cope with harsh climates, their persistence is increasingly threatened by anthropogenic pressures. However, the behavioural strategies they use to cope with these combined environmental challenges remain understudied. Using multi-year accelerometer data from springbok (
Antidorcas marsupialis
), greater kudu (
Tragelaphus strepsiceros
), and common eland (
Taurotragus oryx
) in northern Namibia, we examined diel and seasonal behaviour in relation to vegetation greenness (NDVI), temperature, lunar phase, and individual differences. While activity was mainly diurnal, nocturnal behaviour was closely linked to the lunar cycle: during moonlit nights, antelope, particularly springbok, increased feeding and walking while reducing rumination and resting. Seasonal patterns tracked plant phenology, with head-up feeding rising sharply during the woody flush at the onset of the green season, while head-down feeding followed grass growth but declined as the season progressed. Seasonal dynamics differed from studies in other regions, suggesting that prolonged dryness and mild winters favour energy conservation over compensatory feeding. Hierarchical partitioning showed that feeding behaviours were environmentally cued, driven by plant phenology and seasonality, whereas walking, rumination, and resting were shaped mainly by individuality. Ambient temperature added little explanatory power, indicating that long-term rhythms are governed more by vegetation cycles and photoperiod than by thermal conditions. Our findings reveal that external cues such as phenology and moonlight synchronise foraging across individuals, while intrinsic factors contribute most to the variation in walking, ruminating and resting, potentially buffering populations against environmental variability. Recognising the combined influence of environmental cues and individual variation is essential for predicting how dryland herbivores will respond to climate and land-use change.},
keywords = {African, Antelope, Antidorcas marsupialis, common eland (Taurotragus oryx), greater kudu (Tragelaphus strepsiceros), springbok, Ungulate},
pubstate = {published},
tppubtype = {article}
}
Abstract
Large herbivores play a central role in dryland ecosystems, influencing vegetation dynamics, nutrient cycling, and trophic interactions. While they are adapted to cope with harsh climates, their persistence is increasingly threatened by anthropogenic pressures. However, the behavioural strategies they use to cope with these combined environmental challenges remain understudied. Using multi-year accelerometer data from springbok (
Antidorcas marsupialis
), greater kudu (
Tragelaphus strepsiceros
), and common eland (
Taurotragus oryx
) in northern Namibia, we examined diel and seasonal behaviour in relation to vegetation greenness (NDVI), temperature, lunar phase, and individual differences. While activity was mainly diurnal, nocturnal behaviour was closely linked to the lunar cycle: during moonlit nights, antelope, particularly springbok, increased feeding and walking while reducing rumination and resting. Seasonal patterns tracked plant phenology, with head-up feeding rising sharply during the woody flush at the onset of the green season, while head-down feeding followed grass growth but declined as the season progressed. Seasonal dynamics differed from studies in other regions, suggesting that prolonged dryness and mild winters favour energy conservation over compensatory feeding. Hierarchical partitioning showed that feeding behaviours were environmentally cued, driven by plant phenology and seasonality, whereas walking, rumination, and resting were shaped mainly by individuality. Ambient temperature added little explanatory power, indicating that long-term rhythms are governed more by vegetation cycles and photoperiod than by thermal conditions. Our findings reveal that external cues such as phenology and moonlight synchronise foraging across individuals, while intrinsic factors contribute most to the variation in walking, ruminating and resting, potentially buffering populations against environmental variability. Recognising the combined influence of environmental cues and individual variation is essential for predicting how dryland herbivores will respond to climate and land-use change.
Large herbivores play a central role in dryland ecosystems, influencing vegetation dynamics, nutrient cycling, and trophic interactions. While they are adapted to cope with harsh climates, their persistence is increasingly threatened by anthropogenic pressures. However, the behavioural strategies they use to cope with these combined environmental challenges remain understudied. Using multi-year accelerometer data from springbok (
Antidorcas marsupialis
), greater kudu (
Tragelaphus strepsiceros
), and common eland (
Taurotragus oryx
) in northern Namibia, we examined diel and seasonal behaviour in relation to vegetation greenness (NDVI), temperature, lunar phase, and individual differences. While activity was mainly diurnal, nocturnal behaviour was closely linked to the lunar cycle: during moonlit nights, antelope, particularly springbok, increased feeding and walking while reducing rumination and resting. Seasonal patterns tracked plant phenology, with head-up feeding rising sharply during the woody flush at the onset of the green season, while head-down feeding followed grass growth but declined as the season progressed. Seasonal dynamics differed from studies in other regions, suggesting that prolonged dryness and mild winters favour energy conservation over compensatory feeding. Hierarchical partitioning showed that feeding behaviours were environmentally cued, driven by plant phenology and seasonality, whereas walking, rumination, and resting were shaped mainly by individuality. Ambient temperature added little explanatory power, indicating that long-term rhythms are governed more by vegetation cycles and photoperiod than by thermal conditions. Our findings reveal that external cues such as phenology and moonlight synchronise foraging across individuals, while intrinsic factors contribute most to the variation in walking, ruminating and resting, potentially buffering populations against environmental variability. Recognising the combined influence of environmental cues and individual variation is essential for predicting how dryland herbivores will respond to climate and land-use change.
24.
Ulrey, Erin E.; Goodman, Paige E.; Watkins, Sara A.; Bakner, Nicholas W.; Wightman, Patrick H.; Argabright, Chad M.; Lavretsky, Philip; Kilgo, John C.; Bothwell, Helen M.; Collier, Bret A.; Chamberlain, Michael J.
Female biased offspring sex ratios of eastern wild turkeys across the southeastern United States Journal Article
In: Journal of Avian Biology, vol. 2025, no. 5, pp. e03515, 2025, ISSN: 0908-8857, 1600-048X.
Abstract | Links | BibTeX | Tags:
@article{ulrey_female_2025,
title = {Female biased offspring sex ratios of eastern wild turkeys across the southeastern United States},
author = {Erin E. Ulrey and Paige E. Goodman and Sara A. Watkins and Nicholas W. Bakner and Patrick H. Wightman and Chad M. Argabright and Philip Lavretsky and John C. Kilgo and Helen M. Bothwell and Bret A. Collier and Michael J. Chamberlain},
url = {https://nsojournals.onlinelibrary.wiley.com/doi/10.1002/jav.03515},
doi = {10.1002/jav.03515},
issn = {0908-8857, 1600-048X},
year = {2025},
date = {2025-09-01},
urldate = {2025-12-03},
journal = {Journal of Avian Biology},
volume = {2025},
number = {5},
pages = {e03515},
abstract = {Prevailing theory suggests that sex ratios of offspring at birth should not differ from parity if costs of producing offspring of both sexes are similar. However, offspring sex ratios may deviate from parity when there is sex specific variation in fitness returns. We assessed offspring sex ratios of eastern wild turkeys (
Meleagris gallopavo silvestris
) across the southeastern United States by molecular determination of sex from eggshell membranes of hatched clutches. Our objective was to evaluate whether offspring sex ratios differed from parity and to examine potential drivers of variation in offspring sex ratios across and within our study sites. We sexed 724 offspring from 83 nests using molecular markers and identified 278 males and 446 females, with a sex ratio of 38% male. We found that offspring sex ratios were biased towards females on three hunted study sites but did not differ from parity at our remaining non‐hunted site. Specifically, on sites with spring hunting, where male mortality was increased due to harvest, the probability of producing male offspring was 47% lower than on our non‐hunted site. Our findings suggest that female wild turkeys may adaptively adjust the sex ratio of their offspring based on predictable, sex specific mortality, favoring the sex with higher survival, thereby enhancing their lifetime fitness. Our results provide insights into reproductive strategies of wild turkeys and the influence of hunting on sex ratios in Galliform offspring.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Prevailing theory suggests that sex ratios of offspring at birth should not differ from parity if costs of producing offspring of both sexes are similar. However, offspring sex ratios may deviate from parity when there is sex specific variation in fitness returns. We assessed offspring sex ratios of eastern wild turkeys (
Meleagris gallopavo silvestris
) across the southeastern United States by molecular determination of sex from eggshell membranes of hatched clutches. Our objective was to evaluate whether offspring sex ratios differed from parity and to examine potential drivers of variation in offspring sex ratios across and within our study sites. We sexed 724 offspring from 83 nests using molecular markers and identified 278 males and 446 females, with a sex ratio of 38% male. We found that offspring sex ratios were biased towards females on three hunted study sites but did not differ from parity at our remaining non‐hunted site. Specifically, on sites with spring hunting, where male mortality was increased due to harvest, the probability of producing male offspring was 47% lower than on our non‐hunted site. Our findings suggest that female wild turkeys may adaptively adjust the sex ratio of their offspring based on predictable, sex specific mortality, favoring the sex with higher survival, thereby enhancing their lifetime fitness. Our results provide insights into reproductive strategies of wild turkeys and the influence of hunting on sex ratios in Galliform offspring.
Meleagris gallopavo silvestris
) across the southeastern United States by molecular determination of sex from eggshell membranes of hatched clutches. Our objective was to evaluate whether offspring sex ratios differed from parity and to examine potential drivers of variation in offspring sex ratios across and within our study sites. We sexed 724 offspring from 83 nests using molecular markers and identified 278 males and 446 females, with a sex ratio of 38% male. We found that offspring sex ratios were biased towards females on three hunted study sites but did not differ from parity at our remaining non‐hunted site. Specifically, on sites with spring hunting, where male mortality was increased due to harvest, the probability of producing male offspring was 47% lower than on our non‐hunted site. Our findings suggest that female wild turkeys may adaptively adjust the sex ratio of their offspring based on predictable, sex specific mortality, favoring the sex with higher survival, thereby enhancing their lifetime fitness. Our results provide insights into reproductive strategies of wild turkeys and the influence of hunting on sex ratios in Galliform offspring.
25.
Curk, Teja; Santangeli, Andrea; Rast, Wanja; Portas, Ruben; Shatumbu, Gabriel; Cloete, Claudine; Beytell, Piet; Aschenborn, Ortwin; Melzheimer, Joerg
Using animal tracking for early detection of mass poisoning events Journal Article
In: Journal of Applied Ecology, vol. 62, no. 9, pp. 2202–2212, 2025, ISSN: 0021-8901, 1365-2664.
Abstract | Links | BibTeX | Tags:
@article{curk_using_2025,
title = {Using animal tracking for early detection of mass poisoning events},
author = {Teja Curk and Andrea Santangeli and Wanja Rast and Ruben Portas and Gabriel Shatumbu and Claudine Cloete and Piet Beytell and Ortwin Aschenborn and Joerg Melzheimer},
url = {https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.70128},
doi = {10.1111/1365-2664.70128},
issn = {0021-8901, 1365-2664},
year = {2025},
date = {2025-09-01},
urldate = {2025-12-02},
journal = {Journal of Applied Ecology},
volume = {62},
number = {9},
pages = {2202\textendash2212},
abstract = {Abstract
Amidst the sixth mass extinction, some animal groups, such as vultures, the only obligate scavengers among vertebrates, are disappearing at an unprecedented rate. Vulture populations worldwide are declining, primarily due to poisoning. As many vulture species are social foragers, they can congregate in large numbers to scavenge at a carcass, potentially increasing their exposure to poisoning risk. Current anti‐poisoning prevention and mitigation measures are insufficient to tackle this threat. There is an urgent need for new effective strategies to prevent mass vulture mortality.
In this study, we applied agent‐based modelling using white‐backed vulture (
Gyps africanus
) data from Namibia to: (1) quantify the impact of different foraging strategies on vulture poisoning risk and (2) evaluate the cost‐effectiveness of using vultures as sentinels for poisoning detection. This approach involves GPS tracking of various numbers of vultures and using the data to quickly detect poisoning incidents and decontaminate carcasses. These actions help mitigate further vulture mortality and prevent mass poisoning.
Our findings demonstrate that social foraging significantly increases the risk of poisoning among white‐backed vultures. However, GPS tracking of individual vultures enables earlier detection of poisoning events, thereby reducing associated mortalities. Poisoning mitigation effectiveness improves with both the number of tracked individuals and the speed of decontamination response. According to our agent‐based model tailored to our study system and species, tracking approximately 5% of the population (25 individuals) offers a good balance between cost and effectiveness, requiring an estimated budget of USD 60,000. Using this strategy and approach, and assuming a response time within 2 h, up to 45% of poisoning‐related deaths could be prevented.
Synthesis and applications
: Our results suggest that, in order to reduce mortality incidences from poisoning in our study system and species, it is sufficient to track a small proportion of the vulture population, which would act as sentinels for the rest. By evaluating the costs and ecological benefits of alternative strategies, varying in number of birds tagged or response time, we provide evidence‐based solutions that practitioners can use to design conservation plans. These findings are therefore instrumental in supporting vulture and scavenger conservation policy and practice.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract
Amidst the sixth mass extinction, some animal groups, such as vultures, the only obligate scavengers among vertebrates, are disappearing at an unprecedented rate. Vulture populations worldwide are declining, primarily due to poisoning. As many vulture species are social foragers, they can congregate in large numbers to scavenge at a carcass, potentially increasing their exposure to poisoning risk. Current anti‐poisoning prevention and mitigation measures are insufficient to tackle this threat. There is an urgent need for new effective strategies to prevent mass vulture mortality.
In this study, we applied agent‐based modelling using white‐backed vulture (
Gyps africanus
) data from Namibia to: (1) quantify the impact of different foraging strategies on vulture poisoning risk and (2) evaluate the cost‐effectiveness of using vultures as sentinels for poisoning detection. This approach involves GPS tracking of various numbers of vultures and using the data to quickly detect poisoning incidents and decontaminate carcasses. These actions help mitigate further vulture mortality and prevent mass poisoning.
Our findings demonstrate that social foraging significantly increases the risk of poisoning among white‐backed vultures. However, GPS tracking of individual vultures enables earlier detection of poisoning events, thereby reducing associated mortalities. Poisoning mitigation effectiveness improves with both the number of tracked individuals and the speed of decontamination response. According to our agent‐based model tailored to our study system and species, tracking approximately 5% of the population (25 individuals) offers a good balance between cost and effectiveness, requiring an estimated budget of USD 60,000. Using this strategy and approach, and assuming a response time within 2 h, up to 45% of poisoning‐related deaths could be prevented.
Synthesis and applications
: Our results suggest that, in order to reduce mortality incidences from poisoning in our study system and species, it is sufficient to track a small proportion of the vulture population, which would act as sentinels for the rest. By evaluating the costs and ecological benefits of alternative strategies, varying in number of birds tagged or response time, we provide evidence‐based solutions that practitioners can use to design conservation plans. These findings are therefore instrumental in supporting vulture and scavenger conservation policy and practice.
Amidst the sixth mass extinction, some animal groups, such as vultures, the only obligate scavengers among vertebrates, are disappearing at an unprecedented rate. Vulture populations worldwide are declining, primarily due to poisoning. As many vulture species are social foragers, they can congregate in large numbers to scavenge at a carcass, potentially increasing their exposure to poisoning risk. Current anti‐poisoning prevention and mitigation measures are insufficient to tackle this threat. There is an urgent need for new effective strategies to prevent mass vulture mortality.
In this study, we applied agent‐based modelling using white‐backed vulture (
Gyps africanus
) data from Namibia to: (1) quantify the impact of different foraging strategies on vulture poisoning risk and (2) evaluate the cost‐effectiveness of using vultures as sentinels for poisoning detection. This approach involves GPS tracking of various numbers of vultures and using the data to quickly detect poisoning incidents and decontaminate carcasses. These actions help mitigate further vulture mortality and prevent mass poisoning.
Our findings demonstrate that social foraging significantly increases the risk of poisoning among white‐backed vultures. However, GPS tracking of individual vultures enables earlier detection of poisoning events, thereby reducing associated mortalities. Poisoning mitigation effectiveness improves with both the number of tracked individuals and the speed of decontamination response. According to our agent‐based model tailored to our study system and species, tracking approximately 5% of the population (25 individuals) offers a good balance between cost and effectiveness, requiring an estimated budget of USD 60,000. Using this strategy and approach, and assuming a response time within 2 h, up to 45% of poisoning‐related deaths could be prevented.
Synthesis and applications
: Our results suggest that, in order to reduce mortality incidences from poisoning in our study system and species, it is sufficient to track a small proportion of the vulture population, which would act as sentinels for the rest. By evaluating the costs and ecological benefits of alternative strategies, varying in number of birds tagged or response time, we provide evidence‐based solutions that practitioners can use to design conservation plans. These findings are therefore instrumental in supporting vulture and scavenger conservation policy and practice.
26.
Paschotto, Fernanda Riera; Pacífico, Erica; Filadelfo, Thiago; Favoretto, Gabriela Rodrigues; Oshima, Júlia; Cardoso, Paulo; Dénes, Francisco Voeroes
2025.
Abstract | Links | BibTeX | Tags:
@misc{riera_paschotto_revealing_2025,
title = {Revealing the unknown world of the endangered Lear's macaw using GPS-tracking data: identification of critical habitats for conservation},
author = {Fernanda Riera Paschotto and Erica Pac\'{i}fico and Thiago Filadelfo and Gabriela Rodrigues Favoretto and J\'{u}lia Oshima and Paulo Cardoso and Francisco Voeroes D\'{e}nes},
url = {https://ecoevorxiv.org/repository/view/10029/},
doi = {10.32942/X2W06Z},
year = {2025},
date = {2025-08-01},
urldate = {2025-12-02},
abstract = {Understanding space use and home range is essential for the conservation planning of threatened species as it helps to assess the suitability, extent, and placement of conservation areas that are imperative for species survival and protection. The Endangered Lear’s macaw (Anodorhynchus leari), a highly mobile frugivore, feeding specialist and endemic to Brazil’s Caatinga dry forest, faces ongoing habitat degradation. In this study, we identified critical habitats by examining the spatial distribution of feeding, resting, and roosting sites and investigating home range size and its temporal variation. We GPS-tracked juvenile macaws and estimated fortnightly home ranges with autocorrelated kernel density estimators. We assessed if extrinsic factors, such as tagging site, seasonality, rainfall and vegetation productivity (proxies for food availability) influenced home range size. Our findings reveal considerable variation in home ranges, with an average of 850.15 km² (1.24-8,549.48 km²). Home ranges expanded significantly during the dry season (mean 1,097.06 km²), representing a 2.14-fold increase from the wet season. We also found that site and season primarily drove home range size, while vegetation productivity and rainfall had limited influence. This suggests that macaw movements may respond to complex interactions between rainfall, landscape composition and configuration, and food availability rather than direct resource fluctuations. This is the first study to estimate home ranges for Lear’s macaw, providing critical insights into its spatial ecology. Our findings underscore the importance of preserving key roosting and feeding areas and highlight the need for continuous monitoring to address threats posed by environmental changes and human activity.},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Understanding space use and home range is essential for the conservation planning of threatened species as it helps to assess the suitability, extent, and placement of conservation areas that are imperative for species survival and protection. The Endangered Lear’s macaw (Anodorhynchus leari), a highly mobile frugivore, feeding specialist and endemic to Brazil’s Caatinga dry forest, faces ongoing habitat degradation. In this study, we identified critical habitats by examining the spatial distribution of feeding, resting, and roosting sites and investigating home range size and its temporal variation. We GPS-tracked juvenile macaws and estimated fortnightly home ranges with autocorrelated kernel density estimators. We assessed if extrinsic factors, such as tagging site, seasonality, rainfall and vegetation productivity (proxies for food availability) influenced home range size. Our findings reveal considerable variation in home ranges, with an average of 850.15 km² (1.24-8,549.48 km²). Home ranges expanded significantly during the dry season (mean 1,097.06 km²), representing a 2.14-fold increase from the wet season. We also found that site and season primarily drove home range size, while vegetation productivity and rainfall had limited influence. This suggests that macaw movements may respond to complex interactions between rainfall, landscape composition and configuration, and food availability rather than direct resource fluctuations. This is the first study to estimate home ranges for Lear’s macaw, providing critical insights into its spatial ecology. Our findings underscore the importance of preserving key roosting and feeding areas and highlight the need for continuous monitoring to address threats posed by environmental changes and human activity.
27.
Jorzik, Isabel; Fiedler, Wolfgang; Kaatz, Michael; Rotics, Shay; Nathan, Ran; Wikelski, Martin; Flack, Andrea
Timing shapes flyway selection in juvenile white storks at the European migratory divide Journal Article
In: Journal of Ornithology, 2025, ISSN: 2193-7192, 2193-7206.
Abstract | Links | BibTeX | Tags: Ciconia ciconia, White Stork
@article{jorzik_timing_2025,
title = {Timing shapes flyway selection in juvenile white storks at the European migratory divide},
author = {Isabel Jorzik and Wolfgang Fiedler and Michael Kaatz and Shay Rotics and Ran Nathan and Martin Wikelski and Andrea Flack},
url = {https://link.springer.com/10.1007/s10336-025-02322-z},
doi = {10.1007/s10336-025-02322-z},
issn = {2193-7192, 2193-7206},
year = {2025},
date = {2025-08-01},
urldate = {2025-09-16},
journal = {Journal of Ornithology},
abstract = {Migratory divides are junctures where populations of the same species following different migratory routes intersect. In white storks (Ciconia ciconia), migration strategies differ between the western and eastern flyways, yet the factors influencing flyway selection remain unclear. In this study, we used GPS tracking data from 151 juvenile storks to examine what determines flyway selection of juvenile, first-time migrants. Generalized linear mixed models revealed that timing-related variables were the primary factors correlated to flyway choice. Eastern flyway storks had significantly later fledging dates, shorter pre-migratory periods, and a narrower migration onset window compared to Western flyway storks. While temporal co-occurrence was observed in the overlap areas, western storks generally used these areas earlier. Wind and sex were not found to affect the juvenile flyway choice. Our results show that western storks may be experiencing favorable conditions of reduced time pressure and shorter overall migration routes. These migratory differences could still potentially contribute to the concurrent shift in population dynamics at the migratory divide toward the Western flyway, by inducing carry-over effects or affecting the adults' reproduction success. We suggest that understanding the dynamics of the migratory divide is important for maintaining behavioral diversity and preventing the loss of migratory routes.},
keywords = {Ciconia ciconia, White Stork},
pubstate = {published},
tppubtype = {article}
}
Migratory divides are junctures where populations of the same species following different migratory routes intersect. In white storks (Ciconia ciconia), migration strategies differ between the western and eastern flyways, yet the factors influencing flyway selection remain unclear. In this study, we used GPS tracking data from 151 juvenile storks to examine what determines flyway selection of juvenile, first-time migrants. Generalized linear mixed models revealed that timing-related variables were the primary factors correlated to flyway choice. Eastern flyway storks had significantly later fledging dates, shorter pre-migratory periods, and a narrower migration onset window compared to Western flyway storks. While temporal co-occurrence was observed in the overlap areas, western storks generally used these areas earlier. Wind and sex were not found to affect the juvenile flyway choice. Our results show that western storks may be experiencing favorable conditions of reduced time pressure and shorter overall migration routes. These migratory differences could still potentially contribute to the concurrent shift in population dynamics at the migratory divide toward the Western flyway, by inducing carry-over effects or affecting the adults' reproduction success. We suggest that understanding the dynamics of the migratory divide is important for maintaining behavioral diversity and preventing the loss of migratory routes.
28.
Paschotto, Fernanda Riera; Pacífico, Erica; Filadelfo, Thiago; Favoretto, Gabriela Rodrigues; Oshima, Júlia; Cardoso, Paulo; Dénes, Francisco Voeroes
2025.
Abstract | Links | BibTeX | Tags:
@misc{riera_paschotto_revealing_2025-1,
title = {Revealing the unknown world of the endangered Lear's macaw using GPS-tracking data: identification of critical habitats for conservation},
author = {Fernanda Riera Paschotto and Erica Pac\'{i}fico and Thiago Filadelfo and Gabriela Rodrigues Favoretto and J\'{u}lia Oshima and Paulo Cardoso and Francisco Voeroes D\'{e}nes},
url = {https://ecoevorxiv.org/repository/view/10029/},
doi = {10.32942/X2W06Z},
year = {2025},
date = {2025-08-01},
urldate = {2026-04-16},
publisher = {Biology},
abstract = {Understanding space use and home range is essential for the conservation planning of threatened species as it helps to assess the suitability, extent, and placement of conservation areas that are imperative for species survival and protection. The Endangered Lear’s macaw (Anodorhynchus leari), a highly mobile frugivore, feeding specialist and endemic to Brazil’s Caatinga dry forest, faces ongoing habitat degradation. In this study, we identified critical habitats by examining the spatial distribution of feeding, resting, and roosting sites and investigating home range size and its temporal variation. We GPS-tracked juvenile macaws and estimated fortnightly home ranges with autocorrelated kernel density estimators. We assessed if extrinsic factors, such as tagging site, seasonality, rainfall and vegetation productivity (proxies for food availability) influenced home range size. Our findings reveal considerable variation in home ranges, with an average of 850.15 km² (1.24-8,549.48 km²). Home ranges expanded significantly during the dry season (mean 1,097.06 km²), representing a 2.14-fold increase from the wet season. We also found that site and season primarily drove home range size, while vegetation productivity and rainfall had limited influence. This suggests that macaw movements may respond to complex interactions between rainfall, landscape composition and configuration, and food availability rather than direct resource fluctuations. This is the first study to estimate home ranges for Lear’s macaw, providing critical insights into its spatial ecology. Our findings underscore the importance of preserving key roosting and feeding areas and highlight the need for continuous monitoring to address threats posed by environmental changes and human activity.},
keywords = {},
pubstate = {published},
tppubtype = {misc}
}
Understanding space use and home range is essential for the conservation planning of threatened species as it helps to assess the suitability, extent, and placement of conservation areas that are imperative for species survival and protection. The Endangered Lear’s macaw (Anodorhynchus leari), a highly mobile frugivore, feeding specialist and endemic to Brazil’s Caatinga dry forest, faces ongoing habitat degradation. In this study, we identified critical habitats by examining the spatial distribution of feeding, resting, and roosting sites and investigating home range size and its temporal variation. We GPS-tracked juvenile macaws and estimated fortnightly home ranges with autocorrelated kernel density estimators. We assessed if extrinsic factors, such as tagging site, seasonality, rainfall and vegetation productivity (proxies for food availability) influenced home range size. Our findings reveal considerable variation in home ranges, with an average of 850.15 km² (1.24-8,549.48 km²). Home ranges expanded significantly during the dry season (mean 1,097.06 km²), representing a 2.14-fold increase from the wet season. We also found that site and season primarily drove home range size, while vegetation productivity and rainfall had limited influence. This suggests that macaw movements may respond to complex interactions between rainfall, landscape composition and configuration, and food availability rather than direct resource fluctuations. This is the first study to estimate home ranges for Lear’s macaw, providing critical insights into its spatial ecology. Our findings underscore the importance of preserving key roosting and feeding areas and highlight the need for continuous monitoring to address threats posed by environmental changes and human activity.
29.
Sidiropoulos, Lavrentis; Whitfield, D. Philip; Bounas, Anastasios; Kret, Elzbieta; Navarrete, Elisabeth; Vafeidis, Panagiotis; Doukas, Dimitrios; Michalopoulou, Panagiota; Zakkak, Sylvia; Kati, Vassiliki
Poisoned baits drive record golden eagle mortality in northern Greece: A call for urgent conservation actions Journal Article
In: Biological Conservation, vol. 308, pp. 111223, 2025, ISSN: 00063207.
Abstract | Links | BibTeX | Tags: Aquila chrysaetos, Bird Solar, Bird Solar Cellular, Golden Eagle
@article{sidiropoulos_poisoned_2025,
title = {Poisoned baits drive record golden eagle mortality in northern Greece: A call for urgent conservation actions},
author = {Lavrentis Sidiropoulos and D. Philip Whitfield and Anastasios Bounas and Elzbieta Kret and Elisabeth Navarrete and Panagiotis Vafeidis and Dimitrios Doukas and Panagiota Michalopoulou and Sylvia Zakkak and Vassiliki Kati},
url = {https://linkinghub.elsevier.com/retrieve/pii/S0006320725002605},
doi = {10.1016/j.biocon.2025.111223},
issn = {00063207},
year = {2025},
date = {2025-08-01},
urldate = {2025-09-16},
journal = {Biological Conservation},
volume = {308},
pages = {111223},
abstract = {Despite an overall recovery of European large raptor populations, the golden eagle (Aquila chrysaetos) population in Greece is Endangered. Poisoning from baits set illegally for carnivore control is known as an important mortality factor, impacting a wider avian scavenger assemblage in our study area. We analysed golden eagle mortality data from northern Greece for the last 35 years, including the fates of 29 satellite-tagged individuals from the last decade. Poisoning accounted for 65 % of the overall mortality, the highest percentage recorded globally for any eagle population. Known fate survival models from telemetry data revealed 0.78 and 0.85 annual survival rates for immature and adults, respectively (the lowest reported in telemetry studies), improving markedly when censored for poisoning mortality. Poisoning occurred disproportionally close to protected areas, more often in areas with high carnivore livestock depredation and almost exclusively in winter when eagles were more likely to scavenge. Golden eagles were usually poisoned by directly feeding on carcasses and offal baits laced predominantly with illegal toxic substances (e.g. carbofuran and methomyl). Electrocution was the second cause of mortality, and collision with turbines was also recorded. The main conservation implication of our findings is that urgent policy changes are required to reverse the population's decline, mainly against the illegal use of poisoned baits and across prevention, legislative and enforcement levels. We propose specific measures towards this direction, such as improving livestock husbandry, further capacity building for wildlife crime investigation and reforms in relevant legislation.},
keywords = {Aquila chrysaetos, Bird Solar, Bird Solar Cellular, Golden Eagle},
pubstate = {published},
tppubtype = {article}
}
Despite an overall recovery of European large raptor populations, the golden eagle (Aquila chrysaetos) population in Greece is Endangered. Poisoning from baits set illegally for carnivore control is known as an important mortality factor, impacting a wider avian scavenger assemblage in our study area. We analysed golden eagle mortality data from northern Greece for the last 35 years, including the fates of 29 satellite-tagged individuals from the last decade. Poisoning accounted for 65 % of the overall mortality, the highest percentage recorded globally for any eagle population. Known fate survival models from telemetry data revealed 0.78 and 0.85 annual survival rates for immature and adults, respectively (the lowest reported in telemetry studies), improving markedly when censored for poisoning mortality. Poisoning occurred disproportionally close to protected areas, more often in areas with high carnivore livestock depredation and almost exclusively in winter when eagles were more likely to scavenge. Golden eagles were usually poisoned by directly feeding on carcasses and offal baits laced predominantly with illegal toxic substances (e.g. carbofuran and methomyl). Electrocution was the second cause of mortality, and collision with turbines was also recorded. The main conservation implication of our findings is that urgent policy changes are required to reverse the population's decline, mainly against the illegal use of poisoned baits and across prevention, legislative and enforcement levels. We propose specific measures towards this direction, such as improving livestock husbandry, further capacity building for wildlife crime investigation and reforms in relevant legislation.
30.
Oehler, Felicitas; Arnold, Janosch; Hackländer, Klaus; Signer, Johannes; Schai-Braun, Stéphanie C.; Hagen, Robert
Identifying dispersal events of red foxes (Vulpes vulpes) using early warning signals Journal Article
In: Movement Ecology, vol. 13, no. 1, pp. 55, 2025, ISSN: 2051-3933.
Abstract | Links | BibTeX | Tags:
@article{oehler_identifying_2025,
title = {Identifying dispersal events of red foxes (Vulpes vulpes) using early warning signals},
author = {Felicitas Oehler and Janosch Arnold and Klaus Hackl\"{a}nder and Johannes Signer and St\'{e}phanie C. Schai-Braun and Robert Hagen},
url = {https://movementecologyjournal.biomedcentral.com/articles/10.1186/s40462-025-00579-w},
doi = {10.1186/s40462-025-00579-w},
issn = {2051-3933},
year = {2025},
date = {2025-07-01},
urldate = {2025-12-02},
journal = {Movement Ecology},
volume = {13},
number = {1},
pages = {55},
abstract = {Abstract
Background
Many animals disperse to find their own territory, mates to reproduce or suitable environments to live. Dispersal can be described as a three-phase process consisting of two stationary phases (S
1
and S
2
) at the beginning and the end of a dispersal event. These stationary phases are temporally separated by a transient phase (T), where the animal moves from S
1
to a new area S
2
in space. The net squared displacement (NSD) is a frequently used metric to identify these phases from animal tracking data.
Methods
We tested whether early warning signals (EWSs) on time series of the NSD, can be used to predict dispersal events. To identify EWSs we conducted a rolling window approach and evaluated the dispersal events by performing a spatial cluster analysis with the mechanistic range shift analysis (MRSA). We used data from 22 GPS-collared red foxes (
Vulpes vulpes
) as an example of a mammal species in which the juvenile (sub-) adult transition usually involves dispersal.
Results
Applying EWSs resulted in the identification of both transitions from S
1
to T and from T to S
2
. For 10 individuals we detected EWSs. For 8 out of these 10 individuals (80%) we identified a spatial shift between S
1
and S
2
via a MRSA. Accordingly, for 8 out of 22 individuals (36%) we observed a transient phase (T) which led to a major and persistent transformation of red fox locations.
Conclusion
Even though the identification of dispersal events based on movement data is challenging using well known techniques such as state space models or the MRSA, our results suggested that EWS in combination with MRSA is appropriate to detect and identify dispersal events in radio-collared mammals. Thus, in the context of identifying dispersal events using EWSs we recommend to evaluate the existence of stationary and transient phases using the MSRA. The benefit of using EWSs is the calculation of the NSD and simple statistics (standard deviation, autocorrelation) and no requirement of high resolution tracking data. Additionally, transitions to the stationary or transient phase might be detected where home range calculations are not possible.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract
Background
Many animals disperse to find their own territory, mates to reproduce or suitable environments to live. Dispersal can be described as a three-phase process consisting of two stationary phases (S
1
and S
2
) at the beginning and the end of a dispersal event. These stationary phases are temporally separated by a transient phase (T), where the animal moves from S
1
to a new area S
2
in space. The net squared displacement (NSD) is a frequently used metric to identify these phases from animal tracking data.
Methods
We tested whether early warning signals (EWSs) on time series of the NSD, can be used to predict dispersal events. To identify EWSs we conducted a rolling window approach and evaluated the dispersal events by performing a spatial cluster analysis with the mechanistic range shift analysis (MRSA). We used data from 22 GPS-collared red foxes (
Vulpes vulpes
) as an example of a mammal species in which the juvenile (sub-) adult transition usually involves dispersal.
Results
Applying EWSs resulted in the identification of both transitions from S
1
to T and from T to S
2
. For 10 individuals we detected EWSs. For 8 out of these 10 individuals (80%) we identified a spatial shift between S
1
and S
2
via a MRSA. Accordingly, for 8 out of 22 individuals (36%) we observed a transient phase (T) which led to a major and persistent transformation of red fox locations.
Conclusion
Even though the identification of dispersal events based on movement data is challenging using well known techniques such as state space models or the MRSA, our results suggested that EWS in combination with MRSA is appropriate to detect and identify dispersal events in radio-collared mammals. Thus, in the context of identifying dispersal events using EWSs we recommend to evaluate the existence of stationary and transient phases using the MSRA. The benefit of using EWSs is the calculation of the NSD and simple statistics (standard deviation, autocorrelation) and no requirement of high resolution tracking data. Additionally, transitions to the stationary or transient phase might be detected where home range calculations are not possible.
Background
Many animals disperse to find their own territory, mates to reproduce or suitable environments to live. Dispersal can be described as a three-phase process consisting of two stationary phases (S
1
and S
2
) at the beginning and the end of a dispersal event. These stationary phases are temporally separated by a transient phase (T), where the animal moves from S
1
to a new area S
2
in space. The net squared displacement (NSD) is a frequently used metric to identify these phases from animal tracking data.
Methods
We tested whether early warning signals (EWSs) on time series of the NSD, can be used to predict dispersal events. To identify EWSs we conducted a rolling window approach and evaluated the dispersal events by performing a spatial cluster analysis with the mechanistic range shift analysis (MRSA). We used data from 22 GPS-collared red foxes (
Vulpes vulpes
) as an example of a mammal species in which the juvenile (sub-) adult transition usually involves dispersal.
Results
Applying EWSs resulted in the identification of both transitions from S
1
to T and from T to S
2
. For 10 individuals we detected EWSs. For 8 out of these 10 individuals (80%) we identified a spatial shift between S
1
and S
2
via a MRSA. Accordingly, for 8 out of 22 individuals (36%) we observed a transient phase (T) which led to a major and persistent transformation of red fox locations.
Conclusion
Even though the identification of dispersal events based on movement data is challenging using well known techniques such as state space models or the MRSA, our results suggested that EWS in combination with MRSA is appropriate to detect and identify dispersal events in radio-collared mammals. Thus, in the context of identifying dispersal events using EWSs we recommend to evaluate the existence of stationary and transient phases using the MSRA. The benefit of using EWSs is the calculation of the NSD and simple statistics (standard deviation, autocorrelation) and no requirement of high resolution tracking data. Additionally, transitions to the stationary or transient phase might be detected where home range calculations are not possible.
31.
Alonso, Juan C.; Abril-Colón, Inmaculada; Ucero, Alberto; Palacín, Carlos
Precipitation and female experience are major determinants of the breeding performance of Canarian houbara bustards Journal Article
In: Wildlife Biology, vol. 2025, no. 4, pp. e01345, 2025, ISSN: 1903-220X, 1903-220X.
Abstract | Links | BibTeX | Tags: Bird Solar, Bird Solar Cellular 27g, Chlamydotis undulata fuerteventurae, Houbara Bustard
@article{alonso_precipitation_2025,
title = {Precipitation and female experience are major determinants of the breeding performance of Canarian houbara bustards},
author = {Juan C. Alonso and Inmaculada Abril-Col\'{o}n and Alberto Ucero and Carlos Palac\'{i}n},
url = {https://nsojournals.onlinelibrary.wiley.com/doi/10.1002/wlb3.01345},
doi = {10.1002/wlb3.01345},
issn = {1903-220X, 1903-220X},
year = {2025},
date = {2025-07-01},
urldate = {2025-09-16},
journal = {Wildlife Biology},
volume = {2025},
number = {4},
pages = {e01345},
abstract = {Precipitation is one of the main triggers of reproduction in desert-breeding birds. The unpredictability of rainfall patterns in arid environments has led species to adapt their breeding effort to episodes of abundant food after rainfall. The response is not the same for all individuals in a population, and may vary especially with the age and experience of each female. Here we investigate the effects of precipitation, temperature, body size and breeding experience, among other variables, on reproductive parameters of 20 females of Canarian houbara bustard (Chlamydotis undulata fuertaventurae), an endangered desert bird endemic of the eastern Canary Islands. Precipitation and breeding experience were the main determinants of female breeding performance. Higher rainfall determined an increase in nesting rate, and earlier autumn rains caused an advancement of nesting to October, allowing the breeding season to be extended to eight months. This favoured an extraordinary increase in productivity in more rainy breeding seasons, with 15 times more females nesting in the two most rainy winters than in dry years. In addition, females with more breeding experience showed a higher tendency to breed, higher nest attempt and fledging success, and longer breeding season, which allowed them to rear more chicks. A female even double brooded successfully in the same season, which, considering that chicks remain with the mother for up to six months, indicates a great capacity to optimise reproductive investment, by adapting to highly variable rainfall regimes. In recent decades, the eastern Canary Islands have undergone a process of aridification, and climate models predict a medium-term increase in the frequency and duration of drought periods. Thus, Canarian houbaras are particularly vulnerable to climate change, so measures are urgently needed to reduce their mortality and improve the quality of their habitat, in order to favour their reproduction and prevent their extinction.},
keywords = {Bird Solar, Bird Solar Cellular 27g, Chlamydotis undulata fuerteventurae, Houbara Bustard},
pubstate = {published},
tppubtype = {article}
}
Precipitation is one of the main triggers of reproduction in desert-breeding birds. The unpredictability of rainfall patterns in arid environments has led species to adapt their breeding effort to episodes of abundant food after rainfall. The response is not the same for all individuals in a population, and may vary especially with the age and experience of each female. Here we investigate the effects of precipitation, temperature, body size and breeding experience, among other variables, on reproductive parameters of 20 females of Canarian houbara bustard (Chlamydotis undulata fuertaventurae), an endangered desert bird endemic of the eastern Canary Islands. Precipitation and breeding experience were the main determinants of female breeding performance. Higher rainfall determined an increase in nesting rate, and earlier autumn rains caused an advancement of nesting to October, allowing the breeding season to be extended to eight months. This favoured an extraordinary increase in productivity in more rainy breeding seasons, with 15 times more females nesting in the two most rainy winters than in dry years. In addition, females with more breeding experience showed a higher tendency to breed, higher nest attempt and fledging success, and longer breeding season, which allowed them to rear more chicks. A female even double brooded successfully in the same season, which, considering that chicks remain with the mother for up to six months, indicates a great capacity to optimise reproductive investment, by adapting to highly variable rainfall regimes. In recent decades, the eastern Canary Islands have undergone a process of aridification, and climate models predict a medium-term increase in the frequency and duration of drought periods. Thus, Canarian houbaras are particularly vulnerable to climate change, so measures are urgently needed to reduce their mortality and improve the quality of their habitat, in order to favour their reproduction and prevent their extinction.
32.
Lewis-Bevan, Lynn; Hammond, Philippa; Carvalho, Susana; Biro, Dora
The Travelling Salesbaboon: Chacma Baboon Route Efficiency in Multi-Stop Daily Travel Routes Journal Article
In: Wild, vol. 2, no. 2, pp. 18, 2025, ISSN: 3042-4526.
Abstract | Links | BibTeX | Tags:
@article{lewis-bevan_travelling_2025,
title = {The Travelling Salesbaboon: Chacma Baboon Route Efficiency in Multi-Stop Daily Travel Routes},
author = {Lynn Lewis-Bevan and Philippa Hammond and Susana Carvalho and Dora Biro},
url = {https://www.mdpi.com/3042-4526/2/2/18},
doi = {10.3390/wild2020018},
issn = {3042-4526},
year = {2025},
date = {2025-05-01},
urldate = {2025-09-16},
journal = {Wild},
volume = {2},
number = {2},
pages = {18},
abstract = {The ability to navigate through both familiar and unfamiliar environments is of critical importance for foraging efficiency, safety, and energy budgeting in wild animals. For animals that remain in the same home range annually, such as grey-footed chacma baboons (Papio ursinus griseipes), movement efficiency is expected to reflect familiarity with the home range as well as the nature of the resources within it. For example, resources that are patchy, transient, or seasonal present a greater spatial cognitive challenge, and travel between them may be less efficient than for more widespread or permanent resources. Here, we analyse daily route efficiency in adult female grey-footed chacma baboons at Gorongosa National Park, Mozambique. We use GPS data taken at 15 min intervals from collars deployed on two baboons in each of two study troops (four total) to identify areas of interest used during daily ranging periods (sleep site to sleep site). We then compare the length of the route taken between a given day’s patches to routes calculated by two alternate optimisation heuristics as follows: the nearest neighbour method, in which the subject repeatedly travels to the next most proximate patch and does not necessarily return to the same place, and the Concorde algorithm, which calculates the shortest possible route connecting the day’s patches. We show that baboons travel more efficient routes than those yielded by the nearest-neighbour heuristic but less efficient routes than the Concorde method, implying some degree of route planning. We discuss our novel method of area of interest identification using only remote GPS data, as well as the implications of our findings for primate movement and cognition.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The ability to navigate through both familiar and unfamiliar environments is of critical importance for foraging efficiency, safety, and energy budgeting in wild animals. For animals that remain in the same home range annually, such as grey-footed chacma baboons (Papio ursinus griseipes), movement efficiency is expected to reflect familiarity with the home range as well as the nature of the resources within it. For example, resources that are patchy, transient, or seasonal present a greater spatial cognitive challenge, and travel between them may be less efficient than for more widespread or permanent resources. Here, we analyse daily route efficiency in adult female grey-footed chacma baboons at Gorongosa National Park, Mozambique. We use GPS data taken at 15 min intervals from collars deployed on two baboons in each of two study troops (four total) to identify areas of interest used during daily ranging periods (sleep site to sleep site). We then compare the length of the route taken between a given day’s patches to routes calculated by two alternate optimisation heuristics as follows: the nearest neighbour method, in which the subject repeatedly travels to the next most proximate patch and does not necessarily return to the same place, and the Concorde algorithm, which calculates the shortest possible route connecting the day’s patches. We show that baboons travel more efficient routes than those yielded by the nearest-neighbour heuristic but less efficient routes than the Concorde method, implying some degree of route planning. We discuss our novel method of area of interest identification using only remote GPS data, as well as the implications of our findings for primate movement and cognition.
33.
Panter, Connor T.; Nebel, Carina; Raab, Maximilian; Strauss, Verena; Freytag, Clara; Wojta, Manuel; Böing, Hannah; Hacker, Patrick; Raab, Rainhard; Windt, Jendrik; Posautz, Annika; Kuebber‐Heiss, Anna; Scherler, Patrick; Grüebler, Martin U.; Kormann, Urs G.; Kolbe, Martin; Millon, Alexandre; Puente, Javier De La; Viñuela, Javier; Orr‐Ewing, Duncan; Krone, Oliver; Langgemach, Torsten; Åkesson, Susanne; Mattsson, Brady; Sumasgutner, Petra; Fuente, Manuel Alcántara De La; Alvarez, Ernesto; Arizaga, Juan; Pagès, Albert Bach; Bermejo, Ana; Ceccolini, Guido; Chakarov, Nayden; Derpmann‐Hagenström, Peter; Dostál, Marek; Fabian, Gerd; Fiedler, Wolfgang; Galán, Manuel; Ganier, Clément; Gärtner, Andreas; Glesener, Liza; Godino, Alfonso; Guziová, Zuzana; Haraszthy, László; Karlsson, Caka; Klein, Katharina; Literák, Ivan; Lorenzini, Nicolas; Löwold, Manuela; Lüning, Christopher; Maderič, Boris; Makoň, Karel; Mammen, Kerstin; Mammen, Ubbo; Marczak, Torsten; Matušík, Hynek; Mionnet, Aymeric; Morollón, Sara; Mráz, Jakub; Nachtigall, Winfried; Nicolai, Bernd; Fernández, Marta Olalde; Ottensmann, Meinolf; González, María Jesús Palacios; Paquet, Jean‐Yves; Pečeňák, Vladimír; Peške, Lubomír; Pfeiffer, Thomas; Pudwill, Robert; Rak, Dušan; Rapp, Tim Maximilian; Resetaritz, Alexander; Rijn, Stef Van; Riols, Romain; Rodríguez, Arturo; Scholze, Luisa; Schulte, Laura; Seynes, Aurélie De; Škrábal, Jan; Spakovszky, Péter; Steinborn, Eike; Svetlík, Ján; Talhoet, Samuel; Vaczi, Miklós; Verdier, Anne‐Gaelle; Vermouzek, Zdenĕk; Inglada, Diego Villanúa; Westphal, Jörg; Raab, Rainer
In: Ecology and Evolution, vol. 15, no. 4, pp. e70975, 2025, ISSN: 2045-7758, 2045-7758.
Abstract | Links | BibTeX | Tags:
@article{panter_span_2025,
title = {A \<span style="font-variant:small-caps;"\>LEAP\</span\> Forward in Wildlife Conservation: A Standardized Framework to Determine Mortality Causes in Large \<span style="font-variant:small-caps;"\>GPS\</span\> ‐Tagged Birds},
author = {Connor T. Panter and Carina Nebel and Maximilian Raab and Verena Strauss and Clara Freytag and Manuel Wojta and Hannah B\"{o}ing and Patrick Hacker and Rainhard Raab and Jendrik Windt and Annika Posautz and Anna Kuebber‐Heiss and Patrick Scherler and Martin U. Gr\"{u}ebler and Urs G. Kormann and Martin Kolbe and Alexandre Millon and Javier De La Puente and Javier Vi\~{n}uela and Duncan Orr‐Ewing and Oliver Krone and Torsten Langgemach and Susanne r{A}kesson and Brady Mattsson and Petra Sumasgutner and Manuel Alc\'{a}ntara De La Fuente and Ernesto Alvarez and Juan Arizaga and Albert Bach Pag\`{e}s and Ana Bermejo and Guido Ceccolini and Nayden Chakarov and Peter Derpmann‐Hagenstr\"{o}m and Marek Dost\'{a}l and Gerd Fabian and Wolfgang Fiedler and Manuel Gal\'{a}n and Cl\'{e}ment Ganier and Andreas G\"{a}rtner and Liza Glesener and Alfonso Godino and Zuzana Guziov\'{a} and L\'{a}szl\'{o} Haraszthy and Caka Karlsson and Katharina Klein and Ivan Liter\'{a}k and Nicolas Lorenzini and Manuela L\"{o}wold and Christopher L\"{u}ning and Boris Maderi\v{c} and Karel Makov{n} and Kerstin Mammen and Ubbo Mammen and Torsten Marczak and Hynek Matu\v{s}\'{i}k and Aymeric Mionnet and Sara Moroll\'{o}n and Jakub Mr\'{a}z and Winfried Nachtigall and Bernd Nicolai and Marta Olalde Fern\'{a}ndez and Meinolf Ottensmann and Mar\'{i}a Jes\'{u}s Palacios Gonz\'{a}lez and Jean‐Yves Paquet and Vladim\'{i}r Pe\v{c}ev{n}\'{a}k and Lubom\'{i}r Pe\v{s}ke and Thomas Pfeiffer and Robert Pudwill and Du\v{s}an Rak and Tim Maximilian Rapp and Alexander Resetaritz and Stef Van Rijn and Romain Riols and Arturo Rodr\'{i}guez and Luisa Scholze and Laura Schulte and Aur\'{e}lie De Seynes and Jan \v{S}kr\'{a}bal and P\'{e}ter Spakovszky and Eike Steinborn and J\'{a}n Svetl\'{i}k and Samuel Talhoet and Mikl\'{o}s Vaczi and Anne‐Gaelle Verdier and Zden\u{e}k Vermouzek and Diego Villan\'{u}a Inglada and J\"{o}rg Westphal and Rainer Raab},
url = {https://onlinelibrary.wiley.com/doi/10.1002/ece3.70975},
doi = {10.1002/ece3.70975},
issn = {2045-7758, 2045-7758},
year = {2025},
date = {2025-04-01},
urldate = {2025-09-16},
journal = {Ecology and Evolution},
volume = {15},
number = {4},
pages = {e70975},
abstract = {ABSTRACT
Anthropogenic activities threaten many wildlife populations by increasing mortality rates, making it crucial to identify the locations and causes of mortality to inform conservation actions. Technological advancements, such as GPS satellite tracking, enable precise recording of wildlife movements. High‐resolution data from such devices can facilitate rapid carcass recovery and provide insights into the mortality causes of tagged individuals. Obtaining required information to determine these causes is complex, and standardized approaches can overcome these limitations. In this study, we introduce the LIFE EUROKITE Assessment Protocol (LEAP), a framework for determining the timing, locations, and causes of mortality in GPS‐tagged birds. LEAP is a multifaceted approach that integrates: (1) GPS tracking data, (2) evidence from the mortality location (site investigation), and (3) necropsy results to derive the mortality cause and a corresponding certainty score. We supplement the detailed description of LEAP with case studies assessing its effectiveness. Using 329 deceased GPS‐tagged red kites (
Milvus milvus
) we compared conditions of the carcasses processed using LEAP with 145 opportunistically collected raptor carcasses. We also show that LEAP improves carcass condition and therefore allows for higher quality necropsy results. Additionally, we assessed how availability among sources of information (tracking, site investigation and necropsy) influences the quality of mortality assessments. Applying LEAP with all data sources provided the highest quality assessments in 64% of cases. Some 35% of cases were of high quality without necropsy, instead drawing evidence only from tracking data and site investigations. Predation related mortality was less prevalent (11%) when relying on necropsy compared to cases without necropsy (36%), while poisoning showed the opposite trend. Furthermore, we provide guidelines and empirical examples of mortality assessments. Our standardized LEAP approach ensures the best use of all available information regarding mortality events in GPS‐tagged birds and advances wildlife mortality research as a valuable tool for conservationists and wildlife managers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
ABSTRACT
Anthropogenic activities threaten many wildlife populations by increasing mortality rates, making it crucial to identify the locations and causes of mortality to inform conservation actions. Technological advancements, such as GPS satellite tracking, enable precise recording of wildlife movements. High‐resolution data from such devices can facilitate rapid carcass recovery and provide insights into the mortality causes of tagged individuals. Obtaining required information to determine these causes is complex, and standardized approaches can overcome these limitations. In this study, we introduce the LIFE EUROKITE Assessment Protocol (LEAP), a framework for determining the timing, locations, and causes of mortality in GPS‐tagged birds. LEAP is a multifaceted approach that integrates: (1) GPS tracking data, (2) evidence from the mortality location (site investigation), and (3) necropsy results to derive the mortality cause and a corresponding certainty score. We supplement the detailed description of LEAP with case studies assessing its effectiveness. Using 329 deceased GPS‐tagged red kites (
Milvus milvus
) we compared conditions of the carcasses processed using LEAP with 145 opportunistically collected raptor carcasses. We also show that LEAP improves carcass condition and therefore allows for higher quality necropsy results. Additionally, we assessed how availability among sources of information (tracking, site investigation and necropsy) influences the quality of mortality assessments. Applying LEAP with all data sources provided the highest quality assessments in 64% of cases. Some 35% of cases were of high quality without necropsy, instead drawing evidence only from tracking data and site investigations. Predation related mortality was less prevalent (11%) when relying on necropsy compared to cases without necropsy (36%), while poisoning showed the opposite trend. Furthermore, we provide guidelines and empirical examples of mortality assessments. Our standardized LEAP approach ensures the best use of all available information regarding mortality events in GPS‐tagged birds and advances wildlife mortality research as a valuable tool for conservationists and wildlife managers.
Anthropogenic activities threaten many wildlife populations by increasing mortality rates, making it crucial to identify the locations and causes of mortality to inform conservation actions. Technological advancements, such as GPS satellite tracking, enable precise recording of wildlife movements. High‐resolution data from such devices can facilitate rapid carcass recovery and provide insights into the mortality causes of tagged individuals. Obtaining required information to determine these causes is complex, and standardized approaches can overcome these limitations. In this study, we introduce the LIFE EUROKITE Assessment Protocol (LEAP), a framework for determining the timing, locations, and causes of mortality in GPS‐tagged birds. LEAP is a multifaceted approach that integrates: (1) GPS tracking data, (2) evidence from the mortality location (site investigation), and (3) necropsy results to derive the mortality cause and a corresponding certainty score. We supplement the detailed description of LEAP with case studies assessing its effectiveness. Using 329 deceased GPS‐tagged red kites (
Milvus milvus
) we compared conditions of the carcasses processed using LEAP with 145 opportunistically collected raptor carcasses. We also show that LEAP improves carcass condition and therefore allows for higher quality necropsy results. Additionally, we assessed how availability among sources of information (tracking, site investigation and necropsy) influences the quality of mortality assessments. Applying LEAP with all data sources provided the highest quality assessments in 64% of cases. Some 35% of cases were of high quality without necropsy, instead drawing evidence only from tracking data and site investigations. Predation related mortality was less prevalent (11%) when relying on necropsy compared to cases without necropsy (36%), while poisoning showed the opposite trend. Furthermore, we provide guidelines and empirical examples of mortality assessments. Our standardized LEAP approach ensures the best use of all available information regarding mortality events in GPS‐tagged birds and advances wildlife mortality research as a valuable tool for conservationists and wildlife managers.
34.
Gilmour, Morgan E.; Pollock, Kydd; Adams, Josh; Block, Barbara A.; Caselle, Jennifer E.; Filous, Alex; Friedlander, Alan M.; Game, Edward T.; Hazen, Elliott L.; Hill, Marie; Holmes, Nick D.; Lafferty, Kevin D.; Maxwell, Sara M.; McCauley, Douglas J.; Schallert, Robert; Shaffer, Scott A.; Wolff, Nicholas H.; Wegmann, Alex
Multi‐Species Telemetry Quantifies Current and Future Efficacy of a Remote Marine Protected Area Journal Article
In: Global Change Biology, vol. 31, no. 4, pp. e70138, 2025, ISSN: 1354-1013, 1365-2486.
Abstract | Links | BibTeX | Tags: CMIP6, GPS-tracking, marine spatial planning, movement ecology, pseudo-absence, satellite-tracking
@article{gilmour_multispecies_2025,
title = {Multi‐Species Telemetry Quantifies Current and Future Efficacy of a Remote Marine Protected Area},
author = {Morgan E. Gilmour and Kydd Pollock and Josh Adams and Barbara A. Block and Jennifer E. Caselle and Alex Filous and Alan M. Friedlander and Edward T. Game and Elliott L. Hazen and Marie Hill and Nick D. Holmes and Kevin D. Lafferty and Sara M. Maxwell and Douglas J. McCauley and Robert Schallert and Scott A. Shaffer and Nicholas H. Wolff and Alex Wegmann},
url = {https://onlinelibrary.wiley.com/doi/10.1111/gcb.70138},
doi = {10.1111/gcb.70138},
issn = {1354-1013, 1365-2486},
year = {2025},
date = {2025-04-01},
urldate = {2025-09-16},
journal = {Global Change Biology},
volume = {31},
number = {4},
pages = {e70138},
abstract = {Large-scale marine protected areas (LSMPAs; \> 1000 km2) provide important refuge for large mobile species, but most do not encompass species' ranges. To better understand current and future LSMPA value, we concurrently tracked nine species (seabirds, cetaceans, pelagic fishes, manta rays, reef sharks) at Palmyra Atoll and Kingman Reef (PKMPA) in the U.S. Pacific Islands Heritage Marine National Monument. PKMPA and the U.S. Exclusive Economic Zone encompassed 39% and 54% of species movements (n = 83; tracking duration range: 0.5\textendash350 days), respectively. Species distribution models indicated 73% of PKMPA contained highly suitable habitat. Under two projected future scenarios (SSP 1\textendash2.6, “Sustainability”; SSP 3\textendash7.0, “Rocky Road”), strong sea surface temperature gradients initially could cause abrupt oceanic change resulting in predicted habitat loss in 2040\textendash2050, followed by an equilibrium response and regained habitat by 2090\textendash2100. Current and future suitable habitats were available adjacent to PKMPA, suggesting that increased MPA size could enhance protection. Our three-tiered approach combining animal tracking with publicly available remote sensing data and future projected environmental scenarios could be used to design, study, and monitor protected areas throughout the world. Holistic approaches that encompass diverse species and habitat use can enhance assessments of protected area designs. Animal telemetry and remote sensing may be helpful for ascertaining the extent to which other MPAs protect large mobile species in the future.},
keywords = {CMIP6, GPS-tracking, marine spatial planning, movement ecology, pseudo-absence, satellite-tracking},
pubstate = {published},
tppubtype = {article}
}
Large-scale marine protected areas (LSMPAs; > 1000 km2) provide important refuge for large mobile species, but most do not encompass species' ranges. To better understand current and future LSMPA value, we concurrently tracked nine species (seabirds, cetaceans, pelagic fishes, manta rays, reef sharks) at Palmyra Atoll and Kingman Reef (PKMPA) in the U.S. Pacific Islands Heritage Marine National Monument. PKMPA and the U.S. Exclusive Economic Zone encompassed 39% and 54% of species movements (n = 83; tracking duration range: 0.5–350 days), respectively. Species distribution models indicated 73% of PKMPA contained highly suitable habitat. Under two projected future scenarios (SSP 1–2.6, “Sustainability”; SSP 3–7.0, “Rocky Road”), strong sea surface temperature gradients initially could cause abrupt oceanic change resulting in predicted habitat loss in 2040–2050, followed by an equilibrium response and regained habitat by 2090–2100. Current and future suitable habitats were available adjacent to PKMPA, suggesting that increased MPA size could enhance protection. Our three-tiered approach combining animal tracking with publicly available remote sensing data and future projected environmental scenarios could be used to design, study, and monitor protected areas throughout the world. Holistic approaches that encompass diverse species and habitat use can enhance assessments of protected area designs. Animal telemetry and remote sensing may be helpful for ascertaining the extent to which other MPAs protect large mobile species in the future.
35.
Ucero, Alberto; Abril-Colón, Inmaculada; Palacín, Carlos; Álvarez-Martínez, Jose Manuel; Alonso, Juan Carlos
Nest-site and brood-rearing habitat selection in Canarian houbara bustards: the importance of concealment and food availability Journal Article
In: Journal of Ornithology, vol. 166, no. 2, pp. 399–413, 2025, ISSN: 2193-7192, 2193-7206.
Abstract | Links | BibTeX | Tags:
@article{ucero_nest-site_2025,
title = {Nest-site and brood-rearing habitat selection in Canarian houbara bustards: the importance of concealment and food availability},
author = {Alberto Ucero and Inmaculada Abril-Col\'{o}n and Carlos Palac\'{i}n and Jose Manuel \'{A}lvarez-Mart\'{i}nez and Juan Carlos Alonso},
url = {https://link.springer.com/10.1007/s10336-024-02224-6},
doi = {10.1007/s10336-024-02224-6},
issn = {2193-7192, 2193-7206},
year = {2025},
date = {2025-04-01},
urldate = {2026-04-16},
journal = {Journal of Ornithology},
volume = {166},
number = {2},
pages = {399\textendash413},
abstract = {Abstract
Using two scales, landscape and microhabitat, we analysed the factors determining nest-site and brood-rearing habitat selection in the endangered Canarian Houbara Bustard
Chlamydotis undulata fuertaventurae
. We measured vegetation cover and food abundance, presence of human infrastructure, and visibility using a very high-resolution LiDAR-based digital elevation model of the terrain. Houbara females choose nest-sites with abundant arthropod biomass and high vegetation. To rear their brood, they look for substrates with few stones, high species richness, and low density of human infrastructure. These features allow females to hide the nest, themselves and their chicks from predators, reduce anthropogenic disturbance, and secure access to food during the whole breeding process. The less stony ground during brood-rearing allows female and chicks to walk more easily and safely, something that is important in a ground-dwelling bird. This study represents the first detailed analysis of nesting and breeding site selection for this globally threatened subspecies. To minimise disturbance during such a sensitive phase, and considering the major tourist destination in which this species lives, we recommend to restrict vehicle and human traffic in the breeding areas, prohibit new constructions in houbara habitats, and preserve the vegetation and breeding-habitat quality, avoiding the current indiscriminate ploughing of uncultivated fields and limiting goat grazing areas.
,
Zusammenfassung
Nistplatzwahl und Bruthabitat der kanarischen Saharakragentrappe: die Bedeutung von Nahrungsangebot und m\"{o}glichen Verstecken.
Auf zwei verschiedenen Ebenen\textemdashumgebende Landschaft und Mikrohabitat\textemdashanalysierten wir die Auswahlkriterien, die bei der gef\"{a}hrdeten kanarischen Saharakragentrappe
Chlamydotis undulata fuertaventurae
f\"{u}r die Wahl des Nistplatzes und des Habitats f\"{u}r die Aufzucht der Jungen ausschlaggebend sind. Hierf\"{u}r erfassten wir mithilfe eines hochaufl\"{o}senden LiDAR-basierten digitalen H\"{o}henmodells die Vegetationsdecke und das Nahrungsangebot, das Vorhandensein menschengemachter Infrastrukturen und die Sichtverh\"{a}ltnisse im Gel\"{a}nde. Die Weibchen w\"{a}hlten Nistpl\"{a}tze mit reichhaltiger Arthropoden-Biomasse und hohem Pflanzenbestand. F\"{u}r die Aufzucht ihrer Jungen suchten sie nach B\"{o}den mit wenig Steinen, mit hohem Artenreichtum und mit nur wenig anthropogener Infrastruktur. So k\"{o}nnen die Weibchen das Nest, ihre Jungen und sich selbst vor Raubtieren verstecken, St\"{o}rungen durch den Menschen reduzieren und den Zugang zu Nahrung w\"{a}hrend der gesamten Brutzeit sicherstellen. Der steinarme Boden erm\"{o}glicht es Weibchen und K\"{u}ken w\"{a}hrend der Aufzucht, leichter und sicherer zu laufen, was f\"{u}r einen bodenbewohnenden Vogel besonders wichtig ist. Diese Untersuchung ist die erste detaillierte Analyse der Nist- und Brutplatzwahl bei dieser weltweit bedrohten Unterart. Um St\"{o}rungen in dieser sensiblen Phase so gering wie m\"{o}glich zu halten, empfehlen wir in Anbetracht der touristischen Bedeutung der Insel, auf der diese Unterart lebt, den Verkehr von Fahrzeugen und Menschen in den Brutgebieten einzuschr\"{a}nken, alle Neubauten in den Lebensr\"{a}umen der Saharakragentrappe zu verbieten und die Pflanzenvielfalt des Bruthabitats in ihrer jetzigen Qualit\"{a}t zu erhalten, indem das derzeitige wahllose Pfl\"{u}gen von unbestellten Feldern vermieden und die Weidefl\"{a}chen f\"{u}r Ziegen eingeschr\"{a}nkt werden.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract
Using two scales, landscape and microhabitat, we analysed the factors determining nest-site and brood-rearing habitat selection in the endangered Canarian Houbara Bustard
Chlamydotis undulata fuertaventurae
. We measured vegetation cover and food abundance, presence of human infrastructure, and visibility using a very high-resolution LiDAR-based digital elevation model of the terrain. Houbara females choose nest-sites with abundant arthropod biomass and high vegetation. To rear their brood, they look for substrates with few stones, high species richness, and low density of human infrastructure. These features allow females to hide the nest, themselves and their chicks from predators, reduce anthropogenic disturbance, and secure access to food during the whole breeding process. The less stony ground during brood-rearing allows female and chicks to walk more easily and safely, something that is important in a ground-dwelling bird. This study represents the first detailed analysis of nesting and breeding site selection for this globally threatened subspecies. To minimise disturbance during such a sensitive phase, and considering the major tourist destination in which this species lives, we recommend to restrict vehicle and human traffic in the breeding areas, prohibit new constructions in houbara habitats, and preserve the vegetation and breeding-habitat quality, avoiding the current indiscriminate ploughing of uncultivated fields and limiting goat grazing areas.
,
Zusammenfassung
Nistplatzwahl und Bruthabitat der kanarischen Saharakragentrappe: die Bedeutung von Nahrungsangebot und möglichen Verstecken.
Auf zwei verschiedenen Ebenen—umgebende Landschaft und Mikrohabitat—analysierten wir die Auswahlkriterien, die bei der gefährdeten kanarischen Saharakragentrappe
Chlamydotis undulata fuertaventurae
für die Wahl des Nistplatzes und des Habitats für die Aufzucht der Jungen ausschlaggebend sind. Hierfür erfassten wir mithilfe eines hochauflösenden LiDAR-basierten digitalen Höhenmodells die Vegetationsdecke und das Nahrungsangebot, das Vorhandensein menschengemachter Infrastrukturen und die Sichtverhältnisse im Gelände. Die Weibchen wählten Nistplätze mit reichhaltiger Arthropoden-Biomasse und hohem Pflanzenbestand. Für die Aufzucht ihrer Jungen suchten sie nach Böden mit wenig Steinen, mit hohem Artenreichtum und mit nur wenig anthropogener Infrastruktur. So können die Weibchen das Nest, ihre Jungen und sich selbst vor Raubtieren verstecken, Störungen durch den Menschen reduzieren und den Zugang zu Nahrung während der gesamten Brutzeit sicherstellen. Der steinarme Boden ermöglicht es Weibchen und Küken während der Aufzucht, leichter und sicherer zu laufen, was für einen bodenbewohnenden Vogel besonders wichtig ist. Diese Untersuchung ist die erste detaillierte Analyse der Nist- und Brutplatzwahl bei dieser weltweit bedrohten Unterart. Um Störungen in dieser sensiblen Phase so gering wie möglich zu halten, empfehlen wir in Anbetracht der touristischen Bedeutung der Insel, auf der diese Unterart lebt, den Verkehr von Fahrzeugen und Menschen in den Brutgebieten einzuschränken, alle Neubauten in den Lebensräumen der Saharakragentrappe zu verbieten und die Pflanzenvielfalt des Bruthabitats in ihrer jetzigen Qualität zu erhalten, indem das derzeitige wahllose Pflügen von unbestellten Feldern vermieden und die Weideflächen für Ziegen eingeschränkt werden.
Using two scales, landscape and microhabitat, we analysed the factors determining nest-site and brood-rearing habitat selection in the endangered Canarian Houbara Bustard
Chlamydotis undulata fuertaventurae
. We measured vegetation cover and food abundance, presence of human infrastructure, and visibility using a very high-resolution LiDAR-based digital elevation model of the terrain. Houbara females choose nest-sites with abundant arthropod biomass and high vegetation. To rear their brood, they look for substrates with few stones, high species richness, and low density of human infrastructure. These features allow females to hide the nest, themselves and their chicks from predators, reduce anthropogenic disturbance, and secure access to food during the whole breeding process. The less stony ground during brood-rearing allows female and chicks to walk more easily and safely, something that is important in a ground-dwelling bird. This study represents the first detailed analysis of nesting and breeding site selection for this globally threatened subspecies. To minimise disturbance during such a sensitive phase, and considering the major tourist destination in which this species lives, we recommend to restrict vehicle and human traffic in the breeding areas, prohibit new constructions in houbara habitats, and preserve the vegetation and breeding-habitat quality, avoiding the current indiscriminate ploughing of uncultivated fields and limiting goat grazing areas.
,
Zusammenfassung
Nistplatzwahl und Bruthabitat der kanarischen Saharakragentrappe: die Bedeutung von Nahrungsangebot und möglichen Verstecken.
Auf zwei verschiedenen Ebenen—umgebende Landschaft und Mikrohabitat—analysierten wir die Auswahlkriterien, die bei der gefährdeten kanarischen Saharakragentrappe
Chlamydotis undulata fuertaventurae
für die Wahl des Nistplatzes und des Habitats für die Aufzucht der Jungen ausschlaggebend sind. Hierfür erfassten wir mithilfe eines hochauflösenden LiDAR-basierten digitalen Höhenmodells die Vegetationsdecke und das Nahrungsangebot, das Vorhandensein menschengemachter Infrastrukturen und die Sichtverhältnisse im Gelände. Die Weibchen wählten Nistplätze mit reichhaltiger Arthropoden-Biomasse und hohem Pflanzenbestand. Für die Aufzucht ihrer Jungen suchten sie nach Böden mit wenig Steinen, mit hohem Artenreichtum und mit nur wenig anthropogener Infrastruktur. So können die Weibchen das Nest, ihre Jungen und sich selbst vor Raubtieren verstecken, Störungen durch den Menschen reduzieren und den Zugang zu Nahrung während der gesamten Brutzeit sicherstellen. Der steinarme Boden ermöglicht es Weibchen und Küken während der Aufzucht, leichter und sicherer zu laufen, was für einen bodenbewohnenden Vogel besonders wichtig ist. Diese Untersuchung ist die erste detaillierte Analyse der Nist- und Brutplatzwahl bei dieser weltweit bedrohten Unterart. Um Störungen in dieser sensiblen Phase so gering wie möglich zu halten, empfehlen wir in Anbetracht der touristischen Bedeutung der Insel, auf der diese Unterart lebt, den Verkehr von Fahrzeugen und Menschen in den Brutgebieten einzuschränken, alle Neubauten in den Lebensräumen der Saharakragentrappe zu verbieten und die Pflanzenvielfalt des Bruthabitats in ihrer jetzigen Qualität zu erhalten, indem das derzeitige wahllose Pflügen von unbestellten Feldern vermieden und die Weideflächen für Ziegen eingeschränkt werden.
36.
Russo, Nicholas J.; Takuo, Jean Michel; Tegebong, Valorian; LeBreton, Matthew; Dean, Morgan; Ferraz, António; Barbier, Nicolas; Wikelski, Martin; Ordway, Elsa M.; Saatchi, Sassan; Smith, Thomas B.
In: Movement Ecology, vol. 13, no. 1, pp. 30, 2025, ISSN: 2051-3933.
Abstract | Links | BibTeX | Tags:
@article{russo_spaceborne_2025,
title = {Spaceborne and UAV-LiDAR reveal hammer-headed bat preference for intermediate canopy height and diverse structure in a Central African rainforest},
author = {Nicholas J. Russo and Jean Michel Takuo and Valorian Tegebong and Matthew LeBreton and Morgan Dean and Ant\'{o}nio Ferraz and Nicolas Barbier and Martin Wikelski and Elsa M. Ordway and Sassan Saatchi and Thomas B. Smith},
url = {https://movementecologyjournal.biomedcentral.com/articles/10.1186/s40462-025-00552-7},
doi = {10.1186/s40462-025-00552-7},
issn = {2051-3933},
year = {2025},
date = {2025-04-01},
urldate = {2025-09-16},
journal = {Movement Ecology},
volume = {13},
number = {1},
pages = {30},
abstract = {Background Animals with key ecological roles, such as seed-dispersing fruit bats, rely to varying degrees on habitat structure to indicate the locations of resources and risks.
Methods To understand how variation in vegetation structure influences fruit bat habitat selection, we related movement steps of hammer-headed bats (Hypsignathus monstrosus) to attributes of canopy height, vertical and horizontal vegetation structure, and habitat type in a mature rainforest of southern Cameroon. Vegetation structural metrics were measured with UAV-LiDAR at 10 m resolution for a 25 km2 study area. Because bats frequently moved outside the study area, we also characterized vegetation height and horizontal complexity over the full extent of bat movement trajectories by upscaling UAV-LiDAR measurements using primarily GEDI LiDAR data.
Results At the site level, hammer-headed bats preferred areas of intermediate canopy height (13.9\textendash32.0 m) close to large canopy gaps (≥ 500 m2). Individual bats varied in selection for vertical vegetation complexity, distance to smaller canopy gaps (≥ 50 m2) and plant volume density of intermediate vegetation strata (10\textendash20 m). Over the full extent of movement trajectories, hammer-headed bats consistently preferred intermediate canopy height, and areas closer to canopy gaps. At both spatial extents, bats moved the shortest distances in swamp habitats dominated by Raphia palms. These behaviors indicate the use of forest types that vary structurally, with a preference for open airspace during foraging or moving among resources, and for dense swamp vegetation during roosting and resting periods. In addition, most bats regularly made long flights of up to 17.7 km shortly after sunset and before sunrise and limited their movements to three or fewer destinations throughout the tracking period.
Conclusions These results highlight the importance of structurally diverse landscapes for the nightly movements of hammer-headed bats. Our results show how remote sensing methods and animal tracking data can be integrated to understand habitat selection and movement behavior in tropical ecosystems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background Animals with key ecological roles, such as seed-dispersing fruit bats, rely to varying degrees on habitat structure to indicate the locations of resources and risks.
Methods To understand how variation in vegetation structure influences fruit bat habitat selection, we related movement steps of hammer-headed bats (Hypsignathus monstrosus) to attributes of canopy height, vertical and horizontal vegetation structure, and habitat type in a mature rainforest of southern Cameroon. Vegetation structural metrics were measured with UAV-LiDAR at 10 m resolution for a 25 km2 study area. Because bats frequently moved outside the study area, we also characterized vegetation height and horizontal complexity over the full extent of bat movement trajectories by upscaling UAV-LiDAR measurements using primarily GEDI LiDAR data.
Results At the site level, hammer-headed bats preferred areas of intermediate canopy height (13.9–32.0 m) close to large canopy gaps (≥ 500 m2). Individual bats varied in selection for vertical vegetation complexity, distance to smaller canopy gaps (≥ 50 m2) and plant volume density of intermediate vegetation strata (10–20 m). Over the full extent of movement trajectories, hammer-headed bats consistently preferred intermediate canopy height, and areas closer to canopy gaps. At both spatial extents, bats moved the shortest distances in swamp habitats dominated by Raphia palms. These behaviors indicate the use of forest types that vary structurally, with a preference for open airspace during foraging or moving among resources, and for dense swamp vegetation during roosting and resting periods. In addition, most bats regularly made long flights of up to 17.7 km shortly after sunset and before sunrise and limited their movements to three or fewer destinations throughout the tracking period.
Conclusions These results highlight the importance of structurally diverse landscapes for the nightly movements of hammer-headed bats. Our results show how remote sensing methods and animal tracking data can be integrated to understand habitat selection and movement behavior in tropical ecosystems.
Methods To understand how variation in vegetation structure influences fruit bat habitat selection, we related movement steps of hammer-headed bats (Hypsignathus monstrosus) to attributes of canopy height, vertical and horizontal vegetation structure, and habitat type in a mature rainforest of southern Cameroon. Vegetation structural metrics were measured with UAV-LiDAR at 10 m resolution for a 25 km2 study area. Because bats frequently moved outside the study area, we also characterized vegetation height and horizontal complexity over the full extent of bat movement trajectories by upscaling UAV-LiDAR measurements using primarily GEDI LiDAR data.
Results At the site level, hammer-headed bats preferred areas of intermediate canopy height (13.9–32.0 m) close to large canopy gaps (≥ 500 m2). Individual bats varied in selection for vertical vegetation complexity, distance to smaller canopy gaps (≥ 50 m2) and plant volume density of intermediate vegetation strata (10–20 m). Over the full extent of movement trajectories, hammer-headed bats consistently preferred intermediate canopy height, and areas closer to canopy gaps. At both spatial extents, bats moved the shortest distances in swamp habitats dominated by Raphia palms. These behaviors indicate the use of forest types that vary structurally, with a preference for open airspace during foraging or moving among resources, and for dense swamp vegetation during roosting and resting periods. In addition, most bats regularly made long flights of up to 17.7 km shortly after sunset and before sunrise and limited their movements to three or fewer destinations throughout the tracking period.
Conclusions These results highlight the importance of structurally diverse landscapes for the nightly movements of hammer-headed bats. Our results show how remote sensing methods and animal tracking data can be integrated to understand habitat selection and movement behavior in tropical ecosystems.
37.
Arrondo, Eneko; Carracedo, Jorge Martinez; McAllister, Patrick; Morales-Reyes, Zebensui; Scacco, Martina; Pascual-Rico, Roberto; Cortés-Avizanda, Ainara; Donázar, José Antonio; Moleón, Marcos; Sánchez-Zapata, José Antonio
Unravelling the decision making of foraging vultures: insights from a field experiment Journal Article
In: Royal Society Open Science, vol. 12, no. 4, pp. 250085, 2025, ISSN: 2054-5703.
Abstract | Links | BibTeX | Tags:
@article{arrondo_unravelling_2025,
title = {Unravelling the decision making of foraging vultures: insights from a field experiment},
author = {Eneko Arrondo and Jorge Martinez Carracedo and Patrick McAllister and Zebensui Morales-Reyes and Martina Scacco and Roberto Pascual-Rico and Ainara Cort\'{e}s-Avizanda and Jos\'{e} Antonio Don\'{a}zar and Marcos Mole\'{o}n and Jos\'{e} Antonio S\'{a}nchez-Zapata},
url = {https://royalsocietypublishing.org/doi/10.1098/rsos.250085},
doi = {10.1098/rsos.250085},
issn = {2054-5703},
year = {2025},
date = {2025-04-01},
urldate = {2025-09-16},
journal = {Royal Society Open Science},
volume = {12},
number = {4},
pages = {250085},
abstract = {Optimal Foraging Theory (OFT) integrates both the consumer and the resource, yet their simultaneous assessment is uncommon. Vultures represent an ideal model for OFT studies because carrion requires no capture effort and minimal handling, allowing them to focus primarily on food searching. Here, we combined GPS tracking of 61 Iberian griffon vultures (consumers) with photo-trapping monitoring of 49 carcasses (resources) to assess the determinants of vulture foraging and the consequences for carrion consumption in two areas with different carrion abundances. First, we determined the importance of different factors (distance to the resource, hunger and competition) in the decisions of individuals of whether to descend or not on a carcass. Second, we compared carrion consumption patterns (time of carcass discovery and consumption, and maximum number of vultures gathered around the carcass) between areas. We found that distance, rather than hunger, is the primary factor determining whether a vulture descends to a carcass. In parallel, carrion was consumed similarly in areas with different resource availabilities. These findings indicate that vultures tend to eat whenever a nearby opportunity arises, consistent with a type-I functional response.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Optimal Foraging Theory (OFT) integrates both the consumer and the resource, yet their simultaneous assessment is uncommon. Vultures represent an ideal model for OFT studies because carrion requires no capture effort and minimal handling, allowing them to focus primarily on food searching. Here, we combined GPS tracking of 61 Iberian griffon vultures (consumers) with photo-trapping monitoring of 49 carcasses (resources) to assess the determinants of vulture foraging and the consequences for carrion consumption in two areas with different carrion abundances. First, we determined the importance of different factors (distance to the resource, hunger and competition) in the decisions of individuals of whether to descend or not on a carcass. Second, we compared carrion consumption patterns (time of carcass discovery and consumption, and maximum number of vultures gathered around the carcass) between areas. We found that distance, rather than hunger, is the primary factor determining whether a vulture descends to a carcass. In parallel, carrion was consumed similarly in areas with different resource availabilities. These findings indicate that vultures tend to eat whenever a nearby opportunity arises, consistent with a type-I functional response.
38.
Klarevas-Irby, James A.; Nyaguthii, Brendah; Farine, Damien R.
Moving as a group imposes constraints on the energetic efficiency of movement Journal Article
In: Proceedings of the Royal Society B: Biological Sciences, vol. 292, no. 2041, pp. 20242760, 2025, ISSN: 1471-2954.
Abstract | Links | BibTeX | Tags:
@article{klarevas-irby_moving_2025,
title = {Moving as a group imposes constraints on the energetic efficiency of movement},
author = {James A. Klarevas-Irby and Brendah Nyaguthii and Damien R. Farine},
url = {https://royalsocietypublishing.org/doi/10.1098/rspb.2024.2760},
doi = {10.1098/rspb.2024.2760},
issn = {1471-2954},
year = {2025},
date = {2025-02-01},
urldate = {2025-09-16},
journal = {Proceedings of the Royal Society B: Biological Sciences},
volume = {292},
number = {2041},
pages = {20242760},
abstract = {Movement is a key part of life for many species. In solitary animals, the energetic costs of movement can be mitigated through energetically efficient strategies that produce faster, straighter movements. However, little is known about whether moving as part of a collective enhances or limits the ability of individual group members to express such strategies. Drawing on 6 years of population-level, high-resolution (1 Hz) GPS tracking of group-living vulturine guineafowl (
Acryllium vulturinum
), we detected 886 events from 94 tagged individuals where their groups made large, range-shifting displacements in response to changing environmental conditions. We contrasted these movements with data from 94 similarly large displacement events by 19 lone, dispersing individuals. Our results suggest that individuals in groups can significantly reduce their energetic cost of transport when making large displacements (15.3% more efficient relative to their normal daily ranging) by increasing the speed and straightness of their movements. However, even during their most efficient movements, individuals in groups could not achieve or maintain comparable increases in speed to lone individuals, resulting in significantly limited efficiency gains (35.7% less efficient than solitary individuals). Overall, this study provides evidence for a substantial energetic cost arising from collective movement.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Movement is a key part of life for many species. In solitary animals, the energetic costs of movement can be mitigated through energetically efficient strategies that produce faster, straighter movements. However, little is known about whether moving as part of a collective enhances or limits the ability of individual group members to express such strategies. Drawing on 6 years of population-level, high-resolution (1 Hz) GPS tracking of group-living vulturine guineafowl (
Acryllium vulturinum
), we detected 886 events from 94 tagged individuals where their groups made large, range-shifting displacements in response to changing environmental conditions. We contrasted these movements with data from 94 similarly large displacement events by 19 lone, dispersing individuals. Our results suggest that individuals in groups can significantly reduce their energetic cost of transport when making large displacements (15.3% more efficient relative to their normal daily ranging) by increasing the speed and straightness of their movements. However, even during their most efficient movements, individuals in groups could not achieve or maintain comparable increases in speed to lone individuals, resulting in significantly limited efficiency gains (35.7% less efficient than solitary individuals). Overall, this study provides evidence for a substantial energetic cost arising from collective movement.
Acryllium vulturinum
), we detected 886 events from 94 tagged individuals where their groups made large, range-shifting displacements in response to changing environmental conditions. We contrasted these movements with data from 94 similarly large displacement events by 19 lone, dispersing individuals. Our results suggest that individuals in groups can significantly reduce their energetic cost of transport when making large displacements (15.3% more efficient relative to their normal daily ranging) by increasing the speed and straightness of their movements. However, even during their most efficient movements, individuals in groups could not achieve or maintain comparable increases in speed to lone individuals, resulting in significantly limited efficiency gains (35.7% less efficient than solitary individuals). Overall, this study provides evidence for a substantial energetic cost arising from collective movement.
39.
Wanner, Caitlyn P.; Pratt, Aaron C.; Reinking, Adele K.; Liston, Glen E.; Beck, Jeffrey L.
In: International Journal of Biometeorology, vol. 69, no. 2, pp. 469–485, 2025, ISSN: 0020-7128, 1432-1254.
@article{wanner_novel_2025,
title = {Novel environmental variables help explain winter weather effects on activity and habitat selection of greater sage-grouse along the border of Colorado and Wyoming, USA},
author = {Caitlyn P. Wanner and Aaron C. Pratt and Adele K. Reinking and Glen E. Liston and Jeffrey L. Beck},
url = {https://link.springer.com/10.1007/s00484-024-02827-x},
doi = {10.1007/s00484-024-02827-x},
issn = {0020-7128, 1432-1254},
year = {2025},
date = {2025-02-01},
urldate = {2025-12-03},
journal = {International Journal of Biometeorology},
volume = {69},
number = {2},
pages = {469\textendash485},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
40.
Efrat, Ron; Lehnardt, Yael; Berkowic, Daniel; Leshem, Yossi; Dor, Roi; Bragin, Alexander; Bragin, Evgeny; Katzner, Todd; Sapir, Nir
Using GPS tracking data to validate the conservation value of bird migration counts Journal Article
In: Biological Conservation, vol. 302, pp. 110959, 2025, ISSN: 00063207.
Abstract | Links | BibTeX | Tags:
@article{efrat_using_2025,
title = {Using GPS tracking data to validate the conservation value of bird migration counts},
author = {Ron Efrat and Yael Lehnardt and Daniel Berkowic and Yossi Leshem and Roi Dor and Alexander Bragin and Evgeny Bragin and Todd Katzner and Nir Sapir},
url = {https://linkinghub.elsevier.com/retrieve/pii/S000632072400524X},
doi = {10.1016/j.biocon.2024.110959},
issn = {00063207},
year = {2025},
date = {2025-02-01},
urldate = {2025-09-16},
journal = {Biological Conservation},
volume = {302},
pages = {110959},
abstract = {Effective conservation of migratory birds requires gathering of information about their population trends, often acquired using migratory bird counts. These schemes ideally operate at migratory bottlenecks, through which a significant portion of the counted migratory populations is funneled. Yet it is rare to validate the conservation value of the data from these counts. Here we perform this validation using GPS tracking data collected from two migratory species during their movement over two count schemes: the globally endangered steppe eagle counted in Eilat, Israel, and the black kite, counted in Batumi, Georgia. We use tracking data to answer two questions: which populations are counted and what affects the probability that a given individual will be counted. Our results illustrate variability in the effectiveness of these two migratory bird counting schemes. Considering the goal of estimating population trends, we show that Eilat does not represent a good location for understanding population trends of steppe eagles, while Batumi appears to provide better information on demographic trends of black kites. We further present differences in annual and individual variability, evidence regarding the breeding area origins of the counted populations and effects of environmental factors on the raptors’ routes and, consequently, on the probabilities of being counted. Beyond the direct implications of our results, this study provides an example of using telemetry data to parameterize inference from bird counts. Further coupling of migratory bird count data and GPS data can improve our understanding of migration ecology and the conservation of migratory species.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Effective conservation of migratory birds requires gathering of information about their population trends, often acquired using migratory bird counts. These schemes ideally operate at migratory bottlenecks, through which a significant portion of the counted migratory populations is funneled. Yet it is rare to validate the conservation value of the data from these counts. Here we perform this validation using GPS tracking data collected from two migratory species during their movement over two count schemes: the globally endangered steppe eagle counted in Eilat, Israel, and the black kite, counted in Batumi, Georgia. We use tracking data to answer two questions: which populations are counted and what affects the probability that a given individual will be counted. Our results illustrate variability in the effectiveness of these two migratory bird counting schemes. Considering the goal of estimating population trends, we show that Eilat does not represent a good location for understanding population trends of steppe eagles, while Batumi appears to provide better information on demographic trends of black kites. We further present differences in annual and individual variability, evidence regarding the breeding area origins of the counted populations and effects of environmental factors on the raptors’ routes and, consequently, on the probabilities of being counted. Beyond the direct implications of our results, this study provides an example of using telemetry data to parameterize inference from bird counts. Further coupling of migratory bird count data and GPS data can improve our understanding of migration ecology and the conservation of migratory species.
contact@e-obs.de 
+49 (0)89-420016-0 
+49 (0)8153-887 2559 
