Nourani et al. (2024), Developmental stage shapes the realized energy landscape for a flight specialist_elife

The heterogeneity of the physical environment determines the cost of transport for animals, shaping their energy landscape. Animals respond to this energy landscape by adjusting their distribution and movement to maximize gains and reduce costs. Much of our knowledge about energy landscape dynamics focuses on factors external to the animal, particularly the spatio-temporal variations of the environment. However, an animal’s internal state can significantly impact its ability to perceive and utilize available energy, creating a distinction between the ‘fundamental’ and the ‘realized’ energy landscapes. Here, we show that the realized energy landscape varies along the ontogenetic axis. Locomotor and cognitive capabilities of individuals change over time, especially during the early life stages. We investigate the development of the realized energy landscape in the Central European Alpine population of the golden eagle Aquila chrysaetos, a large predator that requires negotiating the atmospheric environment to achieve energy-efficient soaring flight. We quantified weekly energy landscapes using environmental features for 55 juvenile golden eagles, demonstrating that energetic costs of traversing the landscape decreased with age. Consequently, the potentially flyable area within the Alpine region increased 2170-fold during their first three years of independence. Our work contributes to a predictive understanding of animal movement by presenting ontogeny as a mechanism shaping the realized energy landscape.

Ganoe et al. (2024), Fisher activity patterns show potential for behavioral adaptations to human modified landscapes. Global Ecology and Conservation

Fishers (Pekania pennanti) are proving their adaptability in human-altered landscapes, as shown in a recent study from Rhode Island. Using e-obs GPS collars, researchers tracked 34 individuals over two years, revealing that fishers are more active at night, particularly in areas with fewer roads and less human disturbance. Surprisingly, extreme temperatures had little effect on their behavior. Instead, the study found that human activities, such as increased traffic, significantly reduced their activity during the day, especially in summer.

This research offers valuable insights into how fishers navigate environments influenced by human presence, prioritizing safer areas for their movements. It also underscores the importance of advanced tracking technologies, like the e-obs collars, in understanding and conserving wildlife in changing landscapes. Congratulations to the research team for this important work.