Environmental conditions, including weather, influence organisms in a variety of ways. Specifically, animal males and females might be affected differently by ambient temperatures that vary in time and space. In this study, we explored the effect of elevation, which strongly determines ambient temperatures, on the speed of moult of the wing’s flight feathers in the Eurasian Blackbird (Turdus merula). Differences in moult speed may alter the wing’s surface area during the moulting process and hence may influence flight performance, including the ability to escape from predators. Sampling elevations were categorized to locations > 1000 m above mean sea level (AMSL) and locations < 300 m AMSL. We found that birds moulted their primary wing feathers faster at low elevations than at high elevations. In addition, differences in elevation-related moult speed were modulated by bird sex. Males moulted their primary feathers faster than females at high elevations but slower than females at low elevations. Our findings highlight the importance of considering sex-dependent responses to spatial environmental conditions, which may influence key properties of major annual-cycle activities and life-history processes.
Bibliographical noteFunding Information:
We would like to thank Itai Shimshon who collected the data in Regba, Itai Bloch who collected the data at Mt. Carmel and, Ron Haran who collected the data at the Einot Tzukim Nature Reserve under permission from the nature reserve staff. Thanks to Michaela Zinkin for her help with field work and data collection. Thanks also to Eran Levin for discussing several aspects of this study, Eli Haviv for helping with the mapping and the Israel Meteorological Service for providing data from their meteorological stations.
© 2021, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
- Environmental gradients
- Eurasian Blackbird
- Life-history transitions
- Scheduling of physiological processes
- Thermal environment
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics