Abstract

During migration, birds spend more than 80 % of the time at stopover sites to rest and refuel before and after crossing ecological barriers such as deserts or seas. Since stopover has intrinsic costs in terms of energy and time, birds should try to minimize its duration, which is dependent on the combined effects of environmental factors, endogenous programmes, and physiological conditions. Previous studies on long-distance migrants caught after crossing an ecological barrier have indicated that body condition strongly influences the decision whether to prolong stopover or resume migration, with lean birds staying longer than fat birds. In short-distance migrants, evidence is still scarce regarding a determinant role for physiological condition in stopover behaviour after crossing an ecological barrier. Here, we studied whether migratory restlessness (Zugunruhe) at a stopover site is dependent on physiological condition in three European short-distance migratory passerines: black redstarts, European robins, and European stonechats. In all species, an integrated measure of condition based on body mass, amount of subcutaneous fat, and thickness of pectoral muscles predicted the intensity of Zugunruhe. Overall, our results confirmed the importance of energy reserves in determining stopover duration, illustrating similar stopover strategies in short- and long-distance migrants.

Keywords

Birds; Migration; Stopover; Migratory restlessness; Zugunruhe; Body condition

Published in

Journal of Ornithology
2016, Volume: 157, number: 2, pages: 583-589
Publisher: SPRINGER

SLU Authors

• Cardinale, Massimiliano

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG13 Climate action


UKÄ Subject classification

Ecology


Publication Identifiers

DOI: https://doi.org/10.1007/s10336-015-1303-5

Permanent link to this page (URI)

https://res.slu.se/id/publ/79877