Abstract

Knowledge about intraspecific and individual variation in bird migration behavior is important to predict spatiotemporal distribution, patterns of phenology, breeding success, and interactions with the surrounding environment (e.g., human livelihoods). Such variation is key to adaptive, evolutionary responses, i.e., how individuals respond spatiotemporally to the environment to maximize fitness. In this study we used GPS location data from one to three full annual cycles from 76 Greylag geese (Anser anser) to test the hypothesis that geese originating at five latitudinally separated capture sites in Sweden have different migration strategies. We also assessed individual consistency in movement strategy over consecutive annual cycles. We used the scale-independent net squared displacement modeling framework to quantify variables of autumn and spring migration for geese from each capture site: distance, timing, and duration. Our results demonstrate a positive correlation between migration distance and latitudinal origin. Geese from the northernmost site on average migrated farther south and about 15 times as far as the short-moving or resident geese from the two southernmost sites. Movement strategies of individual geese varied considerably both within and among capture sites. Individual consistency in movement strategy from one annual cycle to the consecutive was high in geese from the northern sites moving the farthest, whereas the resident or short-moving geese from the southernmost sites generally showed lower or no individual consistency. These changes have come about during a time span so short (i.e., ca. 35 years or 8-10 generations) that it can unlikely be explained by classical Darwinian between-generation adaptation. Consequently, and given that young geese follow their parents during their first migration, we presume an important role of within-family, inter-generation change as a driver behind the large-scale changed migration habits in Swedish Greylag geese.

Keywords

animal movement; Anser anser; flyway management; GPS telemetry; individual variation; net squared displacement

Published in

Ecology and Evolution
2022, Volume: 12, number: 3, article number: e8740
Publisher: WILEY

SLU Authors

• Nilsson, Lovisa

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Olsson, Camilla

  • Department of Ecology, Swedish University of Agricultural Sciences
    
  • Kristianstad University

• Liljebäck, Niklas

  • Department of Ecology, Swedish University of Agricultural Sciences
    

• Månsson, Johan

  • Department of Ecology, Swedish University of Agricultural Sciences
    

Associated SLU-program

Wildlife Damage Centre
SLU Plant Protection Network


Sustainable Development Goals

Protect, restore and promote sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, and halt and reverse land degradation and halt biodiversity loss


UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1002/ece3.8740

Permanent link to this page (URI)

https://res.slu.se/id/publ/116790