Abstract
Migration is a common phenomenon across many animal taxa. Understanding how migration scales with body size across species is fundamental in the development of migration theory and in making size‐related predictions. Although aerodynamic theory and ecophysiological scaling laws have assisted greatly in generating such predictions, their verifications have been limited by a lack of empirical data across a range of body sizes. The recent development of ultra‐light tracking devices and its rapid application to migration now allows us to put theory to the test. We used tracking data of seven closely related migratory sandpiper species (family Scolopacidae) along the East Asian‐Australasian Flyway to compare their migratory behaviour when migrating towards the breeding grounds as a function of size (50–750 g). We found a marked decline in migration speed (migration distance divided by total migration duration, including time at stopover sites and in flight) with size. Departure date from the non‐breeding (i.e. wintering) ground and arrival date at the breeding ground also scaled negatively with size. Total migration duration, migration distance, total staging duration (the number of days staying at stopover sites plus days preparing, i.e. fuelling, prior to initial migration) and step length (distance covered within one migratory leg) were not significantly related with size. Correction for phylogeny showed consistent results for all variables. Besides improving our fundamental understanding of inter‐specific variation in migration behaviours, the finding of a clear scaling with size in migration speed and migration timing highlight differential size related capabilities and constraints of migrants. Migratory birds, including sandpipers, are declining on a global scale and particularly along the East Asian‐Australasian Flyway. This notion of size‐dependency in migratory traits may have a bearing on their vulnerability to specific environmental disturbances along their flyways.
Highlights
Body size correlates with nearly everything from an animal’s appearance to its physiology and behaviour (Bonner 2011) and may therewith affect animals’ vulnerability to environmental change (Cardillo et al 2005, Schipper et al 2008, Woodward et al 2012)
Understanding the sizerelated, allometric, potentials and constraints on migration behaviours is fundamental for developing migration theory and may be of importance for the conservation of migratory species, since migrants’ vulnerability to environmental change may vary with size (Lindström et al 2014)
According to the time-minimization strategy birds fly and deposit fuel as fast as possible to maximize their overall speed of migration, i.e. migration distance divided by the total time required to prepare/fuel and fly (Alerstam and Lindström 1990, Alerstam 1991, 2011, Lindstrom and Alerstam 1992)
Summary
Body size correlates with nearly everything from an animal’s appearance to its physiology and behaviour (Bonner 2011) and may therewith affect animals’ vulnerability to environmental change (Cardillo et al 2005, Schipper et al 2008, Woodward et al 2012). According to the time-minimization strategy birds fly and deposit fuel as fast as possible to maximize their overall speed of migration, i.e. migration distance divided by the total time required to prepare/fuel and fly (Alerstam and Lindström 1990, Alerstam 1991, 2011, Lindstrom and Alerstam 1992). Such time-minimization strategy is demonstrated to be adopted during migrations towards the breeding grounds (i.e. pre-breeding migration) (reviewed by Nilsson et al 2013), where a timely arrival may provide an advantage over competitors (Kokko 1999, Moore et al 2005) and enables an optimal use of seasonally available local resources (Meltofte et al 2008, McKinnon et al 2012), benefiting reproductive performance (Bety et al 2004)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
