Abstract
AbstractMigratory movements of facultative migrants are poorly understood due to their irregular and often unpredictable occurrence. However, tracking such movements is important for understanding population dynamics, informing annual cycle conservation plans, and identifying possible cues of facultative migration. We used pinpoint GPS tags to track autumn and winter movements of migratory red-headed woodpeckers (Melanerpes erythrocephalus) to better understand migration frequency, timing, and routes for birds breeding in managed oak savanna systems in the North American Great Lakes region. Proportions of individuals migrating differed between the two sites, with 72% of the Ohio population migrating, while no individuals in the Minnesota population migrated. Of the Ohio birds that migrated, their movements were highly variable in distance and direction but generally occurred south of the breeding site. Wintering sites ranged from 111 – 218 km from the breeding site. Cover types occupied during migration and wintering were almost exclusively small patches of closed-canopy hardwood forest within agricultural matrices. We documented one-time movements in migratory and non-migratory individuals during the year that have not previously been described in facultative migrants. We found no evidence of a harness or marker effect on proportions of individuals migrating, migration return rates, or annual survival regardless of migration.
Highlights
Migration is a behavior used by individuals and populations to access resources that may be spatially or temporally limited
We did not include seven individuals (6 GPS-tagged and 1 control) in the migration analysis due to vehicular mortality at the breeding site (N = 1 GPStagged) and apparent movement outside our study site (N = 5 GPS-tagged and 1 control) as they did not survive, or in the case of those that apparently emigrated, could not be confirmed to have survived the breeding season or to be likely to return to our study sites in 2018 if they show breeding site fidelity
4.1 Migration and return proportions winter or if they dispersed to a different breeding site, and such unknown fates complicate efforts to determine rates of survival [44]
Summary
Migration is a behavior used by individuals and populations to access resources that may be spatially or temporally limited. Facultative migrants are often characterized by varying proportions of the population migrating annually. This migration tends to be highly variable among individuals with regard to timing, distances, and direction compared to obligate migration [1]. The inherent variability in individuals’ migration behaviors in populations of facultative migrants presents challenges when attempting to study migration timing, distance, routes, and the location of wintering sites. This limits our ability to understand how those metrics might contribute to population trends
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
