Habitat ecology of Nearctic–Neotropical migratory landbirds on the nonbreeding grounds

Steven Albert, Jared D Wolfe, Jherime Kellerman, Thomas Sherry, Bridget J M Stutchbury, Nicholas J Bayly, Angelina Ruiz-Sánchez

The Condor, Volume 122, Issue 4, 2 November 2020

https://academic.oup.com/condor/article-abstract/122/4/duaa055/5923266?redirectedFrom=fulltext&fbclid=IwAR2MvKxUIGW5mOX-UMbny2etmaPf6TNMTQ3KJ5WRtfKbsYRldp3IIenX_IU

 The abstract reads (in part):

" Of the approximately 716 bird species that breed in North America, 386 (54%) are considered Nearctic–Neotropical migrants by the U.S. Fish and Wildlife Service. In the past 50 yr, scores of these migratory species, including some once considered common, have declined dramatically. Nearctic–Neotropical migrants normally spend 6–8 months in tropical habitats, making the identification, availability, and management of Neotropical habitats critical issues for their conservation. Yet, for most species, complete and nuanced information about their use of tropical habitats and the relative effects of breeding vs. wintering conditions on survival, productivity, and population trends is not available, though many studies point to Neotropical overwintering habitats as being a strong driver of population change. Particularly important for long-distance Nearctic–Neotropical migrants is an understanding of how “carry-over effects” arise and influence population trends when conditions on wintering grounds and tropical stopover areas affect subsequent reproductive performance on breeding grounds."