Feather Hydrogen Stable Isotopes Reveal Migratory and Interhabitat Connectivity of North American Wintering Songbirds in Coastal Secondary Dry Forest on the South Coast of Puerto Rico
This project was established to (1) support and develop a recently established academic program in ornithology and avian conservation (the only such effort in Puerto Rico); (2) employ mist netting, color banding census, stable isotopic analysis, light-level geolocators and mitochondrial DNA (mtDNA) (for Northern Waterthrushes (Parkesia noveboracensis) techniques to establish links between breeding and wintering populations of migratory songbirds that nest in North America and winter, or stop over in Puerto Rico; and, (3) establish a long-term monitoring program for migratory and year-round resident species of terrestrial birds that utilize secondary coastal dry forest and mangroves in and around the area of the Jobos Bay National Estuarine Research Reserve (JBNERR). The project includes undergraduate and graduate student research focusing on long-distance migratory and interhabitat movement, habitat quality, and social structure of migrants and nesting residents, and promote and enhance the academic and professional development of ornithology and citizen science in Puerto Rico. We collected feather samples for stable isotope analysis and mtDNA analysis. Analysis of our first replicate of feather samples and comparison to the new feather isotope atlas for North America have already provided noteworthy results. For ground foragers (Northern Waterthrushes (Parkesia noveboracensis), Ovenbirds (Seiurus aurocapillus)), we found statistical differences overall between the isotopic signatures of wing (P1) and tail (R1) feathers, and discrepancies did occur between specific Isotopic Region assignments of individuals. Similar results were found for canopy foragers, Yellow Warblers ((Setophaga petechia), Prairie Warblers (Setophaga discolor) and Bananaquits (Coereba flaveola)), and there was statistical significance overall between wing and tail feather isotopic signatures of these species. Results also indicate that some individuals continued molting during migration and even upon arrival in Puerto Rico. Some individuals of the canopy foraging species displayed feather isotopic signatures indicative of the marine/mangrove environment, and about 13% of Yellow Warblers sampled appear to be migrants rather than local residents.
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