Multi-Isotopic (δ2H, δ13C, δ15N) Feather Isotopes for Red-winged Blackbirds Associated with Agro-ecosystems

We analyzed stable-hydrogen (δ2H), carbon (δ13C) and nitrogen (δ 15N) isotope ratios in feathers to better understand the molt origin and food habits of Red-winged Blackbirds (Agelaius phoeniceus) near sunflower production in the Upper Midwest and rice production in the Mid-South of the United States. Outer primary feathers grown on the breeding grounds were used from 661 after-second-year (ASY) male blackbirds collected in Minnesota, Montana, North Dakota and South Dakota (breeding collection), and Arkansas, Louisiana, Mississippi, Missouri and Texas (winter collection).