title: Linking breeding and wintering grounds of neotropical migrant songbirds using stable hydrogen isotopic analysis of feathers.
abstract: Recent studies have shown that stable hydrogen isotope ratios (δD) in the tissues of animals often correlate with δD of local precipitation. Here we examined the relationship between δD in feathers and growing season precipitation for neotropical migrant songbirds breeding over a continent-wide isotopic gradient. δD values were determined on feathers of 140 individuals of 6 species of wild insectivorous forest songbirds (Setophaga ruticilla, Empidonax minimus, Vermivora peregrinus, Catharus ustulatus, Seiurus aurocapillus, Hylocichla mustelina) taken from 14 breeding locations across North America. The δD of feathers was strongly correlated with the δD of growing season precipitation at breeding sites across North America. As feather hydrogen is metabolically inert after growth, this relationship was then used to assess the breeding origins of wintering migrants. Deuterium values of feathers from 64 individuals representing 5 species of migrants (Helmitheros vermivorus, Wilsonia citrina, Hylocichla mustelina, Dumetella carolinensis, Seirus aurocapillus) at a wintering site in Guatemala were consistent with those predicted from the known breeding ranges of these species. This study demonstrates hydrogen isotopes may become a powerful tool for linking breeding and wintering grounds of neotropical migrant songbirds, as well as other migratory species moving between isotopically distinct regions.
authors.affiliation: Prairie and Northern Wildlife Research Centre, Environment Canada, Saskatoon, Saskatchewan, Canada, S7N 0X4, , , , , , CA.
authors.forename: K A
authors.initials: KA
authors.lastname: Hobson
authors.affiliation: National Hydrology Research Institute, Environment Canada, Saskatoon, Saskatchewan, Canada, S7N 3H5, , , , , , CA.
authors.forename: Leonard I
authors.initials: LI
authors.lastname: Wassenaar
keywords: Diet; Key words Deuterium; Neotropical migrant; Songbird feathers; Stable isotopes