Stable isotopes in breath, blood, feces and feathers can indicate intra-individual changes in the diet of migratory songbirds

Abstract

We used stable isotopes of C in breath, blood, feces and feathers to identify intra-individual changes in diet and the timescale of diet changes in free-living songbirds at a stopover site. Because accurate interpretation of differences between the delta13C of breath, plasma, and red blood cells (RBCs) relative to diet requires knowing the turnover rate of C within them, we determined the rate of change of C in breath, plasma and RBCs for yellow-rumped warblers (Dendroica coronata). Half-lives of C in breath, plasma, and RBCs were 4.4+/-2.1 h, 24.8+/-12.3 h and 10.9+/-3.2 days, respectively, for yellow-rumped warblers. delta13C of breath, plasma, RBCs and feces from wild-caught golden-crowned kinglets (Regulus satrapa), ruby-crowned kinglets (R. calendula) and gray catbirds (Dumetella carolinensis) indicated that they had maintained an isotopically consistent diet for an extended period of time. However, delta13C of breath and plasma indicated that white-throated sparrows (Zonotrichia albicollis) had recently expanded their diet to include a C4 dietary component. Likewise, delta13C of breath, plasma, RBCs and feces indicated that some wild-caught yellow-rumped warblers had consumed foods with a more enriched protein signature prior to their arrival on Block Island, and since arrival, they had consumed mostly northern bayberry (Myrica pensylvanica). Therefore, comparisons of the delta13C of breath, plasma, RBCs, feces and feathers from individual songbirds can indicate changes in diet and provide an estimate of the timescale of the diet change.

Stable isotope analysis reveals sexual and environmental variability and individual consistency in foraging of thin-billed prions

“…Nisbet et al 2002, Bearhop et al 2006 (Podlesak et al 2005). The RBC samples collected from thin-billed prion chicks therefore represented the diet ingested ca.…”

Stable carbon isotopes in exhaled breath as tracers for dietary information in birds and mammals

“…Carleton et al, 2006) and free-ranging animals (e.g. Podlesak et al, 2005). Dietswitching experiments during which the isotopic composition of the diet is drastically changed at the onset of the experimentfrom e.g.…”

Host behaviour and physiology underpin individual variation in avian influenza virus infection in migratory Bewick's swans

“…Furthermore, the period required to incorporate a specific isotope pattern from diet into body tissue, known as turn-over time, depends on the speed of tissue renewal and determines the temporal window during which changes in the isotopic composition of an animal's diet can be discerned [31]. Blood components show rapid turn-over and therefore archive information on an individual's diet, and hence foraging habitat, in the foregoing days (plasma) to weeks (red blood cells) [36]. Given that infection persists for 3-8 days in free-living ducks [27], d 13 C of blood components was examined to assess the importance of temporally relevant foraging behaviour to intra-population variation in AIV infection.…”