Stable isotope analysis of multiple tissues from Hawaiian honeycreepers indicates elevational movement.

摘要: We have limited knowledge of the patterns, causes, and prevalence elevational migration despite observations seasonal movements animals along gradients in montane systems worldwide. While a third extant Hawaiian landbird species are estimated to be migrants this assumption is based primarily on early naturalist's with empirical evidence. In study, we compared stable hydrogen isotopes (δ2H) metabolically inert (feathers) active (blood plasma, red blood cells) tissues collected from same individual determine if present day populations honeycreepers undergo track areas seasonally high flower bloom that constitute significant food resources. also measured carbon (δ13C) nitrogen (δ15N) examine potential changes diet between time periods. found majority 'apapane (Himatione sanguinea) Hawai'i 'amakihi (Chlorodrepanis virens) captured at elevation, flowering sites fall were not year-round residents capture locations, but had molted their feathers lower elevations presumably summer after breeding. δ2H values for all individuals sampled higher than plasma isotope accounting differences tissue-specific discrimination. did find difference propensity movement 'amakihi, even though considered more sedentary. However, consistent generalist diet, δ15N indicated diverse across trophic levels 'apapane, greater reliance nectar fall. demonstrate collecting multiple tissue samples, which grow different rates or periods, single can provide insights into over an extended period.