... at night when circulating concentrations of melatonin are elevated. Previous work measured nocturnal melatonin levels of migratory birds only in captive animals, because free-living individuals are usually caught in the daytime. In this study, we compared nocturnal melatonin levels of European robins...

...-allocation hypothesis). Here in wild-caught house sparrows ( Passer domesticus ), we tested the second hypothesis, asking whether sustained elevation of baseline glucocorticoids, due to captivity, caused a greater rate of decline in immune functions than flight performance. A greater decline in immune...

...Lynn B. Martin; Laura Kidd; Andrea L. Liebl; Courtney A. C. Coon SUMMARY Some species thrive in captivity but others exhibit extensive psychological and physiological deficits, which can be a challenge to animal husbandry and conservation as well as wild immunology. Here, we investigated whether...

.... * Author for correspondence ( stephanecaut@gmail.com ) 21 10 2010 © 2011. 2011 captivity discrimination factor nitrogen enrichment Orcinus orca turnover Tursiops truncatus Stable isotopes have a broad array of applications in ecology ( Kelly, 2000 ; Crawford et al...