title: Feather corticosterone reveals developmental stress in seabirds.
abstract: In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development.
authors.affiliation: Institute of Arctic Biology, 311 Irving 1, University of Alaska Fairbanks, Fairbanks, AK 99775, USA awill4@alaska.edu.
authors.forename: Alexis P
authors.initials: AP
authors.lastname: Will
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate, 041-8611, Japan.
authors.forename: Yuya
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Zoology, Z320 Duff Roblin Building, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2.
authors.forename: Kyle H
authors.initials: KH
authors.lastname: Elliott
authors.affiliation: Institute for Seabird Research and Conservation, 12850 Mountain Place, Anchorage, AK 99516, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Hatch
authors.affiliation: Graduate School of Fisheries Sciences, Hokkaido University, Minato-cho 3-1-1, Hakodate, 041-8611, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Watanuki
authors.affiliation: Institute of Arctic Biology, 311 Irving 1, University of Alaska Fairbanks, Fairbanks, AK 99775, USA.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Kitaysky
mesh_terms: D000413:Alaska; D000818:Animals; D046091:Charadriiformes / Q000254:growth & development / Q000502:physiology*; D003345:Corticosterone / Q000097:blood / Q000378:metabolism*; D004032:Diet; D004777:Environment; D005241:Feathers / Q000737:chemistry*; D007564:Japan; D012098:Reproduction; D013312:Stress, Physiological
chemical_list: D003345:Corticosterone
keywords: Adrenal function; Nutritional stress; Resource allocation; Rhinoceros auklet