TY - JOUR
T1 - Yolk carotenoids and stable isotopes reveal links among environment, foraging behavior and seabird breeding success
AU - Hipfner, J. Mark
AU - Dale, James
AU - McGraw, Kevin
N1 - Funding Information:
Acknowledgments We thank the many field workers whose tireless efforts made this research possible. We were financially supported by the Nestucca Oil Spill Trust Fund, the Centre for Wildlife Ecology, the World Wildlife Fund Canada, and Environment Canada’s Birds Oiled At Sea, Migratory Bird Conservation and Science Horizons programs. We received invaluable ship and helicopter support from the Canadian Coast Guard, and thank Monica Court, Judy Higham and Connie Smith for top-notch logistical support. We owe special thanks to Moira Galbraith (Institute of Ocean Sciences, Sidney) for providing samples of crustaceans collected on shipboard surveys. During this work, KJM was supported by the College of Liberal Arts and Sciences and the School of Life Sciences at Arizona State University.
PY - 2010/6
Y1 - 2010/6
N2 - Nutrients that are limited in availability, such as carotenoids, are potentially involved in trade-offs between homeostasis and reproduction. Despite their importance, factors that affect the capacity of female birds to meet their carotenoid requirements are poorly understood. We used δ15N stable isotope analysis to relate foraging behavior to yolk carotenoid deposition in two seabirds, Cassin's auklet (Ptychoramphus aleuticus) and rhinoceros auklet (Cerorhinca monocerata), during each of five years. As expected from their narrower trophic range, Cassin's auklets produced yolks with fewer carotenoid types than did rhinoceros auklets (one vs. three). Cassin's auklets also fed on a lower trophic level diet richer in carotenoids, yet had lower total yolk carotenoid levels, which suggests a role for species-specific adaptations for carotenoid uptake and utilization. Within both species, lower trophic-level feeding was linked to higher yolk carotenoid levels, but through different mechanisms. In Cassin's auklets, it was due to a population-wide response to environmental variation: in warm-water years, all females fed at a low trophic level and produced carotenoid-rich yolks. In rhinoceros auklets, it was due to individual differences similarly expressed in all years: females fed across a wide trophic range, and those that fed at a low trophic level produced carotenoid-rich yolks. Rhinoceros auklets bred more successfully in years when their yolks were rich in carotenoids, probably due to a correlated response to stronger marine primary production. Our results are novel because they link avian yolk carotenoid deposition to behavioral and environmental variations.
AB - Nutrients that are limited in availability, such as carotenoids, are potentially involved in trade-offs between homeostasis and reproduction. Despite their importance, factors that affect the capacity of female birds to meet their carotenoid requirements are poorly understood. We used δ15N stable isotope analysis to relate foraging behavior to yolk carotenoid deposition in two seabirds, Cassin's auklet (Ptychoramphus aleuticus) and rhinoceros auklet (Cerorhinca monocerata), during each of five years. As expected from their narrower trophic range, Cassin's auklets produced yolks with fewer carotenoid types than did rhinoceros auklets (one vs. three). Cassin's auklets also fed on a lower trophic level diet richer in carotenoids, yet had lower total yolk carotenoid levels, which suggests a role for species-specific adaptations for carotenoid uptake and utilization. Within both species, lower trophic-level feeding was linked to higher yolk carotenoid levels, but through different mechanisms. In Cassin's auklets, it was due to a population-wide response to environmental variation: in warm-water years, all females fed at a low trophic level and produced carotenoid-rich yolks. In rhinoceros auklets, it was due to individual differences similarly expressed in all years: females fed across a wide trophic range, and those that fed at a low trophic level produced carotenoid-rich yolks. Rhinoceros auklets bred more successfully in years when their yolks were rich in carotenoids, probably due to a correlated response to stronger marine primary production. Our results are novel because they link avian yolk carotenoid deposition to behavioral and environmental variations.
KW - Breeding success
KW - Carotenoids
KW - Foraging
KW - Macronutrients
KW - Trophic range
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U2 - 10.1007/s00442-010-1618-0
DO - 10.1007/s00442-010-1618-0
M3 - Article
C2 - 20397031
AN - SCOPUS:77952323336
SN - 0029-8549
VL - 163
SP - 351
EP - 360
JO - Oecologia
JF - Oecologia
IS - 2
ER -