title: Yolk carotenoids and stable isotopes reveal links among environment, foraging behavior and seabird breeding success.
abstract: 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 delta(15)N 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.
authors.affiliation: Centre for Wildlife Ecology, Simon Fraser University, Canadian Wildlife Service, RR#1 5421 Robertson Road, Delta, BC, V4K 3N2, Canada. mark.hipfner@ec.gc.ca
authors.forename: J Mark
authors.initials: JM
authors.lastname: Hipfner
authors.forename: James
authors.initials: J
authors.lastname: Dale
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: McGraw
mesh_terms: D000818:Animals; D046090:Anseriformes; D001717:Birds / Q000502:physiology*; D001955:British Columbia; D002247:Carbon Isotopes; D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism*; D046091:Charadriiformes; D004530:Egg Yolk / Q000737:chemistry*; D004777:Environment; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D009587:Nitrogen Isotopes; D012098:Reproduction / Q000502:physiology*; D013997:Time Factors
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D002338:Carotenoids
references.citation: Physiol Biochem Zool. 2003 Nov-Dec;76(6):776-90
references.pmid: 14988793
references.citation: Proc Biol Sci. 2004 Feb 7;271 Suppl 3:S79-81
references.pmid: 15101425
references.citation: Proc Biol Sci. 2003 Dec 7;270(1532):2485-9
references.pmid: 14667340
references.citation: Ecol Lett. 2009 Jan;12(1):75-92
references.pmid: 19016828
references.citation: Trends Ecol Evol. 2000 Feb;15(2):47-49
references.pmid: 10652553
references.citation: Comp Biochem Physiol B Biochem Mol Biol. 2006 Feb;143(2):145-52
references.pmid: 16343963
references.citation: Mol Biol Evol. 1996 Feb;13(2):359-67
references.pmid: 8587501
references.citation: Ecology. 2008 Sep;89(9):2584-93
references.pmid: 18831179
references.citation: Philos Trans R Soc Lond B Biol Sci. 2008 Jan 27;363(1490):399-410
references.pmid: 17666390
references.citation: J Exp Biol. 2006 Mar;209(Pt 6):1004-15
references.pmid: 16513926
references.citation: J Evol Biol. 2004 Jan;17(1):156-64
references.pmid: 15000658
references.citation: Oecologia. 2005 Jun;144(1):32-44
references.pmid: 15868160
references.citation: Science. 2005 May 27;308(5726):1280-4
references.pmid: 15845876
references.citation: Ecology. 2009 Mar;90(3):742-53
references.pmid: 19341144
references.citation: Gen Comp Endocrinol. 2008 Aug;158(1):5-9
references.pmid: 18577385
references.citation: J Anim Ecol. 2009 Mar;78(2):460-7
references.pmid: 19021778
references.citation: J Evol Biol. 2005 Nov;18(6):1534-46
references.pmid: 16313466
references.citation: Proc Biol Sci. 2002 Jan 7;269(1486):29-36
references.pmid: 11788033
references.citation: Physiol Biochem Zool. 2003 May-Jun;76(3):367-74
references.pmid: 12905123
references.citation: Am Nat. 2008 Aug;172(2):178-93
references.pmid: 18624664