title: Assessment of concentrations and effects of organohalogen contaminants in a terrestrial passerine, the European starling.
abstract: European starlings (Sturnus vulgaris) are a valuable model species for the assessment of concentrations and effects of environmental contaminants in terrestrial birds. Polybrominated diphenyl ethers (PBDEs) are found in birds throughout the world, but relatively little is known of their concentrations or effects in free-living terrestrial passerines. We used a nest box population of European starlings to 1) measure the variation in egg concentrations of persistent organohalogen contaminants at an agricultural site, and 2) assess whether individual variation in PBDE concentrations in eggs was related to reproductive parameters, as well as maternal or nestling characteristics including body condition, thyroid hormones, oxidative stress, and hematocrit. As PBDEs were the main contaminant class of interest, we only assessed a subset of eggs for other organohalogen contaminants to establish background concentrations. Exposure to organohalogen contaminants was extremely variable over this relatively small study area. Geometric mean wet weight concentrations (range in brackets) of the major contaminants were 36.5 (12-174) ng/g ΣDDT (n=6 eggs) and 10.9 (2-307) ng/g ΣPBDEs (n=14). ΣPCBs at 3.58 (1.5-6.4) ng/g (n=6) were lower and less variable. There were low levels of other organochlorine (OC) pesticides such as dieldrin (2.02 ng/g), chlordanes (1.11 ng/g) and chlorobenzenes (0.23 ng/g). The only form of DDT detected was p,p'-DDE. The congener profiles of PBDEs and PCBs reflect those of industrial mixtures (i.e. DE-71, Aroclors 1254, 1260 and 1262). For all of the contaminant classes, concentrations detected in eggs at our study site were below levels previously reported to cause effects. Due to small sample sizes, we did not assess the relationship between ΣPCBs or ΣOCs and adult or chick condition. We observed no correlative relationships between individual variation in PBDE concentrations in starling eggs and reproductive success, maternal condition, or nestling condition in the corresponding nests.
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada. Electronic address: mea10@sfu.ca.
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Eng
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada. Electronic address: tdwillia@sfu.ca.
authors.forename: Tony D
authors.initials: TD
authors.lastname: Williams
authors.affiliation: Wildlife and Landscape Science Directorate, Science and Technology Branch, Environment Canada, Carleton University, Ottawa, ON K1A 0H3, Canada. Electronic address: robert.letcher@ec.gc.ca.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Letcher
authors.affiliation: Science and Technology Branch, Environment Canada, Pacific Wildlife Research Centre, Delta, BC V4K 3N2, Canada. Electronic address: john.elliott@ec.gc.ca.
authors.forename: John E
authors.initials: JE
authors.lastname: Elliott
mesh_terms: D000818:Animals; D003633:Dichlorodiphenyl Dichloroethylene / Q000378:metabolism; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000378:metabolism*; D004787:Environmental Pollution / Q000706:statistics & numerical data; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism; D006846:Hydrocarbons, Halogenated / Q000378:metabolism*; D010063:Ovum / Q000737:chemistry; D010575:Pesticides / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D046749:Starlings / Q000378:metabolism*
chemical_list: D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D006843:Hydrocarbons, Chlorinated; D006846:Hydrocarbons, Halogenated; D010575:Pesticides; D003633:Dichlorodiphenyl Dichloroethylene; C086401:pentabromodiphenyl ether; D011078:Polychlorinated Biphenyls
keywords: 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene; BC; BCI; British Columbia; CBz; CHL; ELISA; FT3; FT4; HCH; OC; OCS; OSI; Organochlorine pesticides; PBDEs; PCBs; Passerine eggs; Physiology; Polybrominated diphenyl ethers; Polychlorinated biphenyls; Reproductive success; T3; T4; TAC; TCPM; TOS; body condition index; chlordanes; chlorinated benzene; dichlorodiphenyltrichloroethane; enzyme-linked immunosorbent assay; free thyroxine; free triiodothyronine; hexachlorocyclohexane; octachlorostyrene; organochlorine; oxidative status index; p,p′-DDE; p,p′-DDT; polybrominated diphenyl ethers; polychlorinated biphenyl ethers; thyroxine; total antioxidant capacity; total oxidant status; triiodothyronine; tris(4-chlorophenyl)methanol