Full length article Ecological and spatial factors drive intra- and interspecific variation in exposure of subarctic predatory bird nestlings to persistent organic pollutants Igor Eulaers a, ⁎, Veerle L.B. Jaspers a , Jan O. Bustnes b , Adrian Covaci c , Trond V. Johnsen b , Duncan J. Halley d , Truls Moum e , Rolf A. Ims f , Sveinn A. Hanssen b , Kjell E. Erikstad b , Dorte Herzke g , Christian Sonne h , Manuel Ballesteros b , Rianne Pinxten a , Marcel Eens a a Ethology Research Group, Department of Biology, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium b Unit for Arctic Ecology, Norwegian Institute for Nature Research, FRAM — High North Research Centre for Climate and the Environment, Hjalmar Johansens Gate 14, 9296 Tromsø, Norway c Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium d Unit for Terrestrial Ecology, Norwegian Institute for Nature Research, Tungasletta 2, 7485 Trondheim, Norway e Marine Genomics Research Group, Faculty of Biosciences and Aquaculture, University of Nordland, 8049 Bodø, Norway f Northern Populations and Ecosystems Research Group, Department of Arctic and Marine Biology, University of Tromsø, Dramsveien 201, 9037 Tromsø, Norway g Norwegian Institute for Air Research, FRAM — High North Research Centre for Climate and the Environment, Hjalmar Johansens Gate 14, 9296 Tromsø, Norway h Department of Bioscience, Arctic Research Centre, Faculty of Science and Technology, Aarhus University, Frederiksborgvej 399, P.O. Box 358, 4000 Roskilde, Denmark abstract article info Article history: Received 26 November 2012 Accepted 26 March 2013 Available online xxxx Keywords: δ 13 C δ 15 N Body feather Biomagnification Habitat Stable isotope Top predators in northern ecosystems may suffer from exposure to persistent organic pollutants (POPs) as this exposure may synergistically interact with already elevated natural stress in these ecosystems. In the present study, we aimed at identifying biological (sex, body condition), ecological (dietary carbon source, trophic level) and spatial factors (local habitat, regional nest location) that may influence intra- and interspecific varia- tion in exposure of subarctic predatory bird nestlings to polychlorinated biphenyl 153 (CB 153), polybrominated diphenyl ether 47 (BDE 47), dichlorodiphenyldichloroethylene (p,p′-DDE) and hexachlorobenzene (HCB). Dur- ing three breeding seasons (2008–2010), we sampled body feathers from fully-grown nestlings of three ecolog- ically distinct predatory bird species in subarctic Norway: Northern Goshawk (Accipiter gentilis), White-tailed Eagle (Haliaeetus albicilla) and Golden Eagle (Aquila chrysaetos). The present study analysed, for the first time, body feathers for both POPs and carbon (δ 13 C) and nitrogen (δ 15 N) stable isotopes, thus integrating the dietary carbon source, trophic level and POP exposure for the larger part of the nestling stage. Intraspecific variation in exposure was driven by a combination of ecological and spatial factors, often differ- ent for individual compounds. In addition, combinations for individual compounds differed among species. Trophic level and local habitat were the predominant predictors for CB 153, p,p′-DDE and BDE 47, indicating their biomagnification and decreasing levels according to coast > fjord > inland. Variation in exposure may also have been driven by inter-annual variation arisen from primary sources (e.g. p,p′-DDE) and/or possible revolatilisation from secondary sources (e.g. HCB). Interspecific differences in POP exposure were best explained by a combination of trophic level (biomagnification), dietary carbon source (food chain discrimi- nation) and regional nest location (historical POP contamination). In conclusion, the combined analysis of POPs and stable isotopes in body feathers from fully-grown nestlings has identified ecological and spatial factors that may drive POP exposure over the larger part of the nestling stage. This methodological approach further promotes the promising use of nestling predatory bird body feathers as a non-destructive sampling strategy to integrate various toxicological and ecological proxies. © 2013 Elsevier Ltd. All rights reserved. 1. Introduction Being lipophilic and highly resistant to chemical and biological degradation, persistent organic pollutants (POPs) are of concern for the health of ecosystems because of three reasons. Firstly, POPs asso- ciate with organic matter, in particular lipids, and therefore potential- ly bioaccumulate in biological tissues and biomagnify through food chains (Borgå et al., 2012). As a consequence, wildlife feeding at the Environment International 57–58 (2013) 25–33 ⁎ Corresponding author. Tel.: +32 3 265 22 96 (office); fax: +32 3 265 22 71. E-mail addresses: igor.eulaers@ua.ac.be (I. Eulaers), veerle.jaspers@ua.ac.be (V.L.B. Jaspers), jan.o.bustnes@nina.no (J.O. Bustnes), adrian.covaci@ua.ac.be (A. Covaci), trond.johnsen@nina.no (T.V. Johnsen), duncan.halley@nina.no (D.J. Halley), truls.moum@uin.no (T. Moum), rolf.ims@uit.no (R.A. Ims), sveinn.a.hanssen@nina.no (S.A. Hanssen), kjell.e.erikstad@nina.no (K.E. Erikstad), dorte.herzke@nilu.no (D. Herzke), csh@dmu.dk (C. Sonne), manuel.ballesteros@nina.no (M. Ballesteros), annie.pinxten@ua.ac.be (R. Pinxten), marcel.eens@ua.ac.be (M. Eens). 0160-4120/$ – see front matter © 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.envint.2013.03.009 Contents lists available at SciVerse ScienceDirect Environment International journal homepage: www.elsevier.com/locate/envint