title: Corticosterone levels in relation to trace element contamination along an urbanization gradient in the common blackbird (Turdus merula).
abstract: In a rapidly urbanizing world, trace element pollution may represent a threat to human health and wildlife, and it is therefore crucial to assess both exposition levels and associated effects of trace element contamination on urban vertebrates. In this study, we investigated the impact of urbanization on trace element contamination and stress physiology in a wild bird species, the common blackbird (Turdus merula), along an urbanization gradient (from rural to moderately urbanized areas). Specifically, we described the contamination levels of blackbirds by 4 non-essential (Ag, Cd, Hg, Pb) and 9 essential trace elements (As, Co, Cr, Cu, Fe, Mn, Ni, Se, Zn), and explored the putative disrupting effects of the non-essential element contamination on corticosterone levels (a hormonal proxy for environmental challenges). We found that non-essential trace element burden (Cd and Pb specifically) increased with increasing urbanization, indicating a significant trace element contamination even in medium sized cities and suburban areas. Interestingly, the increased feather non-essential trace element concentrations were also associated with elevated feather corticosterone levels, suggesting that urbanization probably constrains birds and that this effect may be mediated by trace element contamination. Future experimental studies are now required to disentangle the influence of multiple urban-related constraints on corticosterone levels and to specifically test the influence of each of these trace elements on corticosterone secretion.
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France. Electronic address: alizee.meillere@gmail.com.
authors.forename: Alizée
authors.initials: A
authors.lastname: Meillère
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France.
authors.forename: François
authors.initials: F
authors.lastname: Brischoux
authors.affiliation: Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS-Université de La Rochelle, F-17000 La Rochelle, France.
authors.forename: Paco
authors.initials: P
authors.lastname: Bustamante
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Michaud
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France.
authors.forename: Charline
authors.initials: C
authors.lastname: Parenteau
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France.
authors.forename: Coline
authors.initials: C
authors.lastname: Marciau
authors.affiliation: Centre d'Études Biologiques de Chizé (CEBC), UMR 7372 CNRS-Université de La Rochelle, F-79360 Villiers-en-Bois, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Angelier
mesh_terms: D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D004785:Environmental Pollutants / Q000378:metabolism*; D005241:Feathers / Q000737:chemistry; D005602:France; D008297:Male; D008670:Metals / Q000378:metabolism; D020308:Songbirds / Q000378:metabolism*; D014131:Trace Elements / Q000378:metabolism*; D014507:Urbanization
chemical_list: D004785:Environmental Pollutants; D008670:Metals; D014131:Trace Elements; D003345:Corticosterone
keywords: Endocrine disruptor; Passerine birds; Stress physiology; Trace metals; Urban environments