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Pollutants increase song complexity and the volume of the brain area HVC in a songbird

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journal contribution
posted on 27.02.2008, 00:00 authored by S Markman, S Leitner, C Catchpole, S Barnsley, C Muller, D Pascoe, Kate BuchananKate Buchanan
Environmental pollutants which alter endocrine function are now known to decrease vertebrate reproductive success. There is considerable evidence for endocrine disruption from aquatic ecosystems, but knowledge is lacking with regard to the interface between terrestrial and aquatic ecosystems. Here, we show for the first time that birds foraging on invertebrates contaminated with environmental pollutants, show marked changes in both brain and behaviour. We found that male European starlings (Sturnus vulgaris) exposed to environmentally relevant levels of synthetic and natural estrogen mimics developed longer and more complex songs compared to control males, a sexually selected trait important in attracting females for reproduction. Moreover, females preferred the song of males which had higher pollutant exposure, despite the fact that experimentally dosed males showed reduced immune function. We also show that the key brain area controlling male song complexity (HVC) is significantly enlarged in the contaminated birds. This is the first evidence that environmental pollutants not only affect, but paradoxically enhance a signal of male quality such as song. Our data suggest that female starlings would bias their choice towards exposed males, with possible consequences at the population level. As the starling is a migratory species, our results suggest that transglobal effects of pollutants on terrestrial vertebrate physiology and reproduction could occur in birds.

History

Journal

Plos one

Volume

3

Issue

2

Pagination

1 - 6

Publisher

Public Library of Science

Location

San Francisco, Calif.

ISSN

1932-6203

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal; C Journal article

Copyright notice

2008, Markman et al.