How Birds Combat Ectoparasites

Dale H. Clayton*, 1, Jennifer A.H. Koop1, Christopher W. Harbison1, 2, Brett R. Moyer1, 3, Sarah E. Bush1, 4
1 Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
2 Current address: Biology Department, Siena College, Loudonville, NY, 12211, USA
3 Current address: Providence Day School, Charlotte, NC, 28270, USA
4 Natural History Museum and Biodiversity Research Center, University of Kansas, Lawrence, Kansas 66045, USA

© 2010 Clayton et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: ( This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

* Address correspondence to this author at the Department of Biology, University of Utah, Salt Lake City, UT 84112, USA; Tel: 801-581-6482; Fax: 801-581-4668; E-mails:


Birds are plagued by an impressive diversity of ectoparasites, ranging from feather-feeding lice, to featherdegrading bacteria. Many of these ectoparasites have severe negative effects on host fitness. It is therefore not surprising that selection on birds has favored a variety of possible adaptations for dealing with ectoparasites. The functional significance of some of these defenses has been well documented. Others have barely been studied, much less tested rigorously. In this article we review the evidence - or lack thereof - for many of the purported mechanisms birds have for dealing with ectoparasites. We concentrate on features of the plumage and its components, as well as anti-parasite behaviors. In some cases, we present original data from our own recent work. We make recommendations for future studies that could improve our understanding of this poorly known aspect of avian biology.

Keywords: Grooming, preening, dusting, sunning, molt, oil, anting, fumigation.