How Birds Combat Ectoparasites

Abstract

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.

Effects of strain and sex on the behaviour of free-range slow-growing chickens raised in a hot environment

“…Spending the most time preening during the 12:00-h period perhaps indicates more than just a simple trade-off between preening and foraging by birds. It is during the hottest period that birds clean their feathers and wad external parasites (Clayton et al 2010). A previous study noted that the preferred time of dust-bathing, a similar behaviour driven by thermal stimulation, is the middle of the day (Wichman & Keeling 2009;Orsag et al 2011).…”

Host correlates of diversification in avian lice

“…Birds exhibit behavioural, physiological and morphological adaptations to reduce louse burdens (Clayton et al, 2010). Plumage maintenance behaviours include preening by the bill and scratching by the foot; louse burdens increase dramatically after experimental impairment of preening (Clayton, 1991).…”

Ecosystem Services Provided by the Little Things That Run the World

“…Nowadays, the behavior involves the bird seizing one or more ants in the bill and then, while holding one or both wings outstretched and the tail bent forward between the legs, wiping the ants into the primary feathers of wings and tail [87]. It is believed that birds use ants to maintain their feathers free from parasites, such as feather lice Mallophaga species and feather mites Acarina species [9], although this is not a consensual belief [88]. Anting has been reported for over 200 species of birds, mostly passerines (reviewed by [87]).…”