Experimental study of micro-habitat selection by ixodid ticks feeding on avian hosts. Issue 13 (December 2019)

• Record Type: Journal Article
• Authors: Fracasso, Gerardo; Matthysen, Erik; Dhondt, André A.; Heylen, Dieter
• Is Part Of: International journal for parasitology. Volume 49:Issue 13/14(2019)
• Page Start: 1005
• Page End: 1014
• Publication Date: 2019-12
• Subjects: Attachment preference -- Attachment site selection -- Bird host -- Host body parts -- Ixodes arboricola -- Ixodes ricinus -- Parus major -- Serinus canaria domestica; Parasitology -- Periodicals; Parasitology -- Periodicals; Parasitologie -- Périodiques; Parasitology; Periodicals; Electronic journals; 571.999
• DOI: 10.1016/j.ijpara.2019.09.003
• Languages: English
• ISSNs: 0020-7519

Abstract

Graphical abstract: Highlights: Ixodid ticks are only found attached to the head of avian hosts in the wild. Ticks show higher attachment success on the head and move to it if possible. Attachment to the head is governed by tick preference rather than host grooming. Site selection might impact disease transmission, and host and parasite evolution. Abstract: Mechanisms of on-host habitat selection of parasites are important to the understanding of host-parasite interactions and evolution. To this end, it is important to separate the factors driving parasite micro-habitat selection from those resulting from host anti-parasite behaviour. We experimentally investigated whether tick infestation patterns on songbirds are the result of an active choice by the ticks themselves, or the outcome of songbird grooming behaviour. Attachment patterns of three ixodid tick species with different ecologies and host specificities were studied on avian hosts. Ixodes arboricola, Ixodes ricinus and Ixodes frontalis were put on the head, belly and back of adult great tits ( Parus major ) and adult domestic canaries ( Serinus canaria domestica ) which were either restricted or not in their grooming capabilities. Without exception, ticks were eventually found on a bird's head. When we gave ticks full opportunities to attach on other body parts – in the absence of host grooming – they showed lower attachment success. Moreover, ticks moved from these other body parts to the host's head when given the opportunity. This study provides evidence that the commonly observed pattern of ticks feeding on songbirds' heads is the result of an adaptive behavioural strategy. Experimental data on a novel host species, the domestic canary, and a consistent number of published field observations, strongly support this hypothesis. We address some proximate and ultimate causes that may explain parasite preference for this body part in songbirds. The link found between parasite micro-habitat preference and host anti-parasite behaviour provides further insight into the mechanisms driving ectoparasite aggregation, which is important for the population dynamics of hosts, ectoparasites and the micro-pathogens for which they are vectors.