Effects of a novel ectoparasite on condition and mouth coloration of nestling barn swallows

Publication Type:Journal Article
Year of Publication:2022
Authors:M. B. Dugas, Border S. E.
Journal:Biological Journal of the Linnean Society
Date Published:Jan 2022
ISSN:0024-4066, 1095-8312
Keywords:barn swallow, begging, host switching, mouth colour, parasite, Petrochelidon pyrrhonata

Parasites have profound and widespread implications for the ecology and evolution of hosts, and human activity has increased the frequency of interactions between hosts and parasites that have not co-evolved. For example, by building habitat attractive for nesting, humans might have facilitated range expansion by cliff swallows (Petrochelidon pyrrhonata) and barn swallows (Hirundo rustica) in North America, concurrently allowing a haematophagous ectoparasite of cliff swallows, the swallow bug (Oeciacus vicarious), to infest the nests of barn swallows. We found that in barn swallow nests infested with swallow bugs, nestlings weighed less and had lower haematocrit, and the within-brood variation in body mass and tarsus length was higher. Information about these negative effects might be available to parents via mouth coloration, a condition-dependent component of the begging signal. We found that nestlings from infested broods had lower-intensity carotenoid-based and ultraviolet mouth colours, although most elements of colour were unrelated to parasites. Host switching by the swallow bug offers excellent opportunities to understand the direct and indirect effects of a novel parasite and might also afford insights into how parasites cope with selective pressures exerted by closely related hosts with key ecological differences.

Online first published Nov. 2021

Taxonomic name: 
File attachments: 
Fri, 2022-07-29 16:41 -- Yokb
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith