Community structure of arthropod ectoparasites on Alaskan seabirds

Abstract

A total of 28 species of arthropods was recovered from 29 common murres (Uria aalge), 8 thick-billed murres (Uria lomvia), 22 black-legged kittiwakes (Rissa tridactyla), and 10 red-legged kittiwakes (Rissa brevirostris) collected from the Pribilof Islands, Alaska, U.S.A. The ectoparasite community on each bird species almost invariably consisted of three species of chewing lice, two species of ticks, and five to nine species of mites. Astigmatid feather mites (Alloptes spp., Laronyssus martini (Trouessart)) were the most numerous group of ectoparasites except on black-legged kittiwakes on which Ixodes ticks were the most abundant. The second most abundant taxa were ticks on common murres and thick-billed murres, and quill mites (Syringophilidae) on red-legged kittiwakes. Kittiwakes usually supported more diverse communities of ectoparasites than did murres, probably because of differences in nesting and foraging behavior. Ectoparasite communities between the congeneric species of birds were particularly similar in terms of species composition and general structure, and supported our hypothesis that phylogenetic relatedness of hosts is reflected in similarity of their ectoparasite communities. Community structure of ectoparasites was much more similar between the two murre species than between the two kittiwake species, probably because of gregarious flocking and mixed-species nesting of murres.