A seasonal study of the parasites of the red-winged blackbird (Agelaius phoeniceus L.) in Manitoba and Arkansas

Abstract

Examination of 223 red-winged blackbirds revealed seven trematodes of which Zonorchis petiolatum, Leucochloridium macrostomum, Tanaisia (Tamerlania) zarudnyi, and Tanaisia (Tanaisia) fedtschenkoi are new host records; three cestodes of which Anomotaenia sp. is a new host record; and six nematodes of which Dispharynx nasuta, Diplotriaena bargusinica, and Tetrameres sp. are new host records. Only one acanthocephalan, Mediorhynchus grandis, and three blood protozoa were found. Two protozoa, Parahaemoproteus (= Haemoproteus) orizivora and Plasmodium vaughani, are new host records. The 12 ectoparasites included two new host records, Ceratophyllus garei and Sternostoma tracheacolum. Four nonparasitic organisms were recovered, none of which have been reported associated with this bird.The most common parasites were the trematode Plagiorchis noblei, the louse Brüelia sp., and the feather mite Proctophyllodes egglestoni. Each showed a characteristic seasonal pattern. Ectoparasites were most abundant prior to host breeding, and endoparasites during the host breeding period. Ten species of parasites were ubiquitous according to Dogiel's classification, nine were breeding-site or northern parasites, three were probably migratory, and eight were wintering or southern parasites. Eight other species were tentatively classified according to Dogiel's system, and one species could not be classified.The highest intake of animal food by the host coincided with the peak of endoparasitism.