New Records of Nematodes in the Yellow-Billed Cuckoo Coccyzus americanus (Cuculiformes: Cuculidae) Based on a Migrant Specimen Found in Brazil

Abstract

The yellow-billed cuckoo, Coccyzus americanus, is a threatened passerine bird native to North America that migrates to overwinter in South America. Although migratory birds have drawn broad attention, given their assumed role in the long-distance dispersal of parasites, studies on the helminth fauna of this cuculid are scarce. In the present study, nematodes found in the gastrointestinal tract of a specimen of C. americanus found in Belo Horizonte, State of Minas Gerais, southeastern Brazil, were characterized morphologically. Five species of gastrointestinal nematodes belonging to 4 families were identified: Synhimantus (Dispharynx) nasuta (Rudolphi, 1819) and Synhimantus (Dispharynx) resticulaCanavan, 1929 (Acuariidae), Microtetrameres sp. (Tetrameridae), and Cyrnea piayaeSandground, 1929 (Habronematidae) and Subulura halli Barreto, 1918 (Subuluridae). Except for Microtetrameres sp., all other nematodes are reported in this host for the first time. Although it is difficult to accurately determine the geographical origin of infections, it is important to note that Sy. (D.) resticula and Su. halli are reported for the first time in Brazil. Additionally, the absence of the former species infecting hosts where the widespread and generalist Sy. (D.) nasuta was found may indicate that Sy. (D.) resticula have either been overlooked in previous studies or that this nematode is rare indeed. Finally, the geographical distribution of Su. halli is greatly expanded and now includes the Americas. Aspects related to the dispersion of these parasites, both in migrating and native hosts, are briefly discussed.