Skip to Main Content
Prevalence of hematozoa infections among breeding and wintering Rusty BlackbirdsAuthor(s): William H. Barnard; Claudia Mettke-Hofmann; Steven M. Matsuoka
Source: The Condor 112(4):849–853
Publication Series: Scientific Journal (JRNL)
PDF: View PDF (106.75 KB)
DescriptionThe Rusty Blackbird (Euphagus carolinus) has declined precipitously over the past several decades,and stressors on both the breeding and wintering grounds are suspected causes. Over 3 years, we collected blood samples from breeding birds in Alaska and Maine and from wintering birds in Mississippi and Arkansas to determine the prevalence of hematozoan infections at different times of the year. The prevalence of hematozoa (percent of birds infected) in Alaska was 44% of 43 birds, lower than previously reported from Newfoundland and Ontario (83% of 23 birds). Blood parasites were found among 67% of 12 Rusty Blackbirds sampled in Maine, not different from the prevalence in Newfoundland and Ontario. Leucocytozoon was the most common parasite; few breeding birds were infected with Plasmodium or Trypanosoma sp. During the winter in Mississippi and Arkansas, the overall prevalence of hematozoa was 49% over three years. In winter as in summer, Leucocytozoon was the most commonly encountered parasite (n = 62 birds), followed by Haemoproteus (n = 5), microfilaria (n = 2), Trypanosoma (n = 2), and Plasmodium (n = 1). The prevalence of hematozoa among wintering Rusty Blackbirds was much higher than expected because winter is generally a time when there are few transmissions and in most birds blood parasites are absent from the peripheral circulation. This high prevalence might indicate a nonseasonal relapse of hematozoan infections among wintering birds; possibly due to high levels of stress, which are known to lower the immune response and trigger nonseasonal relapses.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationBarnard, William H.; Mettke-Hofmann, Claudia; Matsuoka, Steven M. 2010. Prevalence of hematozoa infections among breeding and wintering Rusty Blackbirds. The Condor 112(4):849–853.
KeywordsRusty Blackbird, hematozoa, blood parasites, Leucocytozoon, Haemoproteus, Trypanosoma, microfilaria
- Geographic and seasonal variation in mercury exposure of the declining Rusty Blackbird
- Migratory connectivity in the Rusty Blackbird: Isotopic evidence from feathers of historical and contemporary specimens
- Competition and habitat quality influence age and sex distribution in wintering Rusty Blackbirds
XML: View XML