Could blackbird mortality from avicide DRC-1339 contribute to avian botulism outbreaks in North Dakota?

Wildlife Society Bulletin
By: , and 



Blackbird (family lcteridae) depredation on sunflower (Helianthus annuus) crops in the prairie states of the United States has motivated the proposed use of an avicide, DRC-1339 (3-chloro-4-methylaniline), to decrease their numbers. The resulting mortality of blackbirds at wetland roosts could increase the potential of avian botulism occurring in affected marshes. To assess this possibility, we seeded (artificially placed) blackbird carcasses in selected wetlands in Stutsman County, North Dakota, during August-September 2000 and July-September 2001 to evaluate their rate of decomposition and role in initiating avian botulism outbreaks. We monitored carcasses to determine their persistence, the frequency and amount of maggots produced, and the presence of type C botulinum toxin. In 10 of our 12 study wetlands, blackbird carcasses were not rapidly removed by scavengers, thus providing substrate for maggot growth and potential production of Clostridium botulinum toxin. Decomposition of carcasses occurred rapidly, and maggot production averaged 4a??5 g per carcass within 9 days. We were unable to detect C. botulinum type C toxin in any of the 377 blackbird carcasses or the 112 samples of maggots we collected in 2000 or 2001. None of the 25 blackbird carcasses we tested contained botulinum spores, the most probable explanation for the absence of botulinum toxin production. Our results indicate that the likelihood of DRC-1339-poisoned blackbirds causing botulism outbreaks would be minimal in North Dakota wetlands during late summer and early autumn.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Could blackbird mortality from avicide DRC-1339 contribute to avian botulism outbreaks in North Dakota?
Series title Wildlife Society Bulletin
DOI 10.2193/0091-7648(2004)032[0870:CBMFAD]2.0.CO;2
Volume 32
Issue 3
Year Published 2004
Language English
Publisher U.S. Fish and Wildlife Service
Contributing office(s) National Wildlife Health Center
Description 11 p.
First page 870
Last page 880
Country United States
State North Dakota, South Dakota
Online Only (Y/N) N
Additional Online Files (Y/N) N
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