Avian botulism is a disease of birds resulting from the ingestion of a paralyzing toxin produced by the bacterium, Clostridium botulinum type C. The toxin is closely related to botulism toxins A and B, which are responsible for a similar food-borne disease in humans. Affected birds lose coordination and show signs of paralysis of the legs and wings and labored breathing. In advanced stages of the disease, the birds cannot hold their heads up, and often drown or suffocate.
Most outbreaks of type C botulism occur in ducks, and species such as pintails, shovelers, and mallards are among those that suffer the greatest losses. However, almost all birds are susceptible to the disease, says Dr. Creekmore, and in recent years, losses in other species, including pelicans, herons, and egrets have been increasing.
Dr. Tonie Rocke, a veteran scientist also at the USGS National Wildlife Health Center, who has spent years studying botulism explains, "Often the disease will occur in one wetland and not occur in an adjacent wetland just a few yards away. If we could determine the environmental factors that trigger the disease, we may be able to devise wetland management methods to lower the risk of outbreaks and reduce mortality."
Dr. Rocke and her colleagues have made significant progress in determining the conditions that are associated with avian botulism outbreaks. The organism is widely distributed in wetland sediments and factors such as acidity (pH), salinity, and temperature apparently play major roles in increasing or decreasing the risk of outbreaks. The next step is to determine if management actions influence these key environmental conditions.
The USGS National Wildlife Health Center is the foremost wildlife diagnostic and investigative facility of its type, devoted to identifying causes and possible management responses for episodes of death or debilitation among free-ranging wild creatures throughout the United States and, on a consulting basis, other nations.
As the nation's largest earth and biological science and civilian mapping agency, the USGS works in cooperation with more than 1,200 organizations across the country to provide reliable, impartial, scientific information to resource managers, planners, and other customers. This information is gathered in every state by USGS scientists to minimize the loss of life and property from natural disasters, contribute to wise economic and physical development of the nation's natural resources, and enhance the quality of life by monitoring water, biological, energy, and mineral resources of the nation.
The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.
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