RJ
08-10-2006, 06:53 PM
Advisory Issued After Several Birds Were Found to Have Died of Type C Botulism
New York State Department of Environmental Conservation (DEC) Regional Director Peter A. Scully today issued an advisory for local residents requesting that they refrain from feeding waterfowl during the remaining summer days after 12 dead mallard and abandoned domestic ducks were recovered from the shoreline of the West Babylon Creek in West Babylon. Preliminary analysis at the State’s DEC Wildlife Pathology Lab indicates that the birds died of type C botulism.
Type C botulism is typical for waterfowl and the most common botulism strain found in wildlife. Type C botulism poses virtually no human health risks. Large-scale outbreaks of type C botulism often are associated with periods of hot weather, high water temperature, low water levels, or changing water levels. Since the toxin is destroyed by heat, no problem with botulism will result from eating thoroughly cooked waterfowl.
"While the DEC always advises against feeding wildlife, the recent extreme heat wave we experienced has exasperated conditions in our local waters increasing the amount of decaying plant matter and other organic material," Director Scully said. "This natural process combined with people’s well placed intentions to feed waterfowl concentrates animals in places where the bacteria responsible for the toxin can proliferate. The bacteria establishes on naturally decaying plants or decaying food such as bread or grain placed out for the birds."
Botulism is a paralytic condition brought on by the consumption of a naturally occurring toxin produced by the bacterium Clostridium botulinum. It is an intoxication rather than an infectious disease. The bacterium is widespread in soils in North America and elsewhere in the world. Type C and type E, botulism have affected wildlife in New York.
Type C botulism occurs principally in waterfowl and other birds living in an aquatic environment and can cause tremendous losses. In New York, outbreaks occur in ducks and shorebirds whenever conditions are favorable for botulism. There have been reports of botulism along the Lake Ontario coast as well as along the St. Lawrence River as well as on Long Island this summer.
Type C botulism becomes prevalent when the toxin-producing bacteria has access to organic material under anaerobic conditions such as those produced on mudflats exposed to high heat. After the bacteria becomes established on the decaying material, aquatic invertebrates and birds ingest the bacterium when feeding. Toxin production takes place in decaying animal carcasses.
Toxins accumulate in carcasses of dead invertebrates, in the flesh of birds dying of botulism, and in maggots feeding on toxic carcasses. Flies deposit eggs on carcasses, which are fed upon by resulting maggots. These maggots then concentrate the toxin, and the toxic maggots are ingested by birds. These birds then die, leading to the proliferation of more maggots. As the cycle accelerates, major die-offs can occur.
Outbreaks are characterized by the presence of dead birds in varying numbers. Typically a few sick birds are usually located nearby. The only meaningful sign of botulism is the loss of strength due to muscular paralysis. The degree of paralysis is related to the dose and time of exposure and the amount of toxic material consumed.
The best way to reduce the prevalence of the toxin is to remove the organic material hosting the bacteria. This means removing any rotting vegetation or other organic matter and removing the carcasses of any dead animals from the area. Though type C botulism generally is not an issue for humans, whenever anyone handles a dead animal they should avoid direct contact and use gloves or use an inverted plastic bag to grab the animal. The animals can be double-bagged and disposed of in the trash, buried away from the shoreline area or brought to an incinerator. To help prevent the reestablishment of type E botulism, a no feeding ordinance should be adopted and enforced.
Food handouts often result in large numbers of birds competing for very limited food supplies in small concentrated areas. Such crowding and competing for foods, especially during this summer period in small canals, concentrates animals where the type C botulism toxin may be present. Even under normal weather conditions, feeding of waterfowl makes them dependent on less nutritious food, and often encourages migratory birds to stay in an area that may increase their exposure to harsh weather and susceptibility to life threatening diseases such as avian cholera, duck plague and avian botulism. Infected birds may also spread these diseases to other birds.
To learn more about waterfowl in New York, please visit the DEC’s website at http://www.dec.state.ny.us/website/dfwmr/wildlife/waterfowl/index.html. Additional information on feeding waterfowl may be obtained from the U.S. Fish and Wildlife Service at http://training.fws.gov/library/Pubs9/caution_waterfowl.pdf Individuals may also contact the DEC’s Regional Wildlife Unit at (631) 444-0310 if they have questions about waterfowl in their area.
New York State Department of Environmental Conservation (DEC) Regional Director Peter A. Scully today issued an advisory for local residents requesting that they refrain from feeding waterfowl during the remaining summer days after 12 dead mallard and abandoned domestic ducks were recovered from the shoreline of the West Babylon Creek in West Babylon. Preliminary analysis at the State’s DEC Wildlife Pathology Lab indicates that the birds died of type C botulism.
Type C botulism is typical for waterfowl and the most common botulism strain found in wildlife. Type C botulism poses virtually no human health risks. Large-scale outbreaks of type C botulism often are associated with periods of hot weather, high water temperature, low water levels, or changing water levels. Since the toxin is destroyed by heat, no problem with botulism will result from eating thoroughly cooked waterfowl.
"While the DEC always advises against feeding wildlife, the recent extreme heat wave we experienced has exasperated conditions in our local waters increasing the amount of decaying plant matter and other organic material," Director Scully said. "This natural process combined with people’s well placed intentions to feed waterfowl concentrates animals in places where the bacteria responsible for the toxin can proliferate. The bacteria establishes on naturally decaying plants or decaying food such as bread or grain placed out for the birds."
Botulism is a paralytic condition brought on by the consumption of a naturally occurring toxin produced by the bacterium Clostridium botulinum. It is an intoxication rather than an infectious disease. The bacterium is widespread in soils in North America and elsewhere in the world. Type C and type E, botulism have affected wildlife in New York.
Type C botulism occurs principally in waterfowl and other birds living in an aquatic environment and can cause tremendous losses. In New York, outbreaks occur in ducks and shorebirds whenever conditions are favorable for botulism. There have been reports of botulism along the Lake Ontario coast as well as along the St. Lawrence River as well as on Long Island this summer.
Type C botulism becomes prevalent when the toxin-producing bacteria has access to organic material under anaerobic conditions such as those produced on mudflats exposed to high heat. After the bacteria becomes established on the decaying material, aquatic invertebrates and birds ingest the bacterium when feeding. Toxin production takes place in decaying animal carcasses.
Toxins accumulate in carcasses of dead invertebrates, in the flesh of birds dying of botulism, and in maggots feeding on toxic carcasses. Flies deposit eggs on carcasses, which are fed upon by resulting maggots. These maggots then concentrate the toxin, and the toxic maggots are ingested by birds. These birds then die, leading to the proliferation of more maggots. As the cycle accelerates, major die-offs can occur.
Outbreaks are characterized by the presence of dead birds in varying numbers. Typically a few sick birds are usually located nearby. The only meaningful sign of botulism is the loss of strength due to muscular paralysis. The degree of paralysis is related to the dose and time of exposure and the amount of toxic material consumed.
The best way to reduce the prevalence of the toxin is to remove the organic material hosting the bacteria. This means removing any rotting vegetation or other organic matter and removing the carcasses of any dead animals from the area. Though type C botulism generally is not an issue for humans, whenever anyone handles a dead animal they should avoid direct contact and use gloves or use an inverted plastic bag to grab the animal. The animals can be double-bagged and disposed of in the trash, buried away from the shoreline area or brought to an incinerator. To help prevent the reestablishment of type E botulism, a no feeding ordinance should be adopted and enforced.
Food handouts often result in large numbers of birds competing for very limited food supplies in small concentrated areas. Such crowding and competing for foods, especially during this summer period in small canals, concentrates animals where the type C botulism toxin may be present. Even under normal weather conditions, feeding of waterfowl makes them dependent on less nutritious food, and often encourages migratory birds to stay in an area that may increase their exposure to harsh weather and susceptibility to life threatening diseases such as avian cholera, duck plague and avian botulism. Infected birds may also spread these diseases to other birds.
To learn more about waterfowl in New York, please visit the DEC’s website at http://www.dec.state.ny.us/website/dfwmr/wildlife/waterfowl/index.html. Additional information on feeding waterfowl may be obtained from the U.S. Fish and Wildlife Service at http://training.fws.gov/library/Pubs9/caution_waterfowl.pdf Individuals may also contact the DEC’s Regional Wildlife Unit at (631) 444-0310 if they have questions about waterfowl in their area.