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(yield-not BF, but note incinerating most birds, and overcrowding at watering holes could lead to future problems)
Chill, disease killing waterfowl
By Carrie Peyton Dahlberg - Bee Staff Writer
Published 12:00 am PST Tuesday, January 16, 2007
With icy ponds forcing ducks and geese to crowd closer and closer together, wildlife refuge managers are continuing the grim task of collecting the dead in an effort to slow an outbreak of avian cholera.
The bacterial disease has killed more than 1,500 birds so far at the Butte Sink section of the Sacramento National Wildlife Refuge complex, said Mike Carpenter, one of the wildlife biologists who's been scooping the dead birds from ponds and shorelines.
An additional 214 were collected Sunday, on a refuge boat that sometimes broke through a half-inch-thick layer of ice on its rounds, Carpenter said.
A few birds were saved for testing, but most went into an incinerator: little gray and black coots, ruddy ducks streaked with vivid green, and wigeons, a compact duck with male breeding plumage that turns russet and is set off by a blue beak.
"I don't like picking up dead birds," said Carpenter, but "you're saving lots of birds by staying on top of the disease."
Fueled by cold, crowding and low water levels, cholera can fell tens of thousands of birds in a bad winter. This year's episode, while not unusual in cold weather, is one of the harsh realities facing migratory waterfowl.
"I've actually seen birds drop out of the sky from avian cholera," said Bob McLandress, president of California Waterfowl Association, whose graduate work included studying the disease. "All of a sudden a bird will fall down, and within 20 minutes it's stone dead."
The disease poses no risks to hunters, he said, as long as any ducks they take are thoroughly cooked.
So far, avian cholera doesn't appear to have spread significantly through the network of wildlife refuges, flooded rice fields and duck clubs that dot the Central Valley, McLandress said, but that could change.
Once the disease has taken hold in one place, "the chances of it flaring up during the rest of the winter will be higher," he said. "I don't think it's the end of it."
Often avian cholera seems to target a species or two and spare many others, he said, but the victims can vary from year to year, with some outbreaks tougher on snow geese or Ross' geese.
Overcrowding is a key factor in spreading avian cholera from bird to bird, and right now, conditions are ripe for overcrowding.
With 3 million to 4 million waterfowl in the Central Valley now, the relative lack of rain means there are fewer places for migratory birds to gather, McLandress said.
Cold weather compounds the problem, both because the birds stay closer for warmth and because some wetlands freeze, making even less open water available to the birds.
For bird watchers, the crowding can also mean a chance to see bigger flocks than usual gathered in one place.
Refuge officials plan to take a boat out again today to continue monitoring for cholera, searching for more dead birds at Butte Sink Wildlife Management Area, an 18,000 acre complex west of the Sutter Buttes and east of the town of Colusa.
The birds saved for testing are also being checked for avian flu, a far more worrisome disease because it has the potential to mutate into a deadly flu that could spread easily among humans.
Migratory flocks are tested regularly in California for bird flu, but it hasn't yet been detected here.
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Chill, disease killing waterfowl
By Carrie Peyton Dahlberg - Bee Staff Writer
Published 12:00 am PST Tuesday, January 16, 2007
With icy ponds forcing ducks and geese to crowd closer and closer together, wildlife refuge managers are continuing the grim task of collecting the dead in an effort to slow an outbreak of avian cholera.
The bacterial disease has killed more than 1,500 birds so far at the Butte Sink section of the Sacramento National Wildlife Refuge complex, said Mike Carpenter, one of the wildlife biologists who's been scooping the dead birds from ponds and shorelines.
An additional 214 were collected Sunday, on a refuge boat that sometimes broke through a half-inch-thick layer of ice on its rounds, Carpenter said.
A few birds were saved for testing, but most went into an incinerator: little gray and black coots, ruddy ducks streaked with vivid green, and wigeons, a compact duck with male breeding plumage that turns russet and is set off by a blue beak.
"I don't like picking up dead birds," said Carpenter, but "you're saving lots of birds by staying on top of the disease."
Fueled by cold, crowding and low water levels, cholera can fell tens of thousands of birds in a bad winter. This year's episode, while not unusual in cold weather, is one of the harsh realities facing migratory waterfowl.
"I've actually seen birds drop out of the sky from avian cholera," said Bob McLandress, president of California Waterfowl Association, whose graduate work included studying the disease. "All of a sudden a bird will fall down, and within 20 minutes it's stone dead."
The disease poses no risks to hunters, he said, as long as any ducks they take are thoroughly cooked.
So far, avian cholera doesn't appear to have spread significantly through the network of wildlife refuges, flooded rice fields and duck clubs that dot the Central Valley, McLandress said, but that could change.
Once the disease has taken hold in one place, "the chances of it flaring up during the rest of the winter will be higher," he said. "I don't think it's the end of it."
Often avian cholera seems to target a species or two and spare many others, he said, but the victims can vary from year to year, with some outbreaks tougher on snow geese or Ross' geese.
Overcrowding is a key factor in spreading avian cholera from bird to bird, and right now, conditions are ripe for overcrowding.
With 3 million to 4 million waterfowl in the Central Valley now, the relative lack of rain means there are fewer places for migratory birds to gather, McLandress said.
Cold weather compounds the problem, both because the birds stay closer for warmth and because some wetlands freeze, making even less open water available to the birds.
For bird watchers, the crowding can also mean a chance to see bigger flocks than usual gathered in one place.
Refuge officials plan to take a boat out again today to continue monitoring for cholera, searching for more dead birds at Butte Sink Wildlife Management Area, an 18,000 acre complex west of the Sutter Buttes and east of the town of Colusa.
The birds saved for testing are also being checked for avian flu, a far more worrisome disease because it has the potential to mutate into a deadly flu that could spread easily among humans.
Migratory flocks are tested regularly in California for bird flu, but it hasn't yet been detected here.
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