Retirement comes early for sentinel chickens
By James Kirley
Tuesday, January 22, 2008
Their working careers are spent outdoors as mosquito bait, housed in wire cages custom built to foil attacks by raccoons and other hungry wild animals. Weekly, they are bled for scientists who look for evidence of viruses that can sicken humans.
Retirement comes early for so-called sentinel chickens used on the Treasure Coast and elsewhere in Florida as living barometers for mosquito-borne diseases. They usually are retired by winter of each year, when they are given to petting zoos or rural families that keep flocks for eggs.
"We give them away, usually to farmers out in Okeechobee (County)," said Charles Mahon, operations supervisor at Martin County Mosquito Control. "They're still laying eggs. All we use are hens, because they're just more docile and easier to handle."
Sentinel chickens are used to detect the presence of naturally occurring viruses that cause West Nile and St. Louis encephalitis. Birds bitten by infected mosquitoes quickly develop telltale antibodies to the viruses. When large numbers of sentinel chickens test positive for these antibodies, scientists know there are enough infected mosquitoes on the wing to pose a human health problem.
The virus doesn't cause disease in the chickens and their eggs and meat are safe to consume, said Don Shroyer, medical entomologist with the Indian River Mosquito Control District in Vero Beach. In fact, he added, chickens raised for food by commercial farms can be exposed to mosquitoes bites and the same viruses.
But once sentinel chickens test positive, they are useless to predict disease. So each spring, mosquito control officials put out new flocks of young birds.
The Indian River district in Vero Beach puts out flocks of six chickens at each of eight sites spread throughout Indian River County.
About 30 of Florida's 67 counties use sentinel chickens to detect mosquito-borne illness.
The district has its own mosquito-proof chicken coop to prevent premature exposure to bites. Currently, it houses a reserve flock of 50 birds from 2007 that will be put out in February. A short time later, 150 baby chicks will arrive from Iowa and move into the coop.
They will be ready for posting as disease sentinels when they reach 10 weeks old, Shroyer said.
Chickens retired due to viral exposure or old age are given to district employees like Bruce Lewis, who keeps a flock at his rural home.
"We eat the eggs and pretty much let them live the good life," Lewis said.
Shroyer also knows a few local families who adopt retired chickens.
"We've never been in a position where we've had to euthanize them," Shroyer said. "It's far better to have some purpose to the rest of their lives."
Some end up at Noah's Barn, the petting zoo at Life for Youth Camp west of Vero Beach. Camp Director Sherri Stevens said the mosquito control district first asked to post a cage of sentinels on the property during an epidemic of St. Louis encephalitis in 1990.
"Shortly after that, they wanted to know if we'd like to keep some of them," Stevens said.
So retired chickens now move into a coop next to pens of goats, rabbits, quail and other animals kept for the amusement of upwards to 700 children who attend the Christian day camp during school breaks.
Eddie Roper, the camp's maintenance director, tends the animals.
"These chickens are pretty lucky," Roper said. "They get plenty of food and water. We let them run free during the day and put them in the coop at night to keep them safe from wild animals."
Most of the camp's children have been raised in cities.
"A lot of them don't know what a chicken is," Roper said. "When they see an egg in the nest, they say, 'Hey, Mr. Eddie, there's an egg!'
"Most of the time the only eggs they see come from a grocery store."
By James Kirley
Tuesday, January 22, 2008
Their working careers are spent outdoors as mosquito bait, housed in wire cages custom built to foil attacks by raccoons and other hungry wild animals. Weekly, they are bled for scientists who look for evidence of viruses that can sicken humans.
Retirement comes early for so-called sentinel chickens used on the Treasure Coast and elsewhere in Florida as living barometers for mosquito-borne diseases. They usually are retired by winter of each year, when they are given to petting zoos or rural families that keep flocks for eggs.
"We give them away, usually to farmers out in Okeechobee (County)," said Charles Mahon, operations supervisor at Martin County Mosquito Control. "They're still laying eggs. All we use are hens, because they're just more docile and easier to handle."
Sentinel chickens are used to detect the presence of naturally occurring viruses that cause West Nile and St. Louis encephalitis. Birds bitten by infected mosquitoes quickly develop telltale antibodies to the viruses. When large numbers of sentinel chickens test positive for these antibodies, scientists know there are enough infected mosquitoes on the wing to pose a human health problem.
The virus doesn't cause disease in the chickens and their eggs and meat are safe to consume, said Don Shroyer, medical entomologist with the Indian River Mosquito Control District in Vero Beach. In fact, he added, chickens raised for food by commercial farms can be exposed to mosquitoes bites and the same viruses.
But once sentinel chickens test positive, they are useless to predict disease. So each spring, mosquito control officials put out new flocks of young birds.
The Indian River district in Vero Beach puts out flocks of six chickens at each of eight sites spread throughout Indian River County.
About 30 of Florida's 67 counties use sentinel chickens to detect mosquito-borne illness.
The district has its own mosquito-proof chicken coop to prevent premature exposure to bites. Currently, it houses a reserve flock of 50 birds from 2007 that will be put out in February. A short time later, 150 baby chicks will arrive from Iowa and move into the coop.
They will be ready for posting as disease sentinels when they reach 10 weeks old, Shroyer said.
Chickens retired due to viral exposure or old age are given to district employees like Bruce Lewis, who keeps a flock at his rural home.
"We eat the eggs and pretty much let them live the good life," Lewis said.
Shroyer also knows a few local families who adopt retired chickens.
"We've never been in a position where we've had to euthanize them," Shroyer said. "It's far better to have some purpose to the rest of their lives."
Some end up at Noah's Barn, the petting zoo at Life for Youth Camp west of Vero Beach. Camp Director Sherri Stevens said the mosquito control district first asked to post a cage of sentinels on the property during an epidemic of St. Louis encephalitis in 1990.
"Shortly after that, they wanted to know if we'd like to keep some of them," Stevens said.
So retired chickens now move into a coop next to pens of goats, rabbits, quail and other animals kept for the amusement of upwards to 700 children who attend the Christian day camp during school breaks.
Eddie Roper, the camp's maintenance director, tends the animals.
"These chickens are pretty lucky," Roper said. "They get plenty of food and water. We let them run free during the day and put them in the coop at night to keep them safe from wild animals."
Most of the camp's children have been raised in cities.
"A lot of them don't know what a chicken is," Roper said. "When they see an egg in the nest, they say, 'Hey, Mr. Eddie, there's an egg!'
"Most of the time the only eggs they see come from a grocery store."