http://www.dfw.com/mld/dfw/news/9019447.htm?1c
DALLAS - Something has happened to the coyotes that roam the underbrush and dank creeks and drains that wind through northeast Dallas.
Built like canine tanks, the coyotes in this North Texas pack are taller, longer and more massive than the streamlined, wasp-waisted coyotes found elsewhere in the state.
They make their homes alongside sleepy subdivisions and bustling thoroughfares. Drainage canals that eventually dump into Dallas' White Rock Lake have become a kind of superhighway for the four-legged.
Reports of these enormous animals have drawn the attention of one of the nation's foremost wolf biologists, L. David Mech, a research scientist with the U.S. Geological Survey and professor at the University of Minnesota. A typical Texas coyote weighs 25 to 35 pounds, Mech said, and these animals weigh between 40 and 50 pounds.
No researcher before has reported coyotes of this size in Texas, he said.
"Coyotes and wolves are closely related," Mech said. "When I heard about those large coyotes in Dallas, I thought it was worth looking into because they are consistently large. It isn't just one extra-large animal but several, like the whole pack is larger than usual."
Coyotes -- traditionally known as solitary creatures that howl in the distance at night -- have learned to live among humans. And researchers say that the coyotes captured in North Texas may have a remarkable ability to adapt to their changing environment or have crossbred with other canine species.
"It's possible that the coyote is changing genetically," said veteran trapper Mike Trpkosh, who has caught a number of these coyotes. "The coyotes are huge. They're off the charts -- a super species of coyote."
He has combed through tangles of mesquite, ragweed and cottonwood in the reedy outback of the Lochwood area near White Rock Lake in search of coyote tracks, waste, kill sites and dens, hoping to track down an enormous alpha male coyote.
"I've been looking for him for over a year," he said. "I found some scat with bones and a large print in the gravel on Tuesday. I'm pretty sure it's him."
Trpkosh contracts with a number of cities, including Dallas, to trap and dispose of coyotes and other nuisance animals.
Over the past few years, he said, he started noticing a change in some of the coyotes he was trapping, particularly in the Lochwood neighborhood. These coyotes are bulkier than most, with deeper chests and fur with a downy undercoat like a dog's.
At first he attributed the coyotes' change to diet.
"I figured they were eating pets and pet food and their size was a product of good nutrition -- but good nutrition's not enough to explain the change," he said.
These "super coyotes" may be the first signs that the species is crossbreeding with dogs, Mech and other researchers say.
In March, Mech flew to Dallas to collect DNA samples from the coyotes' fecal matter, and geneticists at the university are examining it to determine why the coyotes are so big. The results will be available in August.
Mech said crossbreeding between coyotes and dogs has been well-recorded in the Northeast but is new to Texas.
Some animal experts are skeptical.
Ron Cornelison, a public health technician with the Texas Department of Health, attributed the coyotes' size to diet.
"They simply have more access to dog food or cat food," he said. "The food supply is more plentiful, so you'd expect to see coyotes a few pounds heavier with a better coat and appearance."
Cornelison said he doubts that dogs and coyotes are interbreeding.
"Coy-dogs are very rare," he said. "People claim to see these mixes -- and genetically they can breed, they're not that far apart -- but most of the time coyotes and dogs just don't mix."
But Mech said arguments in favor of diet fall short. Coyotes throughout Texas have the same access to the usual fare of rodents, rabbits and garbage in addition to pet food and small, domesticated animals found in greenbelts and neighborhoods, he said, and record weights are being reported only in a specific area of the state.
Crossbreeding between coyotes and dogs might also explain the animals' aggressive behavior.
"A coyote bred with a dog is dangerous -- it removes their fear of humans," said Capt. Garry Collins of the Texas Parks and Wildlife Department. "They can be aggressive if you're between them and a food source."
However, Collins said he is unaware of a population of coy-dogs in the Dallas area. "Dogs are a bigger problem," he said. "I think that's what people are seeing."
Mech said a second explanation might be that Trpkosh stumbled upon a pack of coyotes that had bred with wolves. This cross-hybridization accounts for larger coyotes in the Northeast and in Canada. But given that Texas' indigenous red wolf population was virtually hunted to extinction and has not been seen in the state for nearly 30 years, Mech said this theory is not likely.
Trpkosh said the trend reaches beyond a single strain or group of giant coyotes; the big animals have been trapped in Garland, Murphy and Mesquite, 15 miles away. Packs usually range five to seven miles, Trpkosh said.
DALLAS - Something has happened to the coyotes that roam the underbrush and dank creeks and drains that wind through northeast Dallas.
Built like canine tanks, the coyotes in this North Texas pack are taller, longer and more massive than the streamlined, wasp-waisted coyotes found elsewhere in the state.
They make their homes alongside sleepy subdivisions and bustling thoroughfares. Drainage canals that eventually dump into Dallas' White Rock Lake have become a kind of superhighway for the four-legged.
Reports of these enormous animals have drawn the attention of one of the nation's foremost wolf biologists, L. David Mech, a research scientist with the U.S. Geological Survey and professor at the University of Minnesota. A typical Texas coyote weighs 25 to 35 pounds, Mech said, and these animals weigh between 40 and 50 pounds.
No researcher before has reported coyotes of this size in Texas, he said.
"Coyotes and wolves are closely related," Mech said. "When I heard about those large coyotes in Dallas, I thought it was worth looking into because they are consistently large. It isn't just one extra-large animal but several, like the whole pack is larger than usual."
Coyotes -- traditionally known as solitary creatures that howl in the distance at night -- have learned to live among humans. And researchers say that the coyotes captured in North Texas may have a remarkable ability to adapt to their changing environment or have crossbred with other canine species.
"It's possible that the coyote is changing genetically," said veteran trapper Mike Trpkosh, who has caught a number of these coyotes. "The coyotes are huge. They're off the charts -- a super species of coyote."
He has combed through tangles of mesquite, ragweed and cottonwood in the reedy outback of the Lochwood area near White Rock Lake in search of coyote tracks, waste, kill sites and dens, hoping to track down an enormous alpha male coyote.
"I've been looking for him for over a year," he said. "I found some scat with bones and a large print in the gravel on Tuesday. I'm pretty sure it's him."
Trpkosh contracts with a number of cities, including Dallas, to trap and dispose of coyotes and other nuisance animals.
Over the past few years, he said, he started noticing a change in some of the coyotes he was trapping, particularly in the Lochwood neighborhood. These coyotes are bulkier than most, with deeper chests and fur with a downy undercoat like a dog's.
At first he attributed the coyotes' change to diet.
"I figured they were eating pets and pet food and their size was a product of good nutrition -- but good nutrition's not enough to explain the change," he said.
These "super coyotes" may be the first signs that the species is crossbreeding with dogs, Mech and other researchers say.
In March, Mech flew to Dallas to collect DNA samples from the coyotes' fecal matter, and geneticists at the university are examining it to determine why the coyotes are so big. The results will be available in August.
Mech said crossbreeding between coyotes and dogs has been well-recorded in the Northeast but is new to Texas.
Some animal experts are skeptical.
Ron Cornelison, a public health technician with the Texas Department of Health, attributed the coyotes' size to diet.
"They simply have more access to dog food or cat food," he said. "The food supply is more plentiful, so you'd expect to see coyotes a few pounds heavier with a better coat and appearance."
Cornelison said he doubts that dogs and coyotes are interbreeding.
"Coy-dogs are very rare," he said. "People claim to see these mixes -- and genetically they can breed, they're not that far apart -- but most of the time coyotes and dogs just don't mix."
But Mech said arguments in favor of diet fall short. Coyotes throughout Texas have the same access to the usual fare of rodents, rabbits and garbage in addition to pet food and small, domesticated animals found in greenbelts and neighborhoods, he said, and record weights are being reported only in a specific area of the state.
Crossbreeding between coyotes and dogs might also explain the animals' aggressive behavior.
"A coyote bred with a dog is dangerous -- it removes their fear of humans," said Capt. Garry Collins of the Texas Parks and Wildlife Department. "They can be aggressive if you're between them and a food source."
However, Collins said he is unaware of a population of coy-dogs in the Dallas area. "Dogs are a bigger problem," he said. "I think that's what people are seeing."
Mech said a second explanation might be that Trpkosh stumbled upon a pack of coyotes that had bred with wolves. This cross-hybridization accounts for larger coyotes in the Northeast and in Canada. But given that Texas' indigenous red wolf population was virtually hunted to extinction and has not been seen in the state for nearly 30 years, Mech said this theory is not likely.
Trpkosh said the trend reaches beyond a single strain or group of giant coyotes; the big animals have been trapped in Garland, Murphy and Mesquite, 15 miles away. Packs usually range five to seven miles, Trpkosh said.
) wolf-husky-hybrid, and he looked just like that critter, and weighed about what they claimed that animal weighed.
