By Jeremy P. Meyer
Denver Post Staff Writer
Article Launched: 08/09/2006 01:00:00 AM MDT
The number of lynx kittens born in the wild in this year dropped 75 percent, leading state wildlife officials to halt the animal's reintroduction program until they figure out why.
This spring, biologists found four dens with 11 kittens, compared with 18 litters with 50 kittens in 2005 and 14 litters with 39 kittens in 2004.
"There is no way that we can say what the issue is," said Tanya Shenk, researcher with the Colorado Division of Wildlife. "It could just be an off year. It could be as simple as that."
The lynx program has been among the most successful in reintroducing endangered species to the wild.
The cat with the distinctive tuft of hair on its ears had disappeared from the southern Rocky Mountains by the early 1970s.
In 1999, lynx began to be relocated in remote areas of the San Juan Mountains. More than 200 lynx from Alaska and Canada have been released.
Researchers have found 116 kittens in winter and spring searches from 2003 to 2006.
This spring a lynx born in Colorado in 2004 produced kittens - a first since the reintroduction program began, according to the Division of Wildlife.
"When you're getting into wildlife biology, it's a very dynamic situation up there," said Joe Lewandowski, a division spokesman. "It takes a lot of years to know what is going on."
In the first year, many of the cats were dying after being released and the protocol was changed, allowing the lynx to feed, be released later in the spring and acclimate to the environment, Lewandowski said.
"Mortality went way down," he said. "They were finding plenty of prey, and reproduction shot up substantially."
Now, researchers want to know whether the lack of kittens is an aberration or a real problem.
Mortality rates haven't increased, and most cats are staying in their established territories, wildlife officials say.
Examinations of dead lynx show the cats had lived healthy lives and were getting enough to eat.
One theory on the decline in kittens is that newly reintroduced cats are interfering with established social structures, said Shenk.
"We have a high number of lynx in the state, and as we put new adults in the spring, they have to find a territory," she said. "They may be interrupting the social structure."
Eventually, any species may level off in numbers because their habitat only supports so many, she said.
Jacob Smith, executive director of the Center for Native Ecosystems, said a key for the animal's survival was protecting more lynx habitat.
"We all know and the biologists know that the missing piece in this is the habitat protection," he said.
Staff writer Jeremy P. Meyer may be reached at 303-820-1201 or firstname.lastname@example.org.