Researchers for the Colorado Division of Wildlife recently completed their annual search for lynx kittens.

The highlight was documenting for the first time that a Colorado-born female lynx has produced kittens. The cat, born in 2004, gave birth to two males in mid-June.

"Proving that kittens born to released lynx can survive, establish territories, find mates and have kittens of their own is a significant milestone that brings the program a step closer to success," said Jeff Ver Steeg, assistant director for wildlife programs for the DOW.

However, the number of lynx kittens born and the number of litters found in 2006 is down significantly from the previous three years. Four dens were found with a total of 11 kittens. Researchers found six litters containing 16 kittens in 2003; 14 litters and 39 kittens in 2004; and 18 litters with 50 kittens in 2005.

More kittens were likely born to other lynx that can't be tracked because they are not equipped with radio collars. DOW biologists estimate the number of lynx in Colorado is holding steady at about 200. Most of the cats live in the southern mountains.

DOW biologists are puzzled by the lower number of kittens and dens this year and are evaluating a number of possible explanations, said Rick Kahn, terrestrial program manager for the DOW. Despite the decline in dens, the rate of lynx mortality has not increased and most cats are staying in established territories. Examination of lynx mortalities by DOW veterinarians shows that the animals had been healthy, leading biologists to think that this is not related to the amount of food available.

As a result of this year's decline in the number of females successfully breeding, the DOW is not planning to release any lynx in Colorado next spring.

"Given the high number of lynx currently out there we want to give them an opportunity to settle down and establish a stable social structure," Kahn said. "We have some indication from our radio-marked animals that adding new adults, via the spring releases, to the established population may be disrupting breeding."

The DOW will evaluate the need for additional releases in the future and make recommendations to the Colorado Wildlife Commission sometime next year.

DOW biologists will continue to monitor lynx movements. A new study of snowshoe hare ecology has also started.

A total of 218 lynx from Canada and Alaska have been released in the Creede area in 1999, 2000, 2003, 2004, 2005, and 2006. Field crews have found a total of 116 kittens during the spring and winter searches in 2003-2006.

Funding for the lynx reintroduction program comes from Great Outdoors Colorado through the Colorado Lottery and from the Colorado Division of Wildlife.

For more information about the Division of Wildlife visit wildlife.state.co.us.