A Rocky Mountain Success Story
A mother lynx watches warily as her kittens are evaluated by Colorado Division of Wildlife Biologists.
Photo credit: Colorado Division of Wildlife
Permitted use provided by: U.S. Fish & Wildlife Service
Thirteen years ago, the Canada lynx (Lynx canadensis) returned to its native range within the state of Colorado. Through a committed state-led initiative, this elusive cat has made a remarkable resurgence within a part of its southern-most range, from which it had been absent for more than 25 years.
Historically, the lynx ranged across the vast northern boreal forests from Alaska to eastern Canada, including the northernmost U.S., and extending in an increasingly patchy distribution along the coniferous forests of the Rocky Mountains as far south as Colorado. For reasons that are not completely understood, the lynx is believed to have disappeared from Colorado by 1973. Presumed to be extirpated from the Centennial State, the cat was listed as state endangered in 1976.
In 1999, Colorado Parks and Wildlife (CPW), known then as the Colorado Division of Wildlife, began an ambitious reintroduction program by releasing 96 lynx captured from Alaska and Canada into southwestern Colorado's remote San Juan Mountains. CPW continued to release and monitor radio- and satellite-collared lynx for several years, as the species started to colonize the area and spread into other parts of Colorado's high country.
The U.S. Fish and Wildlife Service (Service) was supportive of CPW's reintroduction effort, and, once lynx was listed as a federally threatened species under the Endangered Species Act in the lower 48 states in 2000, provided Section 6 funding for experimentation of suitable monitoring techniques of lynx reintroduced into Colorado. By 2006, over 200 of these medium-sized cats had returned to Colorado's landscape.
To help evaluate the success of the reintroduction program, CPW established a set of benchmarks for tracking the progress of the lynx population and the criteria it must meet before it is considered self-sustaining. Released lynx were to exhibit a high rate of survival in the critical first months after release, maintain low mortality rates over the long-term, and remain in good habitat at densities sufficient for breeding. CPW also hoped to document successful recruitment—reintroduced lynx would successfully reproduce, and Colorado-born lynx would survive and successfully reproduce. A final goal was to determine that recruitment could equal or exceed mortality over an extended period of time.
"Colorado's lynx reintroduction was successful because we had large amounts of suitable, unoccupied habitat across broad geography in the state," says Eric Odell, Carnivore Species Conservation Program Manager for CPW.
A lynx kitten in a tree. Photo Credit:
Colorado Division of Wildlife
Starting in 2003, CPW documented many successful behaviors by the reintroduced lynx. Den visits identified 16 native kittens that year, and another 39 the following year. By 2010, information gathered from den visits indicated that the lynx had successfully produced third-generation Colorado kittens and that 30 to 40 percent of female lynx bore litters totaling 141 kittens. With all of the CPW's benchmarks for successful lynx reintroduction met, biologists were pleased that the lynx was adjusting well to Colorado's rugged mountains.
"The lynx project showed that a state-led process could be successful in restoring a native species," says CPW Director Rick Cables. "It hadn't been done with lynx before and the adaptive nature of our effort can provide a lot of information for others interested in similar efforts."
Today, Colorado's lynx population consists of surviving reintroduced adults, lynx born to reintroduced animals, and the offspring of first- and second-generation and native-born lynx. While the exact size of the population in Colorado is not known, CPW estimates there are currently between 200 to 300 lynx in the state.
"Colorado Parks and Wildlife's biggest accomplishment was restoring an amazing animal to Colorado's landscape," says Cables. "Conserving wildlife is an important part of our mission and we're proud of the work our staff was able to do with our partners including the ski industry, U.S. Forest Service, and U.S. Fish and Wildlife Service."
To track future trends in the reintroduced population, CPW's lynx program has shifted its focus to developing a strategy to monitor lynx occurrence, distribution and activity within the state. Estimating the exact number of lynx in Colorado is challenging, given the elusive nature of the species. Biologists now use minimally invasive techniques like trail cameras, snow-tracking and genetic sampling to monitor the presence of lynx in established and potential habitats.
While the lynx faces uncertainty regarding predicted changes in climate and snow conditions, the future of the Colorado lynx population is certainly brighter now thanks to these reintroduction efforts.
"The Service commends the proactive conservation efforts initiated by CPW in cooperation with the U.S. Forest Service, National Park Service, Bureau of Land Management, the ski industry, and private timber interests," says Bridget Fahey, Chief of Endangered Species in the Service's Mountain-prairie Region. "This project is a great example of how different interests can work together to conserve listed species in a manner compatible with other land uses."
The lynx reintroduction program is one of the most successful reintroductions of a threatened species and a remarkable conservation success.