Assessing Release Protocols for Canada Lynx Reintroduction in Colorado

Reintroductions are a common strategy to restore ecosystem integrity, especially when top predators are involved. Reintroductions are often time consuming, expensive, and controversial, and thus understanding what aspects are important for a successful program is needed. Focusing on the example of the reintroduction of Canada lynx (Lynx canadensis) to Colorado, we investigated how different release protocols (RP) affected mortality within the first year post-release. We found that average monthly mortality in the study area during the first year decreased with time in captivity from 0.205 (95% CI = 0.069, 0.475) for lynx having spent up to 7 days in captivity to 0.028 (95% CI = 0.012, 0.064) for lynx spending > 45 days in captivity before release. Our results also suggest that keeping lynx in captivity beyond 5-6 weeks accrued little benefit in terms of monthly survival. We found that, on a monthly average basis, lynx were as likely to move out (P = 0.196, SE = 0.032) as well as back onto (P = 0.143, SE = 0.034) the reintroduction area during the first year after release. Mortality was 1.6 times greater outside of the study area, suggesting that permanent emigration and differential mortality rates on and off reintroduction areas should be factored into sample size calculations for an effective reintroduction effort. A post-release monitoring plan is critical to providing information to assess aspects of RP and to improve survival of individuals. Future lynx and other carnivore reintroductions may use our results to help design reintroduction programs including both the release and post-release monitoring protocols. (C) 2011 The Wildlife Society.