LB 11-145 - Translocation as a tool to conserve a threatened lagomorph in Southern New England

Background/Question/Methods:

Lagomorphs have a long history of being translocated to mainland and island locations by people, usually for hunting and consumption. Less often, translocations have been used to help conserve lagomorphs by establishing new populations or augmenting existing populations. Even more rarely, translocations to islands have been used to create breeding colonies to seed mainland populations. Over the past decade, translocations have been used in all these facets to help conserve the New England cottontail (Sylvilagus transitionalis). In collaboration with state biologists, federal biologists, and zoos, we have helped to establish and monitor New England cottontail populations on an island and two mainland release sites in Rhode Island. The source of founders has mainly been wild animals that were brought into captivity to produce first generation juveniles for subsequent release. We have used VHF/GPS radio collars and genetic analyses to monitor the populations and help guide management decisions. Telemetry data were combined with remote-sensing data on vegetation characteristic, including a novel use of LiDAR point clouds, to evaluate the spatial use, resource selection, and survival of translocated cottontails. Genetic analyses were used to document reproduction and estimate their change in population size, gender ratio, and genetic diversity.

Results/Conclusions:

The home range and resource selection of translocated New England cottontail was highly variable among all sites. Surprisingly, we found substantial variation among individuals, with a five-fold range of estimated home ranges and only two cases of qualitative consensus on resource selection, suggesting that population-level inferences may fail to capture important aspects of animal ecology at the individual level. We did find some evidence for selection of dense understory, which is consistent with previous studies. We found evidence of reproduction at each site despite reduced survival post translocation. The island population size was relatively stable with an even gender ratio. Their genetic diversity also was maintained over time—even with the removal of animals for subsequent releases to seed mainland release sites. The island and mainland populations continue to be intensively monitored to ensure their success. Our main goal is to reestablish viable mainland populations. Zoos and islands have played a critical role and will continue to serve as essential components in helping to conserve New England cottontail.