E. Merrill | USGS Science

USGS2018

Moving in the Anthropocene: Global reductions in terrestrial mammalian movements

Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission.

Science↗

USGS2012

Ungulate management in national parks of the United States and Canada

Enabling legislation—that which gives appropriate officials the authority to implement or enforce the law—impacts management of ungulates in national parks of Canada and the United States (U.S.). The initial focus of such legislation in both countries centered on preserving natural and culturally significant areas for posterity. Although this objective remains primary, philosophies and practices have changed. A Canadian vision for ungulate management emerged during the latter half of the 20th century to protect and maintain or restore the ecological integrity of representative samples of the country’s 39 distinct landscapes, and to include provisions for traditional hunting and fishing practices representative of past cultural impacts on the environment. The current ungulate management approach in the U.S. relies on natural (ecological) processes, as long as normal conditions are promoted and there is no impairment of natural resources. Emphasizing natural processes as the basis has been a challenge because ecosystem dynamics are complex and management is multi-jurisdictional. Additionally, natural regulation typically will not prevent ungulates from reaching and sustaining densities that are incompatible with preservation or restoration of native flora and fauna, natural processes, or historical landscapes.

The Wildlife Society Technical Review↗