Updates from the field: finding rare carnivores by sampling the air

Photo Credit

USDA Forest Service photo by Thomas Franklin

Passive filters collecting airborne environmental DNA in the northern Rocky Mountains

Detecting rare animals is difficult, yet important to tailoring forest management practices that protect natural resources. Forest carnivores are particularly thorny to survey because they are  elusive, wide-ranging, and sparsely distributed. Remote cameras can be effective but labor-intensive to deploy at scale. What if it were also possible to detect the presence of rare species simply by pulling down trace amounts of  DNA freely floating in the air?

Forest Service scientists are piloting a study to evaluate the potential of surveying terrestrial species using airborne environmental DNA. The method involves hanging small filters from trees to passively capture airborne DNA particles, then using targeted molecular assays to detect wolverine and lynx from only a few DNA copies. To test the approach, researchers paired air filters with baited winter cameras at known wolverine and lynx locations, with filters set at varying distances and check times. These comparisons are helping researchers understand  how sensitive the method is and how detection is influenced by distance and timing.

This pilot study represents an early step in determining whether airborne DNA could become a practical tool for broad-scale surveys of forest wildlife, potentially opening new survey options in places and seasons that are hardest to access.