Which Animals Use Cave Entrances? Camera Traps at Great Basin National Park

What animals pass through the entrances of caves in Great Basin National Park? To find out, the park set up remote cameras in the summer of 2013. They ran around the clock and took pictures whenever movement set them off.

The survey

Data from eight caves were analysed. The cameras were out for a total of 372 trap days, an average of 46.5 days per cave (between 28 and 62).

They recorded 632 separate events, counting sightings of the same species as separate only when they were more than an hour apart. Seventeen kinds of animal turned up. The most often photographed were mice, chipmunks, people, woodrats and squirrels. Cottontail rabbits, bats, skunks, foxes, insects, birds and pet dogs also appeared at cave entrances, and a ringtail caught on camera in one of the park's caves made the cover of the Journal of Cave and Karst Studies.

Night and day

Animals came and went most often between 6 p.m. and 6 a.m. The commonest night visitors were bats, mice, skunks and ringtails. By day the entrances belonged mostly to chipmunks, people, birds and squirrels.

Still counting

For most caves, the number of species recorded was still rising after fifty days of filming — a sign that it can take a long time to catch every animal that uses a cave entrance.

Very little had been recorded before about the animals that use cave entrances. Camera traps disturb nothing and can be repeated, so they can help managers learn about both the common and the secretive species of a cave's entrance and twilight zone, and about when they are busiest.

The full study appeared in the Journal of Cave and Karst Studies, volume 77, number 3.

Sources

• Gretchen Baker, ecologist, "Quantifying Wildlife at Cave Entrances," The Midden (Great Basin National Park), vol. 16, no. 1, summer 2016, National Park Service. https://www.nps.gov/articles/000/quantifying-wildlife-at-cave-entrances.htm