Use of visual stimuli increases count estimates for prairie dogs

Abstract

Throughout North America, all 5 species of prairie dogs (Cynomys spp.) have experienced drastic population declines over the past century, which has subsequently affected a host of affiliated species. Tools and techniques used to monitor prairie dogs have important implications for the management and conservation of grassland ecosystems. Behavioral responses by prairie dogs to predators may offer an opportunity to improve techniques that rely on visually based survey techniques by increasing the visibility of individuals. We evaluated whether the use of a visual stimulus resembling a common predator could increase the number of white-tailed prairie dogs (C. leucurus) observed during visual count surveys conducted in June and July of 2017 in Wyoming, USA. We designed a visual stimulus consisting of a remote-controlled toy car fitted with a badger (Taxidea taxus) pelt. We found counts of prairie dogs increased from 14.2 (95% CI ¼ 10.4-18.0) to 32.6 (95% CI ¼ 24.1-41.1) individuals/4-ha plot when this visual stimulus was deployed. Our top model predicted counts to be 2.3 times greater when a visual stimulus was used. The increase in counts elicited by use of a visual stimulus may therefore improve the accuracy and efficiency of traditional visual counts and other visually based monitoring techniques for prairie dogs. By enabling managers to take advantage of behavioral responses, use of a visual stimulus as described here could aid efforts to monitor and manage prairie dog populations and consequently conserve prairie ecosystems. Ó

Tunnel Diameter as a Noninvasive Method of Detecting Pocket Gopher (Geomyidae) Occupancy

“…), are regularly seen aboveground and use burrows principally for rearing young and protection from predators and weather (Murie and Michener 1984, Hoogland 1995). The conspicuousness aboveground facilitates species identification and field observation, without needing to trap individuals (Slade and Balph 1974, Fagerstone and Biggins 1986, Menkens et al 1990, Proulx et al 2012, Boulerice et al 2019). In contrast, subterranean species spend their lives almost entirely underground and, as a result, are often poorly understood and difficult to detect.…”