Use of remote infrared cameras to survey for kit fox (Vulpes macrotis) in the Grand Valley, Colorado

Neubaum, Daniel; Duckett, Stephanie

Historic documentation of kit fox (Vulpes macrotis) in Colorado is minimal with records from 1960’s in and around the Grand Valley, Mesa County and from McElmo Canyon, Montezuma County. After extensive live trapping efforts in the 1990’s, researchers speculated that the Grand Valley population was not sustainable based on the lack of documented reproduction, low number of individuals captured and recaptured, lapse time between recaptures, and distance between captured foxes. More recent survey efforts incorporated several non-invasive techniques such as track plates and hair snares with the goal of simply detecting presence of kit fox, which they did not. The goal of this study was to utilize modern, state of the art remote infrared cameras to survey areas in the Grand Valley where kit foxes had previously been documented or where recent anecdotal observations had been made. Cameras identified 20 species from 443 photos (10,513 photos total). No kit foxes were photographed during this effort but interspecific competitors such as gray (Urocyon cinereoargenteus) and red foxes (Vulpes vulpes), coyotes (Canis latrans) and domestic dogs (Canis domesticus) were prevalent. Presence of coyotes at over 80% of the sites we sampled, and red fox at 50%, suggests that interspecific competition may be suppressing existing kit fox populations or inhibiting their ability to recolonize after extirpation. The complete lack of detections using multiple techniques, continued urbanization, and documented presence of interspecific competitors suggest that kit fox may be extirpated from the Grand Valley. However, anecdotal observations from a wildlife officer and a trapper, along with documented kit fox in the Cisco Desert less than 20 miles west of the state line into Utah, suggest that a few widely spaced individuals could still exist. Techniques used in this study and others may not be able to detect extremely low populations if they do exist, making follow up investigations on all future anecdotal reports important to determining the final status of this species in the Grand Valley.