The Boulder County Parks and Open Space Department offers grants for research on county open space lands each year. All proposals are reviewed by a team of resource specialists, and awarded research projects are monitored during their activities on open space. The following is a summary of a 2015 study conducted by Joseph Ehrenberger, Kevin Urbanek, and Tom Mathies. Their project focused on a general herpetofauna assessment and mapping of hibernacula at Rabbit Mountain Open Space.
Executive Summary
Rabbit Mountain Open Space is a centerpiece of ecological diversity recognized for its largely intact and high quality foothills natural communities, mountain mahogany shrublands, and Piedmont grassland communities. Its herpetofaunal component, however, has yet to be systematically investigated. Information on the herpetofauna on the property is needed to better inform management practices for the Rabbit Mountain Open Space Management Plan, which is currently undergoing an update over the 1986 version.
The goal of this project was to provide an account of all reptile and amphibian species occurring on Rabbit Mountain, with emphasis on locating species of state and county concern, and identification of areas of critical habitat. Field survey work by Adaptation personnel and expert volunteers, began March 28, 2015, and continued to September 25, 2015 using visual encounter surveys and turning of surface objects. Search effort implemented was 491 hours search time over approximately 656 miles foot/vehicle travel.
Results of the survey confirm that there are at least three species of amphibian (Western Tiger Salamander, Woodhouse’s Toad, Boreal Chorus Frog), one species of lizard (Prairie Lizard), and for the Front Range, a remarkably large assemblage of at least nine snake species (Eastern Yellow-bellied Racer, Milksnake, Bullsnake, Plains Black-headed Snake, Terrestrial Gartersnake, Plains Gartersnake, Common Gartersnake, Lined Snake, Prairie Rattlesnake). Two amphibian species and three snake species are Boulder County Species of Special Concern. The Colorado Natural Heritage Program tracks the Common Gartersnake and Lined snake as sensitive species and ranks them as G5 S3 and “watchlisted”, G5 S3, respectively. Both species are uncommon in the state and Boulder County. This new location for the Lined Snake stands as the northernmost known location for the species in the state. One particular survey site was exceptional in that it yielded eight of the nine snake species documented on the property.