Southern California mule deer survey dataset

In March 2019, October 2019, and February 2020 the California Department of Fish and Wildlife conducted total count aerial surveys (Schlossberg et al., 2016) in the three study areas using a contracted four seat Bell 407 helicopter (Air Shasta Rotor & Wing, Redding, CA). These surveys were designed to cover the entire study area at three study sites in San Diego County: San Felipe Valley Wildlife Area and San Felipe Hills (SFVH), Kitchen Creek (KC), and Rancho Jamul Ecological Reserve and Hollenbeck Canyon Wildlife Area (RJHB). Surveyors flew parallel transects spaced approximately 300 m apart, with transects over mountainous terrain oriented along contour lines. All surveys occurred between 0700 and 1700 hours each day. To reduce the possibility of double counts of deer groups, where observers record the same marked deer more than once, each survey site was split into polygons that were each completed with one load of fuel if possible, with adjacent polygons completed consecutively, and each survey site covered in two days or less. During survey flights, observers simultaneously recorded data for the double observer (DO) and sightability methods.