PRONGHORN FAWN SURVIVAL AND POPULATION DYNAMICS IN NORTHEAST CALIFORNIA.
Colton Wise; Institute for Wildlife Studies; 140 H Street, Blue Lake, CA, 95525; (832) 244-8271; wise@iws.org; David Garcelon, Brian Hudgens
California's Modoc Plateau population of pronghorn (Antilocapra americana) has experienced a steady decline since the winter of 1992-1993. Declines in ungulate populations are typically associated with factors causing high fawn mortality, such as severe weather conditions, decreases in habitat quality, or increased predation. To better understand how fawn survival impacts population dynamics for this area we monitored 53 fawns with VHS or GPS collars in 2015, 2016, and 2018. The overall fawn survival rate for the first four months after birth was 44%. Overall fawn survival was similar for each year (2015 = 44%, n=24; 2016 = 44%, n=18; and 2018 = 45%, n=11), as was survival between agricultural (45%, n=30) and non-agricultural habitat (43%, n=23). Survival for female fawns was 57% (n=24) and 34% (n=29) for males. Fawn survival rates in our study area were generally higher than reported in studies from other areas. Modeling suggests that fawn survival alone does not explain the steady decline in this pronghorn population. We are examining other vital rates, such as pregnancy rates and adult survival, and landscape characteristics to better elucidate the factors influencing the decline of the pronghorn population in this area.
Poster Session