Summary Report 2019 Pronghorn antelope abundance survey in south-central Washington

By the start of the 20th century, pronghorn antelope were extirpated from Washington. The Yakama tribe reintroduced pronghorn onto the Yakama Reservation in Washington, releasing 198 animals from 2011 to 2019. These pronghorn dispersed from their release locations and increased in abundance (Oyster et al. 2015, 2017). We conducted a third biennial aerial survey on February 6-7, 2019 in parts of Benton, Klickitat, and Yakima counties in south-central Washington, including the Yakama Reservation and private lands. The objective of the survey was to obtain a minimum population estimate for pronghorns. We counted a total of 225 pronghorns from the air and an additional 23 from ground counts, for a total minimum population estimate of 248 pronghorns. The true abundance is likely to be greater as shallow snow conditions made detecting pronghorns and ground travel difficult. However, this remains a relatively small population and there is currently no legal harvest of the species in areas under the auspices of the Washington Department of Fish and Wildlife or Yakama Nation. The Yakama Nation and WDFW are developing plans regarding future management for this herd.