In a move that underscores the continuous effort to monitor and safeguard wildlife in the region, the Washington Department of Fish and Wildlife (WDFW) is poised to conduct aerial surveys of bighorn sheep populations in southeast Washington. Scheduled for December 12 and 13, these operations depend on favorable weather conditions and will cover the expanse from Joseph Creek to the Grande Ronde River's proximity to Troy, Oregon. The maneuver entails a helicopter flying low through the area, which may grab the notice of residents, as per a news release from WDFW.
These crucial surveys serve a dual purpose for the WDFW. They provide intel on the number of bighorn sheep in the Black Butte and Mountain View sub herds and offer insights into their health. Looming over this wildlife is the shadow of a respiratory disease brought on by the Mycoplasma ovipneumoniae bacterium, colloquially termed Movi, that has notoriously battered bighorn populations without the possibility of treatment or vaccine. According to the Washington Department of Fish and Wildlife (WDFW), a recent pneumonia outbreak amongst these herds has compounded their vulnerability, necessitating a closer examination to gauge the die-off's extent.
Tackling the intricacies of this task, Acting District Wildlife Biologist Mark Vekasy emphasized the importance of the surveys, noting, "Bighorn herds in southeast Washington were impacted by a pneumonia outbreak in late 2023, which has spread among the herds along the Snake and Grande Ronde rivers, and more recently Movi was detected in Asotin Creek." Vekasy stressed to WDFW the urgency of evaluating the aftermath of this affliction compared to previous population estimates.
Specifically, due to the roadless terrain it frequents along the Grande Ronde River corridor, the Black Butte herd presents a substantial challenge to ground surveys, making aerial observation pivotal. These upcoming surveys aim to classify bighorn sheep swiftly by age and sex, attentively minimizing the stress inflicted during the process. Data culled from this endeavor, coupled with mortality rates from radio-collared sheep—alarming figures exceeding 60%—will help sketch a baseline for herd composition and enumeration while verifying mortality estimates.
Washington's landscape is a sanctuary for an estimated 1,690 wild bighorn sheep, which are dispersed across 17 herds in the eastern and central regions of the state. WDFW, committed to its mission, strives tirelessly to preserve the fish, wildlife, and ecosystems under its conservancy while ensuring recreational and commercial opportunities for the public endure for generations to come.
