YAKIMA, Wash. – The Washington Department of Fish and Wildlife (WDFW) will conduct aerial surveys of bighorn sheep herds in Yakima Canyon, Quilomene, and Cleman Mountain next week.
Residents in these areas, especially along the Columbia River and east of Highway 410 in the Oak Creek Wildlife area, may notice a low-flying aircraft May 24-27, WDFW said in a release.
The surveys strive to collect data crucial for bighorn sheep management, with a focus on disease management efforts. WDFW said it’s particularly interested in identifying carriers of Mycoplasma ovipneumoniae (Movi). This pathogen causes bronchial pneumonia in sheep, leading to high lamb mortality rates.
In February 2025, WDFW identified multiple adult sheep as Movi carriers in the Yakima Canyon. Starting March 27, these carriers will be lethally removed to protect lambs and other herds.
Movi does not affect humans, but its impact on bighorn lambs is significant, WDFW added.
