You can help save the bighorns

To the editor,

The Colorado Backcountry Hunters & Anglers (BHA) are looking for Weminuche Wilderness bighorn sheep observation volunteers. Weminuche bighorns are listed by the U.S. Forest Service as a sensitive species, meaning there is concern for their long-term viability. The Weminuche bighorn population numbers about 425 and is designated as a highly valued “Tier 1” population because it is believed to be one of only three herds statewide that have received little or no augmentation. That means these are true native bighorns, and as such, they represent an important historic gene pool for the San Juan Mountains and state.

Historically, bighorn sheep were once among the most abundant wild ungulates in the American West. Population estimates range from 1.5 to 2 million at the onset of the 19th century. Today, there are an estimated 7,000 bighorns in Colorado, up from 2,000 in 1995. Yet in recent years, bighorn population growth has stagnated across the West despite continued restoration efforts. Bighorn populations are failing to thrive because of recurrent herd-level respiratory disease outbreaks associated with exposure to domestic sheep.

Domestic sheep carry strains of pneumonia that are devastating for bighorn sheep. According to a joint issue statement of The Wildlife Society and the American Association of Wildlife Veterinarians (released in March 2015): “It is now apparent that disease transmission from domestic sheep to wild sheep is a significant risk factor for the conservation and restoration of wild sheep populations,” and “effective separation of domestic sheep from wild sheep is the only currently available management solution for preventing or minimizing disease transmission.”

Terribly, a single outbreak can kill most bighorn sheep in a herd. In addition, according to Colorado Parks & Wildlife research recently published in the Journal of Wildlife Diseases, significant lamb mortality can occur for many years in a herd following a single exposure. A 2008 study by Colorado Division of Wildlife showed that a single domestic sheep that wandered onto bighorn winter range caused a die-off of more than 86 bighorns from 1997-2000.

In the Weminuche Wilderness, north and east of Durango, researchers are particularly interested in looking for bighorns at the northern and eastern boundaries of an area with three active domestic sheep-grazing allotments. Each allotment has a band of sheep (approx. 750 ewes and their lambs for a total of about 2,000 - 2,500 sheep) and one herder. Any bighorn sightings in an active allotment or within a mile or so of any of the active allotments should be reported immediately to the Forest Service and CPW, preferably with photos and GPS coordinates.

Both the USFS and BHA have online reporting/survey forms. BHA will compile all the surveys and return them to the Forest Service at the end of September. For additional information, see the Colorado BHA Bighorn Observation Volunteer page: www.backcountryhunters.org.

If you’re able to volunteer to look for bighorns near these sheep-grazing allotments, contact Colorado BHA Southwest Regional Director Dan Parkinson (docdanp@gmail.com) for additional information.

– David Lien, chairman, Colorado Backcountry Hunters & Anglers