Bighorns Rebounding
Wildlife research
Bittersweet news is coming from researchers studying the disease-ravaged bighorn sheep of Hells Canyon.
This spring, biologists and veterinary researchers from Idaho, Washington and Oregon caught three dozen pregnant bighorn ewes, fitted them with radio collars, gave them tests and then turned them loose.
Half the ewes were given a vaccine developed in Colorado that researchers hope will protect wild sheep from pneumonia epidemics.
More than 100 bighorn perished along the Snake in Washington and Oregon during a dieoff that began in November 1995. Last spring, it continued.
Even on the Idaho side of the river, where few adult sheep died, the lamb crop suffered. A helicopter survey a year after the dieoff showed that only two lambs survived among 30 ewes.
This spring, however, all of the dozen radio-collared ewes on the Idaho side of the river had lambs, and all survived, researchers say.
The success may be encouraging for bighorn fans, but does little for research. Lambs both from ewes with the vaccine and without it survived equally well.
In Washington, seven of the 12 ewes had lambs at their side. Four others may have had lambs that were stillborn and one ewe was missing.
In Oregon, tests showed 10 of 12 collared ewes were pregnant. Four never were seen with lambs. Among the remaining six, five still have lambs.