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Black Ridge Bighorn Sheep Monitoring and Assessment

Project Name:  Black Ridge Desert Bighorn Sheep Monitoring and Assessment Project

Project Collaborators:  Colorado Division of Wildlife, Bureau of Land Management, Rocky Mountain Bighorn Sheep Society, and the Wild Sheep Foundation (formerly FNAWS)

Project Dates:  2007 - 2012

Project Description:  Since 2007, the Colorado Division of Wildlife has monitored the Black Ridge desert bighorn sheep herd to learn about the herd and to manage the sheep more effectively.  Monitoring efforts annually document population size, distribution, reproduction, recruitment, survival, evidence of disease in captured or dead animals, mortality causes, overall range, habitat selection within that range, and interaction with other desert bighorn sheep herds.

A total of 38 sheep were captured for this project from across the entire range of the Black Ridge herd.  All animals were fitted with radio telemetry collars and unique ear tags for identification purposes.  All were tested for diseases commonly afflicting bighorn sheep in Colorado and released on site.  

Monitoring efforts have produced valuable information about the Black Ridge herd.  Lambing has been documented in early February through mid-May, a much longer time period and with a significantly earlier start than previously documented.   No interchange between the Black Ridge desert sheep and the Dominguez-Escalante herd has been documented.

Currently, about 200 sheep exist in the Black Ridge herd, which is much higher than previous estimates of 75 sheep. 

Throughout the project, there has been tremendous public support for the improved management of these sheep.  The cooperation and assistance of the Bureau of Land Management, the National Park Service, and the environmental groups concerned for the Black Ridge Canyons Wilderness Area has provided the opportunity for the use of helicopter net-gunning in the Wilderness Area, capture in the Colorado National.

There have been 10 mortalities during the nearly three years of the project.  Four collared sheep were killed by mountain lions, reaffirming that mountain lions may continue to be a major cause of mortality.  One died in a fall, and one died in a flash flood.  The cause of death in the other four instances was undetermined.

Monument allowing for safer and more effective capture of these sheep.  The support for these activities has been integral to the success of this project.