The Sierra Nevada Bighorn Sheep

Sierra Nevada Bighorn Sheep. 2009. Seattle, Washington.

The Sierra Nevada Bighorn Sheep; Road to Recovery

By: Gwen Wagner

Sierra Nevada bighorn sheep is distinct subspecies of bighorn sheep which is unique to the Sierra Nevada mountains of California. Sierra bighorn range in color from white to dark brown, with a white rump and dark tail. They have specialized hooves with special adhesive like soles which provide traction in the steep rocky terrain of their habitat. Female bighorn have shorter, narrow horns, while male bighorn have massive, curving horns both of which are composed of a dense layer of keratin covering a bone core. Because of their specialized mountain habitat, they eat a variety of plant species that span the Sierras. Males can weigh up to 220 pounds and female can reach up to 150 pounds. The average lifespan is about eight to twelve years for both males and females.

Prescott, Ed. 2007. N.p.

Sierra bighorn choose to habitat areas which consist of open areas of rocky land which is sparsely vegetated, and areas of steep slopes and canyons. Sierra Nevada bighorn sheep utilize a highly specialized habitat, specifically in elevations above 4,000 meters or 13,120 feet along the highest crests of the Sierra Nevada, and to winter ranges at the eastern base of the Sierra Nevada which can be as low as 1,450 meters or 4,760 feet.

The Sierra Nevada bighorn sheep was listed as endangered on January 3, 2000 in response to an emergency listing on April 20, 1999 due to
incredibly low population numbers. 

Sierra Nevada bighorn sheep population was at an all time low in 1995, with only 100 individuals spread across five different areas in the central and southern Sierra Nevada mountain range in California and Nevada. Since being listed, population numbers have experienced favorable growth and now sits around 600 as measured in 2014. The Sierra Nevada bighorn sheep recovery plan faces several key limiting factors such as disease, low population numbers, mortality caused by predators, loss of genetic diversity due to low population size, habitat availability, and limited distribution.

The objective of the Sierra Nevada bighorn sheep is raise population numbers and make it so that the geographic ranges they populate will be able to assure long-term viability of the overall population. Through following the recovery plan, the overall goal is delisting the Sierra Nevada bighorn sheep as an endangered species. 

To insure the recovery of the Sierra Nevada bighorn sheep, several key things need to happen. 

1. The existing herds and populations need to be protected through managing predator activity and keeping predator mortality low as well as maximizing population growth. 

2.Enlarging small herds so that they can fare better and make more adequate use of winter range

habitat. This is also essential because it can make the herds more resilient to the effects of predation. 3. Keeping the Sierra Nevada bighorn sheep away from other species of domestic sheep or goats. 

In short, this recovery plan calls for development of a captive breeding contingency plan and separate implementation plans for: monitoring; translocation; predator management; genetic and disease management. For the best case scenario, the hope of the Sierra Nevada bighorn sheep is for

them to be downlisted by 2017, and eventually delisted ten years later in 2027.

So what can we do to help? Well, there isn't much that the average person can do because of the highly specialized range of their habitat. The personal actions that can be taken to contribute to the Sierra Nevada bighorn sheep recovery plan are mostly monetary in the forms of donations to organizations such as the Sierra Nevada Bighorn Sheep Foundation. They also need to be left alone so anything you can do to limit human contact ad interaction in their habitat is important to keep the recovery plan working as well as it has been over the last fifteen years.