Citizen Science

Bighorn Identifying Characteristics

Sierra bighorn ewes

Male and female bighorn sheep have horns, even young lambs, but adult rams have significantly larger horns than ewes (see photos of females and lamb above, males below).

Note the yellow right eartag on the ewe, above, and the red right eartag on the ram, below. Eartag color and configuration are how we identify individual sheep (eartag number is even better if you get close enough to see it). Collar color and size are other helpful identifiers.

Sierra bighorn rams
Sierra bighorn of different ages

Adult rams and ewes look very different from each other and are easy to tell apart. Not only do adult rams have much bigger and more flared horns, they are also much larger in body size.

Young rams can be difficult to distinguish from ewes (see drawings above and photo below). Rams have horns that are more flared than ewes, and they are thicker at the horn base.

Sierra bighorn young rams

Below is a photo sent to us by a backcountry skier. Some observations, such as this one, can yield priceless data and let us know a collared animal is still alive.

Sierra bighorn Warren herd

How You Can Help

Tracking bighorn sheep throughout the entire Sierra Nevada is a big job for a small crew. Each year we attempt to survey every herd of Sierra bighorn, which includes counting and identifying all individuals. If you are out hiking or skiing and see bighorn, we would love to hear about it. We record all observations sent to us. A few of these have even shown us range expansions we were unaware of, such as the Convict Creek herd years ago. It is impossible for us to have eyes everywhere, but with your help we can collect data over a much broader area. If you would like to help, here are some things you can do:

  • Bring binoculars and/or spotting scope with you when you hike—usually bighorn are a long distance away in steep terrain and not easily seen with the naked eye.
  • When you see SNBS record date, specific location (latitude/longitude or UTMs if possible), # of animals, and all identifying characteristics (especially: age/sex/eartag colors/collar details--see below)
  • Email your observations (photos too, if you have them!) to: asksnbs@wildlife.ca.gov

If all you can tell us is where you saw bighorn sheep, but you weren’t able to get any details, this is fine! Sometimes knowing there are bighorn in an area is a priceless discovery on its own.

The Sierra Nevada Bighorn Sheep Recovery Program thanks you in advance for your efforts!

Contact

Sierra Nevada Bighorn Sheep Program
787 N. Main Suite 220
Bishop CA 93514
(760) 872-1171
asksnbs@wildlife.ca.gov

Inland Deserts Region (Region 6)
Regional Manager: Heidi Calvert
3602 Inland Empire Boulevard, Suite C-220
Ontario, CA 91764
AskRegion6@wildlife.ca.gov