California Mule Deer

Odocoileus hemionous californicus   
(click on images for larger view)

Two California Mule Deer

I had not observed a mule deer at the lake until today, when I got to see a group of four or five of them. We spotted one by a tree on a small isthmus, and an upon moving in for a closer look, we realized there were a few others running playfully around a group of oaks. Once we got close to the shoreline, they definitely noticed us but did not seem too concerned. They are protected from humans in this area because the public is not allowed to dock along the northern shore (our naturalist guide scolded one family for doing so, making for a pretty awkward moment). They are territorial, which may have explained why we saw the group seemed to be picking on one of the deer that may not have belonged with the rest. Our guide even said that one of these deer had been seen stalking a bobcat. 


The deer had black tails, a white rump patch, and no antlers which had fallen off during earlier in the winter and will grow again in the spring enabling males to compete for mates. Males are slightly larger than females, ranging from about 100-325 pounds and shoulder height of about 40 inches. These individuals seemed to be above the median size for the species, possibly due to an abundance of succulent forage provided by the lake and only minimal competition from livestock in the area. 

Source: CA Department of Fish and Game websit

These deer, along with white-tailed deer, share the order Odocoileus and exist within the Cervidae family with the rest of the common types of deer such as elk, moose, and caribou. One distinction is that almost all male deer in this family grow and shed their antlers every year. This subspecies of mule deer (hemionous) is native to California, with the Native Americans of California known to have hunted them since about 12,000 BC. However, much of their natural habitat has been consumed through modern urban development. Thus, the deer have been known to approach suburban yards to drink from fountains and browse through greenery. Subsequently, the California Department of Fish and Game has an educational program that attempts             (HD recommended)            
to prevent encounters from happening called "Keep
Me Wild." They emphasize enclosing gardens and picking up fallen fruit, and even recommend certain repellent products. Doing so will also keep their hunters, mountain lions, away from homes. It is also illegal to feed deer as this could diminish their natural fear of humans (from the way the looked at us on the lake, they didn't seem too threatened. Then again, we were on a boat at least 50 feet away). Other management considerations include parasitic diseases and bacterial diseases that can be spread to and from livestock. High density and malnutrition are factors that may predispose populations to infection. Aside from mountain lions, their other greatest predators are sport hunters.

Sources:

Anderson, Allan & Wallmo, Olof. "Odocoileus hemionus." Mammalian Species 219. The American Society of Mammalogists, 27 Apr. (1984): 1-9. PDF.

California Department of Fish and Game. Keep Me Wild. 2011. Web. 22 Feb. 2012.http://www.dfg.ca.gov/keepmewild/

Misuraca, Michael. "Odocoileus hemionus."Animal Diversity Web. University of Michigan Zoology, 1999. Web. 22 Feb 2012 http://animaldiversity.ummz.umich.edu/site/accounts/information/ Odocoileus_hemionus.html

Note: All photos and videos were taken by the author on the date of the trip unless otherwise noted.

Links:

CA DFG Website