Mountain Lion

Distribution

Reproduction

Ecology

Management

Literature Cited

Ecology

Human interference, lack of prey, and lack of stalking cover have limited the distribution of mountain lions in the western hemisphere.  Mountain lions require habitat that is remote and undeveloped by humans.  They have been reported from sea level to 4,000 m, and from desert areas to the tropical rain forests of South America.  However, they are probably not limited by lack of any given prey species, since they have the ability to catch and eat many different kinds of animals.

A hunting mountain lion can travel an average of 8.5 km per night (Beier 1993).  Ideal mountain lion habitat in the western U.S. consists of desert and shrub communities with sparse overstories of pinyon pine (Pinus edulis) and Utah juniper (Juniperus osteosperma), as well as Gambel oak (Quercus gambelii) and quacking aspen (Populus tremuloides) (Hemker et al. 1984).  In these areas, mule deer (Odocoileus hemionus) and elk (Cervus elaphus) are the major large prey items available (Hemker et al. 1984).

Mule deer generally make up about 75% of the bulk of a mountain lion’s diet in winter and about 60% in summer in western North America; however, lions are highly opportunistic carnivores and will take advantage of whatever food source is available (Robinette et al. 1961, Young and Goldman 1946).  Hornocker (1970) calculated that an adult mountain lion needs to kill and consume from 860 to 1,300 kg of large prey animals per year (5 to 7 elk or 14 to 20 deer).  Large carcasses probably decompose before full utilization by a lion in warm weather areas, but this bias is usually offset by the larger percentage of smaller animals in the diet during summer months (Young and Goldman 1946).

Hornocker (1970), after an extensive predator-prey study, concluded that elk and deer populations were limited by winter food supply rather than predation by lions, but that lion predation dampened prey oscillations and distributed the deer and elk more widely over the available range.  Grizzly bears, wolverines, and jaguars are possible competitors where they coexist with mountain lions, and coyotes, black bears, bobcats and other small felids probably compete with mountain lions for smaller mammals and sometimes for deer throughout most of the mountain lion’s range (Young and Goldman 1946).

Mountain lions are solitary.  The only social unit that endures more than a few days is the maternal bond between a female and her kittens.  Females with small kittens avoid interactions with other adult lions, but as the kittens approach independence and the mother approaches estrous, she tolerates contact with other mountain lions of either sex.  When she fully enters estrous, a male will usually join and travel with her until estrous is complete (Seidensticker et al. 1973).  Males may be found together immediately after independence from their mother, but only rarely as established adults.

Territory tolerated by adult mountain lions is usually established at a maximum of one lion every 25 to 50 km², and home range size at or below this density is probably dependent on prey density and stalking cover in relation to prey density (prey vulnerability) (Seidensticker et al. 1973).

It is likely that the main cause of mortality of mountain lions in western North America, and probably in South America, is hunting by humans (Hornocker 1970).  Other causes of mortality found have been tapeworms (Taenia omissa) obtained from eating the immature stages in lungs or pericardium of deer (Odocoileus spp.) in the northern hemisphere, and the roundworm (Filaroides striatum) has been reported in mountain lions in Brazil (Young and Goldman 1946).