Desert bighorn sheep

Description:

Desert bighorn sheep are stocky, heavy-bodied sheep, similar in size to mule deer. Weights of mature rams range from 115 to 280 pounds (55 to 90 kg), while ewes are somewhat smaller. Due to their unique concave elastic hooves, bighorn are able to climb the steep, rocky terrain of the desert mountains with speed and agility. They rely on their keen eyesight to detect potential predators, such as mountain lions, coyotes, and bobcats, and they use their climbing ability to escape. Both genders develop horns soon after birth, with horn growth continuing more or less throughout life. Older rams have impressive sets of curling horns measuring over three feet long with more than one foot of circumference at the base. The ewes' horns are much smaller and lighter and do not tend to curl. After eight years of growth, the horns of an adult ram may weigh more than 30 pounds. Annual growth rings indicate the animal's age. The rams may rub their own horns to improve their field of view.[3] Both rams and ewes use their horns as tools to break open cactus, which they consume, and for fighting.[The desert bighorn has become well adapted to living in the desert heat and cold and, unlike most mammals, their body temperature can safely fluctuate several degrees. During the heat of the day, they often rest in the shade of trees and caves. Southern desert bighorn sheep are adapted to a desert mountain environment with little or no permanent water. Some may go without visiting water for weeks or months, sustaining their body moisture from food and from rainwater collected in temporary rock pools. They may have the ability to lose up to 30% of their body weight and still survive. After drinking water, they quickly recover from their dehydrated condition. Wildlife ecologists are just beginning to study the importance of this adaptive strategy, which has allowed these small bands to survive in areas too dry for many of their predators.

Habitat:

The desert bighorn sheep (Ovis canadensis nelsoni) is a subspecies of bighorn sheep found in the desert Southwest United States and the northern regions of Mexico. The trinomial of this species commemorates the American naturalist Edward William Nelson (1855–1934). The characteristics and behavior of desert bighorn sheep generally follow those of other bighorn sheep, except for adaptation to the lack of water in the desert; bighorn sheep can go for extended periods of time without drinking water. Populations of the desert bighorn sheep declined drastically with European colonization of the American Southwest beginning in the 16th century. As of 2004, desert bighorn sheep numbers are extremely low, although the overall population trend has increased since 1960. These declines were followed by a period of population stabilization ascribed to conservation measures.

Notes:

Pictures are taken at Burgers Zoo, Netherlands