Mammals

Ron Niebrugge

Mammals are in the vertebrate class with hair or fur which helps keep them warm-blooded, maintaining a near constant body temperature. Dolphins, porpoises and whales have blubber, in lieu of fur or hair to keep them insulated. Except the platypus and echidnas of Australia, mammals are born live, and not as hatchlings from eggs. Their distinctive three bone ear structure; the malleus, incus and stapes aid in hearing through amplifying sound. Although mammals share this three bone structure, teeth vary markedly according to species and diet. Instead of teeth, whales have baleen, brush-like structures used to filter plankton.

Over 4,600 mammals have been documented worldwide in habitats that range from mountain, ocean, forest and desert. Bats are the only mammals that truly fly and one of many that you may observe at night in the Mojave. Seemingly unrelated to dolphins both share echolocation, which is a form of communication through sound waves.

There are 50 documented mammal species living within Mojave National Preserve. Some notable Mojave mammals are described below:

Coyote (Canis latrans) is another frequently seen desert mammal. One of four members of the dog family (Canidae) found within the Preserve, coyotes in the desert are significantly smaller and are lighter in color than those living in other habitats. Although mainly carnivores, coyotes may eat plants, and this adaptability has contributed to their survival in the face of habitat destruction. Although largely nocturnal, coyotes may be seen during the day. Coyotes, the most vocal of the Mojave mammals, have a complex vocabulary which includes the distinctive and legendary howl call.

Bats: (Order Chiroptera), The only mammals with true wings capable of powered flight. Scientists theorize that bats evolved from gliding ancestors, whereas birds, from bipedal creatures that ran quickly along the ground. Unlike birds, bat wings are supported by the arm and four elongated fingers of the hand. Bats rely on echolocation in catching prey; the use of high-frequency sound in determining the location of objects. Nine species of bats live in the Mojave National Preserve's boundaries.

 

 

A female bighorn sheep perches on a rock.

NPS photo

Bighorn Sheep: Ovis canadensis is one of the most regal and resilient animals in the Mojave with an unsurpassable climbing ability. Traversing rocky terrain with ease and surviving on limited water, bighorn are able to evade most predators. Bighorn sheep glean maximum nutritive value from plants of marginal quality through a complex nine-stage digestive system. Bighorn have a livespan of of 10-15 years.

Black-tailed jackrabbits (Lepus californicus) are among the most commonly seen of desert mammals. Jackrabbits are larger and leaner than resident cottontail rabbits (Sylvilagus sp.) with longer legs and ears. A significant amount of blood flows through the many blood vessels of a jackrabbit's ears, which helps dissipate heat, an important adaptation in the desert. Jackrabbits are mainly nocturnal and may be seen in large numbers by the side of the road at dusk. However, they are easily startled and will frequently bolt out from under bushes where they spend the daylight hours resting. Female jackrabbits are larger than male, a condition which is not common in mammals.