Coyote (Canis latrans)
[Photo above taken on December 6, 2008 in Lower Hot Springs Canyon. Click on the image to enlarge it.]
Main sources: Nowak, Ronald, 1991, Walker's Mammals of the world, Fifth Edition (two vols.), Baltimore: Johns Hopkins University Press; Hoffmeister, D. F., 1986, Mammals of Arizona, Tucson: University of Arizona Press; Burt, W. & R. Grossenheider, eds., 1976, A Field Guide to the Mammals, Peterson Field Guides: Houghton Mifflin; Eisenberg, John, 1980, The Mammalian Radiations, Chicago: University of Chicago Press; Budiansky, Steven, 2001, The Truth about Dogs, Penguin Books.
Despite their physical similarities to domestic dogs (Canis familiaris), coyotes are more remotely related to dogs than dogs are to wolves (Canis lupus). According to Budiansky (see above), genetic analysis suggests that dogs and wolves share a common ancestry that separated only about 135,000 years ago, while coyotes separated from this pair's ancestors at least 1 million years ago. This truth is obscured by the fact that all these species can interbreed (as well as with some species of jackals), but the fact is that all three conduct such different lifestyles that their active populations effectively exclude one another.
The Arizona Department of Game and Fish provides a nice paired contrast between the Coyote and the Mexican wolf:...
Coyotes differ from foxes in having larger size, heavier weight, and bigger bones and teeth. Their bodies are roughly 3 feet long, their very bushy tails up to 16" long, and their weight between 20-50 lbs -- males somewhat larger than females. They are about the size of a "medium-sized dog" (Burt & Grossenheider, p. 69). They hold their tails (which are bushier than those of dogs) down beneath their hind legs when running, and their hair colors are gray to reddish gray, with rusty legs, feet, and ears, while throat and belly are whitish. The pair of images just above this text are of an elderly animal, probably killed and substantially consumed by a predator. (Click on each image to enlarge it.) In the images above you can see that the upper teeth that fit astride the lower canine are but stumps, while a closer view of the side of the jaw, below, shows that the premolars and carnassial are also substantially worn down. (Click on the image to enlarge it.)
Coyotes are very difficult to photograph in the wild -- when we have seen them on or near our lands, they move promptly out of sight. The banner image at the top of the page was taken with our automatic infra-red camera. The three photos above are of a head collected by Barbara Clark from near the Teran Wash confluence.
Coyotes have been living in Arizona since the Pleistocene and they are present throughout the state, including the drier and lower western deserts (indeed, in recent years they are approaching an all-North-America distribution). This success reflects their omnivorous scavenging and effective hunting -- they may kill animals larger than themselves by attacking the throat, and sometimes will chase down deer in cooperative groups. They kill small creatures by stalking and pouncing, and will eat almost anything -- carrion as well as a variety of vegetable materials. They are mainly nocturnal and typically range several miles during a night's hunting, but typically move quickly away from humans (they are fast -- can run up to 40 mph) and are seldom seen (except glancingly), though their yip-yapping communications (at least 11 different vocalizations have been distinguished) are often evident in the desert at night.
Typically they dig dens into the ground, but other locations -- hollow logs, ledges, thickets -- may serve as well. Females produce just one set of eggs per breeding season (from mid-January to mid-March in Arizona), and an average of 5 young are born two months later. Though coyotes (unlike wolves) do not mate for life, both parents share in feeding the young, bringing food (or regurgitating it) inside the den. The entire family moves out of its den after the young reach about 10 weeks in age.