Because of the size and complexity of the Mustelidae, it is more easily treated by division into subfamilies (only North American ones listed):
The otters are semiaquatic; the Mustelinae and Guloninae concentrate on active prey (though the American Badger has specialized for fossorial and semi-fossorial prey).
Lutrinae: Our sole representative is the River Otter (Lontra canadensis), and only one specimen documents its presence in New Mexico (Gila River). However, there are reports from earlier times from the Canadian River drainage (northeastern New Mexico) and the upper Rio Grande. This is a relatively large mustelid (10 - 20 lb.) with webbed feet. Most food is aquatic and includes fish, frogs, turtles, and crayfish, among other items. The species was placed in the genus Lutra until separation of the New World from the Old World species.
Mustelinae: Mustelines include the Marten (Martes americana), Ermine (Mustela erminea), Long-tailed Weasel (Mustela frenata), Black-footed Ferret (Mustela nigripes), Mink (Mustela vison), and American Badger (Taxidea taxus). Most mustelines have delayed implantation.
To considerable degree, mustelines tend to specialize on a restricted size range of prey (and, as a group, the most carnivorous of the mustelids). Thus the small Ermine tends to concentrate on mouse-sized animals (although prey up to lagomorph size is taken), particularly in competition with larger weasels. The Long-tailed Weasel tends to rely more on prey the size of ground squirrels and rabbits. The Black-footed Ferret specializes on prairie dogs. Members of the genus Mustela are built to go into burrows after prey, with short legs and a long, thin body. Members of the genus show noteworthy sexual dimorphism (the males larger), so much so that the male of a small species may be close in size to the female of the next larger species.
The Marten and Ermine are northern creatures entering our area only in the high mountains of northern New Mexico (south to the Sandia Mountains in the case of Ermine). Although both are trapped elsewhere for fur, the limited geographic extent and relative rarity render them unimportant economically in the region. Mink are quite aquatic compared to others of the genus Mustela and are primarily northern animals. In our region, they get south to Los Lunas (south of Albuquerque) in the Rio Grande Valley and occur also in the northern mountains and the San Juan Valley. The Black-footed Ferret's geographic range pretty much paralleled that of its prey animals, the Black-tailed and Gunnison's prairie dogs, from the prairies of western Canada to above Big Bend in Texas and west into central Arizona. This is an endangered species with captive populations and some releases in recent years, primarily in Wyoming.
Only the Long-tailed Weasel and the Badger are common
in the Southwest, and both are widespread geographically and ecologically (desert to high mountains) in our region. The weasel is adapted for medium-sized prey and is an active hunter. The
Badger is relatively large and very robust, with greatly developed forelimbs and long claws on the front feet—it concentrates on digging out it prey from burrows rather than going in after
the prey. Apart from its digging specializations, it has a very heavy skin that is loose enough to allow it to twist within it to considerable degree (many a dog thinking it had a firm grip on the
animal found this out the hard way). There are a number of reports of Badgers and Coyotes traveling together, presumably utilizing each others predatory strengths to more efficiently feed
themselves.
Dorsal view of the skull of the Long-tailed Weasel (Mustela frenata). The proportions are typical of weasels in general.
The last mustelid of our region is the Wolverine (Gulo gulo, formerly G. luscus). There is no verified occurrence in the region, but there is a record in Colorado very close to the New Mexican line. Powerful predators, these mustelids are primarily northern (and, like a number of other immigrants from the Old World via Beringia, conspecific with the Eurasian species).
Smithsonian Field Guide: Mustelidae.
We have four representatives of the skunk family within the New Mexico/Trans-Pecos Texas region: the Striped Skunk (Mephitis mephitis), the Hooded Skunk (Mephitis macroura), the Hog-nosed Skunk (Conepatus mesoleucus), and the Spotted Skunk (Spilogale gracilis). Skunks tend to be relatively slow moving, not particularly bright compared to other carnivores, and roadkill. All of these characteristics probably trace back to the efficient protective mechanism provided by their scent glands. It also is suggested that the coloration (various patterns of white on black) is aposematic (warning) in nature (conspicuous black and white, red, red and black, and yellow or orange and black often denote distasteful or dangerous animals, thus warning off possible predators). Several predators, however, apparently are not deterred; for example, Great Horned Owls seem to regularly prey on them.
The Striped Skunk occurs throughout our area from low desert to high mountains, and is the most commonly seen skunk. Home ranges overlap considerably, suggesting a lack of territoriality. Geographic distribution is broad, with a range from well into Canada south into northern Mexico.
The Hooded Skunk is a southern species getting into the U.S. from Big Bend to the Gila country of western New Mexico and northwest into central Arizona. It appears rare in our region and seems most often to occur along waterways. Relatively little is known about its natural history.
The Hog-nosed Skunk is widespread (from southern Colorado to Nicaragua and western Arizona to near the Texas-Louisiana line), but seems relatively rare in the north. With its naked, well developed nose, it is aptly (if exaggeratedly) named, for it commonly roots for invertebrates, leaving the ground characteristically disturbed.
The Spotted Skunk is a smaller animal than the other three. Taxonomically, the U.S. populations seem to have settled down to being recognized as two species, an eastern (Spilogale putorius) and a western (S. gracilis). At times in the past, all forms were recognized as S. putorius, but it appears that differences in breeding time prevents gene exchange along their contact within the western portion of the Great Plains. These skunks will take plant food, but invertebrates and small rodents probably predominate in the diet. As reasonably good climbers, bird eggs and young are partaken when possible. The scent of these skunks seems somewhat less obnoxious than that of other species. This species is well known for its threat behavior of doing a handstand.
Smithsonian Field Guide: Mephitidae.
The Procyonidae includes, in our area, the Ringtail (Bassariscus astutus), Raccoon (Procyon lotor), and Coatimundi (Nasua nasua)—the latter often in the literature as N. narica. These are omnivores, although the Ringtail tends toward a carnivorous diet.
Ringtails (sometimes called "civet cats," a term to be avoided since they are neither civets nor cats) basically are limited to broken country and range from desert into the lower forest zones. They are excellent climbers, not only able to maneuver along narrow ledges and through vertical crevices, but also able to bounce off of surfaces to reach an otherwise isolated perch. They also possess partially retractile claws. Although considerable plant material is eaten, many small vertebrates are taken and carrion is fed upon (the latter illustrating the danger of assuming that presence of cattle, deer, or sheep in scats indicates predation—even the most avid haters of carnivores have a hard time visualizing a ringtail taking down a deer). Ringtails extend as far north as Oregon, Wyoming and Kansas and as far south as Oaxaca in southern Mexico. They occur commonly in Pleistocene fossil sites in the Southwest.
The coatimundi is a predominantly Mexican species that enters the U.S. in southern Arizona, southwestern New Mexico, and southern Texas (including the Big Bend); its geographic range continues south into South America. In our region, it appears to be a regular occurrence in the mountains of the bootheel of New Mexico and possibly into the Gila area of southwestern New Mexico; sporadic appearance farther north (reportedly to the vicinity of Truth or Consequences) likely are wandering males.
More social than other northern procyonids, the coatimundi frequently is found in fairly large troops, consisting largely of females and their young. Fruit, invertebrates, and small vertebrates appear to form the diet. Coatimundis are good climbers and foraging may take place in trees at times. There appears to be no Pleistocene fossil record from the U.S.
Unlike Coatis, Raccoons tend to be solitary animals. They are widespread in New Mexico and Trans-Pecos Texas, mainly along watered valleys and in forested highlands. They are among several mammals that entered the region late, after the end of the Pleistocene (as far as we can tell from the fossil record); they also appear rare in archaeological sites and there is a suggestion that they have increased in number since early in the century. Part of their commonness today may be due to increased human populations providing crops and garbage usable for food. They are omnivorous in diet.
Smithsonian Field Guide: Procyonidae.
Last Update: 10 Aug 2009