Part 16

The scientific name of the wolverine is interesting. Gulo, the Latin term for throat, no doubt has reference to the gluttonous habits of the animal. Luscus, also Latin, means one-eyed or, as some authors suggest, blind. This may refer to the small eyes, so deeply set as to be almost invisible at a little distance, or may date back to the first wolverine taken to Europe from Hudson Bay. This specimen was said to have lost one eye, and the name may have been derived from that. At any rate, the normal wolverine is neither one-eyed nor blind.

The wide distribution of the wolverine provides an admirable example of what life zones mean. This same species lives at timberline in the high mountains of desert country and is also found at or near sea level far north of the Arctic Circle. It is well adapted to this environment, with exceptionally thick and heavy fur which does not mat easily with snow. In addition, during the season of greatest snowfall, the edges of the feet and toes grow stiff hairs which, in effect, act as small snowshoes, and enable the animal to travel with less effort.

Food habits of the wolverine are far from selective. Heavy and clumsy in build, it is doubtful if many large game animals fall prey to this awkward hunter. However, it does not hesitate to drive larger predators away from their kills and appropriate them for itself. At such times it eats as much as it can, then hides the rest for future repasts. It will return to the site until the remains are completely devoured, even if they spoil in the meantime. Natural prey includes rodents which it can dig out of burrows, and such ground-nesting birds as it comes across in its travels. It is said to be one of the few successful predators of the porcupine. Thief, predator, and scavenger, the wolverine roams its isolated ranges feared by hunter and hunted alike.

The wolverine is one of the few animals that seems to take malicious delight in harassing human beings. Though robbing of traps can be explained by hunger, theft and destruction of the traps themselves seems to represent deliberate and clever planning. So, too, does the breaking into and entering of isolated cabins with attendant pilferage of their contents. What cannot be eaten is either broken up and defiled or carried away and hidden.

Marten Martes americana (Latin: a marten ... America)

Range: North America from Alaska through the greater part of Canada, thence through northwestern, United States and south into California, Utah, Colorado, and New Mexico.

Habitat: Usually coniferous forests of the Canadian Life Zone up to the Alpine Zone.

Description: In the trees, this animal is often mistaken for a large squirrel. On closer inspection it will resemble a house cat with a short, bushy tail. Total length 22 to 27 inches. Tail 7 to 9 inches. Weight 2 to 4 pounds. The coloration of the marten is distinctive. The body is a beautiful, soft, yellow-brown, darker on the back, legs and tail. On the chest the color lightens to a pale buff or sometimes a rather distinct orange. The underparts are lighter than the rest of the body. The fur is extremely fine and thick. It is distinctive in being almost entirely underfur, there being very few guard hairs. The body is extremely graceful with relatively long legs and small feet. The head is small with features somewhat resembling those of the weasel. The ears are large for a member of the weasel family and lend an alert appearance to the face. This alertness is further borne out by the lively movements of this animal, which is the most active of any in that group.

The marten, often called “pine marten,” is one of the most solitary animals of a group whose members habitually travel alone. Perhaps this is because in this family of predators each species is fully able to overpower any resistance put up by its accustomed prey, individually and not through force in numbers. Perhaps, too, it is because the entire group is made up of voracious eaters which, if they ran in packs, could not encounter enough prey to adequately feed them all. Finally, this clan has several species which instinctively kill far in excess of normal needs. This is a practice which, almost without exception, is confined to those members of the weasel family which prey on rodents. It is evidently one of Nature’s methods of controlling the rodent population. To operate at highest efficiency these killers should hunt alone. These factors all apply in some degree to the marten. As a consequence, although there may be many in an area, the marten is usually found alone except for a brief time during the breeding season or in the case of a female with young. The male evidently has no part in bringing up the family.

The marten has always been more or less plentiful throughout its range, and there is no reason to believe that it will not continue to be seen by alert observers for many years to come. Its chosen habitat is among the evergreens near timberline. This is also an area of rock slides, and the marten loves to hunt the small rodents which make their homes there. Indeed, it divides its time between the two environments, hunting in the talus slopes during summer months, and taking to the trees in winter when rock slides are buried deep beneath the snow. It is an extremely hardy creature which holes up in an abandoned squirrel or woodpecker nest only during the short periods of storm, when hunting would be useless. As might be expected, its summer and winter diets vary widely. Both, however, have as their basic item the spruce squirrel, the important host of the marten, and like it a hardy creature that is abroad throughout the year.

There is considerable variety in the summer diet. On and in the ground there is available an amazing number of species which are denied to the marten during the winter, some because of protection afforded them by the deep snowdrifts and others because they hibernate. Among these are pikas, ground squirrels, woodrats, chipmunks, and many species of mice. In summer, the marten also takes eggs and young of ground-nesting birds. In the trees are found other nests, not excepting those of the woodpecker, into which the marten inserts its forepaw and comes out not only with young birds, but often the adult as well. Martens are known to eat quantities of the larger insects and, since they are fond of fruits and berries when raised in captivity, there is little doubt that they indulge in these delicacies in the wild.

Winter diet consists of the spruce squirrel, augmented by such other small creatures as may be abroad during cold weather. Though it would seem that the marten might suffer from the curtailment of its lavish summer menu, the opposite is the case. They remain fat and healthy under weather conditions that would seriously hamper most other predators. To a large extent, this ability to survive is due to the untiring perseverance and great skill with which they hunt. In addition, few creatures have been endowed with so many adaptations with which to withstand the long, cold winter.

It will be apparent, even to the casual observer, that the marten is most precisely evolved to meet the frigid conditions imposed by its boreal habitat. The long, fine-haired winter coat is extremely warm and does not mat with snow or frost. With such an insulated covering any hollow log or woodpecker’s nest will do as a resting place. Snow is the least of the marten’s troubles; not only does it stay warm among the drifts, but travels across them with ease on its “built-in” hair snowshoes, which also keep the toe pads warm. The midwinter track of a marten is rather confusing, as it shows no definite toe marks, but is a blurry outline in soft snow, and on harder snow scarcely registers at all. However, if it is remembered that this animal travels much like a weasel, that is, it jumps instead of walking, the larger prints will serve to identify it as a marten.

Interesting as the physical adaptations of the marten may be, the response of its life history to the pressures of a long winter are no less fascinating. As has been stressed, the marten is a solitary and more or less nomadic animal. Apparently the only time of the year that is favorable for breeding is during the summer, as this is the only time when adults of the two sexes are commonly found together. This starts a reproductive cycle which, while not too uncommon, is unusual enough to excite one’s interest. For the following information, I am indebted to James Campbell of Hope, Idaho, who live-trapped and raised many of these interesting animals years ago when knowledge concerning them was relatively meager.

Box traps were used to take the marten during the middle of the winter, when snow lay from 15 to 25 feet deep along the trap lines. This was at an elevation of up to 6,500 feet in the panhandle of northern Idaho. As a sprung trap was approached, the outraged captive could be heard growling its resentment and struggling to escape. A flour sack would be placed around the entrance and the door opened. The marten, apparently mistaking the white glare for snow, invariably would leap out into the sack. Great care was necessary at this point, for the marten was usually wet with perspiration from its struggles within the box trap, and if allowed to chill would quickly die from exposure. The sack was placed within several others and the bundle placed in a pack-sack and carried down the mountain, where the marten was cooled gradually in the house, then put in the outdoor pens. Here they soon became so tame that they would readily accept food from the hand, never becoming treacherous like their unpredictable cousins, the mink. They loved fruit and berries, and were especially fond of chocolate candy.

Early in the venture, it was observed that winter-caught females were giving birth to young in April. Further observation revealed that breeding took place from the early part of July into late August, but that no matter when breeding was accomplished the young would be born in April. The first signs of pregnancy, however, would not be apparent until about 50 days before birth of the young. This indicates that, like most of the hibernating bats, breeding takes place in one season, but the fertilized ova remain quiescent and do not begin to develop until conditions are propitious for the birth of the young. This also insures arrival of the little ones quite early in the season, so that they may enter the following winter fully grown. The number of young varies from three to five, usually the smaller number.

No description of the marten would be complete without mention of its tremendous vitality. In trees it is superior to the squirrel, especially in long, arching leaps, which it makes from one lofty perch to another. In winter time it will often leap from the trees into soft snowdrifts, seemingly for the sheer thrill of the sport. It is not uncommon for martens to burrow through snowdrifts for some distance apparently in search of rodents. I have found that a marten, startled in the forest, is not usually too afraid of its arch enemy, man. At first it will run away but, if pursued too hotly, will come to bay on a low limb and put on a great display of hissing and growling while baring its sharp, white teeth. It is not improbable that if it were pressed further it might attack its tormenter.

River otter Lutra canadensis (Latin: otter ... of Canada)

Range: Most of North America south to central Arizona and New Mexico in the Southwest, and south to the Gulf of Mexico in the east.

Habitat: Along and in fresh water streams and lakes.

Description: A short-legged, stream-lined creature with a thick tapered tail, usually seen in the water. Total length 3 to 4 feet. Tail 12 to 17 inches. Weight up to 20 pounds. Color mostly a rich, dark brown with a silvery sheen on the underparts. The throat and chest are lighter than the rest of the body. The otter is well adapted to aquatic life, having a long, round body and short, muscular legs. All four feet are webbed. The head is long and round, with short ears. Long, stiff whiskers stand out near the rather thick nose. The tail is thick at the base, and the body literally tapers off into the tail, increasing the general “torpedo” effect.

The otter, never plentiful in the Southwest, has become extremely rare in recent years. This is due in large part to its highly specialized habits, coupled with an inability to compete with man in the use of the few fresh water streams and lakes in the desert mountains. Yet, it has been recorded often enough in the past decade to warrant the hope that with careful management and complete protection it might increase in numbers. This is much to be desired because the otter is unique in several respects among our native mammals. This mild-mannered member of the weasel family lacks many of the fierce and blood-thirsty habits of its more ferocious relatives. It is, instead, gentle, even playful.

Outstanding among these characteristics is the otter’s habit of building slides. These are probably nothing more or less than a refinement of the way otters travel through the tules and slippery mud flats, in which they spend much of their time hunting crayfish and small amphibians. The remarkable thing about the slides is that they seem to be built for one specific purpose, that of sport, an activity which ordinarily is one of the least important to most mammals. In soft or muddy places, even in soft snow, the otter slides along on its chest with head held high and forelegs trailing alongside the body. Motive power is furnished by thrusts of the hind legs. Excessive wear on the underparts is reduced by many coarse, close-set overhairs which seem to have been developed for this very purpose. The slide itself is only a narrow groove, 12 to 20 inches wide, that is worn down a steep bank to the water’s edge. The wet bodies of the otters make it smooth and slippery, and soon they are able to shoot down it with only an occasional helping kick of the hind feet. This fascinating game may go on for hours on end. The descent often is followed by a general rough and tumble in the “swimming hole.” There the action is almost too fast for the eye to follow, because few mammals can match the otter for grace and speed in the water.

Aquatic as the otter is, it does not care to be always wet, and this leads to another curious institution in its way of life. Near the slide, and usually at several other places along the waterway which is frequented by a family of these delightful creatures, will be found areas several feet in diameter, located among dry tules or in tall grass, where the animals roll and thus dry themselves. These seem also to be community news centers, because usually near such areas are found the scent “posts,” where otters deposit scent from the glands common to all members of the weasel family. In otters these glands do not secrete the high-potency perfume produced by those of skunks and minks. Nevertheless, it is sufficiently “loud” to be identified with the otter.

The dens present great contrast in location and type. They are usually situated near water, but one was found more than half a mile from the nearest stream. On the other hand, an otter will often take over the abandoned burrow of a bank beaver, and access to this abode must be by an underwater entrance. In many instances, the den is merely a nest in a thick clump of tules completely surrounded by water.

The two to four young are born in early spring. At birth they are blind, toothless, and amazingly helpless in comparison with their development 6 weeks later. At this age they begin to leave the den, and before long are quite at home in the water. Though the male may be in the neighborhood, the female will not allow him near the young until they are half grown. At this time, the family will begin to live together until the young are fully able to make their own way.

Otters are cosmopolitan in their tastes; being carnivores, they will prey on many species. Fish is their preferred food, and in most cases they capture rough fish species, these as a rule being slow and easy to catch. They are fully capable of catching trout, however, should other supplies fail. Otters in captivity do not thrive on fish alone, so evidently the great numbers of other small animals upon which they prey must be necessary adjuncts to their diet. These include crayfish, frogs, several species of small mammals, and such birds and eggs as may be available.

The presence of otters in an area is not difficult to detect. A slide, “rolling place,” or characteristic web-toed track are all sure indications that this interesting animal is a neighbor. Cultivate its acquaintance if you can. The otter is diurnal as well as nocturnal, and should you be so fortunate as to see this happy animal coast down his slippery slide, I am sure you will get as big a thrill from it as he does.