AMERICAN BLACK BEAR. Ursus americanus Pallas

Field characters.—Size large (adults, total length up to 60 inches, height at shoulder up to 40 inches); forefoot squarish (size, up to about 6-1/2 by 4 inches), hind foot triangular in outline (total length from heel, up to about 9 inches, width to 4-1/2 inches); all five toes and claws showing in track of each foot (pl. 22b); tail very short, 6 inches or less. Pelage long and heavy, in color either glossy black, or cinnamon brown of varying shades. Voice: Commonly only sniffs or snorts; when badly frightened or wounded, a loud growl or bawl.

Occurrence.—Resident on west slope of Sierra Nevada, chiefly in Transition and Canadian zones. Recorded, or reported on good authority, from 3 miles east of Coulterville, from near Bagby, and from Bullion Mountain, eastward to Tuolumne River at 8000 feet, to McGee Lake, and to Tenaya Lake. Lives on forest floor or about brush thickets, taking shelter in caves, under rock piles, or in hollow trees. Cubs run with mother through first year.

The Black Bear is the largest carnivorous animal now to be found in the Yosemite region, and, strangely enough, also the one most often seen by visitors to the Park. Indications of its presence, in the form of foot prints, claw marks on tree trunks, and droppings, are to be seen in many places during the summer and fall months, so that persons who do not succeed in catching sight of the animals themselves are apt to find plain evidence of their presence. In former years the Grizzly Bear, a much larger and more ferocious animal than the subject of the present account, was found in the western part of the Yosemite region; but as told in the chapter on that species, it became extinct there, at the hand of man, many years ago.

Our Yosemite Black Bear exhibits two color phases. That is to say, there are both 'black' and 'cinnamon' bears; but these two phases seem to hold somewhat the same relation to one another as do brunettes and blonds in the human species. A cinnamon-colored mother bear has been seen with 2 coal-black cubs, and several cases have been reported in which a female has had one black and one cinnamon-colored cub in the same litter. The proportion of cinnamon and black bears in the Yosemite region is not known. One resident stated that it was 10 to 1; but our experience points exactly in the opposite direction—we happened to see no cinnamon-colored bears at all while in the region!

The Black Bear is an animal of the Transition and Canadian zones and only rarely ranges above or below the limits of those two zones. So far as known it occurs only on the western flank of the Sierra Nevada, and in this region seldom goes above 9000 feet or below 2000 feet altitude. On the west it was probably restricted in range in former times by the presence of the bellicose Grizzly and it does not seem to have taken much advantage of the disappearance of its larger congenor to increase its range, while in the higher zones conditions are evidently not suitable for its existence.

The density of the bear population of the Yosemite National Park varies widely from place to place. It has been estimated that at times there have been 15 or 20 bears living in Yosemite Valley, the greater percentage of these being about the lower part of the Valley. On the trail between Aspen Valley and Gentrys, a distance of 8 or 9 miles, the junior author saw tracks of 5 or 6 different Black Bears in one day, October 19, 1915. But in other likely-looking places the animals are much scarcer, or absent altogether. Perhaps there are, at the present time, somewhere in the neighborhood of 125 bears in the 1124 square miles of territory included within the Park, or about one individual for every 9 square miles of territory. The mecca of the bears in the Yosemite region is the north-central part of the Park, in Tiltill and Pleasant valleys, Kerrick Cañon, and on the slopes of Rancheria Mountain. Bears are said to be abundant in each of these localities. In Pleasant Valley (north of the Tuolumne River) the brushy slopes are said to be traversed in many directions by their deeply worn trails.

Most carnivorous animals are abroad and active throughout the year, and if, in winter, the presence of heavy snow either directly or indirectly restricts or cuts off their food supply they descend to lower altitudes. Such is the case with the Mountain Coyote and the Mountain Lion. But the Black Bear, depending as it does on plant life for so much of its food, is a striking exception to this general rule and meets the situation in an entirely different way. It hibernates, after the manner of some of the rodents. With the arrival of the first heavy storm of the winter (usually in December or January) it seeks a warm and sheltered cave among the rocks or some other similar situation and there sleeps during the time that heavy snow covers the ground outside. It remains in hibernation until the middle or end of April, when the bulk of the snow at middle altitudes has melted. In 1920 the first bear tracks noted in the lower part of Yosemite Valley were seen on March 18. Those individuals which live below the limit of heavy snow (about 3500 feet in this latitude) are prone to come out and forage actively abroad from time to time throughout the winter. Some residents of the region have suggested to us that the bears living in the higher mountains perform a limited altitudinal migration, but we have no definite information on this point.

The dens used by the bears in the Yosemite region are chiefly such as are found in the heaps of talus and slide rock which abound in various parts of the Park. The bears which feed at the garbage pits in the Yosemite Valley are thought to have their dens in the rock slides under Cathedral Spires, for in this vicinity a trail leads from the pits toward the wall of the Valley.

When the Black Bears go into hibernation in the early winter they are very fat, but most of this excess fat is used up during the long winter sleep. When they first emerge in the spring they are not very active and little is to be seen of them for some time. Soon, however, they begin to eat again, sparingly at first, and then more greedily, until in summer and fall they amply justify the oft-made remark, "hungry as a bear." As the summer wanes their search for food leads them farther and farther afield, their tracks and sign become more and more in evidence, and they themselves are more frequently seen by visitors. During the autumn they must eat not only to sustain their bodies from day to day, but enough in addition to provide another supply of fat to carry them through the following winter. This fat is especially important in the case of the females, as their cubs are born in midwinter and the only source of nourishment for the young until they emerge in the spring is the milk elaborated in the bodies of the mothers from this reserve of fat.

Under original conditions of life the Black Bear is active in the daytime as well as at night, but most of the depredations which it commits in the vicinity of camps and buildings are done under the cover of darkness. The Black Bear is an adept at climbing, from the day that it first emerges from the den, a young cub in the care of its mother, on throughout its entire life. When frightened it often seeks safety by ascending the nearest tree strong enough to support it. When trailed by dogs it finally evades them in this manner.

The tracks of a bear are not likely to be mistaken for those of any other animal. The toes and claws, of which there are five on each foot, all leave distinct impressions in the soft earth of roads and trails, while the square pad of the forefoot and the triangular-shaped heel pad of the hind foot are both of distinctive character (pl. 22b). The track of the rear foot resembles in appearance the print of a human foot. We have measured hind-foot tracks which were 9 inches long, but the average length is considerably less.

Bears are adaptable creatures and profit by the presence of man in several ways. They make much use of man-made trails, especially when going up or down hill, and when doing so follow each turn and zig-zag with remarkable fidelity. Their own trails are as distinctive in character as are their footprints. Through tracts of dense brush the openings left are low—so low in fact that a man in traversing one of them must stoop or crawl on his hands and knees. Then, too, each bear steps in exactly the same place as the one which preceded him, literally "walking in the footsteps of his predecessors," and if a bear comes into a trail of this sort at some point along its course he adapts his tread to that of the main trail. These traits are well shown in a trail through light snow, where the tread of the animals crushes down and melts the snow where they step, yet leaves the snow between the footprints undisturbed (pl. 22a).

Black Bears usually have 2 cubs at a birth, but on June 19, 1910, the junior author saw a black female with 3 black cubs near Camp Curry on the floor of Yosemite Valley. In the account of the Grizzly killed by R. S. Wellman there is mention of 3 Black Bear cubs with their dam, these being actively abroad as late in the season as October 17. Sometimes a litter consists of but a single cub. The earliest report of young out of the den is that by Mr. O. R. Prien who, during the week of April 29, 1916, saw a female with 2 black cubs less than 18 inches long. The cubs of one litter travel with the mother until she dens up for the following winter. Mr. Gabriel Souvelewsky saw tracks of an old bear and two "good-sized" cubs near Mirror Lake, on December 14, 1914.

As regards food the Black Bear will eat anything and everything it can lay its paws on. It is an omnivorous feeder in every sense of that word, departing widely from the customs of most carnivorous animals in this respect. In its natural environment our Yosemite bear eats various kinds of seeds, fruits, and berries, including those of the coffee berry (Rhamnus californicus), green manzanita (Arctostaphylos patula), wild cherry (Prunus demissa), and poison oak (Rhus diversiloba). Grasses, liliaceous plants, and seed heads of various annuals are consumed. Carpenter ants and other insects are taken in considerable numbers. In the vicinity of human habitations it finds a wide choice of fare. It visits isolated or unguarded camps and purloins hams, bacon, canned goods and fruits, raids garbage cans, and digs up heaps of tin cans and other kitchen refuse buried by campers. A considerable number of the bears living in Yosemite Valley regularly forage at the garbage pits and incinerators in the vicinity of Cathedral Spires, as many as 10 and even 15 having been seen there by attendants, usually at late dusk. Tin cans are nosed over and thoroughly cleaned of any remaining particles of their original contents, and melon rinds and other vegetable materials are readily devoured. Peach, plum, and olive pits, watermelon, muskmelon, and apple seeds, lemon rinds, eggshells, bones of chickens, mammal hair, and bones from various cuts of meat are among the objects we found to have been devoured by these bears. Even papers which have been wrapped around butter and cured meats are eaten for the grease and salt which they have absorbed. At the storehouse of the construction camp in Hetch Hetchy Valley, in the winter of 1915-16, bears ripped 2-by-12-inch planks off the window openings, clambered in, and made way with hams, bacon, and canned goods, even while lights were burning in the house and persons were present in other portions of the building.

As regards the relation of Black Bears to stock, Mr. George Smith of Jamestown, Tuolumne County, has told us that in the seventies it was necessary to 'thin out' the bear population before sheep could be run with safety in the mountains. At that time almost every meadow had its bear trap or pen, a small log house of stout construction with a heavy door so arranged that when a bear entered and seized the bait the door would fall and the animal would be imprisoned. Some of these traps may still be seen on meadows in the northern part of the Park. Horses readily take fright at the sight of a bear, although we know of no case in which a bear has actually attacked a horse. In Hetch Hetchy Valley Mr. C. C. Bull has told us of bears visiting hog pens and feeding in the troughs alongside of the rightful partakers without molesting or disturbing the latter. Mr. John L. McLean has told us that bears come down around his ranch on Smith Creek (6 miles east of Coulterville) to feed on acorns, but that they have never molested either poultry or stock. However, he knew of one occasion when some pigs were taken by Black Bears on Bullion Mountain.

Finally in regard to persons: We know of but two instances in which a Black Bear has even attempted to molest any human being in the Park. One case, of a mother bear resenting disturbance of her young, is recounted in the chapter on the Grizzly Bear. The second instance is as follows. Mr. George Smith states that while cruising timber in the Tuolumne basin a number of years ago he was chased down-hill by a she-bear. He distracted the attention of the animal by picking up stones and pieces of wood and throwing them to one side or another as he ran. Finally he jumped upon and ran along a fallen tree trunk and dropped into a willow thicket at the base of the log. The bear, evidently losing the trail, thereupon gave up the chase. Mr. Gabriel Souvelewsky relates that while traveling along the south wall of the Tuolumne Cañon late one afternoon he came to a rock ledge occupied by two cinnamon bears. One of these growled and made threatening advances so that Mr. Souvelewsky thought it best not to continue farther in their direction. But he was not actually pursued. The female mentioned above as being seen by the junior author near Camp Curry in June, 1910, even though accompanied by her cubs, was not unduly resentful of human intrusion. Several persons were taking pictures of her while she had her cubs in sight, and later, when she had hidden them, she came down and fed at a garbage heap while some forty people looked on and snapped pictures at as short a distance as twenty feet.