Owls Aren't Wise and Bats Aren't Blind (46 page)

According to those who have witnessed it, a fight between two big bulls is even more spectacular. Smashing their antlers together, the two leviathans shove back and forth in a test of strength, tearing up the ground for yards around. If they’re evenly matched, this battle for dominance can go on for quite a few minutes until one of the bulls is convinced that the other is bigger and stronger. Then the vanquished bull will break away, turn, and flee. The victor is apt to pursue him hotly for a short distance, often goring his erstwhile foe in the process, but breaks off the chase as soon as he’s sure his rival is well and truly beaten.

Although bull moose are polygamous, they breed far fewer females than does a dominant whitetail buck. Perhaps this has something to do with the fact that moose, being so much larger than deer, have a lower population density, and thus would have to travel much greater distances to find so many females.

One means by which bulls locate cows during the rut is by construction of pits, often called “wallows.” The bull first scrapes out a shallow hollow in the earth, then urinates in it and spreads scent from glands on his legs. Finally he rolls about in the malodorous affair, liberally coating himself with its scent. These wallows attract cows by their pungent odor; a bull will have several of these moose equivalents of a singles bar scattered about his territory, and will visit them frequently in search of females in heat. The wallows’ aroma that the bull attaches to himself may also attract cows and put them in an amorous mood.

Not long after the rut is over, moose begin to seek their winter quarters. Both winter quarters and wintering habits of moose are very different from those of white-tailed deer. Whereas deer tend to winter in large areas containing many deer, moose spend the cold months in small groups in equally small pockets of good winter habitat. Two or three moose—rarely as many as six or seven—seek small groves of softwood trees located near plenty of good hardwood browse. Also, in latitudes where the ranges of moose and whitetails overlap, moose generally winter at higher elevations than the deer.

Strange as it may seem, moose actually need the shade of the coniferous trees in late winter to prevent them from overheating. No doubt their very dark color acts as a solar collector and contributes to overheating when the sun’s rays grow more direct with the approach of spring.

Most cow moose are bred around the first week of October. With a gestation period of a little under eight months, that means most calves are born from mid-May to the first of June. About 20 percent of the yearling cows breed; these almost invariably have a single calf. Likewise, most of the two-year-olds bear single calves. Cows from ages four to nine are considered to be the prime breeders, and about 40 percent of those cows have twins. Triplets occur, but are rare.

The calves weigh twenty-five to thirty-five pounds at birth. Although their long legs are wobbly at first, they can follow their mother around after only three or four days. Like whitetails, moose have very rich milk, so the calves gain weight at a phenomenal rate. They put on a pound a day for the first month and two pounds a day for the next three or four months. As a result, these huge “babies” often weigh three hundred pounds or more by December—far more than most mature whitetails. Although the calves can survive on their own after two months if something happens to the cow, they normally continue to nurse until October. By the following October, the year-old moose will weigh a remarkable four hundred to six hundred pounds!

Summer food for moose is quite different from their winter fare. Because of a winter diet consisting almost exclusively of browse, moose emerge from the long winter months deficient in sodium and certain other elements. To remedy this lack, succulent aquatic plants now become an important part of their diet. These plants are rich in sodium, iron, and other nutrients, and moose begin to feed on them eagerly as soon as they become available.

Good moose habitat contains plenty of wetlands—shallow, boggy lakes, beaver ponds, and similar areas. These serve a dual function: first, they provide a rich source of aquatic plants for food; second, they keep the moose cool in hot weather and offer some relief from the hordes of biting insects that torment them at that time of year.

Moose are powerful swimmers, so at home in the water that they might almost be called semiaquatic during the summer months. They have hollow hairs that provide considerable buoyancy, so, despite its great bulk, a moose has little difficulty staying afloat. Most of a moose’s aquatic time, however, is spent wading in relatively shallow water, where it can submerge head and neck in order to bring up favored plants to be munched above the surface.

Thanks to this trait, my wife and I had a memorable experience with a moose. We were canoeing the shoreline of a pond, looking for moose while the September dusk was starting to settle. Suddenly we began to hear what sounded like a waterfall, although we knew there were none nearby. Moreover, the sound was sporadic, rather than the steady noise made by falls. Suspicion dawned on us, and we paddled hurriedly toward the source of the sound, along the far shore some distance behind us.

Sure enough, there was a huge bull moose, one of the largest we’ve ever seen. Although he was deeply engrossed in feeding and paid no attention to us as we approached, we maintained the properly respectful distance befitting such a forest monarch. Each time he raised his head from beneath the water, his mouth stuffed with plants, water cascaded off the wide palms of his majestic antlers, temporarily imitating the sound of a miniature waterfall.

One of the most misunderstood aspects of moose biology is their interaction with deer. Over and over, the refrain is heard in some circles, “Moose drive out the deer.” When people correctly observe that there are more moose and fewer deer in a particular area, they frequently make the erroneous assumption that this is a clear case of cause and effect. It isn’t.

There is no physical conflict between moose and whitetails; the two species go their separate ways and don’t bother each other. Any effect that moose have on deer, then, real or imagined, must be related to food supplies, and there are at least two reasons why this is rarely a problem.

First, although moose and deer feed on the same species of trees and shrubs, moose mainly browse at a considerably higher level than deer. Second, summer browse isn’t usually a problem; it’s browse in the wintering areas that’s critical. As already noted, moose winter in small groups at elevations higher than most deer wintering areas, so there’s seldom competition between the two species for winter food. There have been a few documented cases of competition for winter food between moose and whitetails, but these are very uncommon.

Then why do deer populations often decline while moose numbers rise in the same area? The answer lies in habitat change—but change caused by humans rather than moose. As previously described, wholesale clearcutting has benefited moose greatly by creating a sea of browse, often called “moose pastures.” Frequently these huge clearcuts destroy deer wintering areas by removing the mature softwood stands so critical to whitetail survival in severe winters. Without the shelter of these softwoods, deer flounder in the deep snow, and many perish, while the powerful, long-legged moose continue to move freely. As a result of this major habitat change, moose thrive and deer decline.

Far from being driven out by moose, white-tailed deer can actually have a harmful effect on moose. Enter the villain, a diminutive roundworm with the outsized name of
Parelaphostrongylus tenuis,
better known as the brainworm. The interrelationship between deer, moose, and brainworm is complex, yet sufficiently fascinating to be well worth exploring.

Brainworms, threadlike parasites less than four inches long, are found in the brain covering
(meninges)
of the majority of deer. However, deer seem unaffected by their presence. Eggs of this parasite travel in the bloodstream to the lungs, where they develop into larvae. The larvae then move up to the throat, where they’re swallowed and eventually pass out of the deer in the feces.

This would be the end of the cycle—and the brainworm—if it weren’t for snails and slugs. These pick up the larvae from the deer feces, and the larvae then develop further inside their new host. Eventually the snail or slug, brainworm larvae and all, may be accidentally ingested by a browsing moose.

Once inside the moose, the larvae migrate to the spinal cord. There they mature into adult brainworms and travel to the brain. Then the parasites attack the brain itself, rather than living in the meninges, as they do in deer. The result is a condition known as “moose sickness,” which is nearly always fatal.

Moose afflicted by this condition display a variety of symptoms. They may act very tame and lethargic. (No doubt this is the source of many of the “tame” moose that people foolishly try to pet.) Later symptoms may include such things as lack of coordination, walking in circles, and even blindness. Finally the moose becomes paralyzed and dies.

Because deer are the ultimate source of brainworm infection in moose, a high population of deer can inhibit moose numbers. When deer populations decline as the result of large-scale clearcutting, moose benefit not only from vast areas of browse, but from fewer deer, as well. Thus if there is any interaction between the two species, it’s the deer that are more likely to drive out the moose, no matter how indirectly, rather than vice versa.

Brainworm isn’t the only affliction suffered by moose. There is also the winter tick. This parasite sometimes infests moose in such quantities that
thirty thousand
or more of them can be found on a single animal! As moose try to dislodge these pests, they scratch with their hind hooves and repeatedly rub against trees. In the process, they may remove substantial portions of their outer coat; especially in calves, this added exposure to winter cold may prove fatal.

Moose are less vocal than deer throughout most of the year, primarily because they lack the whitetail’s high, whistling snort of alarm. The bulk of their noisemaking comes during the rut, when the bulls utter their deep grunts. At that time, cows facilitate the process of finding a mate by uttering high-pitched, moaning cries and what’s sometimes described as a bellow.

Calves aren’t entirely silent, either. One late September evening, my wife and I were in a canoe watching a cow moose and her calf feeding along the shoreline. They stuck tightly together for quite some time. Then the calf’s attention wandered, while the mother slowly fed her way along until she was perhaps thirty or forty yards ahead. Suddenly discovering that he had been abandoned, the hulking calf, which certainly weighed well over two hundred pounds, began to squeak and whimper, much in the fashion of a distraught puppy. This whining continued until the calf had once again reached its mother’s side. The incongruity of such pathetic little sounds emerging from an animal of that size made this incident truly amusing!

We also observed another interesting moose trait. Two cow moose emerged from the woods and begin to drink from a little rivulet. As we watched, they apparently decided that reaching down so far to drink was too difficult, so they both knelt on their front knees and continued to drink for some time. I have no idea whether or not moose commonly drink in this fashion, but they clearly do on occasion.

Although moose can become too numerous and cause serious problems for humans, they are nonetheless a welcome sight in reasonable numbers. Unique in appearance, towering in height, and massive in frame, they represent an evolutionary masterpiece, superbly designed to thrive in regions of deep snow and bitter cold. Their recent success assures us that we will continue to see and wonder at their majestic presence.

24

The All-American: The Bison

MYTHS

The bison is a buffalo.

Bison are still quite scarce.

Bison are docile animals, safe to approach closely.

ONCE THEY WERE THE GLORY OF THE NORTH AMERICAN PRAIRIES, DARKENING THE PLAINS IN NUMBERS BEYOND COUNTING, AND SHAKING THE EARTH WITH THE IMPACT OF MILLIONS OF HOOVES. Then, in a few short decades, the seemingly inexhaustible herds of the majestic bison were reduced to such a pathetic remnant that extinction of this Plains monarch seemed imminent. The bison’s near demise, followed by its renascence, is a tale worth repeating, filled with carelessness, ignorance, and greed, followed by concern and the beginnings of wisdom.

The North American bison is an astonishingly tough creature, perfectly adapted to an often incredibly harsh life. It’s usually incorrectly referred to as a buffalo, but buffaloes are Old World animals such as the Cape buffalo of Africa and the water buffalo of India. The bison of North America is distinctly different, for it evolved with an ability to live in harmony with the North American prairies, a harmony so profound that bison and prairie became mutually dependent on each other. Because of this unique quality, it seems fitting to conclude this book with an account of a creature that epitomizes the Old West and the prairies of the United States and Canada.

Bison in North America are actually divided into two subspecies. The American, or Plains, bison is
Bison bison bison.
North of the prairies in southern Canada is the wood buffalo,
Bison bison athabaesca.
The two are quite similar, as evidenced by the fact that they are subspecies, rather than separate species. However, the wood bison is a bit longer than the Plains bison, as well as a little heavier in the hindquarters.

American (Plains) bison

The story of the bison’s near extinction is well known, but it bears repetition. Even relatively early European settlers had contact with bison, for bison ranged well eastward of the Great Plains into areas such as Indiana and Kentucky. There they lived in openings within partly forested areas. These were only the tip of the iceberg, however. As white settlers surged westward in the mid-1800s, especially after the American Civil War, they encountered seemingly endless herds of bison on the prairies.

These animals were the perfect denizens of the Great Plains. Moving in gigantic herds, they effectively gave the prairie an annual haircut and shave by cropping the plants almost to the ground. As the bison grazed, their dung—the famous buffalo chips—fertilized the land. This system permanently maintained a rich variety of annual and perennial plants, and held encroaching forestland at bay.

Simultaneously, the diversity of prairie plants nourished the bison and provided an ecosystem for which it was perfectly adapted. Able to tolerate drought and the searing heat of summer on the Plains, the bison was also able to withstand the shrieking, howling winds, driving snow, and subzero temperatures of prairie blizzards. With heads, necks, and front quarters insulated by incredibly dense, woolly fur, the bison simply faced into the blizzards and endured, where lesser creatures, such as domestic cattle, soon perished.

So huge were some of the bison herds that we can scarcely imagine them today. George Armstrong Custer wrote of leading troops through a herd for six consecutive days, during the last three of which the bison were steadily and continually moving across their path! These were part of a mighty population estimated as high as 75 million, although 60 million is the most widely accepted estimate.

For centuries the Plains Indians had shared the land with the bison and had developed an almost mystic relationship with the great, shaggy creatures. On foot for hundreds of years, and subsequently with the advent of horses obtained from Spanish explorers in the sixteenth century, these Native Americans hunted bison. Their prey provided them not only with food, but also with most of their other necessities: clothing and tepee covers from the hides; cups and ladles from the horns; knives, arrowheads, sled runners, and hoes from the bones; bowstrings from sinews; dried dung for fuel; and the skull and horns as ceremonial and religious objects.

Then, with railroads reaching their tentacles into the West, white settlers came in earnest, and the slaughter began. In one of the most disgraceful chapters in the pillage of North America’s natural resources, this enormous population of bison was nearly extinguished within a few short years. With the aid of modern weaponry—repeating rifles and more powerful rifles with longer range—bison were hunted in every available manner. They were shot by men on foot, on horseback, and even leaning out the windows of trains.

Some of the killing was at least for the legitimate purpose of procuring meat and hides, but much was simply wanton slaughter. Bison were shot by the thousands, their tongues cut out as a delicacy, and the remainder left to rot. Even worse, thousands more were shot by wealthy “sportsmen” from train windows and wagons for no better purpose than the fun of it.

Exacerbating the situation was an underlying government policy of eliminating the bison as a means of solving the “Indian problem.” Rid the Plains of bison, the reasoning went, and the Indians will vanish also. No less a figure than Lieutenant General Philip Sheridan, the great Union Civil War leader, declared in 1875, “These [hide hunters] have done in the last two years, and will do in the next year, more to settle the vexed Indian question than the entire Regular Army has done in the last thirty years. They are destroying the Indians’ commissary . . . let them kill, skin, and sell until the buffaloes are exterminated. Then your prairies can be covered with speckled cattle and the festive cowboy. . . .” However misguided its aims, this policy was unquestionably effective in achieving its purpose.

Incredibly, by 1885 the bison were nearly gone. This creature, which had darkened the Plains in great, thundering rivers of living animals, and which was strong enough and fast enough to face down or outrun most predators, was no match for man and his rifles. By 1893 it was estimated that perhaps as few as three hundred bison remained.

Fortunately, a few ranchers and true sportsmen, appalled by what was happening, rounded up a few of the fast-dwindling remnant bison and began to raise them in captivity. In 1905 the noted biologist William Hornaday became the cofounder and first president of the American Bison Society, dedicated to saving and restoring the bison. Meanwhile, President Theodore Roosevelt successfully pushed Congress into establishing a number of wildlife preserves. Many of these, along with several national parks, were restocked with animals from private bison owners, and the former monarch of the Plains began its slow march back from the brink of extinction.

There seems to be a rather vague sense that the bison, though no longer endangered, is rather uncommon. In fact, it’s thriving, and its numbers will eventually be limited only by available habitat. Today there are an estimated 250,000 bison in North America, found in nearly every province and state, including Alaska. Most are captive animals, but at least three herds aren’t confined by fences.

Captive doesn’t equate with tame, however. Bison often seem placid and docile, but they’re not domestic livestock. Those most familiar with bison warn that they are
not
tame and should not be approached closely by anyone other than those experienced in handling them. Bison, they caution, despite their seeming docility, are dangerous because of their size, speed, and unpredictability.

A former National Wildlife Federation colleague of mine was an accidental participant in the sort of drama that bison experts warn against. He happened to be driving past a ranch where bison were confined by high and extremely heavy fencing. There he noticed a man on the outside taking pictures of a young boy within, standing beside a group of bison cows. As he took in this scene, he also noticed a buffalo bull some distance away, angrily pawing the ground in preparation for a charge.

Slamming on the brakes, my colleague jumped out of the car and climbed over the fence. There he seized the boy, tossed him over the fence, grabbed the top of the fence, and hoisted himself out of range just as the angry bison slammed into the fence just below his feet! His bravery and quick thinking had undoubtedly saved the lad’s life.

This story has a rather dispiriting sequel. Rather than being grateful to my colleague and remorseful for his own stupidity, the father sued him because the son was slightly injured when he hit the ground. Fortunately justice prevailed: the judge promptly dismissed the lawsuit.

Three bison herds in the United States and one in Canada are essentially wild. That is, they’re unfenced, although they’re managed to one degree or another to control their numbers. One, called the Wild Bunch after Butch Cassidy’s gang, roams freely in the wild fastnesses of the Henry Mountains in southern Utah (a portion of that herd also ranges near the northern rim of the Grand Canyon in northern Arizona). Another unfenced herd is located in Alaska. These two herds are kept in balance with their habitat by carefully regulated hunting. There is also a wild herd of wood bison in Wood Bison Park in Canada, the same park that’s home to nesting whooping cranes.

Then there is the bison herd in Yellowstone National Park, a source of great controversy. Because national parks have a no-hunting policy, no control has been exerted over Yellowstone’s bison. As might be expected, the result is overpopulation, and excess bison regularly spill outside the park’s boundaries.

Because some of these bison are infected with brucellosis, a disease that causes domestic cows to abort their calves, Montana officials have killed the bison outside the park, ostensibly to protect ranchers’ livestock. This seems reasonable on the surface, but there are some very troubling aspects to it. First, there has never been a documented case of brucellosis transmission from wild bison to domestic cattle. Second, Montana rejected a National Wildlife Federation proposal to reimburse nearby ranchers for vaccinating their livestock against brucellosis.

Third, a coalition of forty-six Native American Tribes, organized as the Intertribal Bison Cooperative, wants to relocate these Yellowstone escapees onto various tribal lands as a means of restoring at least a small portion of the tribes’ natural and cultural heritage. Further, these transplanted animals would eventually generate surplus bison that could be used to restock various public lands. So far, Montana officials have chosen to kill these wandering bison rather than allow them to be moved to tribal lands.