"C o m p a s s i o n H u r t s
when you feel connected to everything you also feel responsible for everything. And you cannot turn away. Your destiny is bound to the destines of others. you must either learn to carry the universe or be crushed by it. You must grow strong enough to love the world yet empty enough to sit down at the same tablewith it's worst horrows"
~ Andrew boyd
A few major animals in Yellowstone include
Adult elk usually stay in single-sex groups for most of the year. During the mating period known as the rut, mature bulls compete for the attentions of the cow elk and will try to defend females in their harem. Rival bulls challenge opponents by bellowing and by paralleling each other, walking back and forth. This allows potential combatants to assess the other's antlers, body size and fighting prowess. If neither bull backs down, they engage in antler wrestling, and bulls sometimes sustain serious injuries.
Dominant bulls follow groups of cows during the rut, from August into early winter. A bull will defend his harem of 20 cows or more from competing bulls and predators. Only mature bulls have large harems and breeding success peaks at about eight years of age. Bulls between two to four years and over 11 years of age rarely have harems, and spend most of the rut on the periphery of larger harems. Young and old bulls that do acquire a harem hold it later in the breeding season than do bulls in their prime. A bull with a harem rarely feeds and he may lose up to 20 percent of his body weight. Bulls that enter the rut in poor condition are less likely to make it through to the peak conception period or have the strength to survive the rigors of the oncoming winter.
Bulls have a loud vocalization consisting of screams known as bugling, which can be heard for miles. Bugling is often associated with an adaptation to open environments such as parklands, meadows, and savannas, where sound can travel great distances. Females are attracted to the males that bugle more often and have the loudest call. Bugling is most common early and late in the day and is one of the most distinctive sounds in nature, akin to the howl of the gray wolf.
Although the brown bear is primarily nocturnal, it is frequently seen in morning and early evening hours. In summer through autumn, it can double its weight, gaining up to 180 kg (400 lb) of fat, on which it relies to make it through winter, when it becomes very lethargic. Although they are not full hibernators and can be woken easily, both sexes like to den in a protected spot, such as a cave, crevice, or hollow log, during the winter months. Brown bears are mostly solitary, although they may gather in large numbers at major food sources (e.g., moth colonies, open garbage dumps or rivers holding spawning salmon) and form social hierarchies based on age and size. Adult male bears are particularly aggressive and are avoided by adolescent and subadult males. Female bears with cubs rival adult males in aggression, and are more intolerant of other bears than single females. Young adolescent males tend to be least aggressive, and have been observed in nonantagonistic interactions with each other. Dominance between bears is asserted by making a frontal orientation, showing off canines, muzzle twisting and neck stretching to which a subordinate will respond with a lateral orientation, by turning away and dropping the head and by sitting or lying down. During combat, bears use their paws to strike their opponents in the chest or shoulders and bite the head or neck. Sounds expressing anger or aggravation include growls, roars, woofs, champs and smacks, while sounds expressing nervousness or pain include woofs, grunts, and bawls. Sows will bleat or hum when communicating with their cubs.
The moose is a herbivore and is capable of consuming many types of plant or fruit. The average adult moose needs to consume 9,770 kcal (40.9 MJ) per day to maintain its body weight. Much of a moose's energy is derived from terrestrial vegetation, mainly consisting of forbs and other non-grasses, and fresh shoots from trees such as willow and birch. These plants are rather low in sodium, and moose generally need to consume a good quantity of aquatic plants. While much lower in energy, these plants provide the moose with its sodium requirements, and as much as half of their diet usually consists of aquatic plant life. As an adaptation for feeding on plants under water, the nose is equipped with fatty pads and muscles that closes the nostrils when exposed to water pressure, preventing water from entering the nose. In winter, moose are often drawn to roadways, to lick salt that is used as a snow and ice melter. A typical moose, weighing 360 kg (790 lb), can eat up to 32 kg (71 lb) of food per day.
Moose lack upper front teeth, but have eight sharp incisors on the lower jaw. They also have a tough tongue, lips and gums, which aid in the eating of woody vegetation. Moose have six pairs of large, flat molars and, ahead of those, six pairs of premolars, to grind up their food. A moose's upper lip is very sensitive, to help distinguish between fresh shoots and harder twigs, and the lip is prehensile, for grasping their food. In the summer, moose may use this prehensile lip for grabbing branches and pulling, stripping the entire branch of leaves in a single mouthful, or for pulling forbs, like dandelions, or aquatic plants up by the base, roots and all.
A moose's diet often depends on its location, but they seem to prefer the new growths from deciduous trees such as white birch, trembling aspen and striped maple, among many others. Many aquatic plants include lilies and pondweed. Moose are excellent swimmers and are known to wade into water to eat aquatic plants. In non polar regions this trait serves a second purpose in cooling down the moose on summer days and ridding itself of black flies. Moose are thus attracted to marshes and river banks during warmer months as both provide suitable vegetation to eat and water to wet themselves in. Moose have been known to dive underwater to reach plants on lake bottoms, and the complex snout may assist the moose in this type of feeding. Moose are the only deer that are capable of feeding underwater.
Wallowing is a common behavior of bison. A bison wallow is a shallow depression in the soil, either wet or dry. Bison roll in these depressions, covering themselves with mud or dust. Possible explanations suggested for wallowing behavior include grooming behavior associated with moulting, male-male interaction (typically rutting behavior), social behavior for group cohesion, play behavior, relief from skin irritation due to biting insects, reduction of ectoparasite load (ticks and lice), and thermoregulation. In the process of wallowing, bison may become infected by the fatal disease anthrax, which may occur naturally in the soil.
A group of images by Eadweard Muybridge, set to motion to illustrate the movement of the bison
The bison's temperament is often unpredictable. They usually appear peaceful, unconcerned, even lazy, yet they may attack anything, often without warning or apparent reason. They can move at speeds of up to 35 mph (56 km/h) and cover long distances at a lumbering gallop.
Their most obvious weapons are the horns borne by both males and females, but their massive heads can be used as battering rams, effectively using the momentum produced by 2,000 pounds (900 kg) moving at 30 mph (50 km/h). The hind legs can also be used to kill or maim with devastating effect. At the time bison ran wild, they were rated second only to the Alaska brown bear as a potential killer, more dangerous than the grizzly bear. In the words of early naturalists, they were a dangerous, savage animal that feared no other animal and in prime condition could best any foe (except for wolves and brown bears).
The rutting, or mating, season lasts from June through September, with peak activity in July and August. At this time, the older bulls rejoin the herd, and fights often take place between bulls. The herd exhibits much restlessness during breeding season. The animals are belligerent, unpredictable and most dangerous.
The gray wolf is a social animal, whose basic social unit consists of a mated pair, accompanied by the pair's adult offspring. The average pack consists of a family of 5–11 animals (1–2 adults, 3–6 juveniles and 1–3 yearlings), or sometimes two or three such families, with exceptionally large packs consisting of 42 wolves being known. Triggers for dispersal include the onset of sexual maturity and competition within the pack for food. In ideal conditions, the mated pair produces pups every year, with such offspring typically staying in the pack for 10–54 months before dispersing. The distance travelled by dispersing wolves varies widely; some stay in the vicinity of the parental group, while other individuals may travel great distances of 390 km, 206 km, and 670 km from their natal packs. A new pack is usually founded by an unrelated dispersing male and female, travelling together in search of an area devoid of other hostile packs. Wolf packs rarely adopt other wolves into their fold, and typically kill them. In the rare cases where other wolves are adopted, the adoptee is almost invariably an immature animal (1–3 years of age) unlikely to compete for breeding rights with the mated pair. In some cases, a lone wolf is adopted into a pack to replace a deceased breeder. During times of ungulate abundance (migration, calving etc.), different wolf packs may temporarily join forces.
Wolves are highly territorial animals, and generally establish territories far larger than they require to survive in order to assure a steady supply of prey. Territory size depends largely on the amount of prey available and the age of the pack's pups, tending to increase in size in areas with low prey populations or when the pups reach the age of 6 months, thus having the same nutritional needs as adults. Wolf packs travel constantly in search of prey, covering roughly 9% of their territory per day (average 25 km/d or 15 mi/d). The core of their territory is on average 35 km2 (14 sq mi), in which they spend 50% of their time. Prey density tends to be much higher in the territory's surrounding areas, though wolves tend to avoid hunting in the fringes of their range unless desperate, due to the possibility of fatal encounters with neighboring packs. The smallest territory on record was held by a pack of six wolves in northeastern Minnesota, which occupied an estimated 33 km2 (13 sq mi), while the largest was held by an Alaskan pack of ten wolves encompassing a 6,272 km2 (2,422 sq mi) area. Wolf packs are typically settled, and usually only leave their accustomed ranges during severe food shortages.
Wolves defend their territories from other packs through a combination of scent marking, direct attacks and howling (see Communication). Scent marking is used for territorial advertisement, and involves urination, defecation and ground scratching. Scent marks are generally left every 240 metres throughout the territory on regular travelways and junctions. Such markers can last for 2–3 weeks, and are typically placed near rocks, boulders, trees or the skeletons of large animals. Territorial fights are among the principal causes of wolf mortality, with one study concluding that 14–65% of wolf deaths in Minnesota and the Denali National Park and Preserve were due to predation by other wolves.
Golden eagles are opportunists and virtually any animal of a reasonable size may be predated if encountered. Well over 400 species of vertebrate have been recorded as prey. Prey selection is largely determined by the local availability and abundance of prey species. They normally prefer wild, native prey but can easily adapt to domesticated and/or exotic animals, most often when the prey returns to a feral state. This is most apparent on islands that have very few (or no) native land mammals, such as Corsica in Italy, Santa Rosa and Santa Cruz Islands in California and many of the Inner and Outer Hebrides of Scotland. Most analysis of dietary habits of raptors results from examining the prey remains around an active eyrie at the end of the breeding season (September or October), based on pellets, skeletons and skins found. This method is not comprehensive for prey analysis, as particularly small prey may leave no trace and it cannot take into account the prey selected by wintering adults and highly nomadic juvenile eagles (both of which are believed to include a higher level of carrion and large prey items). However, since eye-witness accounts of hunting and close monitoring of prey brought to the nest are both rare and likely to disturb the eagles, this is the best known method of studying the eagle’s prey. Studies have revealed that the average golden eagle nest contains 3.57 species of prey, although there is considerable variation in the dietary breadth across the range, ranging from an average of 11.2 species in the French Pyrenees to a mere 1.4 in Alaska. In general, the dietary breadth is greater in Eurasia than it is in North America, where eagles frequently only need to hunt two or three species throughout the nesting cycle. This is a moderate dietary breadth by the standards of the Aquila genus, and not remarkable when compared to some other raptors. Overall prey weight has ranged from 10 g (0.35 oz) to at least 114 kg (251 lb), although most prey taken are around half the weight of the predating eagle, with a typical prey weight range of 0.5–4 kg (1.1–8.8 lb) but mostly in the lower half of that range. Studies have shown an estimated mean prey weight of 1.614 kg (3.56 lb) for golden eagles across their range. Only 15.8% of prey weighs over 4 kg (8.8 lb). At a nest studied in Mongolia, prey items were found to be heavier than those known elsewhere in the range, with an estimated mean weight of around 3 kg (6.6 lb). The average estimated weight of prey taken by most other Aquila species is generally much lower but the Wedge-tailed Eagle seemingly takes prey of a similar weight (both in average and range of prey weights) while the Verreaux's Eagle average prey weight is higher, probably over 2 kg (4.4 lb)
(© to refrences on Wikipedia)
