The moose (North America) or Eurasian elk (Europe) (Alces alces) is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic ("twig-like") configuration. Moose typically inhabit boreal and mixed deciduous forests of the Northern Hemisphere in temperate to subarctic climates. Moose used to have a much wider range but hunting and other human activities greatly reduced it over the years. Moose have been re-introduced to some of their former habitats. Their diet consists of both terrestrial and aquatic vegetation. The most common moose predators are wolves, bears, and humans. Unlike most other deer species, moose are solitary animals and do not form herds. Although generally slow-moving and sedentary, moose can become aggressive and move surprisingly fast if angered or startled. Their mating season in the autumn can lead to spectacular fights between males competing for the right to mate with a particular female.
The moose is a herbivore and is capable of consuming many types of plant or fruit. The average adult moose needs to consume 9770 Calories 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. 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 kilograms, can eat up to 32 kg 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 molars and, ahead of those, six pairs of premolars, to grind up their food. A moose's diet often depends on its location, but they seem to prefer the new growths from 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.
A full-grown moose has few enemies, but a pack of wolves can still pose a threat, especially to females with calves. Siberian Tigers and Brown bear are also known to prey on moose, although bears are more likely to take over a wolf kill or to take young moose than to hunt adult moose on their own. American black bears and cougars can be significant predators of moose calves in May and June and can be, in rare instances, can predate adults (mainly cows). Killer Whales are the moose's only known marine predator as they have been known to prey on them when swimming between islands out of North America's Northwest Coast.
In some areas, moose are the primary source of food for wolves. Moose usually flee upon detecting wolves. Wolves usually follow moose at a distance of 100 to 400 metres (330 to 1,300 ft), occasionally at a distance of 2 to 3 kilometres (1.2 to 1.9 mi). Attacks from wolves against young moose may last seconds, though sometimes they can be drawn out for days with adults. Sometimes, wolves will chase moose into shallow streams or onto frozen rivers, where their mobility is greatly impeded. Moose will sometimes stand their ground and defend themselves by charging at the wolves or lashing out at them with their powerful hooves. Wolves typically kill moose by tearing at their haunches and perineum, causing massive blood loss. Occasionally, a wolf may immobilise a moose by biting its sensitive nose, the pain of which can paralyze a moose. Wolf packs primarily target calves and elderly animals, but can and will take healthy, adult moose. Moose between the ages of two and eight are rarely killed by wolves. Though moose are usually hunted by packs, there are cases in which single wolves have successfully killed moose.