Rut (mammalian reproduction) in the context of "Elk"

Ethology is a branch of zoology that studies the behaviour of non-human animals. It has its scientific roots in the work of Charles Darwin and of American and German ornithologists of the late 19th and early 20th century, including Charles O. Whitman, Oskar Heinroth, and Wallace Craig. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of the Dutch biologist Nikolaas Tinbergen and the Austrian biologists Konrad Lorenz and Karl von Frisch, the three winners of the 1973 Nobel Prize in Physiology or Medicine. Ethology combines laboratory and field science, with a strong relation to neuroanatomy, ecology, and evolutionary biology.

Animal attacks are violent attacks caused by non-human animals against humans, one of the most common being bites. These attacks are a cause of human injuries and fatalities worldwide. According to the 2012 U.S. Pet Ownership & Demographics Sourcebook, 56% of United States citizens owned a pet. In the United States in 1994, approximately 4.7 million people were bitten by dogs. The frequency of animal attacks varies with geographical location, as well as hormonal secretion. Gonad glands found on the anterior side of the pituitary gland secrete androgen and estrogen hormones. Animals with high levels of these hormones, which depending on the species can be a seasonal occurrence, such as during rutting season, tend to be more aggressive, which leads to a higher frequency of attacks not only to humans but among themselves. In the United States, a person is more likely to be killed by a domesticated dog than they are to die from being hit by lightning according to the National Safety Council.

Animal attacks have been identified as a major public health problem. In 1997, it was estimated that up to 2 million animal bites occur each year in the United States. Injuries caused by animal attacks result in thousands of fatalities worldwide every year. "Unprovoked attacks occur when the animal approaches and attacks a person(s) who is the principal attractant, for example, predation on humans ..." All causes of death are reported to the Centers for Disease Control and Prevention each year. Medical injury codes are used to identify specific cases. The World Health Organization uses identical coding, though it is unclear whether all countries keep track of animal-related fatalities. Though animals, excluding some tigers, do not regularly hunt humans, there is concern that these incidents are "bad for many species 'public image'."

The impala or rooibok (Aepyceros melampus, lit. 'black-footed high-horn' in Ancient Greek) is a medium-sized antelope found in eastern and southern Africa. The only extant member of the genus Aepyceros, and tribe Aepycerotini, it was first described to Europeans by German zoologist Hinrich Lichtenstein in 1812. Two subspecies are recognised—the grassland-dwelling common impala (sometimes referred to as the Kenyan impala), and the larger and darker black-faced impala, which lives in slightly more arid, scrubland environments. The impala reaches 70–92 cm (28–36 in) at the shoulder and weighs 40–65 kg (88–143 lb). It features a glossy, reddish brown coat. The male's slender, lyre-shaped horns are 45–92 cm (18–36 in) long.

Active mainly during the day, the impala may be gregarious or territorial depending upon the climate and geography. Three distinct social groups can be observed: the territorial males, bachelor herds and female herds. The impala is known for two characteristic leaps that constitute an anti-predator strategy. Browsers as well as grazers, impala feed on monocots, dicots, forbs, fruits and acacia pods (whenever available). An annual, three-week-long rut takes place toward the end of the wet season, typically in May. Rutting males fight over dominance, and the victorious male courts females in oestrus. Gestation lasts six to seven months, following which a single calf is born and immediately concealed in cover. Calves are suckled for four to six months; young males—forced out of the all-female groups—join bachelor herds, while females may stay back.

The estrous cycle (from Latin oestrus 'frenzy', originally from Ancient Greek οἶστρος (oîstros) 'gadfly') is a set of recurring physiological changes induced by reproductive hormones in females of mammalian subclass Theria. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by pregnancies. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species. Some animals may display bloody vaginal discharge, often mistaken for menstruation. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called rut.

The muskox (Ovibos moschatus) is a hoofed mammal of the family Bovidae. Native to the Arctic, it is noted for its thick coat and for the strong odor emitted by males during the seasonal rut, from which its name derives. This musky odor has the effect of attracting females during mating season. Its Inuktitut name "umingmak" translates to "the bearded one".

Its Woods Cree names "mâthi-môs" and "mâthi-mostos" translate to "ugly moose" and "ugly bison", respectively. In historic times, muskoxen primarily lived in Greenland and the Canadian Arctic of the Northwest Territories and Nunavut. They were formerly present in Eurasia, with their youngest natural records in the region dating to around 2,700 years ago, with reintroduced populations in the American state of Alaska, the Canadian territory of Yukon, and Siberia, and an introduced population in Norway, part of which emigrated to Sweden, where a small population now lives.