Male elk, or bulls, are the only ones that have antlers. They begin growing in the spring and fall off, or shed, each winter.
While growing, the antlers are covered with a soft layer of skin called "velvet," which is shed in the summer. Bull elk can sometimes be seen lowering their heads and knocking antlers, an activity that allows them to compete for the attentions of cows and build strength.
This behavior usually occurs during the mating season, or rut, which takes place in the fall. During the rut, bulls experience a dramatic increase in testosterone, making the more aggressive and likely to exhibit dominant behavior. Males will try to attract more than one female, and particularly dominant males in their prime of 6 to 8 years old, may have a harem of 20 or even 40 cows. The elk rut can be several weeks long, and bulls are so excited they forget to eat. Females are pregnant for days and deliver one baby in the spring.
Newborn elk are very well developed, and stand within about 30 minutes of birth. But during the first week of life, they spend most of their time lying quietly in tall grass or woods. They are light red in color with white spots sprinkled across their coats to help them hide. Baby elk will lay still in the woods while their mother feeds, and their spotted coats echo the dappling of the sun through the trees.
They are instinctively quiet, and perfectly still when approached by anyone other than their mother. The newborn has no scent, and can't be detected by predators, so the mother actually stays a few yards away, coming close to nurse, but generally observing from a distance, for the first week or so. By two weeks old, the mother returns to the herd with her new calf.
The elk calf will be weaned in two months, and loses its spots in about six months. The herd is mostly mothers with new babies, yearlings, and older females that did not breed.
They will maintain the calves in little nursery groups, where all adults keep an eye on the youngsters. They are vocal in these groups, communicating with eachother with grunts and squeaks, and they will join together and take on predators, including wolves and grizzlies, if calves are threatened.
The herd will surround the babies, and will strike out with their forelimbs at anything that poses a threat. One well-placed kick can kill a full grown wolf, and if the herd is truly brave and vigilant, they may drive off even the most fearsome threat. Most male deer, and some females, grow, shed, and re-grow antlers on a yearly basis. Antlers are sometimes mistakenly called "horns", but antlers are structurally completely different from horns.
Cows and antelopes grow horns, which are made of keratin, the same stuff as hair and nails. Horns don't fall off, they continue to grow throughout the life of the animal, and in most cases, both males and females grow them.
Antlers are actually made of bone, fall off and are regrown each year, and are usually only found on the males of the species. Antlers grow from two round surfaces of bone called pedecils, that are part of the skull. Hormones triggered by seasonal changes start growing in the spring. They begin when the male has low, not high, levels of testosterone, presumably to focus energy on their growth, and insure that the animals are calm and not combative.
While the antlers are growing they are soft and spongy and can be easily damaged, so males are careful with their movements. Antlers are the fastest growing tissue known in mammals , and each spine of the antler may grow at a rate of half an inch a day. The growing antler is a pulpy tissue filled with nerves and blood vessels.
It is covered with blood-filled, hairy skin called velvet. Weirdest of all elk facts is that while the antler tissue is growing, it can actually be grafted to any part of the elks body, and it would continue to grow. The entire body is dedicated to this remarkable process. By late summer the testosterone level begins to rise, the antler calcifies into solid bone, the velvet dries up and falls off, and the full, pointed rack appears, ready for some jousting action.
An intriguing feature of elk antlers, is how much they look like tree limbs They may also use their antlers males and sharp hooves to protect themselves. During most of the year there is no competition for food between deer and elk, because they are using different eating strategies which include different plants or different parts of the same plant.
However, in winter, the peaceful coexistence scenario shifts. In winter, elk become browsers. Elk are some of the most important and influential animals in the Greater Yellowstone Ecosystem. Elk have shaped the environment of the park, affecting plant growth, influencing the materials beavers use to build dams, and even impacting stream temperatures.
Though they might not appear threatening, elk can be aggressive and attack without warning. In the spring calving season May — June female elk aggressively defend their young.
During the fall mating season Aug — Sept , male elk are particularly belligerent. Do not approach elk in any season as they are dangerous. Predators of elk include mountain lions, gray wolves, and bears.
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