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Rocky Mountain elk

Contrary to popular belief, the Rocky Mountain elk was not an animal of the plains that retreated to the mountains because of the encroachment of man. Elk always lived in the Rocky Mountains. Rocky Mountain elk currently inhabit the Rocky Mountains from central British Columbia and Alberta through Idaho, Montana, eastern Washington, eastern Oregon, northeastern Nevada, Utah, Arizona, New Mexico, Colorado, Wyoming, the western portions of North and South Dakota. There are scattered populations of transplanted animals in many other states; western Nebraska, northeast Minnesota and northern Michigan among them. The current North American elk population is about 800,000. The largest herd of elk lives in Yellowstone National Park. It consists of about 30,000 elk the gather together from about 7 herds to spend the summer.

Rocky Mountain elk bulls weigh 700-800 lb (300-370 kg) and cows 450-550 lb (200-250 kg). Bulls may stand five feet at the shoulder, with legs three feet long and body lengths of eight feet. Their coloration is generally tan with dark brown legs, neck, head and belly, with a buff colored rump. Bulls may be lighter colored than cows, appearing silver at times. White and silver colored animals do not appear in the wild. Antlers of mature bulls usually have six or more points per side with main beam lengths of 5 ft (1.5 m), inside spreads may reach 48 inches.

Life cycle

The Breeding season for an elk starts in August and goes through October. This time of year for the elk is known as the rut. At the start of the rut a mature bull elk will gather a harem of cows to breed with. He and other bulls will also fight for the leadership of the harem and also over cows so that they can make their harem bigger. An experienced bull may gather a harem of up to 60 cows. And sometimes a bull will let a younger bull join his herd as they move down into the valleys and lower lands for winter.

Young bulls usually will not get a cow to accept them until they are two or three years old so they will hang out with the herd or a larger more mature bull.

The gestation period for a cow is around 8 ½ months. The cows usually give birth to one or more calves in May or June. The newborn calves usually weigh about 30 pounds.

The time of the rut is also when the bull will lose the velvet on his antlers. This will fall off eventually or is helped when the bull attacks a tree when he wants to fight.

The bull usually loses his antlers in the spring. And then starts to regrow them during the summer. Elk live up to 18 years old but the average is between 7 and 10.

Elk habitat and food

In the summer the elk usually graze and live in the high mountains in the forest and deep brush. They will also occasionally wander into some of the high meadows to feed; while keeping close to the cover of the trees for protection.

In the summer they usually graze on grass and small tree sapling and green twigs. When the grass dries they chew on bigger saplings, eat mushrooms, and also eat on berries. Elk generally feed an hour before to an hour after sunset and the same at sunrise. The rest of the day they mainly stay bedded down in heavy cover and sometimes they will move around. And graze a little bit in the middle of day if they feel safe.

In the fall and winter they migrate to the lower valleys and wooded slopes. And they eat dried grass and shrubs. They also eat berries and the bark off of small trees.

In the spring elk begin to migrate back up to the higher lands where the bulls lose their antlers and rest up from the rut. At these times you won’t see a single bull for quite a few months since they are so tired. During this time they eat the fresh grass and chew on young trees and get very fat and the end of the summer is when elk weigh the most.

Rutting behavior

Adult red deer usually stay in single-sex groups for most of the year (males form ‘bachelor herds’, females groups are often matrilineal), coming together to mate during October. During the mating ritual, called the rut, mature stags compete for the attentions of the hinds and will then try to defend hinds that they attract. Rival stags challenge opponents by bellowing and walking in parallel. This allows combatants to assess each other’s antler and body size and fighting prowess. If neither stag backs down a clash of antlers can occur, and stags sometimes sustain serious injuries. Either stag might invite contact during the parallel walking by turning to face his opponent or lowering his antlers but only well-matched stags will fight. Opponents push vigorously, trying to gain advantage of a slope, if present. Fights continue until one stag withdraws and runs off; if one slips, the other will attempt a killing or debilitating attack.

Dominant stags follow groups of hinds during the rut, from August into early winter. The stags may have as many as 50 hinds to keep from other less attractive males. Males spend the summer in bachelor herds, but in late August the mature stags over 5 years old become increasingly intolerant of each other and from mid-September the stag groups fragment; stags move off individually to their traditional rutting grounds. Only mature stags hold harems (groups of hinds) and breeding success peaks at about 8 years of age. Stags 2-4 years old rarely hold harems and spend most of the rut on the periphery of larger harems, as do stags over 11 years old. Young and old stags that do acquire a harem hold it later in the breeding season than those stags in their prime. Harem holding stags rarely feed and lose up to 20% of their body weight. Stags that enter the rut in poor condition are less likely to make it through to the peak conception period.

After the rut the stags (bulls) and hinds (cows) separate. The fawns (calves) are born the following June and are usually weaned by eight months, although they may stay with their mother after this time. Their mothers leave the newborn fawns for long periods in long vegetation; their mothers return at intervals to feed them.

Rocky Mountain elk


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