Last updated on March 16, 2014 at 0:04 EDT

Rocky Mountain elk


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 gestation period for a cow is around 8 Â½ 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.


Elk habitat and food





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