While sitting in the kayaks in White Gulch we can hear a beautiful ominous call coming from the surrounding hillsides. The Tule elk are in rut and the bull elk are bugling to attract females to their harem and to ward off potential competing males.
Bulls can be distinguished from the females during the mating season by their antlers. In the spring antlers are covered with velvet, a system of blood vessels that nourish the bone as it grows. A set of elk antlers can weigh over 40 pounds. Older bulls have more points, but they do not grow a point for each year of age. Antlers are used as weapons by the males to compete for the chance to breed. Two evenly matched bulls may use their antlers in combat, if other attempts at intimidation (vocalizations and posturing) have failed.
A bull that has proven himself bigger and stronger than the others defends a harem of up to 30 females. This means he is the primary bull, responsible for 80% of the breeding. Towards the end of the breeding season other secondary bulls may get the opportunity to breed as the primary bull tires.
Males are sexually mature at age two, but usually aren't able to breed until they are strong enough to compete with other bulls to defend a harem of cows. Half the the male population will remain bachelors; most breeding is accomplished by ten percent of the male population.
The Ladies...
Female elk are sexually mature by two years of age, although they may be able to breed as yearlings. Females are gathered into harems by dominant males.
While the males fight for real estate and mating rights to the harem, the females do their own bit of fighting for status within the harem. Almost all female elk will reproduce, having on average, six to ten calves in her lifetime. Calves are born after an 8.5 month gestation period. They nurse for four or five months, but start nibbling on grass when they are less than one month old. The calves remain part of the harem with their mother.
