Late spring is the time for new arrivals in Rocky Mountain National Park. In some cases, such as antelope, the new arrivals are accidental visitors. In other cases they are new babies.
Moose calves (Alces alces shirasi) may arrive as early as the first week of June. Moose were occasional visitors to Colorado in historic times. Starting in 1978 the Colorado Division of Wildlife introduced moose into North Park, Colorado. Since then, populations have expanded into Rocky Mountain National Park. Calves arrive in early June. Moose cows usually have one calf, although between 11 to 29% of the births are twins, and rarely triplets are born.
Elk calves (Cervus elaphus canadensis) are seen on both sides of the park. Most calves arrive in late May or early June. However, depending on when the cows were bred, calves can be born throughout most of the summer.
Appealing as they are, please remember to keep a safe distance away from baby animals. Moose are very large (850 to 1100 pounds), cranky, and unpredictable animals. Elk, while not quite as large (500 to 1000 pounds), can be equally aggressive when protecting calves. Both moose and elk, when protecting their young, can severely injure or kill a human they mistake for a predator. If you happen upon a calf in hiding, you are strongly advised to leave the area immediately to avoid a dangerous encounter.
Pronghorns (Antilocapra americana) are accidental visitors to the park. They have been seen in the recent past by several park visitors and staff in the Grand Lake Entrance- Harbison Meadows area. There had been no previous reports of pronghorns in the park since it was created in 1915. Anecdotal information suggests pronghorns may be visiting the park more frequently than in the recent past as a result of increasing populations of pronghorns west of the park expanding into new habitats.