Baby animal season in the Greater Yellowstone Ecosystem is a joyful time for wildlife viewing. Buckrail photographer Nick Sulzer came across a bison herd that recently has added a few fluffy new members to its ranks.

Bison Calves: A New Generation

Bison calves are known as ‘red dogs’ for their reddish-brown newborn coats. They tend to turn darker brown by the end of summer, according to the National Park Service. Born weighing up to 70 pounds, the calves can keep up with the herd two to three hours after birth. They are well-protected by members of the herd, staying with their mothers for the first year of their lives.

With a life expectancy of about 15 to 20 years, female bison, called cows, have one calf per year and mate during the rut season, which lasts from July to August each year. The gestation period is about nine to nine and a half months. The red-orange coat of a young bison stands out in contrast to their green grazing grounds, making them easy to spot in the dark herd.

Remember to give bison plenty of space, especially when calves are present; parents can become extra defensive.

Original reporting: Buckrail (Jackson WY) — read the source article.