When I planned my trip to Yellowstone, the first thing that popped into my mind was seeing Old Faithful. After doing my research, however, I soon discovered that this national park has a treasure trove of wildlife. There is an extensive variety of mammals, birds, fish, reptiles and amphibians that exist within the Greater Yellowstone Ecosystem. Today we are going to get a feel for what is out there.

The story of the American bison in Yellowstone is fascinating. These mammals have persisted in this area since prehistoric times. Only 50 bison, however, were counted in 1902 as this species was threatened with extinction. Due to a revitalization effort by the park, 21 bison were imported from a few privately owned herds which served as a nidus for breeding at the Lamar Buffalo Ranch of Yellowstone. This project spanned 50 years during which time bison were transplanted to natural habitats along the Firehole River and the Hayden Valley. There are now approximately 4,000 of these mammals roaming the park in herds.

Bison are the largest grazing animals within the park. These herbivores are found within grasslands, meadows and forested plateaus and they are large! A male bull can weigh up to 1,800 lbs., and measure six feet tall at the shoulder. Female cows are 1,300 lbs., and are able to mobilize with great speed if their young are threatened. They can live up to 20-25 years.

I discovered through reading that elk are the most abundant large mammal living in Yellowstone. There is evidence that this species has occupied the park for the past 1,000 years. The census of elk was decreasing when the park was established in 1872 due to hunting of large grazing animals. The U.S. Army was able to stem this tide in 1886 when wildlife slaughter was brought under control.

The number of elk in the park varies with the time of year. You can see more than 30,000 of these mammals from 7-8 different herds in the summer. In the winter the numbers decrease to less than 22,000.

You can tell which elk are bulls by their antlers. Males grow them annually from the time they are one year old. A mature rack has up to 8 points or tines on each side, weighing up to 30 lbs. Each year in March or April, the bulls shed their antlers. In May, a bony growth appears on their heads that has a velvet appearance. The process is completed by August at which time the elk can be seen scraping off the velvet by rubbing their antlers against trees. They are now prepared for the mating season, or rut, which begins in autumn. Each bull gathers 20-30 cows into his harem and defends them by locking antlers with other mature males as they attempt to dominate the herd group. What a scene!

It is now time to search for bears. These animals are one of the most sought-after sights in the park. They can also be elusive. There are 2 types to be found: black bears and grizzlies. Grizzly bears are best seen at night, dawn or dusk. You can recognize them by the hump on their upper back, a rump lower than their shoulders, a rough of long fur and long claws. The males are large, ranging between 200-700 lbs. The females are quite a bit smaller, weighing between 200-400 lbs. They have a life span of up to 30 years, and can move fast when they want to at speeds of up to 45 miles per hour.

Black bears are smaller in size. Males range between 210-315 lbs. and females between 135-200 lbs. I discover that Yellowstone is one of the few places south of Canada where black bears and grizzlies coexist.

After spending 5 days in the park, I am blown away by how much there is to see here. I realize that I have just scratched the surface with respect to witnessing the wildlife. As I discovered in the national parks in Kenya, animal sightings are largely a matter of luck. You have to be in the right place at the right time. When it happens, the rewards are fantastic!