Yellowstone Bison

 Yellowstone is the only place in the lower 48 states of the US where bison have roamed continually. Over 3000 bison roam the park. They are divided into two group or herds, the northern herd and the Hayden Valley or central herd. The Yellowstone bison are pure bison with no cattle genes. They are descendant from the small herd that continued on and was protected in Yellowstone.

Ungulate

 Ungulates are large mammals which support their weight on the tips of their hoofs when they walk. Yellowstone is filled with ungulates. There are several members of the deer family including elk and moose and the largest ungulate in North America the bison. At one time there was estimated to be over 50 million bison that roamed North America but they were hunted by the early European settlers until they were almost extinct.

The bison herds of Yellowstone are protected from hunters. Grizzly Bears and wolves occasionally take calves, the sick and old. The main thing attacking bison in Yellowstone are fleas, flies, ticks and other pests. In the top photo a dust bath on the prairie helps to remove some of the parasites. If that does not work you might be able to get an occasional hitch hiker to help out. Birds such as cowbirds and European starling, above, often ride around on the back of the bison and pick off insects. This is a symbiotic relationship which provides food for the birds and some relief from the bison.

A Future Return to Yellowstone

 I am looking forward to going back to Yellowstone National Park next month. For many people like myself, who fall in love with the park, it is hard to be away for long. Its been almost two years now since we have been there.

The last time that we were there was in 2011. That year winter held out late into the spring and a lot of the park was still buried under the snow. This is a shot of me in front of one of the snow drifts along the side of the road in Hayden Valley. I am over six feet tall and that drift was twice at tall as I was.

Late spring in Yellowstone have typically been better for us for getting pictures. Since most of upper elevations are still covered the wildlife comes down to the lower elevations which is where most of the roads are. During our two snowy spring trips to Yellowstone in 2009 and 2011 is the only time that we have got a chance to see wolves up close. I was hoping that this year would be a repeat, since winter has been hanging on around here but I connected to the Yellowstone forums this week to see what people were seeing and many of the pictures that have been posted show very little snow. either way I am sure that we will have a good time. It is hard not to at a wonderful place like Yellowstone.

Yellowstone - Bison

 Bison are the largest land mammal in North America. Males can weigh over 1,800 pounds and females over 1000. At one time there were over 30 million bison roaming the western plains of North America. Then in the 1800's European settlers began to slaughter the bison herds in order to make room for farms, cattle and horse grazing and the railroads. By the early 1900's the bison herds which once numbered over 30 million were down to several hundred.

 Yellowstone National Park is the only place in the lower 48 states of the US where a population of wild bison have continued to exist. In 1902 the bison population in the park dropped to a low of 50 animals. At that point the park imported 21 bison from private herds and began to captively raise them at the Buffalo Ranch in the Lamar Valley.  By the 1920 the captive raised bison began to mix with the wild herd. In the 1930's bison were transplanted into the Hayden Valley and around the Firehole River. By 1954 the Yellowstone Bison population was close to 1500 animals.

Today around 3,500 bison roam Yellowstone. Typically you find them in open valleys, such as Hayden Valley and Lamar Valley but you can find them almost any where, including crossing bridges as in the pic above. During the winter they usually stay near the thermal areas of the park where the snow is not as deep. They use their large heads, swaying them from side to side, to clear the snow and get at the grasses below. Winter is hardest on pregnant females who carry the calf over the winter. Breeding takes place in July and August and the calves are born in April and May. We usually visit the park late in May so their are plenty of calves frolicking in the fields or snoozing curled up next to mom.