Characteristics and Behavior
Bison is known as the largest land animal in North America. The average bull weighs about 2000 lbs. and stands about 6′ tall at about 5-6 years of age but there have been recordings of 3500 lb. bulls that stood 7′ tall. Females, known as cows, will only average around 1000 lbs. and stand about a foot shorter.
They are still very large and fast. Average speed is 25-30mph and they can run a sustained pace for hours because of the large windpipe that can exchange a large volume of air in and out of the lungs. They are also very quick and can jump objects 6′ or more in height.
Bison seem to be very sensitive to environmental conditions, for example, if there has been a drought, there is a likelihood that many bison cows won’t breed. Normally, cows lose 10-15% of their body weight over the winter, which can be a good thing as it allows for less trouble during calving. Once the calf is born, and a supply of good green grass is available, the cow will add back the pounds very quickly. This is good for the new calf because of the good milk production from the mother, as well as the potential for the cow to breed again. With good nutritional management of the herd, either natural or supplemental, it’s not unusual to have close to 90% breeding rates.
While the bison of “yesteryear” have managed for thousands of years in balancing their diets, today’s bison may have limitations, based on smaller ranges. Even though there may be minerals existing in the soil and therefore the plants and grasses, certain necessary minerals in the water they drink may be lacking. Moving from pasture to pasture and sometimes a free-choice salt block is very helpful in supplementing the minerals required.
Bison are also masters at reading body language. They have had thousands of years to perfect it, and they feel what you feel. When near them move with purpose and never faster than needed or slower than necessary. Movement should show confidence, courage, perfect timing and an understanding of how bison think while associating kindness and consideration for their excitable herd nature.