The males might butt heads or use their horns. Once the female agrees to mate, the pair mates several times. The cows female bison are pregnant throughout the fall, winter, and early spring. The calves are born in mid-spring to increase the likelihood of surviving the next winter.
Most cows only have one offspring. Each calf weighs about 50 pounds 23 kilograms and has reddish fur. Within an hour after birth the calf stands and, soon after, begins to walk. The cows will care for their young for about a year—however, the calves learn to be independent pretty quickly. By the middle of their first winter, juvenile bison are feeding independently and have the typical brown fur of the adults. It will be two to three years for the females, and upward of six years for the males, until they can breed themselves.
Winter can be very hard on bison. The cold and lack of food can take its toll, especially if the bison is sick, injured, young or old. Very young bison have the highest risk of dying over the winter. The average bison that survives to adulthood can live around 20 years. Captive-raised bison typically live longer. Bison once dominated the grassland and prairie ecosystems of the United States.
When the first explorers came to the Great Plains, it is estimated that at least 30 million bison roamed the land. By , a little over a thousand bison could be found with only a handful of wild bison left in Yellowstone National Park. Their numbers dwindled because, even with speeds of more than 30 miles 48 kilometers an hour, bison could not outrun hunters.
Some bison were killed for food, but often they were killed in large numbers just for fun. In addition, starting after the Civil War, bison were exterminated to make way for farmland as people settled the Great Plains. The s brought a change of fortune to the bison. Nearly species of grasslands birds, for example, evolved in some part to adapt to the nature of the environment created by the hoof print of bison upon the land.
One other factor had a major influence on this symbiotic relationship: Predators. The open prairies offered prey animals with little opportunity to hide from predators. To survey, bison evolved as herd animals, where large numbers afforded the best means of defense. Large, tightly-packed units of animals moved quickly across the land. Grasslands, thus evolved to thrive under conditions of short periods of severe grazing, hoof action, and manuring, followed by periods of rest and recovery.
This helps the ground increase surface water retention, most notably during the rainy seasons. After heavy rains, you can find temporary pools of water form in such places and, subsequently, various wetland species. Even after the ponds have dried out, some new plant species emerge, which are drought resistant.
When a bison dies, they are a source of food for scavengers and some predators. If the body decays, it provides a wealth of nutrients that go back into the soil. This makes the land more suitable to support the growth of healthy vegetation. The patchy grazing habit of the bison also encourages plant diversity. The plants that grow offer new habitats to many grassland birds.
The bison maintains not only a healthy ecosystem but also a balanced one. Some birds, such as the magpie, ride on top of the bison to feed on insects found in their fur. Prairie dogs are primarily herbivores. They contribute to a healthy ecosystem by providing shelter to several other animals. Prairie dogs are also the primary source of food for the black-footed ferret. Without prairie dogs, there would not be enough food to sustain them.
Animals such as the black-footed ferret would significantly reduce in numbers and be on the brink of extinction. There is a connection between prairie dogs and bison.
Prairie dogs feed mainly on the short grasses within their range. Want to know how wolverines survive? Find out more in this article I wrote. The most significant impact of the bison on the prairie dog ecosystem is through their grazing. The bison like to graze in large patches, which they revisit throughout the season. This means that there would typically be areas that have been grazed and those that have been left. Black-tailed prairie dogs will generally use areas that have been heavily grazed to dig their burrows.
There is also a natural soil disturbance that occurs when bison graze. The grazing makes the soil loose enough for the prairies dogs to dig their burrows. During the 19th century, settlers killed some 50 million bison for food, sport, and to deprive Native Americans of their most important natural asset. The once enormous herds were reduced to only a few hundred animals. Today, bison numbers have rebounded somewhat, and about , bison live on preserves and ranches where they are raised for their meat.
All rights reserved. Common Name: American bison. Scientific Name: Bison bison. Type: Mammals. Diet: Herbivore. Group Name: Herd. Size: Head and body: 7 to Weight: to 2, pounds. Size relative to a 6-ft man:. Near threatened. Least Concern Extinct.
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