The bulls are in perfect condition and they are growing more belligerent each day. It is breeding season. The noise and fury of the breeding season lasts for just two weeks in the summer, but its an interesting two weeks at that. It occurs in the summer because at this time, all of the females come into heat. This timing also assures that the buffalo calves will be born in the spring, when there is plenty of grass for it and its mother.
When a bull enters the herd, he selects a female in heat. The bulls are exceptionally good at determine which cows are ready, but the cows play hard to get… thus, the bull develops a strategy: He doesn’t leave her sight and remains within one and a half meters of her as he patiently waits for her permission to mate; it is the cow’s decision whether or not to accept him. The bull can spend up to three days following her around, so obsessed by tending to his selected cow and scaring of other males that he rarely stops to eat. During the rut a courting bull can lose up to 90 kilograms. A dominant bull reinforces his superiority with aggressive signals, his tail goes up, he bellows he paws and he wallows in the dirt. The buffalo is polygamous, and so his obsession with one cow fades away and he goes off in search of another. When the threatening postures don’t work, the bulls resort to fighting. All of this is also important for the cow, for it is her job to ensure that her mating partner is the best choice for fathering her calves.
Surprisingly, It’s also this time of year that the buffalo encounter another nomadic animal, the tourist. So many people don’t understand however that the buffalo can be a dangerous animal, and especially during breeding season. With one flip of the head, they can run their horns through your body, crush your chest, or toss you around. There are more injuries each year by buffalo in Yellowstone than by any other animals in the park. They may seem like huge lumbering lawn mowers but they are not, they are nimble and fast and can be very aggressive.