As the third largest mammals in the world, hippos spend the majority of their day in the water, only leaving at night to feed on grass. One of the only times that hippos are seen expending significant amounts of energy during the day are when bachelors challenge the bull for mating rights for all the females. This particular display of aggression only lasted approximately 15 second, but the fighting gets more intense as the territory rights become more essential for survival during the dry season.