This bull is about 20 years old. Though sexually mature at this age, he is about half the size of the older males and cannot begin to compete with them for access to females. In natural populations the many older, larger and more experienced bulls will prevent the younger ones from stealing their mate. Also, the females prefer the older bulls. It's not until they reach their mid 30s that bulls become successful breeders. Until then, they spend much of their time in small groups of other young males, engaging in good-natured sparring. This helps them learn their own strength, build knowledge and develop the skill set they will need as mature bulls.