In the wild, you can often find animals wandering around alone. 99% of the time, this will be a male. Most male mammals have to leave their birth group once they become sexually mature. Nature created this rule, to prevent inbreeding. These young males must then live alone, and some species will form bachelor groups. Elephants, buffalo, lion, Kudu and basically most mammals follow this rule.
Why male animals often live a solo life
Sometimes, the single males are the strong territorial males that herd females into or around his territory, and sometimes it is a very old or very young male on his way to a bachelor herd. In these bachelor groups, the boys will practice fighting in preparation of the day that they have to fight for real. Males will fight for a proper spot in the hierarchy or a territory and off course the right to mate. This is also the reason why in some antelope, only males have horns. The horns are their weapons, where females don’t really need them.
Some male animals however do not have to live alone and will form coalitions with their brothers. Lion and Cheetah for example will live with their brothers forever. Coalitions can consist of up to five brothers, but they are not at all equal. There will be a dominant brother who takes charge when it comes to hunting and mating.
Female animals can also be seen alone. Female Leopard, Cheetah, Rhino, and some Giraffe, and a small amount of other species are not very family orientated and prefer a life of solitude.