Are there more mares than stallions in a herd?

Yes. Typically in any wild herd there is only one stallion with a harem comprising of 10 to sometimes 50 mares. The only other stallions that could be found in this herd are those young male horses that are too young to be ready to breed any females; these are called colts. Once they have reached sexual maturity or are old enough to leave their mothers, the dominating stallion will chase them away.

There are also herds of stallions, often called bachelor herds, which mainly comprise of young teenage-like stallions that don't have their own females to guard and mate yet. Sometimes there may be an older stallion or two with them, depending on whether that old stallion has been replaced by a younger and stronger male.