Research overview: the development and genetics of the lion mane

The lion's mane is a sexually selected ornament whose size and color vary with age, testosterone, climate, and individual condition. This overview surveys what is known about the developmental and hormonal control of mane growth, the heritable component of mane traits, and famous cases such as the maneless lions of Tsavo and the rare maned lionesses, some linked to elevated androgens. It discusses how environmental temperature influences mane expression, why darker manes may signal quality to mates and rivals, and how disentangling genetic from environmental contributions to the mane informs both evolutionary biology and the interpretation of regional lion variation.