Why do giraffes have long necks?

A giraffe’s neck can be about 2 metres long and weigh over 200 kilograms, yet it has the same number of neck vertebrae as a human: seven. The classic explanation is that longer necks let giraffes browse leaves out of reach of competitors, especially acacia leaves. Another theory, “necks for sex”, points out that males swing their necks and heads like clubs in battles called necking, and heavier-necked males tend to win. A 2022 study of a fossil giraffe relative with a thick skull suggested head-butting contests may have helped drive neck evolution. Both feeding and fighting likely played a role.