Abstract: We measured the energy cost of mate sampling by female pronghorn (Antilocapra americana), a species for which there are no apparent direct benefits of mate choice and for which the sampling ...

Trivers (1972) proposed that females may choose to mate with males of high sexual competence (the ability to supply sufficient sperm for fertilisation). This hypothesis was tested by allowing ewes in ...

When female sheep get the choice, they would rather mate with a subordinate male than a dominant one. Dominant rams usually mate with ewes much more often than lower-ranking rams do. But they can ...