Roaring by red deer stags advances the date of oestrus in hinds

Abstract

Some male mammals call loudly and repeatedly during the breeding season^1–5. Although the song of male birds is known to have effects on male–male competition⁶, mate selection and ovulation^8–14, until now the loud calls of male mammals have been shown to affect only competition between males^1,15. Although it has been suggested that loud calling could also serve to attract females^16,17, the possibility that it has a direct effect on reproduction in females has not previously been investigated for any mammal. Here I report that roaring in red deer (Cervus elaphus) advances ovulation and that harem-holding males can improve their mating success by regular calling.