Nicholas Barry Davies FRS[1] (born 1952) is a British field naturalist and zoologist, and Emeritus Professor of Behavioural Ecology at the University of Cambridge,[2] where he is also a Emeritus Fellow of Pembroke College.

[3] His study of a small brown bird, the dunnock, linked detailed behavioural observations of individuals to their reproductive success, using DNA profiles to measure paternity and maternity, and revealed how sexual conflicts gave rise to variable mating systems including: monogamy, polygyny, polyandry and polygynandry.

Other studies include: territory economics in pied wagtails; contest behaviour and mate searching in butterflies and toads; parent-offspring conflict and the transition to independence in young birds.

In 2009, his research was featured as a BBC Natural World program "Cuckoo", produced by Mike Birkhead and narrated by David Attenborough.

[11] In 2017 he appeared in an episode of the BBC Radio 4 Natural Histories series entitled "Cuckoo".