Six species of deer are living wild in Great Britain: Scottish red deer, roe deer, fallow deer, sika deer, Reeves's muntjac, and Chinese water deer. Of those, Scottish red and roe deer are native and have lived in the isles throughout the Holocene. Fallow deer have been reintroduced twice, by the Romans and the Normans, after dying out in the last ice age. The other three are escaped or released alien species.