Fallow deer
Fallow deer returned in the 20th century, probably as a result of escapes from the Sackville estate, Buckhurst Park. The population roaming the forest has grown sharply in the last three decades, in common with deer herds elsewhere in England, and they now number in their thousands. Also present are roe deer (the only native deer roaming the forest) and two recently introduced species, muntjac and sika deer.