90 The Essex Naturalist Background Fallow deer have four main colour varieties - common, menil (pale common), white and black. The deer traditionally associated with Epping Forest are of the black variety. Their distinctive colour and their presence so close to London suggest they qualify as a flagship species. Yen (1993) describes flagship species as "popular, charismatic species that serve as symbols and rallying points to stimulate conservation awareness and action". Heywood and Watson (1995) state they can also provide a highly visible reminder of the progress of a particular management plan. Part of the current management of the deer in the forest aims to limit the movement of the deer from the forest into the bufferlands and other surrounding farmlands. There are currently two principal theories adopted by the Corporation of London as to why the deer are leaving the forest: (i) Human visitor pressure is pushing the deer into quieter areas and forcing them to abandon their traditional forest habitat (ii) The quality of grazing within the forest has decreased, due to scrub encroachment and altered land management such as much less coppicing. Preliminary investigations concerning these theories caused us to believe that the reasons behind the movement of the deer out of the forest were different or more complex. We grouped the two theories proposed above as the historical hypothesis and generated a second theoretical framework, the behavioural hypothesis, based on observations of how the fallow deer of Epping Forest are currently behaving. From interviews with relevant Corporation of London staff it is clear that the current deer management strategy is largely based on the historical hypothesis. Both the historical and behavioural hypotheses are expanded below. The historical hypothesis (as defined here) states : • Epping Forest has a discrete herd of fallow deer, the "forest deer". • The forest is the historical, natural and optimum habitat of these deer. • The original forest herd was of the black variety • It is desirable to keep the forest deer black and prevent them breeding with common fallow • The deer are gradually moving north through the forest due to increasing visitor pressure and decreases in the area of grassy swards The behavioural hypothesis states : • The concept of the "Epping Forest deer" is no longer correct. A better concept for the modern situation is that of the Essex deer - a dynamic and fluctuating population with a fluid proportion of deer to be found at any one time in the forest.