The BTO winter atlas showed that Pheasants were present in most 10km squares during the winters of 1981-82, 1982-82 and 1983-84.
The darker the colour, the higher the relative total count for each 10km square. The darkest blue represents over 9-33 birds seen in a day. Releases of birds reared for shooting varies year by year, so the map represents a snapshot limited to the winters in which the survey was conducted.
Graham Rees