The BTO winter atlas showed that Willow Tits were present in the majority of 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 6 birds seen in a day.
The plotted winter distribution was slightly less widespread than that of the breeding season possibly due to a difference in observer effort, as this species is considered to be sedentary.
Graham Rees