Raven - 1980s winter atlas

The BTO winter atlas showed that Ravens 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 74 birds seen in a day.

The largest roost recorded during this period contained 160 birds.

Graham Rees