This is a complementary graphic to the one in the previous post. It shows the number of species missing from each square. A species is counted as missing for a square if it has been found in more than 50% of adjacent squares.
It is noticeable that some squares have excellent coverage with 0 species needed while ones immediately next door have poor coverage. A good example is TF05 at Scopwick where 28 species could be added while TF16, Martin, next door has 0 species to be added.
So if your local square is saturated why not get out and about and look next door?