Species league tables

The 'league tables' of species in this Atlas, and comparisons with our First Atlas for breeding species, make interesting reading.

The most widespread breeding species obviously are those with catholic habitat preferences (Table 1). Thirteen species are found in the breeding season in 95% of the county's tetrads, and 21 species in 90% of the tetrads. The top thirty are mainly passerines, making up nine of the top ten (the only non-passerine being Woodpigeon), and 17 of the top twenty (with Mallard and Collared Dove as the other non-passerines). The vast majority are land-birds, plus the two aquatic species that utilize almost any waterbody, Mallard and Moorhen. Nearly all are residents, with just four summer migrants in the list. The ranking of the top twenty summer visitors is shown in detail in Table 7.

Table 2 shows that almost all of the top thirty most widespread wintering species are residents, although the local population may be augmented by continental immigrants, with only Redwing (nineteenth) and Fieldfare (twenty-sixth) exclusively winter visitors. There are few significant changes in position between the lists for breeding and wintering seasons.

Comparing the rankings for abundance with those for distribution (Table 3), in general, colonial breeding species are placed higher on the abundance ranking— House Sparrow, Starling, Jackdaw, Linnet, Feral Pigeonand Rook, but not Swallow or House Martin—indicating that they are not widespread but are numerous where they occur. Most of the larger birds are lower in rank order for abundance—Woodpigeon, Carrion Crow and Magpie—as they are conspicuous and widespread but space themselves at lower densities than most smaller birds.