The highest population densities occur in areas of arable farmland that still retain pockets of grassland. High densities also occur on coastal grassland at Marshside, Southport where up to 50 pairs per square km are recorded. Breeding populations persist at various sites within the conurbation, principally at Fazakerley and the Rimrose Valley.
The highest population densities occur on arable farmland in Sefton. Together with adjoining areas of West Lancashire, these mosslands support the largest numbers of Grey Partridges in Lancashire with up to 8 pairs per sq. km being recorded. Good numbers are also found in the Rainford area. Smaller populations persist on uncultivated grasslands within the conurbation, notably at Otterspool and the Rimrose Valley.
A small number of species, including House Sparrow, House Martin and Swift, are truly urban in that they breed almost entirely in or on buildings. Starlings are also highly dependent on buildings for nest sites. All these species are believed to be in significant decline but survey difficulties in urban areas have meant that scientific data have been difficult to assemble. However, both House Sparrow and Starling were added to the list of UK BAP Priority Species in 2007 because of their declining populations.
Although still common and widespread, the Song Thrush went into dramatic decline in the mid-1970s with an estimated reduction in numbers of 73% in farmland and 49% in woodland between 1968 and 1993. Overall numbers fell by 50% between 1970 and 2005 but more recently have increased by 17% between 1994 and 2006. The decline is believed to have been more marked in the north of the country.
The Sefton Coast between Blundellsands and Cabin Hill NNR supports densities of up to 37 pairs per square km – amongst the highest known in the UK lowlands. Farmland around Rainford also supports above average densities (up to 8 pairs per square km). Smaller, but still notable densities are found in Speke/Garston, Tarbock and farmland between St. Helens and Kirkby. Small populations persist in urban areas including at Otterspool and the Rimrose Valley.
The magnitude of the local population decline is not known. Certainly, a decline is indicated from the changes in the peak counts of wintering flocks. The North Merseyside population was estimated at 200 pairs in 1997-99.
The species remains widespread on farmland in the area, but in variable densities. Small populations are found on the edge of the conurbation at Speke, Croxteth, Aintree and Netherton. The highest population densities, reaching a maximum of 4-5 pairs per square kilometre, occur on arable farmland in Sefton, Knowsley and St. Helens. This is the southern part of a fairly continuous area of approximately 200 square kilometres of mosslands, most of it outside Merseyside, which holds the largest population of Corn Buntings in North West England, estimated in 1997-99 to total 1200 pairs, 5% to 7.5% of the UK population. The distribution of birds within this area is typically patchy. The highest densities, around Altcar Withins and Little
Crosby, are similar to the highest densities so far recorded in North West Europe. Most of the UK population makes only local movements of a few kilometres between breeding and wintering areas. Therefore, wintering distributions are likely to be similar to breeding distributions on a coarse scale in North Merseyside. There are local re-distributions, for example of birds onto the dunes at Crosby in winter, where there is no breeding population.