Bullfinch © Steve Round
Bullfinches were reported from 484 tetrads in winter, with 364 tetrads occupied in both seasons, 120 in winter only and 68 in the breeding season only. The winter distribution appears to fill in most of the gaps from the breeding season, and some birds move out of breeding areas into farmland for winter (Brown & Grice 2005). The main changes in recorded habitats from the breeding season are significant drops in birds in woodland and scrub, with large increases on farmland and human sites. The number of tetrads recording birds in hedges doubled between the two seasons, and there were half as many again in human sites: Bullfinches were recorded quite frequently as visitors to bird-feeders in gardens or nature reserves. They do not gather into large flocks like some other seed-eating birds, and most counts were of one or two birds, which is how Bullfinches normally spend their lives. Many observers reported seeing male and female together, and Bullfinches appear to pair for life (Newton 1993). Birds may gather together at favoured feeding locations, and fieldworkers reported groups of 8-12 birds in nine tetrads, but they usually arrive and depart from different directions and seldom stay in flocks (BTO Winter Atlas).
Through the winter, Bullfinches eat whichever seeds they can find, initially those of nettle, birch and rowan, and later those of bramble, dock and ash; in upland areas, they eat heather seeds. Weeds in large fields are not important to them, because the Bullfinch does not forage far from hedgerows and woods, but they do eat seed-bearing weeds in field margins. Where it is available, ash forms a major winter food, but Bullfinches are selective and feed from some trees and not others, choosing those with a lower concentration of the bitter, poisonous phenols and higher fat contents (Newton 1993). As the seed supplies are not replenished during the winter, the size of the initial crops, and the rate at which they are depleted, influence the date when they run out, and Bullfinches have to switch from seeds to buds. Their well-known ability to digest cellulose from buds is a life-saver for the birds, but brings them into conflict with man in gardens and fruit-growing areas. Their favourites include blackthorn, hawthorn and crab apple amongst wild species, with cultivated pear and apple trees.
The winter population comprises mostly the same birds as breed here, as Bullfinches seldom move more than a few kilometres. Occasional influxes of birds from Scandinavia – distinguished by their loud ‘trumpet’ calls rather than the thin piping of the British birds – are usually confined to northern Britain and make no difference to the Cheshire and Wirral numbers. Detailed studies have revealed that individuals may remain for weeks or months within a short distance of a good food source, before suddenly moving to a new site that may be several kilometres away (Migration Atlas). This behaviour could account for movements of two local birds. A bird ringed as a nestling at Frankby, Wirral (SJ28M) in June 1986 and retrapped there as a breeding male in June 1988 was found dead in Staffordshire, 74 km away, in January 1989; and another ringed at Woolston (SJ68P) in 1986 as an adult male, and retrapped there in August 1987, was caught in winter 1990 at Aston (SJ57P), 13km away.
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