Hawfinch

In the 18th century, the hawfinch was recorded as only a rare winter visitor in Britain. The first breeding record was early in the 19th century; by the early 1830s, a well-documented colony was established at Epping Forest in Essex, and breeding was also recorded in other counties east and south of London. Further expansion of the range continued through the 19th and 20th centuries, with breeding occurring as far north as Aberdeenshire by 1968–1972. Peak numbers were in the period 1983–1990. Subsequently, there has been a significant decline of between 37% and 45% between 1990–1999.[14][15][16][17]

Southeastern England is the stronghold of the hawfinch in Britain. One well-known site is Bedgebury Pinetum, where flocks gather to roost in winter. The species is also found in the New Forest; a central roost site exists here, at the Blackwater Arboretum. The only Sussex stronghold is at Westdean Woods in West Sussex, while in Surrey they are regularly seen at Bookham Common in winter. Formerly, hawfinches were regularly encountered in the Windsor Great Park area in winter, though no sizeable gatherings have been reported since the mid-1990s. The recent (2007–11) BTO Bird Atlas shows no evidence of the hawfinch breeding anywhere in this area; the reasons why are unclear.

In Devon (southwestern England), the hawfinch is largely confined to the upper Teign Valley. In western England and Wales, two areas in which hawfinches reliably occur are the Forest of Dean and the Wyre Forest. In Eastern England, the hawfinch is present in the Breckland of East Anglia. In northern England, hawfinches are regularly found in a small number of locations. Prime sites include Fountains Abbey in Yorkshire and Hulne Park in Northumberland. Hawfinches can be seen at Cromford Derbyshire near the canal and at Clumber Park (Nottinghamshire) near the chapel. In Scotland, Scone Palace near Perth is the most well-known site in Scotland for hawfinches. Formerly, they also occurred in the Royal Botanic Garden Edinburgh. In Ireland, they are an annual winter visitor in small numbers: they are most often seen at Curraghchase Forest Park in County Limerick, where a flock of between 15 and 30 birds occurs each winter. A few birds also turn up in Dublin most years.

Coccothraustes coccothraustes eggs

Hawfinches first breed when they are 1 year old.[18] They are monogamous, with a pair-bond that sometimes persists from one year to the next. Pair-formation takes place before the breakup of the wintering flocks.[19] The date for breeding is dependent on the spring temperature and is earlier in southwest Europe and later in the northeast. In Britain, most clutches are laid between late April and late June.[12]

Hawfinches engage in an elaborate series of courtship routines. The two birds stand apart facing one another and reach out to touch their bills. The male displays to the female by standing erect, puffing out the feathers on his head, neck and chest and allowing his wings to droop forward. He then makes a deep bow. The male will also lower a wing and move it in a semi-circular arc, revealing his wing bars and modified wing feathers.[20]

The breeding pairs are usually solitary, but they occasionally breed in loose groups.[19] The nest is normally located high in a tree on a horizontal branch with easy access from the air.[18] The male chooses the site of the nest and builds a layer of dry twigs. After a few days, the female takes over.[21] The nest is untidy and is formed of a bulky twig base and a shallow cup lined with roots, grasses and lichens.[22] The eggs are laid in early morning at daily intervals.[18] The clutch is normally 4–5 eggs.[22] There is considerable variable in the colour and shape of the eggs.[18] They have purple brown and pale grey squiggles on a background that can be buff, grey-green or pale blueish.[22] The average size is 24.1 mm × 17.5 mm (0.95 in × 0.69 in) with a calculated weight of 3.89 g (0.137 oz).[18] The eggs are incubated for 11–13 days by the female.[18] The nestlings are fed by both parents, who regurgitate seeds but also bring mouthfuls of caterpillars.[23] Initially, the male normally passes the food to the female who feeds the chicks, but as they grow bigger both adults feed them directly.[18] The female broods the chicks while they are in the nest.[18] They fledge after 12–14 days and the young birds become independent of their parents around 30 days later.[22] The parents generally only raise a single brood each year.[18]

The hawfinch is highly unusual among cardueline finches in that the male bird chooses the nest site and starts the construction. In other species the female performs these roles.[24] The hawfinch is also unusual in that the nest is kept clean by the parents removing the faecal sacs of the nestlings right up to the time when the chicks fledge. This behaviour is shared by the Eurasian bullfinch, but most finches cease to remove the faecal material after the first few days.[25]

The annual survival rate is not known.[26] The maximum age obtained from ring-recovery data is 12 years and 7 months for a bird in Germany.[27]

The hawfinch feeds primarily on hard seeds from trees, as well as fruit seeds, which it obtains with the help of its strong beak with accompanying jaw muscles. Its jaw muscles exert a force equivalent to a load of approximately 30–48 kg. Thus it can break through the seeds of cherries and plums. Other common sources of food include pine seeds, berries, sprouts and the occasional caterpillar and beetle. They can also break through olive seeds. The bird is known to eat in groups, especially during the winter.

Its flight is quick and its trajectory is straight over short distances. During long flights periodical undulations can be observed in their flight pattern. While on the ground scavenging it hops, and they are quick to fly away at the slightest noise. They are observed to catch insects mid-flight. They fly up to a height of 200 m and they are seen to fly in groups, as well as alone.

The hawfinch is a partial migrant, with northern flocks migrating towards the South during the winter, as shown by ringing techniques. These same studies showed that those hawfinches inhabiting habitats with a temperate climate would often have sedentary behaviour. A few migrants from northern Europe reach Britain in autumn and some are seen on the Northern Isles in spring.