Saturday, 3 June 2006

Enigmatic falcon graces our skies

When asked to name their favourite bird of prey, many birdwatchers will answer “peregrine falcon”. No doubt they are impressed by the size and power of this aerial hunter. However, for me the peregrine is something of a brute and lacks the grace and enigmatic beauty of the smaller hobby, a migrant raptor that breeds here and winters in Africa. Although arrivals usually begin in May, many individuals will only now be reaching our shores. As a breeding bird, the hobby is elusive and tends to be under-recorded, with the sighting of a single bird being the most typical encounter during the summer months. At this time of the year, however, newly arrived individuals may gather together to feed over insect-rich wetlands and along river corridors. Hickling Broad, Catfield Fen, Strumpshaw and the Hockwold Washes are sites where half a dozen or more individuals may be seen feeding on insects, caught and eaten in flight. Large beetles, dragonflies and butterflies are favoured, most often taken on still warm days. The hobby will also take small birds and is well-known for its ability to catch swallows, martins and swifts on the wing. Given the manoeuvrability of these species, it is no surprise that the hobby is a true master of the air. The long tail and long curve of the wings provide the power and dexterity needed to catch such agile prey. Avian prey is most important when there are hungry young to feed.

It is hard to gauge just how many pairs of hobby breed within Norfolk. There are certainly a number of pairs around Breckland, nesting in the abandoned crow nests that can be found in the taller pines so characteristic of Breckland field boundaries. There are also pairs within Thetford Forest, the Stanford Training Area and around the Broads. The most recent estimate suggests that there are between 10 and 20 pairs breeding annually within the county. Favoured breeding territories tend to be used from one year to the next, although the birds may not, necessarily, use the same nest.

The hobby population seems to have faired well over recent decades and there has been a marked increase in the size of the East Anglian breeding population. During the Nineteenth Century, egg collectors and gamekeepers persecuted the species quite heavily, but conditions are now more favourable. It has been suggested that the increase has been driven by the flooding of old gravel workings and the associated boom in dragonfly populations but this may only be part of the story. Bans on the use of harmful pesticides and recent global warming may also have had a part to play. Whatever the reason, it is us birdwatchers who are reaping the benefits. 

No comments:

Post a Comment