Girton Birdwatch - September 2008
You might have heard on the news, or read in the paper, that Cattle Egrets have bred for the first time in Somerset. There have been so many of these birds reported from around Cambridgeshire this year that it seems to be only a matter of time before they breed somewhere near here also, given that their close relative, the Little Egret, has been conspicuously successful in this respect over recent years (There were 30 Little Egrets roosting at Fen Drayton on 17th August). The two birds are very easy to tell apart: the Cattle Egret is the smaller bird and from a distance appears more hunched than its elegant 'cousin'. Its legs are shorter as is its neck. The big giveaway, if you get close enough, is that the Cattle Egret has a thick yellow bill, while that of the Little Egret is black. The Little Egret also has black legs and yellow feet, while those of the Cattle Egret are a uniform pinkish. The Cattle Egret used to be known as the buff-backed heron because of the long hair-like ginger-coloured plumes extending down its back during the breeding season, but this is potentially misleading as for most of the year it simply looks white. It gets its current name from its habit of riding on the backs of grazing animals and, indeed, in South Africa it had a reputation as a tick bird and was believed to rid cattle of their parasites. It was deliberately introduced into Australia because of this reputation. However, although it will occasionally pick off ticks and flies, these are not a major part of its diet and it is much more interested in the many small invertebrates which are disturbed by the feet of all grazing animals, not just cattle but horses, buffalo, hippos and most wild game species too. It is the bird's association with livestock which helps explain its remarkable success in spreading to, and colonising, new areas throughout the world. It was originally confined to Africa, Asia and southern Europe but during the last hundred years or so it has expanded its range to include Australasia and North and South America. It is also one of the few birds to have been recorded in all seven of the world's continents, and that includes Antarctica. Although almost nine tenths of the British records have occurred in the last 30 years there seems to be little doubt that, within the next 5 or 10 years or so, the Cattle Egret will become as common in the British Isles as Little Egrets now are.
While the Cattle Egret has been arousing all the interest and excitement we should not forget that the area, especially around Earith, has also played host to an increasing number of that other member of the heron family: the Night Heron. This is a strikingly attractive species with white under-parts and completely pearl-grey upper wings, set off by patches of glossy black on the back and crown. The bird is rather secretive and nocturnal, roosting by day in thick bushy cover only to emerge to feed when dusk falls. Their grey-black plumage is so effective at breaking up their outline that they are often difficult to spot among their favoured scrubby habitat. In this country, and area, a little suspicion surrounds Night Heron sightings, given that a free-flying colony of about 30 birds has been introduced at Great Witchingham Park, Norfolk, which means an element of doubt exists about the 'provenance' of birds seen recently in eastern England. However, fingers are being crossed that colonisation by these birds might be imminent.
Closer to home, a couple of Turtle Doves were on the Recreation ground in early August accompanied by a whole family of Whitethroat and, apparently, a Ring-necked Parakeet has been seen in the Thornton Road area, with others rumoured to be around Histon. Not too far away, on the Cam Washes near Waterbeach, it was possible to view as many as 16 Avocets during July and August, while on August 17th a Purple Heron passed over Fen Drayton.
It was pleasing to read in a recent edition of the Cambridgeshire Pride magazine that a local housing association, Accent Nene, has been doing sterling work, in partnership with South Cambridgeshire District Council, to counter the decline of the Swift colony in Fulbourn. Accent Nene are in the process of building 270 new homes on the Windmill estate but, in 2006 before starting work, they undertook a survey of Swifts in the area, discovering that as many as 60 pairs were nesting on the estate. In order to ensure that they continue to do so the Association has provided new Swift boxes throughout the estate and there will be around 120 integrated nest bricks in the newly developed houses. By the time this article appears the Swifts will probably have gone for another year but it is a reason for celebration that our local government authorities, and business people, should be in the forefront of efforts to encourage and preserve these iconic birds.