Tuesday, 13 December 2005

Immigrants on the increase

A visit to Norfolk’s coastal saltmarshes will often reward the observer with views of one of the county’s newest breeding species – the little egret. Smaller than the more familiar grey heron, the little egret makes a striking sight, with its white plumage, dark legs and yellow feet. When hunting in shallow water, the egret will edge slowly forward, making frequent stops and taking care not to scare off its prey. From time to time a feeding bird will extend a leg and vibrate it rapidly. This ‘stirring’ motion is used to disturb fish or invertebrates hiding in the mud.

Little egrets were rare vagrants to Britain for many decades, following widespread persecution as a consequence of the Victorian trade in their feathers. During the breeding season, adult little egrets have two, sometimes three, long plumes on their crown and they also sport elongated feathers elsewhere on the body, most notably on the chest and back. It is these feathers that were prized by the Victorians. Between 1952 and 1988, there were just 26 records of this species from Norfolk, with most thought to be spring migrants that had overshot their European breeding grounds. Then, suddenly in 1989, there was an unprecedented influx, though only three of the 120 or so that arrived made it to Norfolk. Over the following years, breeding was noted at sites along the south coast of England and the population started to expand rapidly in both size and distribution. With increasing numbers of little egrets being seen in Norfolk and with the establishment of regular roost sites at Holkham and Titchwell, it was clear that breeding would soon take place within the county. In summer 2002, breeding did occur at two sites, with eight pairs producing 19 young. Last year, 2004, some 55 pairs were thought to have produced 152 young – a staggering increase in such a short space of time.

Given the recent success of the little egret, it is fitting to see it feature on the cover of the recently published Norfolk Bird & Mammal Report for 2004, which, incidentally, contains an article on the species by Ron Harold and Andrew Bloomfield. It also features on the cover of the Wetland Bird Survey Report for 2003/04, published annually by the British Trust for Ornithology, the Wildfowl & Wetlands Trust, RSPB and the Joint Nature Conservation Committee. The Wetland Bird Survey is the national monitoring scheme for non-breeding waterbirds (such as waders, ducks, geese, grebes and herons) and, with annual count information going back to 1966, it has been an invaluable tool for charting the increases and decreases of our various waterbird species, including the sudden rise of Norfolk’s little egrets.

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