RICHARD WILLIAMSON: Bird diversity is silver lining of global warming

Immigration into Britain has continued rapidly over the past decades, foreigners colonising our country at an unprecedented rate.

How we welcome them with open arms, hoping that the stampede will continue.

Most successful has been the little egret.

This small, white, heron-like bird has shown the greatest range expansion of any wintering species, according to the brand-new atlas of breeding and wintering birds in Britain and Ireland recently published by the BTO.

Breeding evidence for this bird has been recorded in 1,214 10km squares.

The bird, which is today familiar to everyone in Chichester and Pagham harbours and indeed around the whole coastline as far north as Yorkshire, was first recorded breeding on Brownsea Island in Dorset in 1996.

One of the best places to see them is on the shore opposite Dell Quay where they stand resting at high tide like white posts or roosting in the oak trees looking like scraps of white paper.

The little egret’s relatives, seeing how easy the living has become, how friendly the climate, and how good the laws protecting the individual, have followed apace.

Closest relative is the cattle egret, easily identified by its yellow beak.

When I took my photograph of cattle egrets in Portugal 20 years ago, I little thought they would start breeding in Britain in 2008, down in the Somerset Levels, when a total of 168 individuals wintered.

Some now overwinter in Scotland.

Another ethnic group travelling north has been the great white egret, which looks like a slim, pure-white heron.

The first breeding success in Britain was again in the Somerset Levels in 2012 when two pairs fledged four young.

These have also been seen in Fishbourne channel, as well as at the WWT Arundel, and they winter as far north as the Outer Hebrides.

A bird which I commonly see in Portugal is the purple heron, a real oddity like a heron with highlights.

Last winter one scuttled into the reedbeds at Fishbourne downstream from the sewage works as I walked along the seawall, a wonderful bonus to the WEBS count.

In 2010, a pair successfully bred at Dungeness in Kent.

Another oddity which I saw last year near Emsworth was a glossy ibis. It looks like a chocolate curlew.

It will soon be breeding here.

Spoonbills already are breeding in East Anglia, the first since 1668.

Yet another marshland bird to come into Britain is a little bittern, half the size of the common bittern, and black and white like a magpie.

Then there are the bee-eaters, which have reared young this year on the Isle of Wight, and also the black-winged stilts which should be in the Mediterranean, but this year raised young in Sussex.

Let’s hope the list goes on and on. There has to be some silver lining to global warming.