Little Egrets, long-necked snowy-white members of the heron family, have established successful nesting colonies in Dorset and Ireland and a new report says climate warming could encourage the population to spread.
Forty years ago, only 23 of the marshland birds with wispy head plumes had ever been recorded here, and keen birdwatchers had to go on Mediterranean holidays for a glimpse.
But numbers subsequently grew in Spain, France and Italy and the population spread north into Normandy, resulting in birds increasingly taking short autumn flights across the Channel to southern England and Ireland over the past decade.
This led to over 1,000 migrant egrets coming to English and Irish shores in some years - the world's most northerly gatherings - and a report in the new edition of the monthly journal British Birds announces the details of what has long been eagerly anticipated by naturalists.
A pair nested, raising three young, on Brownsea Island in Poole Harbour, Dorset, in 1996 - then five pairs reared 12 young there last year. Meanwhile, there was also one pair in an unnamed Irish spot in 1996 - and the outcome last year was around 30 young from 12 pairs of adults.
The report by Leigh Lock, South West England Conservation Officer for the Royal Society for the Protection of Birds, and Kevin Cook, warden of the Dorset Wildlife Trust's Brownsea Island reserve, points out that this is even better productivity than in the egret's heartland in the South of France.
They comment: "If egrets are given adequate protection from disturbance, particularly during the breeding season, they are likely to flourish in southern England in coming decades.
"While the precise effects of climate change are difficult to predict and a number of scenarios have been proposed, mild winters would be likely to encourage further overwintering, and increasingly warm summers would be suitable for breeding.
"If these occur, there may be even greater range expansion, and the Little Egret may become a familiar breeding species along the South Coast, possibly being joined by other southern European species, such as the Black-winged Stilt, before too long."
They point out that, on the Continent, Little Egrets often nest in the same groups of trees as Grey Herons.
This is the case with the Dorset and Ireland birds - and the report reckons that there is plenty of scope for them to nest in other places as well.Reuse content