BIRD-LOVERS are being urged this week to be on the lookout for one of Britain's favourite - and most threatened - summer visitors, the sand martin.
The call comes from organisers of the British Trust for Ornithology's Migration Watch scheme, the first ever bird census organised on the Internet.
Sand martins arrive here even earlier than their cousins, the swallows and swifts, and the first were spotted at the beginning of the month, much to the dismay of BTO scientists: having come from Africa, many of those early arrivals may not have survived the cold, rain and high winds of recent weeks.
Once, the sand martin nested in river banks but came close to extinction when animal rights activists released thousands of American mink from fur farms, vicious killers which thrive near water and are small enough to enter the sand martins' nesting burrows.
Now, however, the bird seems to have made new nesting sites in quarries and sand pits and the BTO is anxious to check their population numbers. Anyone with sightings to report, or seeking more info about the bird, should log onto www.bto.org/migwatch