Hundreds of seabirds have been found all along the south coast, covered in a mysterious sticky oil that is causing conservationists grave concern.
The RSPCA's West Hatch wildlife centre near Taunton took in 139 birds yesterday, though 16 of them had died. More than 200 were found alive but by yesterday morning 20 dead birds had also been discovered at Chesil Beach in Dorset and the RSPB was receiving many reports of distressed birds having been spotted at sea.
Conservationists are becoming increasingly alarmed by the number of birds being covered in the substance, which was confirmed last night to be a mixture of refined mineral oils, but not palm oil. The public has been warned not to touch affected birds but to report them to the RSPCA.
Yesterday a spokeswoman at the Taunton centre said birds were "perky" and doing well.
Most of the birds affected are guillemots, which spend most of their life out at sea, but there are growing concerns that rarer birds may also have been affected.
One bird was found alive as far as Worthing in west Sussex, and is now being cared for at a veterinary surgery. Another, found in the Isle of Wight, is now at a local animal rescue centre.
Around 200 miles of the English coastline, from Cornwall to Sussex, is being investigated. The Environment Agency has taken samples of the water for testing.
Lyme Bay is an internationally important area for seabirds and is currently home to around 25,000 guillemots. One of the RSPB's concerns is that the incident could affect other rarer birds, including divers and grebes. "Impacts on these species could have higher conservation significance," the spokeswoman said.
An RSPCA spokesman said it was pleased with the public's eagerness to help the stricken birds, but said: "We would urge people to be cautious going down to the affected coastline affected.
"The instinctive reaction is to go down and look, or to help out. But we don't know what this substance is, so our message is for people – especially those taking dogs down to the coastline – to please be careful."
West Hatch manager Peter Venn said: "The current situation seems to be that the numbers of the birds coming in to us may have peaked for the time being, but that may change."
West Hatch supervisor Paul Oaten has been cleaning the birds using vegetable oil and margarine, followed by detergent.
"So far the birds have been in the holding room in their individual boxes and the birds that have been deemed fit enough and bright enough to wash have had margarine massaged into the areas of feathering where this very sticky contaminant is," he said.
"We've left that for half an hour, maybe a little bit more, to break down the contaminant and now what we are doing is putting them through our usual wash process. "They're coming up very well. There's a couple of little patches that haven't proofed, where the water beads off the feathers, but we will do these birds in two washes, so we do a pre-clean to get the 99 per cent off and then a final clean to get them 100 per cent clean."
Mr Oaten said that while they still do not know what the contaminant is, they are using a process known to clear sticky substances.
RSPCA animal collection officer Steve Powell, 61, has been working with oiled birds for 25 years and took 23 birds in to West Hatch this morning.
"It initially started on Tuesday and has gradually increased on each day," he said.
"I went down to Portland, which seems to be the main area.
"The ones we've brought in today are a lot thinner than the ones we first collected on Tuesday. Whether they have been fighting at sea against the pollution, or how long they have been out there for without feeding, I don't know. They are quite lively, but also quite thin.
"They do say that for every live bird that is taken off the beach there are probably nine others that have died at sea."
Report stricken birds to the RSPCA by calling on 0300 1234 999.
