An RSPCA manager has said it is "too early" to assess how successful the organisation's attempts to help the 100 guillemots washed up on the south west coast will be.
Peter Venn, RSPCA West Hatch manager, said:
The numbers of birds arriving in to our centre are growing and we are doing all we can to help them - but it is too early to tell how successful these attempts will be.
We do not know what this substance is or where it has come from yet but we do know it is not fuel. It may be bi-product from manufacture, but at this stage we just do not know.
We would urge anyone who finds any of these birds to contact the RSPCA on 0300 1234 999.
There are also reports of the sticky substance washing up on the beach, so we would urge people walking their dogs in the area to also be careful.
More top news
The US Navy says 10 sailors are missing and five are injured after the USS John S. McCain collided with a merchant ship near Singapore
The Crown Prosecution Service says the internet has provided "new platforms for offending behaviour"
A Public Health England report estimated 150,000 to 200,000 Britons are infected with the virus by imported pork every year.