The seabird breeding season at RSPB Bempton has been affected by the cold spring and oil slick off the North Yorkshire coast.
According to staff at the reserve around 500 puffins, and another 500 other seabirds - including kittiwakes and razorbills, were washed up along the East Yorkshire coastline earlier this year, many starving to death and suffering from exhaustion.
Keith Clarkson, senior site manager at the RSPB Bempton reserve, said: “At that point it looked very, very ominous. At the start of the breeding season we found that many of the birds didn’t come back to the colony until very late. Some came back and some were clearly affected.”
The kittiwake population has been especially affected by the poor start to this year, as many of the returning birds have not bothered to breed, or to even build a nest.
However Mr Clarkson is not worried as he expects the kittiwakes to return next year and begin their usual routine.
He said: “They have evolved so if they are not in the best condition they feel it is best just to see out the year and start again next year. They have obviously survived OK as adults and will hopefully come back next year.”
The puffins are also experiencing a shake-up in their usual routine, with many still on the cliffs when they would normally have left for the open sea by the end of July.
One success story are the gannets as currently thousands can be seen tending to their fluffy white chicks on the cliffs.
And the poor start to the season has not affected visitor numbers to the reserve either.
“This hot weather has been an absolute blessing for the area,” said Mr Clarkson.
“We are getting more and more foreign visitors who are visiting the Yorkshire Wolds, so the place is getting on the map.”