Vanishing puffins leave ecology experts baffled

Jul 26 2008 by Tony Henderson, The Journal

EXPERTS have been left baffled by a plunge in puffin numbers on the Farne Islands off the Northumberland coast.

The birds are the top favourite with more than 40,000 annual visitors who go to the National Trust islands, which is the biggest puffin colony in England.

But a census by trust wardens on the islands has revealed that the numbers of breeding puffin pairs has fallen by a third in the last five years.

The survey logged just 36,500 pairs compared to the previous study carried out in 2003, which recorded 55,674 pairs.

David Steel, National Trust head warden on the islands, said: “The results from this survey have completely surprised us as we were predicting another rise in the numbers of breeding pairs.

“Stocks of sand eels, the staple food of puffins in the summer, are in good supply around the islands and there is a lack of ground predators, creating a good environment for puffins to breed.” The puffin count was carried out by the team of nine wardens across eight of the islands.

All eight showed a decrease in population with four islands showing a dramatic decrease of up to 50%.

David said: “Extensive monitoring work shows that good numbers of young puffins are successfully fledging each year but it would appear they are just not coming back to the islands the following years.

“Presumably fewer birds are surviving over winter than are needed to maintain current numbers.”

Staple Island and Brownsman Island, where the majority of puffins can be found, have seen the numbers of breeding pairs fall by more than 30%.

The drop in numbers suggests that the answer lies in what is happening at sea during the winter – possibly an intensification of storms as a result of changing climate which could affect the ability of puffins to find food.

John Walton, trust property manager for the Farne Islands and Northumberland coast, said: “In almost 30 years of working with the Farne puffins, this is the first downturn in the population I have witnessed. With such a dramatic fall in numbers of breeding puffins on the islands, we need to do some further work to find out why things are changing and whether this is a long term trend.

“We’ll being carrying out sample surveys next year on some of the islands to build up a more detailed picture of what is happening.”

Records for the number of breeding pairs of puffins found on the Farne Islands date back to the 1930s but the first detailed count took place in 1969 when there were 6,800 pairs of puffins.

The puffin, with its bright beak and slightly comical walk, nests underground in burrows. During the survey, which began in May, the wardens put their own arms into holes to make sure that the nests are occupied.

Prof Mike Harris, emeritus research fellow with the national Centre for Ecology and Hydrology in Edinburgh, who has studied puffins for 36 years on the Isle of May, in the Firth of Forth, said: “The dramatic decline on the Farnes along with that found earlier this year on the Isle of May leaves no doubt that the North Sea has lost a substantial proportion of its puffins.

“With poor survival of adult birds a likely factor in the decline we urgently need to know more about puffins during the eight months of the year that they spend in the open sea.”

Numbers

The drop in puffin numbers on four of the Farne Islands are:

Inner Farne

2003: 13,069

2008: 9,813

(-25%)

West Wide Open

2003: 8,704

2008: 4,257

(-50%)

Staple Island

2003: 15,583

2008: 10,672

(-31.5%)

Brownsman

2003: 14,438

2008: 9,015

(-37.5%)

The survey carried out on the Isle of May in the Firth of Forth earlier this year showed that numbers of puffin pairs had declined from 69,300 to 41,000 (-41%).

The oldest puffin recorded on the Farne Islands was 31 years old.

Adult puffins arrive at the breeding colonies in March and April and leave again in mid-August. Puffins feed on fish, especially sand eels.