Stubby seabird with comedy beak to help scientists investigate steep decline in seabird populations across Britain

Short, stubby and gifted with a distinctive comedy beak, the puffin is an iconic bird. But seabird may also be the bellwether for a crisis in the seas around Britain.

The puffin now has a new role, helping scientists investigate the causes of a steep decline in seabird numbers across the British Isles using miniaturised digital tracking devices, including one borrowed from in-car satellite navigation systems.

Data for last year shows puffin numbers suddenly and sharply crashed. Scientists found that on the most significant North Sea colonies, puffin populations fell by a third or more. Adult puffins were malnourished, with large numbers washed up dead along the UK’s coast.

Confronted by other evidence of a significant change in the North Sea’s health, which has led to declines of up to 40% in seabird numbers in just eight years, conservationists have begun a series of urgent studies into its possible causes. Many believe climate change is the main culprit.

On the Farne islands, a low-lying archipelago off the Northumberland coast 50 miles north of Newcastle, puffins are now being fitted with equipment which should help plug large gaps in scientific knowledge about the species and, in turn, other threatened seabirds.

Scientists will use three different devices on up to three dozen puffins: GPS monitors; “geo-locators” which work differently; and time and depth recorders.

They will monitor how and where they feed and behave once they leave their burrows on the Farnes, and track their movements while they winter at sea. Each puffin will carry only one small device which will be attached with super-strength glue onto its back.

Food is a critical issue: zoologists believe last year’s population slump – when numbers plummeted on the Farnes from 58,000 in 2003 to just 38,000 – is closely tied to a collapse in their main food source, the sandeel.

Populations of the slender, silvery fish, whose availability may be crucial to the puffins’ long-term survival, have been in decline since the 1990s because of heavy trawling for fishfarm feed and exposure to the changes in plankton distribution brought about by rising sea temperatures.

Puffins nest in dark, dry burrows that the birds carve out each spring from the soft, sandy earth, shaded by sea campion, nettles and coarse, hardy grasses. Their behaviour on land and within sight of the islands is well understood. However at sea, scientists have been largely guessing.

Dr Richard Bevan, a zoologist with Newcastle university who is leading the National Trust research on the Farnes, said: “All we can record at the nests is the number of chicks, how quickly the chicks are growing and the numbers that fledge, but what we don’t know is what they do as soon as they fly away.

“Puffins can theoretically be foraging anywhere within a 60km radius of the islands, which is a huge area for us to cover. But the further they have to forage the more energy they use, and the intervals between when they feed their chicks will increase, so chicks will be fed less and are less likely to do well.”

The results of the hi-tech monitoring will help conservationists establish whether puffins have regular feeding grounds and allow them to protect those places. Evidence that puffins spread across a wide area would present a more difficult problem, perhaps increasing pressure for a more substantial conservation effort.

That information will also help protect the significant Arctic tern, sandwich tern, guillemot and shag colonies on the Farnes, which are home to approximately 160,000 adult seabirds and their offspring.

This research could prove crucial. Last month, the Joint Nature Conservation Committee, the UK’s most authoritative conservation research agency, reported that about 600,000 seabirds had been lost since 2000, 9% of the total population. There are now 40% fewer black-legged kittiwake – another bird that feeds on sandeels – and 33% fewer European shags breeding in the UK than 40 years ago. On Shetland, globally significant colonies have collapsed.

Yet this year’s research so far has given Bevan and the trust grounds for optimism. Their trawls for sandeels around the Farnes suggested the tiny fish were, this year at least, relatively abundant. Puffins are flying in – their short wings urgently flapping 400 times a minute, with sandeels dangling from their beaks.

Bevan believes last year’s population crash may be explained by unusual north-easterly winds during last year’s breeding season, which may have cooled the seas at the wrong time. Herring – a fish which competes for sandeels – were also abundant, and may have out-eaten the puffins.

Last year’s population crash may be a blip, not a trend. But it does indicate there are changes in the marine environment which scientists do not yet understand, Bevan added.

“It’s a warning sign. I’m willing to bet that this year numbers would be up from last year, but not up to pre-2008 levels. The problem is, we don’t know what’s happening out there. There’s a change in the ecology of the North Sea. What the implications are of that, we have no idea.”

Seabirds in trouble

Black-legged kittiwake

Its numbers have fallen by 35% since 2000 due to declines in sand eels caused by overfishing and climate change. Breeding success has fallen markedly on the North Sea.

Herring gull

One of the UK’s best known gulls, notorious for scavenging from trawlers and city dumps, but is a new entry to the UK “red list” of threatened birds because its numbers are sharply falling, down by 69% since 1969 and 33% since 2000.

Arctic skua

This relatively rare inshore seabird was put on the UK’s “red list” of threatened species this year as its numbers are declining rapidly: 2,100 were counted in 2002, but it has declined by 57% since then.

Seabirds on the up

Great skua

Its numbers have rocketed by nearly 400% since 1969 and by 56% in the last eight years alone – but at the expense of others. The large scavenger has outmuscled the herring gull for trawler discards and preyed on Arctic skuas. Cuts in discarded fish suggest it will increasingly have to steal food from other seabirds to survive.