Where do puffins go?

Puffins, with their bright beaks, upright walk and all-action lifestyle, are amongst the most familiar and beloved of Britain's coastal birds. But they are also mysterious, as Oxford scientists explain in The One Show tonight.

Tim Guilford of Oxford University's Department of Zoology studies Atlantic Puffins [Fratercula arctica] on Skomer Island, Pembrokeshire: 'People literally flock to see these beautiful birds busy with their comings and goings to their cliff-top burrow nests during the high summer,' Tim tells us.

'By August, though, the Puffins have gone for the winter. The question is: where?' 

He explains that, like many seabirds that leave our shores every summer, their over-wintering behaviour remains little understood. 

'Traditional methods for studying seabird movements involve the recovery of uniquely numbered metal leg rings from birds found washed up on beaches or found in fishing nets,' he says.

'Logging the distribution of such ‘ringing recoveries’ can provide an idea of where birds go on migration. But Puffin recoveries are few and far between, providing poor resolution and suggesting that they may overwinter far out at sea.'

But this seasonal 'blank' is now being filled in thanks to the development of miniature tracking technologies. Biologists at the Department of Zoology in Oxford, and Microsoft Research in Cambridge, have been using archival light logging devices built by the British Antarctic Survey to record daily positions of Puffins breeding at Skomer Island throughout the winter. 

These 'geolocators' weigh just 1.5g and can be carried safely on a leg ring, and use stored light level records to provide an estimate of Latitude (day length) and Longitude (time of midday). The accuracy is not high compared to satellite tracking (around 100-200km), but still offers a remarkable view of the migratory behaviour of birds weighing just a few hundred grams. 

Tim adds: 'The aim of the project is to understand the at-sea behaviour and movement ecology of a range of predatory seabirds, including the Puffin.  Similar studies on different colonies are ongoing at other institutions, such as CEH Edinburgh.'

'It will be particularly interesting to determine whether there are differences in over-wintering behaviour between Puffins breeding on the Pembrokeshire islands, where breeding and over-wintering survival have been relatively high in recent years, and those breeding in the North East of the UK where birds are sometimes much less successful.'

The project is still in its early stages, as the researchers gather data on the Puffin's mysterious winter behaviour, but we hope to update you with what they discover.

An item on this research airs on BBC One's The One Show on 1 September 2009 at 7pm.

UPDATE: If you missed last night's programme you can watch the report on BBC iPlayer [23:33]