Kittiwakes, the most sea-going members of the gull family, have colonised British Gas's Morecambe Central Gas Platform, midway between the Lancashire coast and the Isle of Man. Two pairs have between them successfully reared three young.
The development might be the beginning of widespread colonisation, said Ross McGregor, recorder of the North Sea Bird Club, which monitors wildlife activity on and around the platforms which have been installed since the early 1970s.
"This is the first record of nesting on a rig in British waters and this could result in more kittiwakes joining them in future and possibly other types of seabirds, such as guillemots and razorbills, being attracted also," he said.
"It's a fantastic development and I hope this is just the start. It would be marvellous if seabird colonies could become established on the rigs."
Kittiwake nesting had been expected for some time but attempts had been foiled by scavenging herring gulls taking the eggs. The two pairs on the Irish Sea platform overcame that problem by choosing a site inaccessible to the marauders.
"The nests were on a ledge behind lots of piping and under another ledge, but still beside a sharp 50ft to 100ft drop to the sea, making it similar to a natural kittiwake site on a sheer cliff face," Mr McGregor said.
"Once a herring gull did try but couldn't land on the ledge, so the nests were clearly protected from the only possible predators - which is the likely reason why they were successful.
"If a colony becomes established, that will be less of a problem as it grows in size. Normally a large colony's size alone effectively protects the eggs and nestlings as predators such as the larger gulls are dissuaded from scavenging."
Mr McGregor said that oil and gas platforms around the British coast were also important to wildlife, providing vital resting points to migrant land birds. "Sometimes thousands gather and there are instances of rigs having had to shut down operations until they leave."
The most unusual bird recorded on a British platform was a Pacific swift, which appeared at a site nearly 30 miles off the Norfolk coast in June 1981. It should have been somewhere between Siberia and Japan.
Kittiwakes have been nesting on man-made structures only since the 1930s. Normally they are coastal, with the most inland site the Tyne Bridge at Newcastle, 10 miles from the sea. Birds nested for the first time last year on a platform put up by Gateshead council near the bridge to compensate for their eviction from the riverside Baltic Flour Mill, which is being converted into an arts complex.Reuse content