Migrating swifts loyally return every year to nests in buildings, study finds

The swift is one of Britain’s most threatened species, having declined in number by 70% since 1995 because of the loss of nesting sites. Photograph: RSPB / Ben Andrew View image in fullscreen The swift is one of Britain’s most threatened species, having declined in number by 70% since 1995 because of the loss of nesting sites. Photograph: RSPB / Ben Andrew Migrating swifts loyally return every year to nests in buildings, study finds Conservationists emphasise importance of protecting nesting sites used by ‘strongly faithful’ red-listed species Migratory swifts loyally return every year to their nests in buildings, according to a study, underlining the importance of providing the endangered birds with hollow nesting bricks if traditional nest sites are lost to renovations. The swift, which is on the red list of conservation concern, is one of Britain’s most threatened species, having declined in number by 70% since 1995 because of the loss of nesting sites, often when old buildings are re-roofed or given better insulation. While Scotland this year made the installation of swift bricks – a simple hollow brick – a legal requirement in new buildings, the government in England has repeatedly refused to oblige builders to include a £35 swift brick in every new home. Scientists for the RSPB studied 190 different swifts from 243 nests over 15 years in a Dartmoor village and found that 94% of the birds reused the same nesting site as the previous year. The 15-year study found that swifts, whose screaming parties over towns and cities are a much-loved sound of summer, have greater loyalty to their nest site than a previous partner, with only six out of 10 (59%) birds pairing with the same partner. Sometimes, as nest camera footage vividly reveals, there are fierce debates over the use of a nesting box. 0:38 Three swifts fight over the use of a nest box – video Researchers collected data from swifts breeding in nest boxes in Drewsteignton, Devon. Breeding swifts were identified by uniquely numbered leg rings that enabled scientists to track which birds bred together and which nest box each swift used every year. Data was collected from 243 nests during this period. Malcolm Burgess, the principal conservation scientist for the RSPB, said: “We’ve anecdotally thought for a long time that swifts are loyal, returning to the same nesting sites and partners each spring. But for the first time, we’ve documented just how strongly faithful they are to their nest sites, which highlights just how important it is to protect their nesting sites in our neighbourhoods. “The decline in swift numbers is a great cause for concern and without increasing the availability of nest sites, and replacing those that are being lost, we will see further declines of this extraordinary bird in our towns and cities.” View image in fullscreen Nest boxes for swifts installed on the side of a house in Leeds. Photograph: Sam Turley/RSPB/PA This spring, holes that had been blocked in a railway