World's largest gannet colony declines by a quarter following bird flu

The world's largest colony of Northern Gannets on Bass Rock has declined by some 25% since the last major count, with bird flu the driving factor behind the decline.

Thousands of birds died in 2022 at the famous site off the Lothian coast after the virus spread though the colony during the breeding season. This summer, however, there were tentative signs of recovery, with no evidence of widespread deaths during the 2023 summer breeding season.

Despite this, the longer-term trend is one of loss. Scientists used imagery collected by a state-of-the-art drone and traditional counting methods to establish that the colony had reduced by 25-30% since the last major count in 2014.

Specialist drones have been used to estimate the population loss on Bass Rock (Scottish Seabird Centre).

The research is the result of a partnership between the Scottish Seabird Centre, the University of Edinburgh's School of Geosciences and the UK Centre for Ecology and Hydrology. Dr Amy Tyndall and Tom Wade from the University of Edinburgh said they were "delighted" with the data collected on the colony, which was of a quality of data that "surpassed our expectations".

Emily Burton a conservation officer at the Scottish Seabird Centre, said it was "reassuring" to see signs of recovery after avian flu.