Puffins are considered globally threatened and the British population is found on only a few sites.
But this spring about 160 pairs were estimated to be on Burhou – a rocky island breeding ground off Alderney.
During a recent visit a trail camera was deployed to survey the grounds, in addition to the Alderney Wildlife Trust’s PuffinCam.
‘We noticed the first food being brought back to the colony in the final week of May, indicating that pufflings have started to hatch,’ said Jack Bush, puffinologist and Alderney Wildlife Trust Ramsar officer.
‘Since then, there has been a lot more activity on the land as puffins interact more whilst provisioning chicks and spending more time outside of burrows as they aren’t required to sit on eggs.’
Estimating Burhou’s population involves counting puffins rafting on the water while the other in the pair sits on eggs from late April and throughout May.
‘The highest count during this time is the likely population size. This year the highest count is 161, representing 161 pairs of puffins in the breeding population, very similar to what we saw last year.’
Pairs were estimated at 140 in 2018 and 150 in 2019.
‘In terms of numbers of birds, the colony seems to be stable, with numbers of puffins growing over recent years.’
Early August will bring breeding success to light, when Mr Bush can review the season’s data.
‘The data I currently have is promising – over 80% of the nests I am monitoring have had food returned, which suggests a large number of the breeding attempts have successfully hatched.’
Populations are surveyed annually and ‘opportunistically’, Mr Bush said, using the PuffinCam to survey rafting birds on water.
Burrows are counted and assessed for occupation at the end of the season, yet signs of occupation may have been weathered away where pufflings have fledged some weeks before.