This spring, around 160 pairs were estimated to be living about 1.4 miles north-west of Alderney, on the rocky breeding ground of Burhou.
Jack Bush, puffinologist and Alderney Wildlife Trust Ramsar officer, said the number of birds in the colony ‘seems to be stable’.
He said: ‘We noticed the first food being brought back to the colony in the final week of May, indicating that pufflings have started to hatch.’
There were an estimated 140 pairs in 2018 and 150 the following year. The figures are established by counting the puffins rafting on the water, while the other in the pair sits on eggs from late April and throughout May.
He said: ‘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.’ He added that the populations were surveyed annually – with burrows counted and assessed for occupation at the end of the season.
Meanwhile, a conservationist has said this generation could be the last to see puffins in Jersey, with just four breeding pairs left in the Island – compared with hundreds of pairs around a century ago.
Cris Sellarés, project officer for Birds on the Edge, said the birds – which can be found between Plémont and Grève de Lecq – were threatened by invasive predators such as feral ferrets and rats, which had played a part in their historical decline.