Rangers at Bedfont Lakes Park are delighted with the booming bird population as the numbers of common terns reached the highest level since 2004.
The number of birds visiting the site this summer has risen for the first time in four years with 16 pairs hatching out 39 chicks.
Countryside Rangers have been encouraging the terns - also known as sea swallows - on to the site by providing floating rafts for them, which replicate their natural habitat and provide a safe place for the birds to lay their eggs.
Claire Griffiths, general manager for John Laing, who now manage the parks, said: "The increase of breeding common terns at Bedfont Lakes is a good example of how people can make a difference to the environment and bring wildlife into the borough."
The adults will be due to leave Bedfont any day now to migrate south for winter in places such as South Africa and Namibia 6,000 miles away, while the youngsters will follow in mid August. They return in mid-to-late April.
Before their migration, volunteers for the Runnymede Ringing Group boated out and ringed 34 of the chicks with a small, numbered metal leg ring, which will allow the Natural History Museum to track their movements and migration patterns.
The borough's only breeding colony of Black-headed Gulls, who live at Bedfont Lakes, had six pairs raising 19 young this summer, another record high.