After several poor summers for Scotland's puffins, the "clowns of the sea" are gearing up to leave the country after a good breeding season, experts have said.

Changes to habitat and food brought on by climate change have created difficult conditions for breeding puffins in recent years, but early indications show that Scotland has enjoyed a positive breeding season, according to the Scottish Seabird Centre.

With pufflings now hatched and ready to take wing, visitors to Scotland have only a few weeks left before the birds – who come to Scottish islands including May, Craigleith, Fidre and Shetland – leave Britain's northern shores in August, said the chief executive, Tom Brock.

A puffin carries fish in its beak on May. Photograph: Danny Lawson/PA

The brightly beaked birds – which stay with the same breeding partner for life and return year upon year to the same nests – arrive in Scotland from mid-March to breed. After mating the female puffin lays one egg which is incubated by both the male and female. Pufflings are strong enough to leave the burrow after four or five weeks, and will take flight with the rest of their colony in August.

"It looks like it has been a good breeding season for puffins," said Brock. "They have had lots of problems in the last few years with climate change, lack of food and winter storms but early indications are that it's going to be a good breeding season for them."