Mother and son at the end of last summer

The site at Pont Croesor, near Porthmadogin, run by the Royal Society for the Protection of Birds (RSPB), expects thousands of summer visitors.

The only pair to breed in Wales have arrived back at their nesting site near Porthmadog for a third year running.

Last year 75,000 visited the centre to see the pair successfully rear two chicks - a male and a female.

The pair spent the winter 3,500 miles away in west Africa. Despite the distance they arrived back in Wales at the end of March within a few days of the date they arrived last year.

If all goes well, we could hope to have eggs in around a month Emyr Evans, RSPB

RSPB osprey project officer Emyr Evans said the orange ring on the male's right leg was proof the bird had returned for another year.

'We may never know for sure whether the female is the same as last year, but they are bonding well already and have even been mating.

"If all goes well, we could hope to have eggs in around a month from now,' he added.

Mr Evans said he was hoping between two and four eggs would be laid at the beginning of May.

"It will take 37 days before they're hatched so that will take us to the beginning of June. Last year the birds didn't leave until September."

The male has returned for the third year to nest

Mr Evans said the centre was manned by four local volunteers and three RSPB officers.

They will help visitors get the best views of the birds through telescopes and binoculars at the viewing site.

"Last year we had over 75,000 visitors who were interested in the project. We had tourists and local people returning daily or weekly to see what was happening," Mr Evans said.

Within a week they intend to set up a nest cam - a small camera will be placed above the nest - so that visitors and bird enthusiasts will be able to watch any developments on the RSPB site.