RSPB Scotland said a "plentiful supply" of sandeels and other small fish seems to have contributed to successes for many species
Scotland's seabirds have had their most productive breeding year for almost a decade, according to RSPB counts.
Colonies across the country have managed to rear young in greater numbers, after a disappointing year in 2008.
RSPB Scotland said a larger supply of food and colder sea temperatures could have helped breeding, but warned that the increases may be a blip.
Despite the news, some seabird numbers have dropped overall by 73% since 1992.
Seabird species and colonies across Scotland have struggled to raise chicks in recent years.
But counts carried out at RSPB coastal reserves have shown some massive increases in hatches this year.
In Orkney, 220 Arctic tern chicks were hatched at the North Hill reserve, compared with none last year.
The Northern Isles have also welcomed a larger number of kittiwakes, guillemots and razorbills, where reserve wardens reported empty cliffs and abandoned nests last year.
Counts at RSPB Fowlsheugh in Aberdeenshire also showed that fulmars and herring gulls had done well this year, while on Ailsa Craig 30,000 pairs of gannets have had a successful nesting season.
However, the improved figures were welcomed with caution by experts.
Doug Gilbert, ecologist with RSPB Scotland, said: "Whilst it is fantastic news that our internationally famous seabird colonies appear to have had a much improved breeding season this year, the long-term picture is one of serious concern.
"Unfortunately, the likelihood is that this year's success is just a blip, and the trend of decline will continue in coming years with further reductions to our magnificent seabird population."
Scotland has seen a decade of breeding failure for some species, caused by the lack of food in coastal waters.
Seabirds rely on sandeels and other small fish for survival - who in turn need plankton for food. But increased sea temperatures have led to a 70% decrease in plankton levels since 1950.
Lloyd Austin, head of conservation policy at RSPB Scotland, said: "Scotland must take precautions to ensure that human impacts from pollution, development and industry give seabirds the best chance of recovery."