Probe into mystery disappearance of rare bird from Scottish skies
Only 22 breeding pairs exist in Scotland, down from about 80 at their peak in the 1970s.
Stuart Benn, RSPB Scotland's conservation officer for the South Highlands, said: "This striking species only began breeding in Scotland just over a century ago, so we still have a lot to learn about its behaviour and its movements in the winter months.
"What is clear is that, while populations are thriving in Iceland and Norway, things aren't going so well here. It would be good to find out why that is and what things we, as conservationists, could be doing to turn around the fortunes of Scotland's Slavonian grebe population.
"To do this, we'll need to focus our research on key areas such as the role of weather and climate, when and why chicks die and compare our results with other countries whose populations are faring well."
The grebes came to Scotland in 1908 from central and eastern Europe. The majority live in the north, in the Loch Ruthven nature reserve and the Great Glen area between Fort William and Inverness, and spend the winter in coastal areas around the Moray Firth and Firth of Forth.
"It is likely that something happened, climate-wise, in the UK to make it more attractive to Slavonian grebes at the turn of the century, but we are not sure what it was," Mr Benn said.
Experts will be monitoring where the birds spend the winter, in case a specific source of pollution is affecting their nesting ability, and the conditions experienced by those in Norway and Iceland, which currently boasts a record number.