BirdWatch Ireland is investigating the recent increase in the population of the tree sparrow, particularly on the east coast and in adjoining counties.
It says the increase is "all the more dramatic" when compared to a severe decline in numbers in the UK.
Breeding productivity will be monitored at several tree sparrow colonies.
This will allow brood and clutch size to be monitored, along with other nesting data.
Tree sparrows are also being trapped and colour-ringed, to determine the numbers that survive in a colony from year-to-year.
Individual birds will also be tracked, to see how they move around the country.
BirdWatch Ireland is appealing for members of the public to get involved by looking for tree sparrows and reporting locations.
It says that the tree sparrow can be distinguished by its chestnut brown head, and is smaller and more active than the familiar house sparrow.
If you can help, please email Alex Copland at email@example.com