University of Otago evolutionary virologist Dr Jemma Geoghegan said whether introduced viruses were indeed spreading to native birds, or even if they presented a threat, remained unknown.
Very little was known about the viruses in New Zealand’s birds, Dr Geoghegan said.
However, a study now under way in Otago could change that, she said.
Along with postdoctoral fellow Dr Benjamin Perry and University of Otago conservation biology Prof Bruce Robertson, Dr Geoghegan was granted permission to catch and release 20 different species of songbirds at 20 locations in coastal Otago.
Across a variety of land uses, both native and introduced species would be caught in mist nets.
The captured birds would be banded, swabbed and released.
Genome sequencing and analysis would reveal to the researchers the viruses present.
The results would form the beginning of an inventory of avian viruses in the country.
"Studying viruses in other animals kind of gives us a better understanding of the true diversity and depth of the ‘virusphere’," she said.
A lot of viruses in nature existed without causing overt disease in the host species.
But knowing more about what was out there could help when viruses did appear in a species and started to cause disease.
Scientists could know what might be the reservoir host for viruses or where the viruses might have jumped from when they started to create issues.
"So we can sort of help prevent those emerging events happening in future," Dr Geoghegan said.
Prof Robertson said the work could be hugely important for conservation.
As offshore islands started "filling up", conservationists had started considering moving birds around the country to new habitats, he said.
The data the study created could help to determine whether certain species of birds were acting as a source of disease for others.
For example, it might help conservationists understand the risks of relocating certain birds to habitat for taonga species, he said.
Generally, the researchers would be sampling healthy birds, Prof Robertson said.
"What we find might be of concern to particular species if they are known to cause disease."