Upland birds have suffered a “worrying decline” in most species.
Scottish Natural Heritage’s (SNH) latest analysis shows ten of 17 breeds have fallen in numbers, with populations plummeting by 16 per cent overall.
The Official Statistic for Terrestrial Breeding Birds looked at data from between 1994 and 2016, which also shows an increase in woodland and farmland birds.
Upland birds are the most “concerning” group, with declines for ten of the 17 species.
Among the worst hit are breeding waders, including curlew, golden plover and lapwing.
SNH said major work was underway to help tackle these declines, including extensive peatland restoration and a Working for Waders project.
Trends analyst Simon Foster said: “It’s wonderful to see that woodland and farmland birds are not only holding their own in Scotland, but that many are thriving.
“However, with some upland birds struggling, there are a lot of people and projects working hard to improve conditions for waders – some of which have seen worrying declines.
“We and many of our partners are hoping to see these birds fare better in the coming years.”
Woodland specialists such as the great-spotted woodpecker and chiffchaff showed the largest increases at 67 per cent.
Great-spotted woodpeckers have expanded across Europe. Researchers said the trend could be as a result of larger forests and woodlands becoming more connected.
For farmland species, goldfinches have continued to rise in number and have become a common sight in most gardens.
Whitethroat, a small migratory warbler, has bounced back from historical lows associated with droughts in their Sahelian overwintering grounds in Africa.