A conservation group has claimed the legal control of predators like foxes, crows and stoats can help grouse and other birds to thrive on Scots moors.
The Game and Wildlife Conservation Trust research was carried out on land near Otterburn in Northumberland.
It said the findings were just as relevant to estates in the Borders.
Dr Kathy Fletcher of the trust said the study found that without predator control less than 20% of breeding birds were able to raise their young.
"We had a nine-year project that looked at what happened on sites where we reduced the level of predators and compared it with sites with higher levels of predators," she said.
"We found that when we had lower levels of predators the birds were breeding much better with about three-times higher breeding success.
"Their numbers actually increased."
More than 50% of breeding pairs were able to successfully raise their young when predator controls, traditionally the preserve of gamekeepers, were in place.
"That is the difference between birds being able to keep their population stable or improve and seeing these serious declines that are happening elsewhere in the country," Ms Fletcher added.
The investigation found that it was not only the grouse population which increased.
The numbers of threatened wading birds such as curlew, lapwing, and golden plover also showed significant rises.
The trust has argued there is a case for using such predator control outside of countryside shooting estates.
However, that approach has been criticised in the past by animal rights groups due to concerns about killing one species to assist another.