The Scottish Gamekeepers Association (SGA) says that despite an assurance by First Minister Alex Salmond the Capercaillie would not be allowed to "die on his watch", keepers fear its disappearance is perilously close.
While individual birds exist in fragmented pockets, the only remaining viable breeding population is in Badenoch and Strathspey.
The SGA says it warned 12 years ago predation by pine martens, foxes and crows would imperil the largest member of the grouse family. The SGA claims a scientific study in 2009, using cameras at 20 nests, showed predators destroying 65% of those nests in Abernethy Forest, part of a reserve run by RSPB Scotland in Badenoch and Strathspey.
Of those destroyed, 57% were proven to be by pine martens which, like the Capercaillie, areprotected but more numerous.
Members of the Scottish Government's Biodiversity Action Plan (Bap) group for Capercaillie had acknowledged the need for a trial removal of pine martens from core areas to assess the problem.
However so far, no research licence has been granted and gamekeepers represented on the group fear conservationists are running scared of making the tough decisions required to prevent the bird becoming extinct.
Allan Hodgson, who sits on the Bap group, said: "If all the right things are done, there is still a good chance we could save the capercaillie. However, there needs to be some hard decisions taken and some bravery from the Government and those advising it when it comes to dealing with the pine marten issue."
Duncan Orr-Ewing, head of species and land management at RSPB Scotland, agreed urgent action was required to help save capercaillie in Scotland, and the role of the pine marten considered. But both species were scarce and protected under wildlife laws, he said. He thought it was much too early to embark on a trial removal without considering other options such as increased deer reduction measures, deer fence removal to reduce mortality of capercaillie through fence strikes and diversionary feeding.
He said: "It is also hugely important to remember that in other countries, such as Sweden, capercaillie and pine marten live side by side, where predation occurs, and neither species is endangered. Levels of predation of capercaillie by pine martens recorded by RSPB Scotland at Abernethy are similar to Sweden and elsewhere on the European continent."
Ron Macdonald, Scottish Natural Heritage's head of policy and advice, said: "We published two reports in 2011 which looked at this subject. One did not find a direct link between pine marten numbers and capercaillie breeding success. The other found a link when the effects of weather were also taken into account. So the ecological situation is complex."
He said two key measures of capercaillie productivity - "chicks per hen" and "broods per hen" -were lower when April was warmer and in forests with more signs of pine martens and more crow sightings. "We are keen to take forward research into the role of predation alongside the effects of land use and climate," he said.
A Scottish Government spokeswoman said: "Our agencies are committed to ensuring its long-term survival."