The capercaillie has had a precarious existence

The European Commission has warned the government its measures to halt a catastrophic decline in the birds' numbers do not go far enough.

The commission wants to see an increase in the population above the present 2,000 or European laws to protect endangered wildlife could be invoked.

The executive claims it has complied with rules to halt the bird's decline.

The turkey-sized capercaillie is the largest bird in the grouse family and one of the UK's most threatened species after numbering 20,000 in the 1970s.

Endangered species

The population of the endangered bird was once predicted to become extinct in the next 15 years but its numbers have risen since 1999 to their present standings.

The removing of deer fencing and legal predator control in key capercaillie areas are among the reasons thought to be behind the bird's recent resurgence.

Good weather during recent breeding seasons is also thought to have helped.

However, a complaint from one of the country's foremost capercaillie experts to the Brussels-based commission has warned the executive is breaking its laws on endangered wildlife.

The complainant claims some special protection areas - including the Kinveachy Forest in Strathspey and one on the Queen's Balmoral Estate - are badly degraded, with overgrazing by deer depriving the birds of vital cover.

The species was wiped out in the UK in the late 1700s and was successfully reintroduced in the 1830s.