The number of mountain hares on moorlands in the eastern Scottish Highlands has fallen to less than 1% of the level recorded more than 60 years ago, according to a long-term study.

The Centre for Ecology & Hydrology and the RSPB teamed up to study counts of the animals over several decades on moorland managed for red grouse shooting and nearby mountain land.

From 1954 to 1999, the mountain hare population on moorland sites decreased by almost 5% every year, the study found, saying the long-term decline was likely to be due to land use changes such as the loss of grouse moors to conifer forests.

However, from 1999 to 2017 the scale of the “severe” moorland declines increased to over 30% every year, leading to counts last year of less than 1% of original levels in 1954, researchers said.

On higher, alpine sites, numbers of mountain hares fluctuated, but increased overall until 2007, and then declined, although not to the lows seen on the moorland sites, the study noted.

The report stated: “The study found long-term declines in mountain hare densities on moorland, but not alpine, sites in the core area of UK mountain hare distribution in the eastern Highlands of Scotland.

“These moorland declines were faster after 1999 at a time when hare culling by grouse moor managers with the specific aim of tick and LIV control has become more frequent.”

Gamekeepers and estate managers claim culls limit the spread of ticks, protect trees and safeguard fragile environments, and a policy of voluntary restraint is in place.

However, campaigners believe the practice is cruel and unnecessary.

The research paper, being published in the Journal of Applied Ecology, stated: “On moorland sites, a long-term decline (4.6% per annum) from 1954 to 1999 increased to 30.7% per annum from then until 2017, with a density index falling to <1% of initial levels after 2008.

“Before 1999, declines were associated with conifer planting and were least severe where heather burning characteristic of grouse management was present. Grouse moors had the highest rate of decline after 1999.”

The findings were revealed after the annual grouse shooting season got under way on Monday.

Grouse season
Grouse-shooting on Forneth moor near Dunkeld, Perthshire (Jane Barlow/PA)

Lead author of the study, Dr Adam Watson of the Centre for Ecology & Hydrology, said: “Having counted mountain hares across the moors and high tops of the eastern Highlands since 1943, I find the decline in numbers of these beautiful animals both compelling and of great concern.

“We need the Scottish Government and Scottish Natural Heritage to take action to help these iconic mammals of the hill – I hope they will listen to the voice of scientific research.”

The RSPB said urgent action is needed to protect mountain hares.

Duncan Orr Ewing, head of species and land management at the charity in Scotland, said: “We consider that large-scale population reduction culls are both illegal under EU law and unwarranted as a method for controlling grouse disease.

“Management of this species should now be more tightly controlled by Scottish Natural Heritage to safeguard mountain hare populations.”

The Scottish Moorland Group said the research is “out of kilter” with other studies on mountain hares.

A spokesman said: “This latest research also flies in the face of what estate owners and land managers see every day on the ground – that hare populations are very high.

“We are perplexed that the author of this report did not seek to get data from moorland managers.

“It should be remembered that mountain hares are only culled when the populations are sufficiently high and culls only control a very small percentage of the population.”

The Scottish Gamekeepers Association said hare numbers remain among the highest in Europe on Scottish grouse moors.

A spokesman said: “This work is largely at odds with what is being seen on the ground in grouse moor areas, where hare numbers – in good breeding seasons – remain very, very high, sometimes reaching densities of up to 200 hares per sq km.

“It will be helpful to scrutinise the study’s methods and consistency given such a discrepancy with the current reality.”

A Scottish Government spokesman said: “Ministers are legally obliged to safeguard the conservation status of mountain hares and take that responsibility seriously.

“We will consider this evidence alongside existing data sources in considering whether further action is required to protect mountain hares.

“The independently-led Grouse Moor Management Group, set up to examine how to ensure grouse moor management is both sustainable and legally compliant, is also looking at mountain hare management as part of its remit.

“It is important to acknowledge that it may be necessary to control mountain hare numbers in some specific circumstances, however large-scale culling cannot be justified.”