Non-native deer breed risk pushing out Scotland's Monarch of the Glen

Landscape home to Scotland’s monarch of the glen is at risk of being dominated by non-native deer, new research suggests.

The sika deer, which is native to eastern Russia and east Asia, are said to breed faster and are more difficult to cull compared to the Scottish red deer.

Researchers also claim the smaller breed have a more damaging impact on the environment compared to their native peers when it comes to browsing.

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It can take about four times as long to cull a sika as a red deer, evidence suggests, because they are more vigilant and can crawl through gaps as low as 25cm. The smaller but tougher sika can tolerate the Highland climate and even if a quarter of their population were culled each year, they would breed enough to maintain their numbers.

Many conservationists consider the high number of deer in Scotland to be negative for nature restoration projects, including tree planting schemes.

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Researchers claim the smaller and in some cases more resilient sika deer could usurp the red deer population | Highlands Rewilding

The Scottish Government is currently debating its new nature bill, which proposes more control of Scotland’s deer population.

Though no one knows the true population size of deer in Scotland, some reports suggest numbers are at about one million, which some have claimed is double what they were in the 1990s.

A new paper, by the environmental body Highlands Rewilding and the Karlsruhe Institute of Technology in Germany, claims sika deer’s natural advantages means the breed will dominate parts of the country if there are no targeted culls.

The paper identifies six features of “super sika” which include being more resilient to harsh winters, better at surviving on scarce resources, more vigilant of humans, better at breeding, more tolerant of disease and able to hybridise with red deer.

Conservationists claim the increase in sika deer is not discussed enough in the wider deer debate | Highlands Rewilding

Research says the native red and roe deer can also be disturbed by the sika’s whistle during the mating season, putting them off breeding.

Calum Brown, a scientist at Highlands Rewilding and a senior researcher at the Karlsruhe Institute, said: “We are deeply concerned that by managing all deer populations in the same way, we might inadvertently help the invasive non-native sika deer to outcompete our iconic native deer species: red and roe deer.

“While the problem of deer population of Scotland is widely recognised, we don’t want to see sika crowned the new ‘Monarch of the Glen’.”

Mr Brown argues much of the national debate around deer has largely ignored the issue of sika.

The new paper, which included research from ecologists, deer stalkers and foresters, calls for greater recognition of the threats posed by sika to support a strategic cull.

Mr Brown said: “Increased deer management and culling which doesn’t account for sika’s advantages is likely to reinforce these advantages. We could see sika and hybrids becoming the dominant species in areas where they are present.”

Deer experts have previously warned the sika population is “out of control.” To keep some native red deer populations free from sika genes, islands off the west coast of Scotland have been designated as red deer refugia.

A Scottish Government spokesperson said: “Managing different species of deer across rural and urban Scotland requires a variety of approaches.

“In all circumstances, we want to ensure deer management in Scotland is sustainable and brings benefits to rural communities and nature.

“That’s why we are supporting four deer management pilot projects this year, trialling a mixture of financial incentives and support for venison.

“These include two projects led by Nature Scotland to increase the annual culling of non-native sika deer in native woodlands and commercial forestry. We will work closely with partners as these schemes progress and use findings to inform future deer management policy.

“NatureScot is in the process of developing a Sika deer management strategy, which will address the concerns around Sika populations in Scotland. This will be published in due course.”