Capercaillie and the issue of human disturbance

A male capercaillie displaying in a forest (credit Ben Andrew (rspb-images.com))

A new RSPB scientific conservation paper published in Bird Study and written by Ron Summers and co-authors, has investigated the association between capercaillie distribution and road and track densities in the Cairngorms National Park.

This paper demonstrates that higher densities of roads and tracks leads to reduced presence of capercaillie.   This is despite the fact that these areas contain suitable capercaillie habitat. 

As with previous research investigating this association (Summers et al, 2007 & Summers et al, 2004), this paper recommends that the density of tracks in capercaillie forests are reassessed and zoning could be used to reduce human usage in sensitive capercaillie areas.

This is the first study to assess this association at a wider landscape scale in Scotland as previous studies have focused on smaller areas. These important results add to the evidence that human disturbance can limit the distribution of capercaillie and effectively act as a form of habitat loss.  

Recent results from the sixth capercaillie National Survey, which demonstrated an approximate 50% decline in the Scottish capercaillie population over the past six years, highlights how vital it is to take steps to secure the future of this species.

In February 2022, NatureScot’s Scientific Advisory Committee published a report as a ‘Review of Capercaillie Conservation and Management’, which was motivated by concerns around the recent decline of these birds.

The creation of refuges free from human disturbance was one of the four options identified in this report as likely to have the greatest immediate positive impact on the capercaillie population. 

The partners involved in the 2015 Cairngorms Capercaillie Framework, including the Cairngorms National Park Authority, NatureScot, Forestry and Land Scotland, and RSPB Scotland, also committed to exploring the potential of refuges.  Measures outlined in this Framework included -   

• Co-ordinate and increase ranger presence in areas where important capercaillie habitat and significant visitor and recreation pressure coincide.
• Encourage people to keep to tracks and avoid sensitive locations – e.g., with natural path side screening
• In refuge areas during the sensitive period (March – August) there should be clear guidance limiting access with dogs and alternative provisions provided nearby.
• Improve ‘refuge areas’ for capercaillie by re-aligning or abandoning infrequently used paths in less disturbed habitat. This will require significant consultation and the creation of specific recreation management plans.
• Proactively guide the creation of new access infrastructure, e.g., mountain bike trails, away from sensitive sites 

RSPB Scotland responded to this NatureScot report in our blog published in spring, which outlined our thoughts on this review and the work that we have been doing to support the long term survival of this species.

There is existing provision within the Scottish Outdoor Access Code to protect sensitive sites and species:

‘Take care to avoid damaging the site or disturbing its wildlife, or interfering with its management or enjoyment by others. Depending on your activity, you might be requested to follow a specific route or to avoid exercising access rights in a specific area.’

Despite this provision, these measures are not currently implemented to their full extent to protect capercaillie from disturbance.

At our Abernethy National Nature Reserve, seasonal signage and rangers are in place to advise people on appropriate behaviour in sensitive areas to mitigate disturbance e.g., keeping to tracks with dogs on leads during the breeding season. Tracks on the reserve are regularly reviewed and, after consultation with the local community, some tracks have been downgraded from vehicle tracks or allowed to grow over entirely, to reduce disturbance risk. 

At the same time, extensive habitat restoration is ongoing on this reserve to create new habitat by expanding the forest and improving the field layer to provide safe areas for capercaillie away from tracks.

The Cairngorms Capercaillie Project is working with residents, mountain bikers, businesses and dog walkers within the Cairngorms National Park to reduce disturbance in capercaillie areas. This includes developing a Mountain Biking Recreation Management Plan for Badenoch and Strathspey with the mountain biking community, landmanagers and NatureScot. The plan stands to deliver win-wins for mountain bikers and capercaillie. Similarly, the project is working with RSPB Scotland, Forestry and Land Scotland, and Rothiemurchus to maximise visitor experiences whilst also providing opportunities for capercaillie to thrive in Abernethy Forest, Glenmore Forest Park, and Rothiemurchus.

There needs to be a commitment from project partners to continue to scale up this work across the capercaillie range, beyond the timeframe of this project (which ends in December 2023), to ensure it continues to reduce the threat of recreation pressure to capercaillie.

These are all positive steps, but more work needs to be done to reverse this rapid decline of capercaillie and to address issues of human disturbance.  Updating and enhancing existing Scottish Outdoors Access Code by the National Access Forum is needed in time for the next capercaillie breeding season from March 2023. This guidance should also be well promoted in capercaillie areas to help protect their fragile population. 

The issue of human disturbance has been recognised for many years and the results from this paper make the case for even stronger and urgent action to significantly reduce this threat and safeguard this iconic species.