Why deer in the Highlands are being fitted with GPS collars

Some 40 stags will be fitted with the collars in the project.

Deer will be fitted with GPS collars in Scotland in a new, joint initiative to track their movement and behaviour for management purposes.

The project is part of a study between rewilding charity Affric Highlands and Durham University, and is supported by the Association of Deer Management Groups (ADMG).

It will focus on red deer in the Ross-shire area of the north west Highlands.

The South Ross Deer Management Group will deploy GPS collars on 22 stags from Glen Affric to the west coast. Twelve stags have already been collared, to be followed by a further 10 this winter.

Collared stag being monitored by researchers and stalkers | Siân Addison

Those behind the initiative said six GPS ear tags have been deployed on deer calves to provide data on hind movements, with a plan to tag more calves next spring.

The collars allow researchers to analyse where red deer prefer to be, and how they interact with the environment, including their habitat preferences during rutting, calving and foraging. Data will be stored on the collars, but also sent via satellite to EarthRanger – an app which allows deer stalkers to view deer movements and manually add their own observations.

The study area includes a range of landowners with different land management practices, from sporting estates to purely conservation work.

While stalkers in Scotland have been using modern technology to track deer for years, the charity said it believes the initiative is the first of its kind in the location where the study is taking place and with the multi-landowner approach.

Affric Highland said so far, 18 deer stalkers from 14 sporting estates are involved, “bringing invaluable knowledge of deer behaviour, built over decades of experience.”

The charity said the new project will help future decisions and collaboration between landholdings on deer management, which has been a point of controversy between different rural groups.

Researcher Dr Eilidh Smith, from Durham University, said: “Through this innovative research, we’ll be tracking and mapping red deer movements to assess their seasonal migrations, home range sizes, and responses to human activities such as fencing, culling and commercial stalking.

“We’ll also conduct habitat surveys in areas where the GPS data reveal that deer have been foraging or sheltering, to analyse their environmental impacts.”

Nicola Williamson, a field officer for Affric Highlands, said: “Strengthening our understanding of how these iconic and ecologically important animals move across estates and habitats is key to recovering ecosystems and improving deer health. This in turn supports rural economies and livelihoods through skilled deer management, and sustainable sport and nature-based tourism.”

Arran Matheson, a deer stalker on Scotland’s west coast who has been involved in the project, said: “Taking part in the red deer collaring project with Nicola and Eilidh has been a great experience. We’ve worked together to locate, track, and fit GPS collars on the deer as part of this important conservation effort. This will give vital data about the deer's habitat use and movement patterns, and it’s something I know a lot of stalkers will be very interested in.”

The project was granted a licence by the UK Home Office and approved by Durham University’s Animal Welfare and Ethical Review Body.

Affric Highlands is currently working to secure additional funding for the initiative, to enable more GPS collars to be deployed and to fund the collation of the two years’ worth of data for use by land managers.

Red deer are Scotland’s largest surviving terrestrial mammal, and a keystone species that plays a crucial role in natural processes, shaping the landscape by grazing grasses and sedges, browsing tree shoots and shrubs, and trampling and wallowing.

Affric Highlands, among other conservation groups, said the current level of deer numbers are “a major barrier” to tree planting initiatives.

Including roe deer and non-native sika, wildlife groups have estimated there are around one million wild deer in Scotland, up from around 500,000 in 1990.