Blog by Ed Snell – Project Support & Development at NatureSpy

From surveying wildlife diversity to focussing on a near-threatened species

The summer 2021 species inventory survey at Alladale Wilderness Reserve helped us to learn about the diversity of wildlife across the reserve’s variety of habitats, ranging from the montane hilltops to the banks of the Alladale River. This survey captured footage of 56 different species, including mountain hares, pine martens, red squirrels, water voles and golden eagles – to name just a few! Check out some of the highlights from this survey in the video below…

A species inventory survey is designed to reveal as many species as possible, so the camera locations are chosen based on effectively covering the variety of habitats across an area. This can then serve as a foundation for more species-focussed or habitat-focussed monitoring, as there will almost inevitably be some questions that arise. For example, you might find species you weren’t expecting, more footage of a particular species than you anticipated, or observe unique behaviours.

Following the inventory survey at Alladale, we decided we wanted to learn more about the reserve’s mountain hares. Given that sightings of mountain hares are infrequent across the reserve, we were pleased to see numerous mountain hare visits to the trail cameras in the montane habitats. This summer we’ve partnered up with Mossy Earth to run a mountain hare survey at the reserve to learn more about the local populations of this elusive species, which will help to inform conservation of mountain hares at Alladale.

A view through Glen Alladale

Mountain hare conservation and monitoring

Mountain hares are classed as a near-threatened species in Britain and were given full protection in Scotland in 2021. The species faces a range of pressures including loss of preferred habitat as a result of land use change, resource competition with brown hares and uncertainty surrounding the impacts of mountain hare control measures. They are an understudied species, in part due to the challenges of monitoring them. The highly effective camouflage of mountain hares changes from grey-brown fur in the summer to white fur in the winter, so they’re well hidden in the high elevations of the uplands and moorlands where they live. They’re also mainly active at night, so the chances of seeing one in person can be slim! A recent, innovative mountain hare survey in Scotland used data collected by citizen scientists, who logged mountain hare sightings using the Mammal Mapper phone app. 66 volunteers covered 1,465km using the app, collecting valuable information to better inform mountain hare conservation. Remote sensing technology such as camera traps are a useful tool for mountain hare monitoring too, as the cameras can be left for long durations, capturing insights into the numbers and activity of mountain hares when they’re most active at night.

A mountain hare in foggy weather at Alladale Wilderness Reserve

Monitoring mountain hares at Alladale Wilderness Reserve

We’ve set up 10 camera stations in a pilot survey for 6 weeks, targeting montane habitats on the reserve where we expect there to be most mountain hare activity over the summer months. This covers 2 of 4 core areas of interest for mountain hare activity across the reserve. Once we’ve got the results of the pilot survey, we’ll consider options to expand the survey and repeat it in winter months to compare mountain hare activity across seasons. Of course there are many other species on Alladale’s hilltops as well, so this will also be a good opportunity to see which other species are active in these higher elevations.

Camera trapping on the high tops

Setting up trail cameras on Alladale’s high tops is a very different experience to surveying in Alladale’s wooded glens. All of the cameras we installed were at elevations over 2000ft (610m), so we were into mountain territory. Within just a few hours we rapidly experienced all kinds of weather, from biting winds to calm sunny spells. This is also a challenging landscape to traverse, with lots of steep features. Over 2 days of setting up the 10 camera traps we travelled 40km with 2000m of ascent. Thankfully though, we had the help of Alladale’s rangers, who took us over the rough terrain with all our gear…

An Argo is the ideal vehicle for this landscape!

What kind of camera traps are suitable for mountain hare surveys?

There are a few main considerations when choosing a trail camera for a mountain hare survey: battery life, large memory cards and clear night-time footage. Montane surveys of this kind are likely to be in harder to reach places, so you want to be able to leave the cameras in place for longer periods and be confident that they won’t run out of storage space or battery power. Clear night time footage is important as we expect most footage of mountain hares to be at night time.

On this survey we used Browning camera traps and have installed a split of no-glow and low-glow models. The reason for this split is that mountain hares are curious animals: we found that they often approached our low-glow infrared cameras in the species inventory survey at Alladale in 2021, so we’re testing out some no-low infrared cameras to see if this reduces the survey bias effect caused by mountain hares’ curiosity. All the cameras are equipped with a fresh set of Energizer lithium AA batteries, as these provide best performance for most camera trap models, along with 64gb memory cards so there’s plenty of storage space.

We’ve opted for camera trap video recording in this survey so we can gather extra data on behaviour where possible, but the core aim of this survey to better understand the populations would also be effective with photos. Set to 20 second video clips, our cameras have the capacity to record up to 1800 video clips each over the 6-week survey period, which will be ample storage based on our experience from the species inventory survey last year.

Key camera trap settings

• 20-second, high quality video recording: for clear images.
• 1-second capture delay: the camera will be ready to trigger again instantly after a capture.
• ‘Fast’ trigger speed: to help with capturing footage of fast moving animals.
• ‘Long range’ IR flash power: so the infrared flash can extend out to animals further from the camera.
• ‘80ft’ motion detection / high sensitivity trigger: this is the highest trigger sensitivity setting on a Browning camera.

A scenic spot for a trail camera

How do you set up a camera trap on a mountain?

Alladale’s hilltops are characterised by montane, heath and bog habitats, so there’s certainly no convenient trees to attach a camera trap to. We used 50cm tall wooden posts as camera supports (and just about managed to get most posts in first try without hitting a rock – a mallet is essential here!). Lens glare from sunlight should always be a consideration with camera trap setups, but this is especially important in open landscapes. Although we anticipate most mountain hare footage to be at night, we still want any daylight clips to be clear, so all cameras were aimed south to keep glare to a minimum. Camera trap height was approximately 25cm from the ground to the lens, and cameras were angled forward slightly so that roughly the top quarter of the field of view was above the skyline. We had plenty of convenient wedge-shaped rocks to hand on the high tops so we could get those angles just right by knocking rocks in behind the posts.