The Aigas Beaver Demonstration Project

In 2006, Aigas began a pioneering conservation project to demonstrate to people the transformative power of the Eurasian beaver (Castor fiber) on wetland environments. These remarkable ecosystem engineers build dams to alter water flow and transform the environment around them, providing habitat for many other species. The Aigas beaver project has been a great success and all it takes now to see the positive impacts of our beavers is a walk around the back of the Aigas Loch during the summer, where you are sure to see a multitude of dragonflies, damselflies, toads, newts and aquatic plants that all make use of the beaver-made pools and channels.

As a result of projects such as the one at Aigas the story of the beaver in Scotland is now entering a new chapter. After years of campaigning, October 2025 marked a milestone: two beaver families were introduced to Glen Affric, where we hope they will replicate the positive impacts seen at Aigas.

It is a perfect time, therefore, for us to bring our project to an end, as our pioneering project has done exactly what we wanted: it has demonstrated the importance of beavers to the Highlands’ landscape. In their natural habitat, beavers will move from place to place every fifteen to twenty years in search of new young trees to feed on. At Aigas, as they were fenced in to stay on the loch, they would be ready to move on to a new area. As such, we now enter the next phase of a beaver-altered environment where we will hope to see coppiced trees grow back healthier and denser, further improving the habitat around the Aigas Loch. It might be too early to think about it but, in another fifteen to twenty years, we may well be seeing wild beavers returning to the loch to take advantage of what we already know is just the sort of habitat that they will enjoy!

The North Highland Twinflower Conservation Project

The twinflower (Linnaea borealis) is one of the most beautiful, but unfortunately also one of the rarest, of Scotland’s wildflowers. Although often appearing as a ‘carpet’ across the woodland floor, 80% of patches in Scotland consist of single, genetically identical plants. Because these clones lack nearby genetically distinct neighbours, they cannot produce seeds, and so sexual reproduction is rare. As such, the twinflower’s numbers have declined by 44% since the 1970s, with populations fragmented by the destruction of habitat, changes in woodland management and over-grazing by sheep and deer.

The Aigas Ospreys

Since Aigas Field Centre was established, ospreys (Pandion haliaetus) have been visiting the loch and often fished on it, yet breeding attempts remained elusive for decades. The original nest was around twelve miles away but there was something about Aigas Loch that drew these birds to the site. The challenge of attracting a breeding pair became an ongoing project for the Field Centre for over forty years. In the 1980s the process begun when John, with help from his friend and Britain’s pre-eminent raptor reintroduction expert Roy Dennis, set up a nesting platform to try and tempt ospreys to settle at Aigas. Ospreys are generally lazy when it comes to nesting and, if they see a suitable nest that has already been built for them, they will usually opt to use it rather than build their own. However, whilst the ospreys did enjoy using the nesting platform as a perch to rest on between fishing sessions, for a long time they never actually bred beside the loch.

By 2016 ospreys were being seen regularly throughout the summer, taking advantage of the fact that the loch was stocked with fish especially for them, and so the project was kicked up a gear. The original nest site was deemed too close to the denser forestry to the north of the loch, and a new post was erected in a more open area. This is the nest platform that we have to this day. It took a few years but in 2024 we finally had a pair of ospreys that decided that this was where they wanted to nest. The pair mated, much to the excitement of John who was spending hours every day monitoring the nest, but, unfortunately, they were unsuccessful. We believe that the female was young and inexperienced and may have been spooked from the nest by a passing buzzard, raven, or another osprey. The next year our female returned, but the result was the same; she mated with a male bird but again left the nest before her eggs hatched. The promising thing is that she did return, so in 2026 we are all crossing our fingers and toes in the hope that third time really is the charm and, after decades of trying, we will finally have ospreys breeding on the Aigas Loch.

Woodland Expansion Project

This is the project that has fundamentally underpinned Aigas’ development over the past 50 years. When John set up the Field Centre in 1976 the environment was very different from what we see today: years of overgrazing from sheep and deer had left much of the area covered by short grass, with small patches of woodland dotted around the loch and up onto the moor. Over the past half-century, however, this has transformed and young trees have begun growing up across the estate. Some of this has been due to planting: fenced exclosures with birch and aspen planted up by the Aigas team have given some of these trees a fighting chance against grazing pressure from herbivores. However, most of this transformation has occurred through careful management of the land. Each winter we cull some of the red deer who use the estate as a feeding ground, through a careful management plan that is updated regularly to support targets set by the government alongside our own goals to bring densities down. We are also working to limit bracken coverage in certain areas, replicating the disturbance that would historically have been caused by large herbivores like aurochs and wild boar. With these species no longer present, it is now the job of the Aigas rangers to bruise the bracken’s stems to keep it from growing tall and shading out young saplings. This can be an arduous task, but it has allowed for pioneer species such as birch and rowan to begin growing up at the back of the old Scots pine plantations, creating a buffer zone between forest and moor.

Other Projects

As well as these core conservation projects, we are currently working on several smaller projects as we aim to further improve the environment around us. Over the past year we have been carrying out a number of surveys to assist with nationwide citizen science projects; from amphibians and reptiles through to waxcap fungi and invertebrates, these are helping us to not only assist in data collection for other organisations but also gain a clearer picture of what exactly we have at Aigas. Furthermore, these results are giving us the foundation to begin new projects. This winter we began clearing an area in the Aigas Quarry to provide a better feeding habitat for the declining pearl-bordered fritillary (Boloria euphrosyne) and over the coming year we aim to also improve their breeding habitat up on the moor. We are also looking into our adder (Vipera berus) population and will be seeking to improve the area for Britain’s only venomous snake. 

We are also currently the possibility of creating a wildflower meadow on the estate. This will create a wonderful environment for a whole host of invertebrate life, and over the coming year we will be considering which style of management best suits the area; will we use livestock and a managed grazing plan, or will it be the job of a ranger with a scythe to take a traditional approach to meadow management? This is an exciting time for conservation at Aigas, so do follow us on our journey as we continue to improve what is already an amazing area for Scottish wildlife.