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15 Jun 2018

Over a century of biological recording at Mar Lodge Estate

Written by Andrew Painting
Scotch argus butterfly on a blade of grass
Scotch argus butterfly
The Mar Lodge Estate species list now includes over a hundred years of data. Read on to discover all about the current biological monitoring and recording projects on Britain’s newest National Nature Reserve.

In 2017 Mar Lodge Estate became the UK’s largest National Nature Reserve. The estate’s 29,380 hectares host a vast collection of species and habitats, from Caledonian pinewoods, blanket bog and heather moorland along the banks of the Dee, to the subarctic tundra, high-level lochs and isolated crags of the Cairngorm plateau. Mar Lodge Estate is a dynamic environment, managed as wild land, which makes it a hugely exciting place for biological recording. Thanks to the size of the reserve, its biodiversity and its remoteness, the chances of turning up something truly special here are really high!

The National Trust for Scotland has looked after Mar Lodge Estate since 1995, but biological recording has been going on here for well over a century. In early 2018 (while we were snowed in), Trust ecologists collated all of the species records that we could find for the estate. It was a task made infinitely easier by access to public records from the National Biodiversity Network, Biological Records Centre and the Botanical Society of Britain and Ireland. But we didn’t stop there! Our eclectic list of sources also included Trust archives, local residents and even a book of flower pressings from the 19th century.

Historical twinflower pressing
Historical twinflower pressing

Here’s a selection of some of the highlights:

Plants (618 species)

There are literally hundreds of exceptional plant species around the reserve. In the Caledonian pinewoods and along the burns you can find the likes of twinflower, small cow-wheat and round-leaved wintergreen; high on the plateau, pockets of Highland saxifrage and Highland cudweed cling to crags in remote corries.

Much of our recent ecological work has focused on the reserve’s Caledonian pinewood, one of the most iconic Scottish habitats. When the Trust took on the estate in 1995, the Caledonian pinewood was struggling, having been hit by a combination of centuries of forestry operations and heavy grazing by deer. Now, after 20 years of careful deer management, we’ve effectively doubled the amount of Caledonian pinewood on the estate. We’re now seeing the first new generation of naturally regenerating pines here since the 19th century.


Another benefit of the alleviation of heavy grazing is that we’re regularly finding new, and previously overlooked, patches of less common species. A significant proportion of our records of common twayblade (a type of orchid) and globeflower come from the last five years.

In 2016–17, in collaboration with Cairngorms National Park, thousands of hectares of upland to an altitude of 900m (2,950ft) were surveyed for montane woodland species (a mixture of willows, birches and juniper). This survey has provided amazing baseline data which will inform plans to increase the abundance of this rare and important habitat.

Scotch argus butterfly on a blade of grass
Scotch argus butterfly

Insects (1,966 species)

With so many insects on our books, the collection of these records is down to a huge number of recorders, to whom we are very grateful.

New insect species continue to turn up on an annual basis. The latest addition, the shining guest ant, was discovered in September 2017 following work with the Rare Invertebrates in the Cairngorms project.

The narrow-headed ant is known to inhabit fewer than 10 sites in the UK, so we keep a very close eye on the nests found here. In 2017, volunteers from the John Muir Trust found several new nests for this rare species, increasing the population here by 20%.

Hats off, finally, to a true rarity - the small empid fly. It was only discovered in 1985 and Mar Lodge Estate is its only known habitat in Scotland.

Black grouse displaying © Rob Hume
Black grouse © Rob Hume

Birds (145 species)

A total of 145 bird species, of which around 110 are seen annually, may not seem too remarkable for a nature reserve, but this number belies the quality and importance of Mar Lodge Estate as a place for some of the UK’s rarest birds. 30% of Britain’s Red-listed bird species regularly breed on the estate, including hen harrier, merlin and ring ouzel on the moors, and spotted flycatcher, tree pipit and cuckoo in the woods. Mar Lodge Estate is one of a handful of places in Scotland that is home to all four of Britain’s grouse species, hosting around 2% of the UK population of black grouse.

The estate is also well known for its birds of prey. In 2017 11 species of raptors and owls were recorded breeding on the reserve. Golden eagles have been monitored on the estate for over a century, making this one of the longest studied eagle populations anywhere in the world. Hen harriers successfully bred here for the first time in living memory in 2016. As part of the RSPB’s Hen Harrier LIFE Project we’ve been satellite tagging some of these birds. Our first tagged bird, Harriet, tends to spend the winter in the Lake District, but she regularly returns here during her springtime forays around the eastern Highlands.

Buxbaumia viridis
Buxbaumia viridis

Lichens and bryophytes (1,135 species)

The most interesting sites for these groups on the estate are the montane areas and the pinewood. The high altitude late-lying snow-beds, home to lichens and bryophytes found nowhere else in the country, are a habitat of national importance. Time will tell how climate change affects these delicate communities.

At lower altitudes, the UK’s largest single population of green shield-moss Buxbaumia viridis was recently discovered very close to the Lodge itself.

The final number?

As with all species lists, the more you look the more you find. A species list will never be ‘complete’, but this latest compilation is an extended snapshot in time, covering over 100 years of biological monitoring on Mar Lodge Estate, and the efforts of hundreds of recorders. We’re happy to say that the Mar Lodge Estate species list currently stands at 5,186 species or, perhaps more accurately, about 5,200 species.

There is one family of creatures, however, which stands head and shoulders above the rest for its under-representation on our species list. It’s ubiquitous – on some visits to the estate it will be the wildlife you remember most clearly – but no species have been officially recorded here. It is, of course, Ceratopogonidae, also known as the midgie.