The Scottish Moorland Group has collated the findings of wildlife audits undertaken at three Scottish estates where grouse shooting is a primary activity.The information from Invermark Estate, Glenogil and Glenturret estates provides a useful insight into the range of conservations benefits delivered by high-quality moorland management practices and techniques.
The activities undertaken by moorland managers on these estates are consistent with best practice adopted on many other estates across Scotland.
Between June and August this year, a team of upland ecologists from consultants Taylor Wildlife sought to identify and catalogue the wildlife on Invermark. The ecologists used a variety of survey techniques to record birds, butterflies, mammals and other species across 80km2 of upland habitats which are specifically managed for grouse.
During the survey period 10 species of raptor were recorded including Merlin, Peregrine, Golden Eagle, White-tailed Eagle, Hen Harrier and Short-eared Owl. The uplands with their associated habitats of dwarf shrub heath, blanket bog, upland burns and birch/willow scrub are an important area for breeding waders and results for the Invermark Estate were encouraging, with eight breeding species recorded.
By far the most numerous wader species were Golden Plover with an estimated 68 breeding pairs, followed by Dunlin with 32 with Common Sandpiper, Snipe, Oystercatcher, Curlew, Lapwing and Woodcock also found (see Graph 1 below). Of the above species Lapwing and Dunlin are UK Red-listed species, meaning they are of the highest conservation concern due to large decreases in their breeding populations over the last 25 years and the other six are Amber listed, meaning they have also suffered declines albeit to a lesser extent.
To have these species breeding on Invermark is testament to the current habitat management regime and also represents an exciting opportunity to find ways to increase their populations and to help to reduce their decline.
Another UK red-listed species that has suffered huge declines in recent years is the Cuckoo. Recent studies by the BTO have shown that Scottish Cuckoos are bucking the downward population trends noted in the rest of the UK and the Invermark results appear to reinforce this with eight singing male Cuckoos recorded during the survey period. Other species that appear to be doing well included Ring Ouzels, Wheatears, Skylarks and Song Thrush, the latter two being birds that are still in serious decline in the lowlands. Other red-listed species found during surveys included Black Grouse, Grasshopper Warbler, Lesser Redpoll, Spotted Flycatcher, Linnet and Starling, with an overall total of 81 bird species recorded as either breeding on the site or using the area as a valuable feeding resource.
Despite this being one of the wettest Scottish summers on record with nine species of butterfly recorded, three of which, the Northern Brown Argus, Small Heath and Small pearl-bordered Fritillary are UK Biodiversity Action Plan species and as such are of national significance. Around 90 species of moth were found, including the Small Dark Yellow Underwing, which as far as can be determined had only been recorded once before in Angus. Other insects recorded including Golden-Ringed Dragonfly (an upland specialist) and the Mountain or Blaeberry Bumblebee, a nationally scarce species.
German scientists Dr. Daniel Hoffmann & Prof. Dr. Wolfgang Rohe led a study group on Glenogil Estate, positioned between Glen Clova and Glen Lethnot in the Angus Glens between April 26 and April 30 this year.
The excursion was conducted to get to know the country and with the objective of survey the bird species in the area and also to test different field methods for counting birds and other species.
At Glenogil Estate 11 Gamekeepers and 1 Headkeeper are responsible for predator control, grouse management, heather burning, organization of the shootings and so on. Their main task is the management of the population of grouse with special focus on the heather sites. The study group assessed the populations of deer, mountain hares, rabbits and grouse and looked in detail at other bird populations.
Extracts from the report:
Black Grouse –
At the time of the excursion black grouse were displaying very intensive and we could observe them on the courtship places especially in the early morning and in the evening. Like many other ground breeding birds black grouse is endangered in many parts of its range in Europe and populations decrease widespread. Bad habitat conditions and high population of generalist predators are the main factors for the decrease. At Glenogil estate on the one hand we find excellent habitat conditions and on the other hand the intensive management of predators leads to high breeding success and high survival rates in adults and especially chicks. Special investigations about breeding success and survival rates would be very interesting to compare these data with unmanaged areas. On the four courtship places we found 16 (no. 4), 16 (no. 2), 19 (no. 3) and 20 (no. 1) mating cocks of black grouse. In total that means a minimum population of male black grouse of 84 individuals.
Commented species catalogue of birds –
Because of bad weather conditions (cold and precipitation frequency with snow and hailstorm) and a short time for examination the number of detected birds must be declared as a minimum list. In total 63 bird species could be identified. High species diversity in birds is associated with diversified use of landscape at Glenogil estate. High habitat quality and low density of generalist predators cause a high diversity in bird species. Using the example of Glenogil it can be demonstrated that the combination of habitat and predator management is the most effective conservation strategy.
The osprey (Pandion haliaetus) was not observed but the gamekeepers reported continuous sightings at the Noran Reservoir and an aerie on a pine was mapped. Also on the reservoir mute swan, greylag goose, grey heron, mallard, widgeon and tufted duck could be observed.
Short eared owls were watched several times in flight on raised stands. The population of black grouse on the estate was of a level that this area can be identified as best practice region for sustainable conservation of black grouse.
A species survey at Glenturret undertaken in 2012 has been re-appraised by the estate. Sixty one different bird species were identified. The survey showed two confirmed breeding attempts by Hen Harriers, with further successes in 2015, and eight species of raptor, all of which are breeding.
The estate habitat also featured a number of red-listed species such as Black Grouse, Cuckoo, Lapwing, Twite and Yellowhammer.
The estate gamekeeping staff this year reported wo pairs of Harriers on the moor, both of which nested, producing three fledglings. The Ring Ouzel, a species of conservation concern, has found an environment at Glenturret in which to thrive because of the moorland management.