Forest of Birse Native Pinewoods: Biodiversity and Importance of the Habitat
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The Forest of Birse Native Pinewoods: Biodiversity and Importance of the Habitat. Alastair Pout 2021 Introduction The Native Pinewoods in the Forest of Birse form a continuous integrated habitat that includes ancient Scots pine woodlands, more recent areas of natural pine regeneration, and native broadleaved riparian woodland along the Water of Feugh and its tributaries. Adjacent to these woodlands are important areas of upland heather moorland, grassland and bog. The flora and fauna found across these habitats, and within the pinewoods, is diverse and includes a number of species that are considered to be of national importance. The conservation and management of the pinewood area should recognise that the scale, connectivity and diversity of these habitats is of importance to the species they support. The main parts of the pinewood are Glen Ferrick, the Finlets, West Bogturk and Allachrowan on the north side of the Feugh and the Laird's Burn and Garrol Burn areas south of the river. Collectively these areas cover nearly 1000 hectares; the pinewood area on the north side of the Feugh extending for over 5 kilometres along the east-west axis of the river. The Glen Ferrick and Finlets pinewoods are Scotland's most easterly surviving Native Caledonian Pinewood. The site is covered by Forestry Commission Scotland's Register of Caledonian Pinewoods and subject under UK legislation to the European Community Council Directive 92/43 as Priority British Vegetation Types in Danger of Disappearance. To quote Scottish Government policy on this designation “These ancient woodlands form an irreplaceable community of adapted genetic stock of plants and animals. This is vitally important from a scientific standpoint but perhaps more importantly to the average person, these old woodlands are just magical places in which to spend time”. These natural woodlands, in addition to Scots pine, also include birch, juniper, oak, alder, rowan, holly, aspen and hawthorn. Within the pinewoods there is an understory rich in heathers, blaeberry, crowberry, ferns and bryophytes, while the structure of the woodlands reflects their natural development and the age and diversity of tree forms; contorted ancient pines, and naturally regenerating younger pines. What follows is a brief survey of some of the monitored and better-known species within the area. Raptors The Forest of Birse pinewoods are an important area for rare and protected raptor species. Golden Eagle, Goshawk, Sparrowhawk and Buzzard all breed within the pinewoods, and of these Goshawk are afforded special protection as a Schedule 1 species under the Wildlife and Countryside Act 1981, and the Golden Eagle is a Schedule A1 species, a designation which extends protection to habitually used nest sites throughout the year. In addition to the current breeding species, the White-tailed Eagle, another Schedule A1 species, has a number of well-established roosting sites in the Glen Ferrick and Finlets pinewoods and these are areas that offer suitable breeding habitat for the species. Red Kite, a Schedule 1 species, have nested in adjacent smaller woodlands and utilise the area for hunting. The more open habitats associated with the pinewoods support breeding pairs of Merlin, and less regularly Hen Harrier and Peregrine, all Schedule 1 species. Kestrel utilise the area as hunting habitat and have bred in the past. A communal Hen Harrier roost, with a long history of monitoring, is within the regenerating pines. Tawny Owl nest in the woodlands in some numbers, Short-eared Owls have bred within the Bogturk bowl, and Barn Owl is a locally rare species that has recently bred in the locality. The Bogturk bowl is a traditional site for wintering Great Grey Shrike. Golden Eagles, Finlets/Glen Ferrick 2018 Sparrowhawk, Finlets 2015 Great Grey Shrike, Bogturk bowl 2015 Hen Harriers coming into roost 2018 Capercaillie and Black Grouse The Capercaillie is a denizen of relic Caledonian pinewoods, with small populations existing in what suitable habitat remains in Scotland. The latest population estimates put the UK population at fewer than 1200 individuals. It is a Red List species under the Birds of Conservation Concern review and is listed on the UK Biodiversity Action Plan (UKBAP) as a priority species, and it is on the Scottish Biodiversity List. The Glen Ferrick and Finlets pinewood habitats support a small but viable population of Capercaillie. Substantial numbers of Black Grouse are to be found in the Forest of Birse pinewoods and their surrounding areas. The understory of blaeberry in the woods is a well utilised food source and the Bogturk bowl is a traditional leking site where the blackcock gather to display in the spring. Capercaillie, Rhachatan, Glen Ferrick 2021 Crossbills The Forest of Birse pinewoods support all three species of Crossbill: the endemic Scottish Crossbill Loxia scotica, the Parrot Crossbill L. pytyopsittacus and the Common Crossbill L. curvirostra. Breeding records exist for the Scottish and Common Crossbills, and the persistence of the Parrot Crossbill in the area suggests that breeding is highly likely though yet to be proved. The size and shape of the bill of these various species are adapted to feeding on different conifer cones. Scottish and Parrot Crossbills favour Scots pine, while the Common Crossbill favours larch and spruce. Large flocks of crossbills can often be seen feeding on the larch at the west end of the West Bogturk pinewoods. Crossbill, Glen Ferrick Pinewoods 2016 Waders and Gulls The Bogturk bowl is a breeding location for Curlew and Common Snipe, and Woodcock occur in the woodlands and their fringes. Common Gull breed in colonies around the Bogturk bowl and on Lamahip. Woodland Passerines and others There are a wide variety of small passerines and other bird species in, and associated with, the Forest of Birse pinewood habitats. These species include breeding records for Great-Spotted Woodpecker, Green Woodpecker, Coal Tit, Goldcrest, Treecreeper, Siskin, Long-tailed Tit, Great Tit, Blue Tit, Spotted Flycatcher, Chaffinch, Song Thrush, Mistle Thrush, Willow Warbler, Chiff Chaff, Tree Pipit, Wren, Robin, Redstart, Jay, Woodpigeon, Redpoll and Bullfinch. Breeding species in the regenerating deciduous and pine woodland north of the Feugh include Meadow Pipit, Whinchat, Stonechat, Whitethroat, and Cuckoo. Migrating flocks of Fieldfare and Redwing invade the woodlands each autumn and feast on the crop of available rowan berries. Crested Tit has been recorded on a number of occasions, most recently in 2020. The Crested Tit is another Schedule 1 species whose habitat requirements limit it to small areas of the semi-natural coniferous woodlands, where it nests in the natural cavities of the older trees found in undisturbed habitats. This is a species that has long been limited to the Spey valley in Scotland, but recent records suggest possible colonisation of areas in the Dee catchment. The records for Birse are the most easterly records for this species in Scotland. Crested Tit, Rhachatan, Glen Ferrick 2020 Spotted Flycatcher Lamahip 2020 Treecreeper, Glen Ferrick 2016 The complete list of Schedule 1 bird species found in and around these woodlands is: Golden Eagle, White-tailed Eagle, Hen Harrier, Goshawk, Red Kite, Barn Owl, Capercaillie, Crested Tit, Scottish Crossbill, Common Crossbill, and Parrot Crossbill. Mammals Badgers and Pine Martins have a known sett and dens respectively in the West Bogturk and Allachrowan pinewoods; Badgers, Pine Martins and Foxes are also known residents of the woodlands at Finlets and Glen Ferrick. Red Squirrels are resident throughout the pinewoods with the name Ferrick being the Gaelic word for squirrel. There are records of wildcats in these woods in the recent past. Otters are resident along the Feugh and are likely to utilise the tributaries on both sides of the river. The pinewoods are extensively used by Roe Deer and Red Deer. Small mammal records from the area include: Pygmy Shrew, Common Shrew, Wood Mouse, Field Vole, Bank Vole, Hedgehog, Mole, Rabbit, Stoat and Weasel. Water Vole activity has been recorded in the vicinity in recent years. Four species of bat have been recorded in Forest of Birse; Common Pipistrelle, Soprano Pipistrelle, Daubenton’s Bat, and Brown Long-eared Bat. Pine martin at its den in the Allachrowan pinewoods, Badgers family group in Glen Ferrick pinewoods. Reptiles and Amphibians The Adder Vipera berus is present in the Forest of Birse with encounter records from throughout the Feugh watershed, including records from the Glen Ferrick, Finlets and West Bogturk pinewoods. In addition, there are a number of communal hibernacula known in the area the largest of which is used by a minimum of 18 individual adders. Other undetected sites are likely to exist in the area. The adder is a species that has undergone a recent 39% contraction in its UK range due to habitat loss, fragmentation and disturbance, and there are concerns for its extinction in large parts of the country. The Viviparous Lizard Zootoca vivipara and the Slowworm Anguis fragilis are both fairly common and have been recorded throughout the area. Slowworms are not infrequently seen baking on roadside verges. Common Frog, Common Toad and Palmate Newt have been recorded in all the woodlands. Spawning pools for the Common Frog and Common Toad are known in the Allachrowan pinewoods Bogturk, Rhachatan, Glen Ferrick and the Laird’s Burn pinewoods. Palmate Newt breeding pools are known in Glen Ferrick and the Finlets woods. The reptiles and amphibians in the area, being relatively slow-moving ground dwelling species, are particularly susceptible to being squashed by traffic on the Forest of Birse road; eight adders were recorded killed on the road between the Finlets and Ballochan in 2020. Adder in Allachrowan Pinewoods July 2018. Butterflies A total of 17 species of butterfly have been recorded in the Forest of Birse. Of particular interest is the Scotch Argus Erebia aethiops, a species whose caterpillars feed on rough grasslands, and which has been recorded in Rhachatan and adjacent to the Laird’s Burn pinewoods.