Craibstone Pine Martens
Pine Marten Martes martes
Pine Martens are members of the mustelid family, found throughout Europe and into Asia. They are slightly smaller than a Badger Meles meles and can be found in coniferous, deciduous or mixed woodland. They are carnivores with the same general body shape as a Stoat Mustela eminea only larger and longer legged, with a brown coat and a small yellow bib on it’s throat/chest. Also the nose is more elongated than the Stoat and the tail is long and bushy.
In the UK, the Pine Marten is largely restricted to Scotland, north of the Firth of Forth, and with a smaller population in Dumfries and Galloway. There are other areas in which there have been reliable sightings in England and Wales where there is hope the species is starting to make a comeback.
Pine Martens are active from dusk until dawn and are very shy. This species is well adapted for life in the trees, usually choosing to rest in holes in trees or amongst the branches, but will come down to ground level to hunt as well. Despite being a carnivore, feeding on rodents, shrews, birds, eggs, amphibians and insects, they will also feed on fruit.
Discovery at Craibstone
As a part of our Rural Skills Club, we got a trail camera on loan from North East Scotland Biological Records Centre (NESBReC) and set it up in the predominantly Beech woodland in the south corner of the estate. It was left for a week and captured about 15 videos. Some of these videos were of the group setting up the camera and a couple of videos had been triggered by twigs blowing in the wind. However, there were 4 videos of Roe Deer Capreolus capreolus and several videos of the same Rabbit Oryctolagus cuniculus (the species we expected due to droppings in the area). One of the videos had also captured a Pine Marten scent marking on the stump that the camera had been tied to on the right hand side of the picture, and then walking across the field of view, close to the camera, going from right to left.
Whilst the image was not terribly clear, the animal that was captured is identified as a Pine Marten by the shape of the nose, the length of the legs and it’s overall size. Stoat Mustela erminea is ruled out based on size, and American Mink Mustela vison is ruled out based on nose shape and leg and ear length, as is Otter Lutra lutra.
This is the first time Pine Marten has been recorded on this site and the trail camera has been set up again in order to hopefully capture more footage of Pine Marten(s) before returning the camera to NESBReC. There is the possibility that a trail camera will be purchased by me, in which case more camera trapping will be carried out in order to hopefully understand the size of the population in the area and the area in which this population may cover.
Possible Distribution around Craibstone
Although it is not certain whether the Pine Marten that was captured by the trail camera does in fact live on the estate or whether it just happened to be visiting the area during the week that the trap was set up, it is possible to make guesses as to where it/they is/are likely be living.
The woodland in which the camera was set up in consists mainly of Beech Fagus sylvatica with a few large Scots Pines Pinus sylvestris, Silver Birches Betula pendula and other deciduous trees mixed in, making it a predominantly deciduous woodland. This patch of woodland is directly next to another patch of mixed woodland following the Gough Burn, towards the main drive from the A96 to the Scottish Rural College campus. This woodland is roughly 600m long, and 50m wide at the narrowest point and 100m wide at the widest point. The total area of woodland is c38km² assuming the Pine Martens would not venture down alongside the main drive due to disturbance. This is a sufficient area to accommodate a Pine Marten as males will have a home range of 10-25km² and females will have a home range of 5-15km². There is no way of telling how much of the area this particular marten holds as its territory at the moment because it’s not possible to tell the sex of the animal. This would be possible if the size of the Pine Marten captured on the trail camera was apparent but there is no clear view allowing size to be determined.
Future camera trapping and tracking by searching for droppings, feeding signs, tracks and other signs will help to build a bigger picture of the area which this animal, or perhaps multiple animals are covering on Craibstone Estate. This will be carried out in my own spare time or once I have purchased my own trail camera as NESBReC only lend them out for a month at a time.
It is possible that the Pine Marten was just passing through the area, although I suspect that is unlikely. The nearest patches of woodland to the patch in the south corner of the estate are commercial conifer woodland consisting of Sitka Spruce Picea sitchensis, Norway Spruce Picea abies and multiple other conifers. Commercial woodlands are not suited for Pine Martens as they have a low biodiversity when compared to mature woodland, and they offer few den sites. The other thing keeping the Pine Martens from simply visiting the area is the new Western Peripheral Bypass which is being built on the edge of this patch of woodland. On other sides of this woodland are open fields, roads and areas in which people are more active. These are all big obstacles for this species as habitat fragmentation means that young have no where to move to when they leave their mothers, roads increase mortality as martens try moving around, and they avoid areas with high disturbance.
Due to all these factors, I would feel fairly confident in saying this Pine Marten lives on the estate. The fact that it is here does bring up the question about whether the bypass constructors know of the presence of an animal with as high protection as the Pine Marten has. They are a fully protected species listed on Schedule 5 of the Wildlife and Countryside Act 1981 (amended 1988) meaning “it is an offence to kill, injure or take a marten without a licence” and it is also illegal to “damage, destroy or obstruct access to a place or structure being used by a marten for shelter or protection; or disturb a marten whilst it is using such a place or structure.” If they were aware of the Pine Martens being present in the area then they have kept very quiet about it, but I doubt they are aware due to the fact that Pine Martens are such secretive creatures. Now that the construction of the bypass is well underway, it seems to me that there is no way for any Pine Marten to actually escape this area without crossing the bypass or several fields and roads. This population, or individual, may be cut off and stuck in this area where it will never find a mate and that would be a great shame.
According to the distribution map on the NESBReC site, there have been 4 sightings of Pine Martens within Kirkhill Forest. This is 3km from Craibstone Estate and appears to be the nearest known population, however I suspect there will be Pine Martens living in Clinterty Woods and West Woods which are both across the A96 from Kirkhill Forest. I have been keeping an eye out for signs of them there but have not found any yet (20/11/15).
The pink pin marks the area in which the Craibstone Pine Marten was filmed. Clinterty and West Woods are also shown
This map shows the sightings in Kirkhill Forest and the route that the Aberdeen Western Peripheral Bypass is going to take (the pink dashed line)
Other Species Present on Craibstone Estate
There are other species that are definitely present on Craibstone Estate that are of similar place on the food chain as the Pine Marten. Red Fox Vulpes vulpes is certainly present, with four seen around the Cruickshank Buildings on one occasion and tracks and scat found in various places, I don’t feel that foxes and martens will come into conflict as they both fill different ecological niches. The only other relatively large carnivore present on campus is a black cat Felis catus that may have a small amount of Scottish Wildcat genes in it because it is large and has a blunt ended tail. However, I am yet to check with the caretaker whether it is perhaps his cat or whether he knows anything about it (20/11/15).
I have found no signs of Badgers Meles meles on the estate and I don’t suspect they would be a problem for Pine Martens anyway. Red Squirrels Sciurus vulgaris are present although I haven’t worked out where their preferred area is. I have found feeding signs about 20m from where the Pine Marten was filmed so perhaps this is yet more evidence that the martens help with the natural eradication of the Grey Squirrel Sciurus carolinensis which are also present on campus, although I have only seen them along the drive near the A96, at the opposite end of the estate to where the Pine Marten and Red Squirrels have been seen.
The fact that the Pine Marten has been caught on film at Craibstone is encouraging, but there are a few possible threats to this species in the area.
The Western Peripheral Bypass has been under construction on the east edge of the estate for a while now and the Pine Marten is still on the estate so I do not suspect that it ventures on to the site or the road where it may become road kill. The bypass prevents any movement of Pine Martens in that direction or to come from the other side so it is possible that this individual has been cut off from other populations of Pine Martens. This makes it more difficult for Pine Martens to breed in the area, and they are slow breeders (only producing c2-3 young in their lifetime) so the bypass doesn’t make it very easy for the Pine Marten to spread further.
There is a single-track road along the north edge of the patch of woodland which the Pine Marten ahs been filmed in and it is used mostly between the hours of 5 and 7pm. In winter it is dark at this time so the martens are likely to be out and therefore are at risk of being run over.
The college is set to be moving off the estate to another area, and the estate is going to be built on by Cala some time in the future. If development goes ahead, I doubt the Pine Martens will be given much consideration.
A check of the camera trap which had been set up facing the stump which the first Pine Marten was seen scent marking on revealed no further sightings of Pine Martens despite being baited with raspberry jam sandwiches. There were, however, some other visitors. A Red Fox Vulpes vulpes visited several times to eat the sandwiches, several Roe Deer Capreolus capreolus wandered past in the night, and one dog ate a single sandwich. There were also two videos captured of a Red Squirrel Sciurus vulgaris which is encouraging given the theory that Pine Martens tend to eradicate Grey Squirrels Sciurus carolinensis as they spend more time on the ground than Red Squirrels and are therefore easier to catch. This implies that Pine Martens are helping with the range expansion of Red Squirrels in the area.
A second camera trap has also been obtained from Nicky Penford which does not need returned to NESBReC, allowing us to continue surveying the area to gain knowledge of the Pine Martens.
The second camera trap has been placed facing two pipes which cross over the Gough Burn and look like a good place for mammals to cross at. Hopefully this is true and Pine Martens are using the pipes to cross. Having failed to produce the desired footage last week, jam sandwiches have been switched for peanut butter sandwiches that have been placed in front of both trail cameras to maximise the chance that a Pine Marten will be recorded on at least one of them.
The camera trap facing the pipes crossing the burn yielded no footage of anything. It has been moved to a spot in the patch of woodland in which the first footage was captured of a Pine Marten, but in an area with more Silver Birch, facing a small clearing.
A walk around the estate at about 13:00 to check to see if the peanut butter sandwiches had gone confirmed that they had been taken. When the NESBReC camera trap is checked next week, we will find out whether it was a Red Fox or Pine Marten or something else.
I continued to walk around the area and ended up searching for tracks and signs of Pine Martens and also for possible resting spots, as documented below.
Possible Resting Places
I went out to the Marten Woods in daylight for once in the hopes of discovering signs of their presence, mainly in the form of tracks or droppings. I never found any signs unfortunately, however I did find some potential resting spots of Pine Martens. Firstly, I was drawn towards a large Douglas-fir Pseudotsuga menziesii that had a lot of feeding signs of Red Squirrel Sciurus vulgaris below it in the form of some shredded cones. This tree was mature enough to have quite thick foliage towards the top which may be thick enough to successfully hide a Pine Marten.
Not far from the base of this tree, I discovered what I thought was most likely a Rabbit Oryctolagus cuniculus hole at the base of a half-fallen Alder Alnus glutinosa and a quick look down the hole using a torch revealed a decent sized cavern where the roots of the tree had once been. This mini cavern may just be used by Rabbits Oryctolagus cuniculus but it may also be used by Pine Martens because they are known to situate their dens in the root masses of fallen trees.
At the base of the Douglas-fir Pseudotsuga menziesii there were several small patches which had clearly been dug at by a small mammal. My first thought would be Rabbits Oryctolagus cuniculus as they are definitely in the area (captured by trail camera) but it may be a Red Squirrel Sciurus vulgaris burying or digging up food that it has stored beneath the soil. There were certainly some cones that had been broken apart by a feeding squirrel at the base of the Douglas-fir Pseudotsuga menziesii.
Next possible rest site I found was another fallen tree’s root mass. This one a lot more open and therefore less likely to be used during the day but it is possible that a Pine Marten may investigate it at night to have a rest. This tree is a Rauli Beech Nothofagus alpina, a tree from Chile which is suited to cool, wet climates. The earth that has been raised up by the falling tree has created a very prominent spot which I thought might be used by a Pine Marten to mark its territory on, but there were no droppings on it.
There was one more fallen tree but it didn’t provide much space for a den or rest site.
I walked a bit further down the Gough Burn to where the pipes are across the burn, and noted the large amount of Ivy Hedera helix in the area. Is it possible that a Pine Marten would enjoy the cover that this would provide? Whilst on this path I realised there was a spruce plantation on the other side of the burn just beyond a small field used for livestock. I decided to check it out in case there were any signs of Pine Martens there, although I have read that commercial plantations do not support Pine Martens very well due to their low biodiversity.
Once at the plantation I realised there was a few abandoned buildings just by it. These could potentially house a Pine Marten, although it is the Beech Marten Martes foina which is better known for living in man-made structures. There was no sign of any Pine Marten activity in the area. Roe Deer Capreolus capreolus tracks were found all over the place and one was heard crashing through the branches as it ran away from me. Rabbit Oryctolagus cuniculus droppings were everywhere, and there was a lot of evidence of Red Squirrels Sciurus vulgaris feeding on Norway Spruce Picea abies cones.
A check of both camera traps yielded no footage of Pine Marten. At least 2 Red Foxes Vulpes vulpes had visited the area multiple times to eat the food that was provided.
The camera trap that has been lent to the group by one of the lecturers is being left in the woods over the winter break, occasionally being checked by a member of the group to ensure it does not get stolen or doesn’t fall from where it has been placed. It has been placed on a tree facing the large Douglas-fir Pseudotsuga menziesii that was mentioned just above. The trap has been baited with peanut butter smeared on the tree in hopes that a Pine Marten will stay in the view of the camera as it tries to get the peanut butter out from the cracks in the bark.