IT’S been more than 150 years since the pine marten was last seen in the wild in the Forest of Dean, but there are plans to re-introduce this small, native predator to the area.
Persecution by Victorian gamekeepers and the loss of its woodland habitat took the species to the brink of extinction in the UK and by the First World War the animal was confined to more remote areas of the country.
But now there is a project, led by conservationist Andrew Stringer, investigating
the feasibility of re-introducing the animal to the Dean and Wye Valley.
Mr Stringer works for the Gloucestershire Wildlife Trust which is behind the project, along with the Forestry Commission and the Herefordshire-based Vincent Wildlife Trust.
He said: “Pine martens were wiped out in the Forest of Dean by Victorian gamekeepers – gamekeeping was about wiping out predators across the landscape to increase game bird numbers.
“When the railways came they were probably still quite common, but by 1850 pine martens were getting rare and were restricted to the north west of Scotland.”
From their stronghold in the area around Inverness, pine marten numbers have gradually increased in Scotland but they remain rare in England and Wales.
Mr Stringer said: “Over the last 30 years, Scotland has been doing quite well, expanding south, and they are now quite common north of Edinburgh and Glasgow, but the population in England and Wales has not recovered because these tiny, scattered pockets were barely hanging on.”
To boost the geographical spread of pine martens, the Vincent Wildlife Trust relocated 51 of the animals to central Wales and the plan for another release in the Forest and Wye Valley is closely related to that.
Mr Stringer said: “The central Wales project has happened over the last three years is doing quite well.
“On the back of that it was thought a second release might be useful – 51 animals isn’t a great number and individuals quickly start breeding with cousins, which we don’t think is a good idea.”
Providing good woodland habitat and just 100 kilometres from that first release in central Wales, the Forest and Wye Valley was identified as a potential new home for another population of martens.
“The Vincent Wildlife Trust, the Gloucestershire Wildlife Trust and the Forestry Commission have been doing a feasibility study over
the last 12 to 18 months trying to work out if this is a good idea.
“The first part of the feasibility study was to establish whether a population of pine martens could live here.
“They are woodland-dependent and there does appear to be good amounts of suitable woodland and we did some habitat surveys.
“They have one of the broadest diets of the mustelids – which also includes the badgers, otters and weasels – and their primary prey is small mammals.
“We had a masters student looking at small mammal abundance such as voles to check that was all right.”
The efforts of Victorian gamekeepers meant that the only native predator left in any numbers was the fox, but a large “guild” of predators is good for an eco-system, added Mr Stringer.
“They cap the populations of our most common species which can allow rarer species to thrive.
“One of the benefits is just the joy of having pine martens in an area but there are wider benefits of predation for the eco-system.
“One of the problems with UK eco-systems is that we don’t really have predators, so we only have foxes left.
“If you restore the predator guild then you restore balance to the eco-system.”
One potential benefit of re-introducing pine martens is that they take grey squirrels, an American invader that can do great damage to trees and has driven out the native red squirrel.
“Pine martens do eat red squirrels but they have lived alongside each other for two million years so it knows how
to avoid pine marten predation,” he added.
“There are no pine martens in the parts of America where there are grey squirrels so they just don’t have that history behind them and so have no real idea of how to avoid predation.
“Grey squirrels have been eradicated from six counties in Ireland where pine martens have been introduced – which is extraordinary and unexpected – and red squirrels have come back in three counties.
“That is being repeated in Scotland where grey squirrels are hitting pine martens heading south.
“The researcher had real difficulties finding areas where there was overlap – it’s this kind of mosaic at the moment but that says something about the potential impact of pine martens.
“There are no red squirrels in the Forest or Wye Valley but if grey squirrels were eradicated completely, we could wait for a natural recolonisation or, perhaps, in 10 or 20 years look at another reintroduction.”
Given the impact of pine martens on grey squirrels it is hoped that the project could get financial backing from owners of private forestry as well as trusts and other funding bodies.
If the public gets behind the project, funding would be needed to embark on a release and a five-year monitoring programme.
The plan is to release 40 animals over two years with each being fitted with a collar to allow it to be tracked – with the funding in place it could take place as early as this autumn but 2019 is the more likely date.
Mr Stringer said: “Releases always happen in September – you catch animals when the kits are no longer reliant on mum but you don’t want to release too close to winter.”
Unlike the proposed re-introduction of beaver, which will take place in an enclosure near Lydbrook, the release of pine martens would be “free range”.
Mr Stringer said: “If you release a marten, they will move between five and 20 kilometres before settling into a home range – you can’t really pick a wood, you pick a region.
“You say: here’s some good habitat, we’re going to track you and we’ll make sure that if you go onto someone’s land we’ll talk to the owners, but we really have to be adaptive to where they want to go rather than proscribing a single location.”
They roam over huge areas – an individual’s home range could be anything between two square kilometres and 30 square kilometres – but numbers are quite low.
“The territories are non-overlapping within sexes, so females will defend a territory against other females and males against other males.”
Pine martens will have den sites to raise their kits in the spring and dozens of resting sites dotted around their territory.
Dens are often in tree cavities which are usually found in old, deciduous woodland and there are areas of the Dean which fit the bill.
There may be three or four dens at key locations which they will move their kits between following birth in the spring.
A female pine marten will have between one and five kits a year but there is a very high mortality rate – as much as 50 per cent – among the young.
One of the key concerns about the viability of a Forest population was the roads: there is far more traffic here than in central Wales or the north of Scotland.
Mr Stringer said: “We compared road density in the Forest of Dean and the Wye Valley with the Netherlands where there are good populations of pine martens.
“We were able to show that road density in the Dean isn’t particularly high compared with the Netherlands so that is less of a concern.”
Population growth is not particularly fast for pine martens, given that they only have one litter a year and the high mortality rate, and it is thought the maximum in the Dean and Wye Valley would be about 200.
The hope is that eventually the Dean and central Wales populations will merge, making the presence of pine in the south west of Britain stronger.
“They don’t really swim, so with the Severn to south, they are going to expand to the north and west, directly towards that Welsh population, and you would expect them to merge over a decent period of time.
“The two populations meeting would be really important for the conservation of the species – we think it would happen surprisingly quickly because they are only 100km apart.
“We think that after 15 or 20 years you will get individuals migrating between the areas – the furthest juvenile disperal distance we’ve seen is more than 200km.
“Once these populations start reinforcing each other, then it becomes more stable as a species.”
“The location here is great, the habitat is pretty good and you’ve got a real mosaic of woodlands which make a really nice mix of habitats.”
The project has also looked at the potential for ‘conflict’ between the new inhabitants and humans, on the one hand, and other species on the other.
The most likely area for a clash between humans and pine marten would be taking poultry in or around woodlands and there is ‘anecdotal’ evidence of chickens being taken in Scotland.
“There are lots of ways of stopping pine martens getting to poultry and they are the same methods that would be used to stop foxes and stoats getting in.
“We know poultry is in their diet and there are anecdotes of pine marten getting into poultry. We don’t know how common it is but intuitively it seems pretty low.”
The big concern is the potential impact on bats – martens will use buildings if suitable trees are not available, which could lead to bat roosts being disturbed.
“The inherent risks of re-introduction are usually pretty low and we have done a review of re-introductions world-wide.
“Because you are re-setting an eco-system, you are re-balancing it to a state it was previously in so the risk of negative effects is pretty low, but we are worried about pine martens disturbing bat roosts in buildings.
“That is a key risk and something we would have to plan for and mitigate against if the re-introduction went ahead.”
If martens were to return to the Forest, they would make up the largest population in England and would be monitored closely.
“We would have collars on every pine marten in the first year so we’d know where they were and check they are all right.
“We’d be doing dietary analysis so we know what they are eating by picking up scats which will be a glamorous job for somebody.
“We would hope to set up a project legacy so the Gloucestershire Wildlife Trust and the Forestry Commission would want a long-term monitoring programme.
“You can monitor them using camera traps and we’ll be doing that for five years. We’re hoping to get a volunteer group set up to follow that on, so we’ve got a handle on what’s happening long-term.”
The re-introduction would follow international guidelines to further reduce the risk of any conflict.
“The boar are a classic example of an illegal release rather than a planned release – if someone had done a feasibility study on the boar they would have seen the high levels of conflict in Europe.
“We’ve been following the guidelines so we know what the costs and benefits of a
re-introduction would be and we can present that to the local community and ask if they want it.
“We would be on hand and be responsible for the re-introduction to help in any way we could.”
Even in areas where pine martens are more common, you would be “extraordinarily lucky”
to see one in the wild, said Mr Stringer.
“We would be quite keen to set up a location where people could have a good chance of seeing pine martens both for the enjoyment of the local community and for promoting things such as eco-tourism.”
As well as the ecological and scientific value of the project, Mr Stringer also believes there is a “moral” dimension.
“As a conservationist I see that we wiped them out and it is almost our duty or a moral obligation to restore what was lost.
“I see this as a positive thing we can be doing, and it could have a much bigger landscape impact by supporting the Welsh re-introduction and establishing the species over a big area.
“We have meddled in nature but I think we are trying to right an historical wrong.”
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WHAT’S YOUR VIEW?
PUBLIC support for the re-introduction of pine marten is crucial to the project with street surveys and an online questionnaire among the tools being used.
Researchers will be asking people for their views on the streets of Coleford, Cinderford and Lydney in the coming weeks and the online version will be open until the end of the month on the Gloucestershire Wildlife Trust’s website, www.gloucestershirewildlifetrust.
Search for pine marten on the site to get to the questionnaire and view videos about the project.
Project manager Andrew Stringer said: “We are getting Forest Research to do our main on-street surveys so it will be completely independent and unbiased. We want the data analysed by the spring.”
Mr Stringer has also been giving talks to interested groups and the next one is to the Chepstow branch of the Gwent Wildlife Trust and takes place on Wednesday, January 17, at 7.30pm at Chepstow Leisure Centre.
He said: “All that consultation will build up a good picture of whether the community wants this because we are not going ahead without their support, that is essential for the project.”