On April 28th we received reports of a pine marten at Yorkshire Wildlife Trust’s Spurn National Nature Reserve in East Yorkshire. Pine marten records are sparse in Yorkshire, but in recent years we have seen a slight increase in pine marten records and reported sightings across the county. This record, however, was unique. Most pine marten sightings are a fleeting glimpse, but this record came with brilliant photographs, taken by Paul Willoughby from Spurn Bird Observatory.
A pine marten watches on at Spurn National Nature Reserve – Photo by Paul Willoughby
Individual pine martens can be identified by the unique shapes and patterns in their creamy-yellow bib fur. Paul’s photographs clearly showed this marten’s bib pattern, which we were able to compare with our own trail camera records from the Yorkshire Pine Marten Project. We discovered that this is a marten we are familiar with from our trail camera monitoring, 60 miles away in Dalby Forest. The two dark spots in this marten’s bib are a distinctive characteristic, and we had plenty of trail camera footage to compare the overall shape of the bib too.
The same pine marten, several months earlier, in Dalby Forest.
Over a 6-month period, we were lucky to see this pine marten on our trail cameras many times in Dalby Forest, observing a variety of behaviours, including denning and preying on a grey squirrel. In this blog, we share what we learnt about this very active little mustelid from our trail cameras in Dalby Forest between August 2022 and March 2023. Follow the link at the end of this article to learn more about this marten’s activity over at Spurn National Nature Reserve.
Matching up the bib pattern across our trail camera footage, we can see that we first recorded this marten on 31st August 2022, exploring a Galloway Lite pine marten den box installed in Dalby Forest. He continued to visit our trail cameras several times a month – often weekly – making the rounds of baited trail camera sites and prospecting den boxes as potential denning sites. He became such a frequent visitor that we gave him a nickname – ‘Two Dots’! Our last record of Two Dots in Dalby Forest was on March 21st 2023, he then roamed south over the next 5 weeks, ending up at Spurn Bird Observatory.
Our first record of ‘Two Dots’ in Dalby Forest, August 2022.
Pine marten home ranges are influenced by several factors, including the number of pine martens in an area (they are highly territorial), potential mates, food availability and den availability. Their home ranges vary greatly in size and have been recorded as anywhere from 0.2km2 to over 30km2 – which is roughly equivalent to the whole of Dalby Forest (Yorkshire’s second-largest forest!).
Due to the spacing of our trail cameras, we can get a sense of part of the home range of this pine marten between August 2022 and March 2023. Our cameras recorded him across 4km2, at times covering this whole area in a single night. This area is very unlikely to represent the full range he was covering and he could well have had regular dens in nearby forests. For example, Dalby Forest is a stone’s throw from Cropton Forest (Yorkshire’s largest forest!).
Due to the lack of pine martens in Yorkshire, Two Dots won’t have been facing the pressures of defending a territory from other martens. The opportunity to find a mate is also unlikely, so we could expect him to roam much larger areas than a typical pine marten territory, far exceeding the 4km2 in which we recorded him.
Our final record of Two Dots in Dalby Forest, March 2023.
Pine marten den boxes are an important part of our pine marten conservation work in Yorkshire. We’ve installed 46 den boxes to date in the North York Moors National Park and we monitor these boxes for signs of use with thermal imagers and trail cameras. Pine marten den boxes create a significant habitat enhancement by providing elevated, insulated resting and breeding dens. Den boxes are especially useful in areas where pine martens are recovering and the age structure or management of a forest means there’s less opportunities for natural denning sites, such as cavities in trees.
We recorded our wandering pine marten at 6 of our den boxes in Dalby Forest. During this time, we did not record him consistently using one den box. He made quick visits, occasionally slept in a den box, then moved on. This prospecting behaviour is encouraging, as it shows that our den boxes are in places where martens are finding and utilising them.
As part of our pine marten monitoring, we set out baited trail camera sites using various foods as attractants to draw animals in. We place the bait 4-5ft off the ground in trees, which means the animal must reach up to retrieve it, giving a better chance of showing off its bib and helping us to identify the individual. Our wandering marten visited 5 of our baited trail camera sites many times, and one of these visits resulted in our first daytime/colour trail camera footage. All of our previous records in Yorkshire were in black and white, when the trail cameras are activated during low light and night-time. Pine martens are often considered nocturnal, however they are active in the daytime too, leaving their dens for around a third of their active time during the day.
We also discovered that this pine marten has an appetite for grey squirrels, having captured footage of it carrying a grey squirrel and several months later finding a pine marten scat at a camera site that contained grey fur and claws. We’ve written a separate article digging into the details of the fascinating dynamics between pine martens, grey squirrels and red squirrels. Research suggests that pine martens could be part of the answer to helping our red squirrels recover in the UK.
As pine martens are currently recovering and expanding their former range across Scotland, England and Wales, we are likely to see them in places that they haven’t been present in for decades. Over the past 5 years, we have recorded at least three different pine martens in the Dalby Forest area. There could well be more in the area, as we cannot always determine different individuals when bib patterns are not fully visible.
Pine marten recorded in Dalby Forest in 2021 with a different bib pattern, helping us to tell apart individuals.
Our trail camera records, along with reported sightings, suggest that pine martens are persisting in low numbers in Yorkshire – which is consistent with reported sightings in region dating back to the 1970s.
We’re unlikely to ever find out the origin of this recent pine marten, but the data we have on this individual suggests that it can travel long distances across habitats that – on paper – are not particularly suitable for pine martens, including many roads, which are a major cause of pine marten mortalities. So, we can’t rule out that it may have ventured from further afield where there are larger, recovering pine marten populations.
Sadly, there have been reports of illegal translocations of pine martens in Britain, which is damaging for animal welfare and creates confusion for projects such as ours that are monitoring natural recolonisation of the species. Legal, humane translocations of pine martens are rigorous processes, involving experienced professionals that ensure the martens are healthy, translocated in numbers that are genetically sustainable and into habitats that are suitable in quality and size. Learn more about the current reintroduction process, standards and requirements in Vincent Wildlife Trust’s Long-Term Strategic Recovery Plan for Pine Marten in Britain.
NatureSpy started the Yorkshire Pine Marten Project in collaboration with Forestry England in 2013. We are currently working towards a set of pine marten conservation objectives in Yorkshire, learn more here.
Please report your sighting to us. Reported sightings help us build the evidence base for pine marten presence in Yorkshire, helping to inform regional conservation of the species.
Carrying on the story of the most-recorded pine marten we’ve ever known in Yorkshire, Rosie Jaques, Reserve and Marine Officer at Yorkshire Wildlife Trust, shares findings from Spurn National Nature Reserve in this blog.
Pine marten exploring a den box in Yorkshire
Article by Ed Snell
