New pine marten footage, den box monitoring and more...

Autumn can be a great time of year for seeing pine marten activity before the quieter winter months.

In this update we share recent findings from our work on the Yorkshire Pine Marten Project over the past few months, including recent camera trap footage, experience using thermal imagers to monitor pine marten den boxes and our new visual guide to Britain’s mustelids…

Update by Ed Snell - Project Support & Development at NatureSpy

A flurry of activity before winter

Pine martens have a busy few months ahead of colder winter weather. Mating season ends in August and this years’ kits born in spring are becoming more independent while still roaming their mothers’ territory. These kits are fully grown by September. In October, pine martens moult into thicker, bushier winter coats. As the days get chillier in November, pine marten activity tends to quieten down, as they spend more time in warm, cosy dens and less time out foraging.

Clear views of a pine marten bib pattern in Yorkshire

New pine marten findings in Yorkshire

Camera traps continue to be our main monitoring tool for pine marten activity in Yorkshire. Using a combination of more structured surveys and responding to reported sightings, we’re able to cover a lot of ground with camera traps. They enable us to keep an eye on a diverse range of forests while making sure we also have some cameras targeted at key area of interest, such as pine marten sightings hotspots and den boxes that show signs of use.

After a quiet first half of 2022, in the later summer months and into autumn we picked up pine marten footage at multiple camera locations in forests on the east side of the North York Moors.

For the first time ever, our cameras have recorded colour, daytime footage of pine martens in Yorkshire. Our footage in previous years has been recorded between dusk and dawn, which is typically when pine martens are more active. Although, pine martens are active in the daytime too, venturing out of their dens for around a third of their active time during the day.

Our camera traps have also recently recorded a pine marten using a den box as a place to sleep and predation of a grey squirrel - follow those links to see the footage and learn more!

Can you spot the sneaky pine marten?

Monitoring pine marten den boxes with thermal imagers

Over the past few years, we’ve installed 46 pine marten den boxes in forests on the North York Moors. In autumn and through winter, we may expect to see pine martens using den boxes more during colder spells, so while out on our regular camera trap surveys, we visit den boxes and use a thermal imager to check if they’re in use. If we find a den box that shows a thermal signal, we then set up a camera trap to confirm if it is a pine marten using the den box (occasionally squirrels use them too!). In some instances we're able to identify individual pine martens from their unique bib fur patterns if the footage is clear enough.

Thermal imagers are proving to be a quick and effective non-intrusive way of monitoring pine marten den boxes. Earlier in the year I spent some time in Galloway Forest trialling this approach in an area with a well-established population of pine martens. Learn more about thermal imagers and monitoring pine marten den boxes here.

Pine marten sightings and our new mustelid ID guide

Public sightings and records and a valuable part of pine marten conservation as this helps projects to identify locations, hotspots and trends in pine marten activity. This information means that conservation activity can be better targeted and tailored to different locations and situations. If you’ve seen a pine marten in Yorkshire – please get in touch!

Pine martens are however not always the easiest of species to identify! There are several species in the mustelid family that they are sometimes mistaken for that share similarities in appearance, with similar body shapes and fur colour. It's also not uncommon for a pine marten sighting to be just a fleeting glimpse at dusk or dawn - so confident identification can be challenging!

We’ve recently published an online version of our mustelid identification guide that’s proven popular at the Dalby Forest and Sutton Bank visitor centres on the North York Moors. This new web version includes illustrations, videos and top tips on distinctive characteristics to help with confidently telling apart pine martens, polecats, stoats and the rest of the mustelid crew! 

Pine marten illustration from our new guide to British mustelid identification

Learn more about the Yorkshire Pine Marten Project…

Learn more about our pine marten conservation work in our recent annual update published in September 2022 and over on the NatureSpy project pages. Click here to read our Pine Marten Conservation Strategy for Yorkshire.