Studying Pine Martens in the Wild: Methods, Tools and Insights

Pine martens are a recovering species in Britain that play an important role in balancing the ecosystems they inhabit. Understanding their distribution, behaviour, and population dynamics is essential for effective conservation efforts, but their secretive nature, mostly nocturnal activity and preference for forest habitats can make them challenging to monitor. 

This article explores a range of non-invasive monitoring techniques, including trail cameras, thermal imaging, citizen science, and genetic analysis, to gain insights into pine marten activity and inform conservation strategies. Each method offers unique insights, and combining them can provide a comprehensive understanding of pine marten populations. We utilise all of the techniques covered here in the Yorkshire Pine Marten Pathways Project. 

Trail camera photo of a pine marten

1. Observation

There are a range of observation tools and techniques available that help with capturing information about pine martens. 

Trail Cameras

A trail camera captures photos or videos when its sensors detect a combination of movement and change in ambient heat (e.g the body warmth of an animal). Trail cameras are a popular tool for monitoring pine martens, owing to their ease of use and versatility. Some common uses include:

Presence/absence: Confirm whether pine martens are in an area.

Behavioural insights: Observe behaviours, activity patterns and habitat preferences.

Identification of individuals: Each pine marten has a distinctive creamy-yellow bib fur pattern. By identifying individuals from their bibs, activity of specific pine martens can be monitored and the minimum number of pine martens in a specific area (e.g. a forest) can be estimated. 

Den box monitoring: Monitor artificial dens for occupancy and behaviours.

Installing a trail camera

Advantages

Beyond the versatility of trail cameras, there are some broader advantages to using this technology for monitoring pine martens. 

Continuous monitoring: Trail cameras can operate 24/7, allowing for uninterrupted monitoring.

Wide area coverage: Multiple cameras can be deployed across large areas, providing extensive coverage.

Engaging footage: Capturing engaging videos of wild animals is an effective way to share the findings of a project with a broad audience. 

Limitations

There are a couple of common challenges to be aware of when using trail cameras. 

Data/footage management: Trail cameras can produce a lot of footage of all the wildlife that passes by, this is especially noticeable when running more than a few cameras simultaneously and can be a time consuming task to sort through.

Detection bias: Trail cameras may miss animals if they are placed improperly or if animals happen to avoid the cameras altogether. Food bait is sometimes used to encourage pine martens to a camera site, for example when bib images are required for individual pine marten identification. However, the use of bait is not suitable when observing natural movement patterns, as the scent of the bait can draw in pine martens from a distance. 

A baited trail camera site for detecting the presence of pine martens in an area

Top Tips

The variety of trail camera models available today can be overwhelming, there are however a few key specifications to look out for that make a good all-round camera for pine marten monitoring. Opt for high-resolution cameras (e.g. 1080p) with fast trigger speeds (less than 0.5s) and large memory cards (32GB+). 

Some popular models include the Browning Recon Force Elite HP5 for high quality video, the NatureSpy Ursus as a durable and budget-friendly camera, and the Camojojo Trace for wireless/4G monitoring in harder to reach locations. 

Thermal Imaging

A thermal imaging camera detects and visualises heat emitted by objects or animals and is used in a handheld way, just like binoculars or a spotting scope.

In recent years, thermal imaging cameras have proven effective with a specific aspect of pine marten conservation: artificial den box monitoring. Artificial den boxes are an important part of pine marten recovery projects in areas where natural denning opportunities are limited. 

Pulsar thermal imaging camera

With a thermal imaging camera, pine marten den boxes can be checked for occupancy from a distance. If an animal is inside, warm patches will appear on the box. A trail camera can then be installed and aimed at the den box to confirm the species present and monitor behaviours. Learn more about this process in our Guidance for Monitoring Pine Marten Den Boxes. 

Thermal image of an occupied pine marten den box

Citizen Science / Public Sightings

Public sightings of pine martens offer valuable data on the distribution and range expansion of the species, especially when reported through online platforms, apps or via local wildlife organisations. Encouraging reported sightings can also be an engaging way to involve a wider audience in pine marten conservation through citizen science. 

Public sightings play a valuable role in supplementing the surveys described in this article. For example, individual records may reveal new locations of pine marten activity, or help to identify hotspots of activity through clusters of records. This information can be helpful in guiding monitoring efforts. 

There are several challenges to consider when gathering public sightings:

Encouraging reports: People may not realise that spotting a pine marten in the wild is a rare occurrence. Improving public awareness of the conservation status of the species in local areas and letting people know what to do if they see a pine marten can help to encourage more reports.    

Reliability and lookalikes: Pine martens belong to the mustelid family, which includes several species that look similar. Commonly mistaken species include polecats and stoats. We highlight the key differences in this guide. 

Sufficient information: Linking to reliability, gathering information on pine marten sightings from the public must be able to discern between martens and other species as best as possible. This means it’s important to capture information on characteristics, size, behaviour and location. 

A Yorkshire pine marten record - Photo credit Paul Willoughby 

2. DNA & Genetic Analysis

Genetic analysis is another way to gather information about pine martens, and there are ways to do this without capturing animals.

Scat Analysis

Pine martens are territorial, and one way that they communicate their presence with one another is via carefully placed poo, referred to as scat. In some areas, pine martens will regularly scat on forest tracks and roads, inadvertently giving people a sign that they’re in the area too. 

DNA analysis is an important part of confirming pine marten scat, as it is easily confused with fox scat. One study found that even expert naturalists fail to reliably distinguish pine marten and fox faeces.

Behaviourally, locating scats reveals insights into presence, habitat preference and activity patterns. More in depth genetic analysis can reveal further information too, including identification of individual pine martens, sex, diet, genetic diversity, population structure and health monitoring. 

Pine marten scat

Different ways to find pine marten scat

Searching for pine marten scat on a forest floor is like trying to find a needle in a haystack. Fortunately, there are some options for increasing the chances of finding it. 

Transects: Since pine martens have a tendency to scat in prominent places, one of the most practical ways to conduct a scat search is along forest roads or trails. A scat transect is carried out on foot and is typically between 1-1.5km. Multiple transects are required to cover forests sufficiently. Repeat transect routes over subsequent years can help to reveal changes in pine marten presence, abundance and activity patterns. 

Den boxes: Pine martens will also scat near to or on top of their dens. For conservation projects that use pine marten den boxes, it’s good practice to check the top of den boxes from a distance using binoculars, as scats on top of the box can indicate current or recent den box use. 

Detection dogs: Wildlife detection dogs can be specially trained on pine marten scat, in fact, the first DNA confirmed pine marten scat we discovered in Yorkshire was thanks to a detection dog! 

Luck! Besides the more structured approach of scat transects, there is always a chance of incidentally finding scats too, so it’s always worth keeping an eye out in the forest. 

Collect scats in plastic bags or sterile containers and freeze them for preservation before sending them to a lab. Remember to write the date and location of where the scat was found on the bag. 

Hair Tubes

Hair tube surveys are a non-invasive method used in wildlife studies, including those focusing on pine martens, to collect hair samples for genetic analysis. It can be challenging to find pine marten scats in some areas, so this is another way to capture genetic material in a non-invasive way that does not require capturing or handling wild animals. 

Hair tube closed, and the same tube open showing chicken as bait.

How hair tubes work

Tube Structure: A hair tube is a cylindrical or rectangular plastic tube, wide enough for the target animal to enter but not too large, so that the animal must brush against the sides. A tube of around 10-12cm diameter (e.g. drainage pipe or cable trunking) will allow a pine marten enough space to enter. The tube is attached to a tree trunk or branch. 

Attractant: To entice a pine marten to enter the tube, bait or a scent lure is placed inside the tube. 

Hair Collection Material: Inside the tube, a sticky substance like adhesive tape or a rough material (e.g., Velcro strips) is placed along the interior walls. As the animal moves through the tube, its hair gets caught on these surfaces. Typically, one end of the tube is closed and this is where the bait is attached, which causes the marten to move backwards out of the tube after taking the bait and increasing the chances of snagging hair. 

Number of hair tubes: Hair tube surveys are typically deployed at a spacing of one tube per kilometer square. Or, an alternative way to use hair tubes is in response to other signs of pine marten presence in an area. For example, pine marten footage may be caught on a trail camera, but the addition of hair samples may yield further information through a few carefully placed hair tubes.

Hair tube surveys can be carried out anytime of year, but autumn is the ideal time as this is the annual peak in pine marten population with kits born in spring still present in their mother’s territory. The heat of summer can spoil bait much quicker, while cold, damp winters can quickly degrade hair collection materials with moisture. Winter is also a time when pine martens are less active. 

3. Combining Methods to Build a Clearer Picture

The methods described in this article can reveal a lot of information about pine martens. To take this a step further, consider how combinations of different approaches can lead to more successful discoveries or produce more detailed findings.

Example Scenarios

• Trail cameras confirm presence → Scat surveys target the area for genetic analysis.

• Thermal imaging detects a den box in use → Install a trail camera to confirm the species in the box and observe behaviours.

• A cluster of public sightings → Delpoy camera traps and/or run scat surveys in that area for further data.

Studying an elusive mammal that is mostly active at night comes with its challenges, but as we’ve illustrated in this article, there are a diverse range of non-invasive monitoring options available to help with studying pine martens. These tools enable conservationists and researchers to make more informed decisions about how best to conserve pine martens while they are at a critical stage of recovery in Britain. 

All of the tools and techniques described in this article are utilised in the North East Yorkshire Pine Marten Pathways Project; a partnership of Forestry England, NatureSpy and Yorkshire Wildlife Trust. The Pathways Project aims to set the future direction for pine marten recovery in Yorkshire. Learn more about the project here.