Camera traps, or remotely activated cameras, are used the world over for monitoring wildlife because they are a non-invasive and cost-effective method of collecting continuous sampling data. Camera traps are particularly useful in a forest environment where animals tend to be secretive in nature and the sheer density of vegetation makes it difficult to see anything further than a few metres away.

The Gola team have been using camera traps for a number of years now, the results are combined with other data (such as nest surveys and community questionnaires) to help build a map of where different species are found within the forest. This allows us to target conservation activities in the right places.

One of the camera traps deployed in Gola Rainforest

Here is a summary of some of the key uses and findings from our camera trap work.

Threatened primates

Gola is home to a number of primate species that are of conservation concern. The population of western chimpanzees (Pan troglodytes ssp. verus), found only in West Africa, has declined significantly over the past 50 years. This decline in population led to the western chimpanzee being re-classified in 2016, it is now considered to be critically endangered in accordance with the IUCN Red List.

Like other threatened primate species found in Gola, for example the western red colobus (Piliocolobus badius), Diana monkey (Cercopithecus diana) and sooty mangabey (Cercocebus atys), chimpanzees are at high risk from poaching and habitat fragmentation, and often utilise areas of habitat both inside and outside of protected areas.

Our camera trapping data can help to identify key areas where these primates are found outside of the protection of the National Park, where different conservation approaches are needed which rely on community engagement. Photos are also useful for gathering information about primate group compositions and behaviours which can be particularly difficult to determine in the thick forest habitat.

One of our most significant findings has been that while most populations of these threatened primates are declining in the region, populations in Gola appear to be stable or increasing. These results are being shared and it is hoped that lessons learnt in Gola can help improve the prospects for primates across West Africa.  


Some of the primates of conservation concern caught on camera in the Gola forest. Top row: western chimpanzee. Bottom left: sooty mangabey. Bottom right: Diana monkey

Endemic species

Many of the species that occur in the Gola Rainforest are found only in the Upper Guinea Forest Belt and therefore the conservation of their habitat is critical. With significant deforestation having occurred across Sierra Leone, in many cases the country’s entire population of these forest dependent species may now be restricted to the Gola Rainforest National Park. As such it is important to monitor the population and distribution of these species across the Park in order to spot any changes early on. Having camera traps distributed evenly across the forest is an effective way to monitor changes in species like antelope and ground-dwelling birds.


Left: Jentick’s duiker – thought to be the rarest duiker in West Africa, and endemic to the Upper Guinea Forest Belt. Middle: Zebra duiker - once widespread throughout Sierra Leone, it is believed they are now restricted to the Gola Rainforest. Right: White-breasted guineafowl - endemic to the Upper Guinea Forest, and in Sierra Leone they are only found in the Gola Rainforest.

Hard to see animals

Camera traps are particularly useful for collecting data on species that are otherwise rarely observed. This may because they are shy and well camouflaged, like the bongo (Tragelaphus eurycerus), or because they are mostly active at night, like the honey badger (Mellivora capensis) and marsh mongoose (Atilax paludinosus).


Left: Bongo - notoriously shy and reclusive, this photo shows just how well camouflaged and difficult it is to spot them in their natural forest habitat. Middle: honey badger & Right: marsh mongoose – two of the Gola species that are primarily active at night, making first-hand observations uncommon.

Behavioural data

When observing wildlife, it can be difficult to accurately monitor natural behaviour because your physical presence can influence the activity to some degree. Camera traps make observations in an unobtrusive way, allowing us to collect data on a wide variety of natural behaviours such as feeding habits and social interactions. One example of where this kind of data is used is for understanding the potential risks associated with human-wildlife conflict, for example where species are believed to be crop-raiding.


Left: Red river hog – often blamed for crop-raiding, camera trap data can provide information on their foraging behaviour. Right: Caught in the act! Young chimpanzee with a cocoa pod in its mouth.

Finally, camera trap images are also great value for just giving us a laugh. Which is a value that should never be underrated.


Ogilby’s duiker taking a selfie!

Over the coming year

Thanks to a generous donation from Zoo Basel we have been able to purchase some additional camera traps which are currently on route out to Sierra Leone. These will be used as part of our pygmy hippo surveying work, which is aiming to gain better insight into these elusive animals, about which we know very little. So hopefully over the next year we will be updating you with new additions to our small collection of images of this enigmatic animal, an icon of the Gola Rainforest.


Left: new camera traps donated by Zoo Basel being packed up ready to leave for Sierra Leone. Right: some of the few clear photos we have of the elusive pygmy hippos in Gola forest.

For more information about the work going on in Gola you can check out the Gola Rainforest website at