July 6, 2013

Training to study sun-bear sign density at Sabangau – a new project at OuTrop!by Aimee Oxley

Photo: Gabriella Fredriksson

The Bornean sun bear (Helarctos malayanus euryspilus or beruang maduin Bahasa Indonesia) is the smallest bear species in the world and is my favourite animal to see in the forest. Relatively little is known about the sun bear as they are a solitary and elusive species. OuTrop is planning a new survey of sun-bears in Sabangau, and to get ready for this, Ciscoes, Ari and I visited sun-bear expert Gabriella Fredriksson in East Kalimantan to learn how to recognise signs of sun-bear and properly estimate their abundance. Gabriella,  now at PanEco, conducted the first long-term study on wild sun bear ecology at Sungai Wain Protection Forest (SWPF) starting in 1997. Along with wild radio-collared sun bears she rehabilitated 3 rescued cubs and released them into the Sungai Wain Protection Forest meaning she was in a unique position to be able to follow them and see their behaviour in the wild.
As well as gaining insights into home range size and use, diet and activity budgets of sun bears, Gaby was also able to study the effect of forest fires on the sun bear population at Sungai Wain. Whilst forest fires are commonplace in the dry season as a result of slash and burn agriculture, rapidly increasing levels of anthropogenic disturbance and land clearance for plantation development coupled with droughts associated with the El Niño-Southern Oscillation (ENSO) phenomena lead to severe trouble for Indonesian forests in 1997-98. In 1998, huge forest fires decimated around 5 million hectares of land in East Kalimantan alone and around 50% of the Sungai Wain Protection Forest was burnt.Obviously trapping and radio-collaring bears is a very time consuming and big project to undertake, so other ways of studying sun bears involve indirect observation methods. Gaby designed a method to monitor sun bear abundance through surveying bear sign in the forest. This involves searching for claw marks, broken termite nests, ripped trees from stingless bees nests or termite foraging and scat. By using this method, Gaby was able to monitor the use of the burnt areas in the SWPF and found densities of sun bear sign close to zero for several years after the fire. However, around a decade later, bear sign density began to increase which shows that forest that has been burned can still be of conservation value for the sun bear. Sadly, the sun bear is not only under threat by forest fires and land clearance for agriculture but also by poaching primarily for body parts for the Chinese medicine market. This makes it really important to conduct long-term monitoring in different habitat types of this charismatic and elusive species.For more information about the sun bear watch this excellent short film made by Gaby and her team.

Gaby came to Sabangau in 2002 to conduct bear sign density surveys and we have decided to resurvey the forest to monitor sign density to see if there have been any changes over the past decade in the period where our forest has been recovering from its previous history of logging which only stopped in 2004. Our initial survey is being undertaken by Georgia Henessey, a volunteer coming out this week who has chosen to do her Bachelors research project as part of her volunteer experience. Before Georgia’s arrival, a small team of OuTrop staff – myself, Ari and Cis-Coes – went to Sungai Wain Protection Forest to recieve training in bear sign survey methods by Gaby. It was a hugely beneficial expedition and we hope to undertake long-term monitoring of bear population trends through these sign surveys at OuTrop. Here’s a little insight into what we learnt… The team (from left, Cis-Coes, Gaby, Ari and Anna) discuss whether this remains of a ripped up log was made by a bear, and how to estimate how fresh a sign it was. Both sun bears and bearded pigs can rummage through rotten wood for beetle grubs and other saproxylics, but we decided this must have been done by a bear as it had been completely decimated. Pigs are more likely to truffle through a number of spots whereas bears can leave a big mess behind and rip an entire area of rotten wood into shreds with their large paws and claws.

Bear signs can be as obvious to note down as these claw marks which could only have been made by a bear, and you can usually distinguish between front and back paws by their shape – puncture marks are made by the back foot as the bear digs in to the tree to climb up and front paws making a more swipe-like scratch as it grabs the tree for support. We then decide on the age of the sign which can be a bit trickier as the bark of the tree species grow at different rates from each other. To help with this we can trace sun bear sightings in the forest and track down some of the signs left behind meaning that we can monitor these as they degrade.

Not all bear signs are as easily identifiable as claw marks and ripped trees – sun bears are omnivorous and spend a large proportion of their time foraging for insects, including termites. A large part our training with Gaby was learning some of the various above ground termite nest species and sometimes identifying bear sign from broken termite nest was very easy as they are often broken into several pieces. 

Other bear sign could be much more subtle though, including this broken termite nest. This species of termite (genus Hospidalitermes) forages for lichens in long columns along the forest floor and makes nests on the sides of trees. A bear has ripped into the colony nest as you can see from the picture, but what makes this clear that it has certainly been done by a bear is the bite marks from the bear ripping the wood at the bottom of the tree to get further inside the nest. A subtle thing to notice perhaps, but thanks to Gaby’s training this is now something that we will notice in the future when doing surveys in the Sabangau forest.

In 2002 the sun bear was adopted as the official mascot of the city of Balikpapan, which is situated only 15 miles away from the Sungai Wain Protection Forest. After this happened, the local mayor confiscated 4 bears which were being kept as pets to make a statement for the protection of bears in the area and decided that these bears should be available for the public to see so they could learn more about their new mascot. Gaby spent the next few years setting up an education centre so that the public did not just see these bears in cages, and that they could have the best life possible in a large enclosure with native tree species (adult rescued bears cannot be released back into the wild, especially ex-pets which often have their teeth filed and claws removed). The public could now become as fully informed as possible about the plight of the sun bear and local conservation issues. After returning from the forest we managed to take a quick visit to the Environmental Education and Recreation Facility (in Indonesian the KWPLH, see en.beruangmadu.org for more info) that Gaby set up and we were lucky enough to catch a glimpse of a sleepy sun bear as well as go through the education centre. It’s a really impressive place and extremely informative engaging a wide audience. It receives around 50,000 visitors a year, so hopefully the visitors are becoming enlightened about conservation issues and the importance of the enchanting sun bear.Cis and Ari checking out the education centre.Many thanks go to Gaby for sharing her time and expertise, and to Agus and Misran for their assistance with logistics. I’m really excited about starting out bear sign surveys at Sabangau – it’ll be interesting to see if there are any differences in sign abundance over the past decade. We’ll keep you posted with our first results…A beautiful dipterocarp towering 50 metres high above the forest at Sungai Wain