We always knew that P26 was going to draw on all our skills to be able monitor him and his survival and we have not been disappointed. As mentioned in a previous post we monitor each pangolin before release. This helped us to build up an idea of each individual’s behaviours and activity patterns so we are best informed about how they are doing post release. From watching P26 we always knew that he was slightly lazy, only emerging for short periods of time usually around 7/8pm and then between 11pm and 2am, again for short periods of time.
After release we tracked him to a hollow underneath the roots of a tree. We don’t just track which tree the animal is in, but if possible whereabouts in the tree it is and then seeing if we can catch a glimpse of the animal. This was important for P26 as we suspected that it would take him a while to adapt and the only way we would be able to tell if he is surviving is by tracking small changes and small movements or changes in the orientation of the transmitter.
After releasing him on the Wednesday we found him on the Thursday with few problems. Friday morning he was still in the same location and didn’t look like he had moved. We came back in the evening and set up camp 60m away. We had taken a bearing from this location in the day as a reference so we could tell when he was active at night. When we arrived in the night, the bearing was slightly different, we went and checked and although he was still in the same den site, the orientation of the transmitter had changed, hence the change in bearing. The first clue that he was still alive. This was reassuring as he was not active for the rest of the night.
Over the weekend we tried to pinpoint the location of the transmitter as closely as possible. He was still essentially at the same tree, but he was digging underneath the roots and we could track where he was. When monitoring on Monday we noticed that at 12:15am the signal didn’t change in direction, but got a lot stronger. Again a clue that the transmitter had moved, possibly he came outside. Activity at this time fitted in with the time he was usually active in captivity. We didn’t go and look directly as we also know he is very wary of people and our presence would stress him. However, this recording was important as on Tuesday morning he was in the same location as Monday.
By Wednesday he had buried into the a neighboring tree and was in a hollow at ground level. He has been found here every morning since then but we have been unable to see him. So how do we know he is still alive? On Wednesday night there were changes in the signal between 1-1.30am and on Thursday again at 8pm and between 11pm-12.30am, fitting in with what we had seen in captivity.
These changes are small, for example the signal sounding louder, or changes in the fade in/fade out of the signal (i.e. the signal can be heard over a much wider angle, but the calculated bearing remains fairly unchanged). It is purely our experience with the other five animals that we have tracked with a prior knowledge about P26 that mean we are able to use these subtle clues to monitor him.
In terms of feeding, we are not sure as yet about his feeding habits, what we do know is that he is a large individual and is currently not expending too much energy so not need to worry too much. We will continue to provision him with food, but to date he has not fed on them. It is also likely that within the tree hollow and under the roots he has access to ants or termites attracted by the rotting wood of the tree.
For any of you still not convinced he is alive this morning, with my head stuck right into a tree hollow, I saw the element of the transmitter. I tried to give it a little pull to see if it was attached to a body or not (we couldn’t actually see him). However, before I had the chance the element started moving of its own accord and we heard some movement. The transmitter is certainly still attached to P26 and P26 is still alive!
Today Thai, who worked as the captive manager at CPCP for several years, presented to some staff at Cat Tien about how to care for confiscated carnivore and pangolins. Steps like this are so important, it took just an hour to share knowledge and experience, swap contact details and provide hand outs to all of these people but all of it will help to improve the care of confiscated animals that are brought to the park.
After the timidness of P26 yesterday night we were keen to check he had moved this morning. When we went to the release site we were glad to see that the travel box was empty, now it was a case of locating where he was.
Staff from the technical department have been working with us throughout the project, but this time we wanted them do to all the radio tracking independently and collect the required data about the sleep site.
The first step is using the yagi element to identify in which direction the the signal is strongest.
As you get nearer the signal gets stronger and you can reduce the gain of the receiver. The lower the number of bars when you can still hear the signal, the closer you are the animal.
When you can hear the signal and the strength is only half a bar you are very close and you can remove the yagi to find exactly where the animal is.
This morning he was sleeping between the roots of the tree, just in the bottom left of the picture. You can just see his scales in the picture below. He is a 8kg animal that squeezed into a hole 16cm wide.
As it is the dry season we left some water next to the tree, as we haven’t released any in the dry season before we want to be extra careful, although he is only 200m away from a river. We have left provisions of live ants at the point where we released him (around 40m away). We haven’t left the right next to his sleep site as we don’t want him to get lazy and need to encourage him to find food in the forest. It is near enough, and at a location he is familiar with to provide support if he needs it.
We are taking data on the tree species, the GPS location, where he was sleeping (at the roots), the width of the hollow and the circumference of the tree. Finally, we set up a camera trap at the den entrance to see what time he leaves this evening.
As we have been monitoring P26 over the past four weeks we had noticed that he is fairly aware of people. For example, when he first arrived in Cat Tien he was very cautious when coming out of the travel box and he only emerged after we had left.
Today we released him into the forest. With other releases the animal has happily come out the box and started investigating the area, P26, however, was lot more nervous.
It is bad practice and stressful to tip the box or lift the animal out, better just to leave it open and let them climb out by themselves. So instead we stood back and waited, but he still did not want to leave.
We decided to minimise stress we would leave food and water very close to the bedbox and to leave him alone. We will head back out first thing tomorrow to find out where he is. Hopefully, he will get used to his new surroundings and smells this evening and find a suitable sleep site in many of the tree hollows around that area.
Since the last post, our efforts have been focused on three main aspects: Monitoring P26; gathering as much data as possible about sleep site selection of released individuals; and trialing a method for tracking populations trends and fluctuations in abundance.
This is done by keeping track of how much he eats, his weight, when he is active and what he does when he is active. At the moment it varies night by night as to how much he eats, but he feeds fairly early on, before 8pm. He is maintaining a weight of 8kg and his digestive systems appears to be fairly regular! We put up a camera trap at the entrance of his tunnel so we can note when he is active. We also watch him all night once or twice a week, so we can monitor his behaviour for indicators of stress and just get more of an idea about what he is like as an animal. He has not shown any stressed behaviours however, he doesn’t climb as much as the other individuals. This is good to note as it may mean he prefers den sites at ground level, but only time will tell. He often emerges a few times a night, for short periods, but doesn’t seem to be active after 2am. He will be released next Wednesday, so we will keep you updated on how he does.
Sleep site selection
To better understand the requirements of released Sunda Pangolin we have been collecting data about their sleep sites to try and figure out what habitat features may be important. At the moment these are all just general observations from a small number of individuals, but sharing this information is only going to help.
The main factor that stands out is that the released individuals rarely climbed a tree to sleep in the branches, this is in contrast to the wild pangolin tracked where 94% (n=15) his sleep sites were in the branches of the trees. The difference could stem from a preference built up in captivity, where they sleep in an underground den.
Pangolin entering the underground den used in captivity
The observations of the wild pangolin could be a result of the extreme historical hunting pressure; if those animals most easily accessible to/spotted by hunters are those in tree hollows and nearer ground maybe the only animals left are those that showed a preference for sleeping high in the branches of the trees, that may have offered a higher level of protection? Who knows.
At 92% of sleep sites (n=36) there was a potential source of termites (usually at the base of a tree or in deadwood, rather than free standing mounds). All trees had a trunk circumference of more than 1m. Interestingly, ant nests were harder to locate and yet this is what they are fed in captivity.
We also took note of the micro habitat; proximity to a water source (or identifying plants that are found in areas where there is a lot of water in the soil); if the area was dominated by Lagerstraemia calyculata (which often have suitable tree hollows); and if the sleep site provided shelter from the rain.
Armed with this information we went to random locations within each individual’s range (n=no. of sleep sites for that individual) and noted the presence or absence of features the features recorded at sleep sites (trees with a circumference > 1m; termite mounds; deadwood; tree hollows etc.) with the aim of working out if/what features are statistically important in sleep site selection.
Tracking population trends
As individual pangolins cannot be identified we have been testing the use of camera traps and the applicability of an occupancy model to estimate abundance, with its potential use to track fluctuations in population (and evaluate the success of a release program). We wanted to trial it as we know that in the area there are at least four individuals (two released and two wild). As it is the dry season, we have also put cameras along the river bed in the sampling area, one at an isolated water source and the others along the dried up bed which provides a clear route to a major water source; it is expected that there will be more animal movement along these routes.
Whether successful or not, all this information will help design and refine methods for surveying for Sunda Pangolin in similar habitats.