VIDEO UPDATE: Danur Swimming?

We have uploaded the video of Danur sent by our monitoring team in Batikap, and it includes some scenes of him playing in the water!

Here’s the video, enjoy! (you can also watch it on our Vimeo channel

Danur In the Water from BOS Foundation on Vimeo.


Danur swimming?

Batikap has very hot days. On one of those days, Joy and Owang from our monitoring team arrived at camp with strange news about Danur. Even they could not really believe it, and they knew that nobody else would, so they brought us a video… of Danur swimming!  When they told us, we really didn’t believe them, we thought it was a just a joke, but then they showed us the video. And yes, we really do have a swimmer in our orangutan group!  At first, Danur went very close to the water a couple of times looking as though he was thinking about going in, but nothing happened. The day got hotter and eventually he could not resist and in he went for a lovely swim!

The day got hotter and eventually Danur went for a lovely swim! -Photo by: Purnomo

The day got hotter and eventually Danur went for a lovely swim! -Photo by: Purnomo

No-one has ever seen wild orangutans swimming – they stay out of the water because of the risk of crocodile attack and because they are not adapted for swimming – they sink very easily. Thus it was a great surprise when orangutans on the islands at Nyaru Menteng started entering the river and experimenting with different swimming techniques. At first they waded in to try to retrieve food that had fallen from the feeding platforms into the water, and in so-doing they slowly got used to being in the water. Some of them started wading up to their neck, others realised they could use floating logs to support their weight and take them into deeper water. Eventually some of them started copying fishermen and tried to catch fish – and were successful on many occasions! These behaviours spread through the population by social learning until many of the males and some of the females became confident in the water. Now that they have been released, it is perhaps unsurprising that these behaviours remain.

Danur swimming? -Photo by: Purnomo

Danur swimming? -Photo by: Purnomo

The river in Batikap is much faster-flowing than at Nyaru Menteng, and can rise and fall rapidly after rains, so the orangutans need to be more careful here. Danur is confident in the water, but it appears he is keeping to areas where he can touch the bottom with his feet. He remains deep in the forest, paddling and swimming in the shallow Posu River upstream from our camp. He appears to be crossing the river by wading and then launching himself with a jump and a few paddle strokes across a narrow stretches of deep water. Despite this, ‘true’ swimming is still not known in orangutans. He wouldn’t be able to cross the deeper, wider rivers that lie downstream.

Menteng and the Boats

Like Danur, Menteng also hangs out near the river, but he is near the wider Joloi River that marks the eastern boundary of our release site and he doesn’t go in too deep. These males spent the best part of eight years on the islands receiving food that arrived by boat with our technicians, and waiting for food deliveries seems to be a hard habit to break! Despite this he is clearly able to find food for himself and he is in good condition, eating well and active.

Menteng is clearly able to find food for himself and he is in good condition, eating well and active. -Photo by: Purnomo

Menteng is clearly able to find food for himself and he is in good condition, eating well and active. -Photo by: Purnomo

We try and observe him every two weeks or so to check his health, but Menteng makes it difficult for us. He is developing into a fully mature male, with growing cheekpads and big body-size, and clearly full of testosterone which means he can sometimes be quite aggressive. He often comes down to the ground when we are near, following us and slowly chasing our observers back to the boat. We assume he simply wants to get food from us, and sometimes gets a bit frustrated if we don’t have it. Sometimes we need to jump into the river to get away! This is the difficult part of our work, as we have a responsibility to all our released orangutans to make sure they are well post-release, but of course need to keep safe ourselves.

Sweet Ebol

Little Ebol is doing very well so far, she is moving and eating very well, the monitoring team were able to follow her on more than three occasions, just to be sure that she is in good condition and happy in the forest.  She likes to eat a lot and make a nest and sleep from early in the evening, then the next day she is again very active and traveling to look for her food.

Markisa’s Special Family

This family is really special. Markisa is taking care of Uli and Mango is taking care of the entire family.  Manggo and her sister Uli both look healthy and they really enjoy playing together. Mango is very protective, and if the monitoring team gets too close she will kiss squeak and breaks branches off the trees. Markisa on the other hand is very gentle, always taking care of baby Uli. They move together and like to travel very much. They love to be together and it is very special to see Uli when her sister Mango comes close, they touch each other, rest, eat and then travel again. We have a lovely photo of Markisa, very quiet letting little Uli sleep, it was a wonderful sight and really sweet.

Markisa’s Special Family. -Photo by: Patricia

Markisa’s Special Family. -Photo by: Patricia

We also have news of Gadis, Astrid, Emen and Isis, all of them healthy and doing very well. Adapting to the forest is not easy, but once they begin to explore, things get better.

And to finish… thanks to Orangutan Outreach for the new radio receivers for radio tracking. We are now getting a lot of signals…  another report very soon!


Text by: Patricia Murcia V. and Ike Naya Silana

Happy News from Monic!

Summer is coming to Batikap…. And with the summer, Monic arrives!

It looks like Monic knows exactly where she wants to be! In March and the beginning of April the whole team were discussing where Monic may have taken herself off to as she hadn’t been seen during routine monitoring. The team had searched everywhere, and even Joy and Purnomo who are really good at finding the orangutans couldn’t locate her. We knew that she was very far away in the north because we could pick up her signal often. So after some lengthy discussions with the team we began making plans to set out on an expedition to locate her and check her health status and especially her pregnancy.


Monic and her pregnancy -Photo by Purnomo

At the same time, very close to camp, we had a visit from Tarzan. His visits are very obvious thanks to his amazing long calls each day, at least three times per day or more! Some of the long calls are full of vigour and energy, some of them are quiet, melancholic, and maybe looking for company?

Then on the morning of April 16, Monic appeared very close to camp! The team was so happy as it was great to have her back… but she arrived alone. Immediately we followed her together with the veterinarian trying to figure out if she was healthy and still pregnant. Three people from the team spent the day with her, two in the morning and one in the evening, so as not to stress her. In the middle of all this Tarzan’s long calls continued in the distance. It was a good day. And close to the end of the evening, Monic found a nest previously made by Tarzan and she spent the night there, resting probably from her long, long trip which possibly took four days of travel from the north.


We wish Monic and baby a smooth and safe delivery. -Photo by Purnomo

The next day Monic was still resting in the nest late into the morning, and all of us were waiting to see her belly! Yes,  Monic is still pregnant! By the look of her swollen and reddened vulva, our vets predict that she might be due anytime soon! And now she is spending some time with the father of her baby, Tarzan. They are very close to Posu camp, so now we just hope that she doesn’t disappear again. Did Tarzan’s long call bring her back? We don’t know, but we hope that at least he can keep her in the same place until she delivers the baby. We wish Monic and baby a smooth and safe delivery!

Text by: Patricia Murcia V. and Ike Naya Silana