Borneo vol. 2 (Dec 2024)
Bornean tarsier (Cephalopachus bancanus ssp. borneanus)
SIPADAN
We’ve wanted to scuba dive in Sipadan from the moment we heard about it. We were fascinated by bumphead parrotfish (Bolbometopon muricatum), the incredible reefs and other marine wildlife inhabiting and visiting the Celebes Sea. Scuba Junkie helped us achieve all that. We started off with 4 dives, including one night dive, in Mabul, and then moved on to Sipadan the next day. Although the visibility wasn’t great, we saw everything we hoped for, from dozens of sea turtles, through different species of sharks and nudibranchs, to frogfish, a barracuda tornado and, of course, bumphead parrotfish. The dive resort was very busy but the dives were well organised and the DMs were locals, extremely knowledgeable about the dive sites and the life on them.
In the video below Karolina used new underwater lights for the first time and she’s aware there’s still room for improvement - practice makes perfect!
Laticauda colubrina (yellow-lipped sea krait) under the Scuba Junkie jetty. There were LOTS of them.
Tawau
1StopBorneo is a conservation organisation, working on protecting the flora and fauna of Borneo through multiple projects. We’ve followed the efforts of Chavez and his team for a long time so it was a pleasure to finally meet them in person and explore Tawau Hills Park together.
It’s well worth visiting their YouTube channel with educational videos as well!
Over 5 nights, we saw 14 species of snakes (Tawau has a great snake diversity but density is rather low, so one has to work really hard to find things), countless invertebrates and many other interesting living things. The magic of Borneo is that its nature is so special and unique, surprising with its astonishing camouflage, sounds and shapes, and it never ceases to amaze. Every day we saw new species while exploring different parts of the park.
Although birds and mammals weren’t a big focus for us in Tawau, a whole family of leaf monkeys (Presbytis rubicunda) blessed us with their presence one afternoon, foraging right next to our lodge. Very peaceful and cute creatures, two of which were white. We were told white individuals are rather rare and only males can come in this colour. We were very sad to hear that shortly after our departure, the white male of that group touched an unprotected electrical cable and, although he was given immediate help, he passed away. The future of its white son is uncertain, depending on when and if another dominant male will join the group.
Artur’s biggest dream was to find the last species of Borneo’s pit vipers on this trip, and it came true! A beautiful female Sumatran pit viper (Trimeresurus sumatranus) made her appearance at the beginning of our stay in Tawau, and she was around until the end. She ate a large dinner in the meantime and kept moving further and further into the forest, with a big lump bulging out of her belly. We have now seen all pit viper species on Borneo. 💚
Sumatran pit viper (Trimeresurus sumatranus)
As mentioned earlier, we saw 14 species of snakes altogether, including the Sumatran pit viper, gorgeous blue-necked keelback (Rhabdophis rhodomelas) and the endemic Borneo pit viper (Craspedocephalus borneensis), along with quite a few lizards and frogs. A small gallery showcasing some species we saw below.
We cannot forget about invertebrates! Some incredible sightings on this trip, starting from an absolutely crazy leaf katydid, Eulophophyllum lobulatum, which you can only locate by listening to the calls of males of this species. We spent quite some time hanging by bushes, trying to find out where they were hiding and it really isn’t an easy feat to spot one of these guys!
Violin beetles (Mormolyce matejmiciaki) were a huge target for Karolina, gracefully delivered by Chavez, who was standing next to a huge tree and pointing to the bracket fungi growing on it, telling us to have a closer look. Sure enough, most fungi were inhabited by at least one violin beetle! These special beetles all possess violin-shaped elytra and live between layers of bracket fungi. Their larvae live in huge (20 to 30 cm wide, or even larger) and very hard bracket fungi, in which they excavate channels. They pupate in the fungi too. After emergence, they create an very small hole (even narrower than their own bodies) to escape from their larval chambers, making it incredible to understand how they manage to get out. Their adults are predatory.
We also saw a pair of mating Uropygi (Thelyphonidae). According to iNaturalist, males secrete a spermatophore, which is transferred to the female following courtship behaviour, in which the male holds the ends of the female's first legs in his chelicerae. The spermatophore is then deposited on the ground and picked up by the female using her genital area. However, in some genera, the male uses his pedipalps to push the spermatophore into the female’s body. Not sure what happened here, but maybe the second mating ‘style’ is more likely as the male kept manipulating around the female and we didn’t see any spermatophores attached to the tree stump where they mated.
Since Artur set up his moth trap on the first night and left it on every night, a large number of moths, mantises, mantidflies (Euclimacia sp.) and other fascinating inverts made their appearance on the screen.
One more interesting fact - we learnt from Chun that harvestmen (Sclerosomatidae) may eat… mushrooms, just like the individual from the gallery below, carrying a white fungus. How crazy is that?!
Kinabatangan
From Tawau, we travelled to Kinabatangan by bus with Chun from 1StopBorneo. By doing only three boat safaris on the Kinabatangan River and hiking to one of the nearby caves, we saw the Borneo Big 5: Bornean orangutan (Pongo pygmaeus ssp. morio), the Bornean pygmy elephant (Elephas maximus ssp. borneensis), the proboscis monkey (Nasalis larvatus), the estuarine crocodile (Crocodylus porosus) and the rhinoceros hornbill (Buceros rhinoceros).
Sadly, Kinabatangan is a fantastic place to see the wildlife (many of which would normally be very shy and stay away from people) because the animals are now restricted to tiny remaining forest areas along the river, having nowhere else to go. And it’s a secondary forest - the huge, old rainforest trees that used to grow there have long been gone. There was a striking difference in the height of the forest in Tawau and Kinabatangan; in Tawau, you looked up and you couldn’t see the top of the trees that have grown there for hundreds of years, while in Kinabatangan most trees are only several dozen years old.
The ecology of the upper reaches of the Kinabatangan river has been severely disrupted by excessive logging and clearing of land for plantations, although the original lowland forest and mangrove swamps near the coast have largely survived. Since the beginning of the early 1950s until 1987, the lower Kinabatangan area was subjected to commercial logging activities, and more than 60,000 hectares of its lowland rainforest have been developed into cocoa and palm oil plantations (many of the latter still remain there - you are looking at a long drive through palm oil plantations before you get to the actual rainforest). In 1997, 270 km2 of the lower Kinabatangan floodplain were declared a protected area. Much of the deeper river area is protected under the Lower Kinabatangan Sanctuary, and a 28,000-hectare reserve was established in 1999 (Wikipedia).
There’s also another serious issue that affected this area quite recently. African Swine Fever (ASF) reached the island of Borneo at the end of 2020. The first mortalities occurred in wild bearded pigs (Sus barbatus) in Sabah, north-east Borneo. The virus then began to spread across the island but, confounded by COVID 19 lockdowns the spread was difficult to monitor on the ground. (…) It has been estimated that 90% of Sabah’s bearded pig population has disappeared.
Prior to the ASF outbreak in Borneo, bearded pigs (Sus barbatus) were listed as Vulnerable by the IUCN Red List of endangered species, and are recognised as ecologically and economically vital. Bearded pigs are cited as ‘ecosystem engineers’ dispersing and predating tree seeds, rooting through soil and removing saplings. (source)
The huge decline in the pig’s population is having a dramatic effect on the entire ecosystem. We’ve learnt about two particular instances of a negative impact it has, but it surely is just the tip of the iceberg.
First, we’ve learnt that Wallace’s and Borneo flying frogs who breed in muddy water, often in wallows of wild pigs, are now extremely difficult to encounter in Tawau as the pigs are mostly gone.
Second, our boat safari guide told us that there are increasing issues with crocodiles. The pigs are scarce and NGOs provided monkeys with bridges so they can easily move from one bank to another, meaning monkeys rarely get in the water. As a result, crocodiles have nothing to eat. There are increasing attacks on humans and crocodiles start leaving their usual hunting grounds in search of food… Who knows how many other species of flora and fauna have been affected by this tragic loss?
Back to herping… We did one night walk near our lodge in Kinabatangan and it was quite productive, starting with a banded civet (Hemigalus derbyanus) casually walking right in front of us, followed by a sighting of a Pyrops whiteheadi lanternfly, which Karolina hoped to see throughout the whole trip; a “catapult spider”, which Chun told us is a very unknown species with its incredible catapult-hunting behaviour unlikely to have been described yet; a “Pepsi spider” (Leucauge sarawakensis); a couple of Phoroncidia comb-footed spiders which we were all surprised to see at such a low elevation - our first encounter with this species was in Kinabalu Park Headquarters, which is at 1,563 metres!; along with some incredible jumping spiders and moths.
What about the boat safaris?
There was one particular male crab-eating macaque (Macaca fascicularis) encountered during our river cruise that was quite memorable, as someone must have taken a bite off his face and left his upper jaw and teeth completely exposed. He did seem to be isolated from the group, as most other members were foraging in the water (in a very smart way by the way, washing their food and picking the juiciest pieces), while he was sat lonely on a nearby bush. One of the mothers had a baby literally attached to her nipple, even when the mother accidentally fell in the water! She jumped out, completely soaked, with the baby still suckling as if nothing had happened. 😂 Watching these animals just makes one realise how close they are to us and how complex their behaviours and relationships are.
We also spent some time with a group of southern pig-tailed macaques (Macaca nemestrina); you can see one of the juveniles pictured in the gallery below, making funny faces at us. He and his buddy seemed not to be too used to humans so they were trying to threaten us, then play with us (?) from a distance and were generally really curious about those funny monkeys with bright orange vests, staring at them from the boat.
The Borneo Big Five
1.Proboscis monkey (Nasalis larvatus)
Obviously, proboscis monkeys must be mentioned here since they were the very reason we came to Kinabatangan in the first place and they are one of the Borneo Big 5 animals. The weirdest of all, big stars of Polish memes with bulging stomachs, absolutely ridiculous to observe. They live in family groups led by a dominant male whose nose and permanent erection make them very special indeed. We saw multiple families; if anyone wants to see this species, this is definitely the right place. We observed them eating, getting bullied by macaques (apparently proboscis monkeys are very peaceful folivores and frugivores so when faced with aggressive and charismatic macaques, they run away) and even… free falling (our guide called it ‘jumping’, but their weight and clumsiness really made it look like free falling, especially that they were using their muscles mostly to rock the trees to then use them as catapults).
Proboscis monkey (Nasalis larvatus)
2. Bornean orangutan (Pongo pygmaeus ssp. morio)
The first orangutan we saw was climbing a jackfruit tree near a ranger’s station to pick and take away a couple of huge fruits. It just makes you realise how strong these animals are (jackfruits may weigh up to 55 kg per fruit)! Once she’s taken the fruits, she proceeded to eating them a bit further away from people.
The second encounter was in the evening on the very last boat safari, when our eagle-eyed guide spotted an orangutan nest (they make one every night) high up on a tree and sure enough, a female orangutan was swinging nearby. It’s amazing to see how agile these animals are in their natural environment.
Bornean orangutan (Pongo pygmaeus ssp. morio)
3. Bornean pygmy elephant (Elephas maximus ssp. borneensis)
Again, our guide has proven extremely experienced at spotting the right things in the right places. Just after we left for our last boat safari, he shouted to the boat operator to stop and turn around. We had no idea what he saw until he pointed to huge bamboo stalks swinging as if there was strong wind, even though there wasn’t even a breeze. Shortly after we noticed a group of elephants foraging close to the river bank, noticeable only through a narrow gap in the vegetation. They were snapping bamboo stalks as if they were straws! We were the first to see them - shortly after, other boats arrived and it became a bit crowded.
Bornean pygmy elephant (Elephas maximus ssp. borneensis)
4. Estuarine crocodile (Crocodylus porosus)
Kudos to our guide yet again, who spotted a baby crocodile resting on a log in the early morning. It was basking in the morning sun and we must admit that its camouflage was brilliant - it takes a well trained eye to distinguish a small croc from the log.
Estuarine crocodile (Crocodylus porosus)
5. Rhinoceros hornbill (Buceros rhinoceros)
The last one of the Big 5, a rhinoceros hornbill. We only saw one, high up on a huge tree, jumping between the branches and munching on fruits among macaques. This place is great for hornbills in general, as we saw 4 species in total including the rhinoceros hornbill: oriental pied hornbill (Anthracoceros albirostris), wrinkled hornbill (Rhabdotorrhinus corrugatus) and black hornbill (Anthracoceros malayanus), which was really cool with its black beak, we actually had no idea it existed before this trip (see the picture in the gallery below of a female - black beak - and a male of this species).
Rhinoceros hornbill (Buceros rhinoceros)
On the boat with Chun.
Kota Kinabalu
On the New Year’s Eve, Kioherp took us to Ulu Kionsom Waterfall in Kota Kinabalu for the final herping night on this trip. We wanted to see Tropidolaemus subannulatus and Pyrops sultanus and we encountered both, so although the night was not extremely productive, we were very happy with the outcome. We celebrated the countdown to 2025 with Jeremy, Charlie, a couple of local cats and some drinks. 🍻
With Jeremy and Charlie from Kioherp.
Huge thanks to all who made this amazing trip possible!
For more photos, visit our Flickr.
