Will Hawkes
E N T O M O L O G Y
Day 7: Cinnamon frogs, leaf spiders and snakes that pretend to be logs.
Cinnamon frog
Waking up on our last full day in the forests of Sungai Wain was much the same as the previous six – hot, humid and covered in mosquito bites. At this point we were just hopeful that the local population didn’t have any malarial parasites within them. Agus Din was taking us for a walk this morning which we always enjoyed most as he is very good at spotting birds. This walk would be slightly different to the others as there was going to be an emphasis on hunting for the rarer birds like peacock pheasant and the Bornean ground cuckoo. We started off along the normal track running past the reservoir, spotting the occasional sun skink flashing up the trees. These lizards are normally far too fast for a photo but I was just about careful enough to sneak up on this one before it skittered off.
Sun skink
I think I slightly prefer night walks to day walks in the jungle mostly because more invertebrate life seems to come out at night, and the wet, pressing heat is nowhere near as pronounced. In the day, I seemed to spend most of my time wiping sweat out of my eyes, wishing I had some sort of headband!
Taking photos in the jungle is quite often a matter of logistics. Because of the dense vegetation very little light penetrates through and so my cheap ring-flash on the front of my lens was in nearly continual use. This continual use meant, however, that its batteries rarely lasted more than a few hour’s walk and I had used up a lot last night. To make things a bit more difficult the screen of the flash unit had cracked while in the plane coming over and had stopped working meaning I was working nearly blind, modifying my flash’s power solely through changing camera settings.
Turning over a nearby leaf revealed a fascinating little beetle. It was two-tone black and orange, the orange melting into the black the further down the beetle’s elytra (wing-cases) it went. However, the most amazing thing was that this beetle was absolutely covered in spines! The beetle was one of the Hispine beetle in the genus Dactylispa and its spines were so sharp that when I picked it up they got stuck in my skin! They definitely would get stuck in the throat of any bird/lizard/mammal/snake or frog that decided it would make a good meal. Enthusiastic photo taking of this amazing beetle put pay to my flash’s batteries. I would have to be more thoughtful with light for the rest of the walk…
Spiky Dactylispa beetle
We had got to a small clearing where we sat to put on a bit more mosquito repellent and to eat some lunch. It is very important, of course, to find food in the jungle and animals that need to provide for more than just themselves have highly adapted sensory signals to find food. As soon as we sat down and got out our lunch, a tiny orange stingless bee turned up in front of me. She had used sensilla on her antennae to smell the sugar in the food and honed in on us.
Orange Halictinae bee
Leaving the clearing on the hunt for the elusive peacock pheasant we came across one of the male’s display grounds where he would stand and call to any females who would listen. Drawn across the display ground however, was a largeish web of one of the armoured kite spiders, in this case Gasteracantha diardi. This spider is quite dark and has prominent spikes on either side of her thick abdomen, although nothing in comparison to the crazy spines of Macracantha arcuata (see day 3).
Gasteracantha diardi spider
Pushing our way through the jungle vines, me at the back looking for the smaller things while Ted and Agus Din scanned (with ears as well as eyes) for the elusive birds. Suddenly I almost walked into Ted as he stopped suddenly pointing upwards. They had heard a Malaysian Honeyguide and spent the last few minutes trying to spot it while I caught up. She was calling high in the trees with a cat-like meow followed by a rattle. These small, fairly non-descript brown birds like to feed on insects, primarily bees and beeswax as their name suggests. It is thought that these birds rely primarily on olfaction (smells) to locate the hive’s location. Researchers showed that these birds could even find an area of beeswax so thin it was nearly invisible to the human eye – the location where hot water had been poured over wax to clean it weeks earlier, providing good evidence that the bird does not rely completely on sight to find its food.
Unfortunately I had only brought my macro lens out to the jungle and so no honeyguide photos, but here is one of Agus Din looking at the bird which is nearly as good.
Agus-Din, our guide
Rounding a tree, a thin, crawling leaf extending upwards towards the canopy held a very strange passenger. It was a giant forest ant Camponotus gigas but it was acting strangely, gripping tightly with jaws and legs to the leaf, fairly high up. Closer inspection revealed it having multiple woodlike projections sprouting from its thorax. This was the result of a brutal but fascinating Cordyceps fungus. If an ant gets parasitized, then the fungus is able to change the ant’s behaviour completely and force it to climb high. When the ant is in position, the fungus compels the insect to clamp down hard with jaws and legs to remain steady. The fungus now explodes out of the ant, rocketing slowly skywards before hundreds of thousands of tiny spores emanate from the sprout, spreading throughout the forest to parastise further unfortunate ants.
Camponotus gigas ant infected by a Cordyceps fungus.
An odd half rolled leaf caught my eye with strands of silk crossing its canoe-like opening. Crouching down, ever wary of fire ants of course, I looked into the leaf and a face looked back at me! Calling Ted over excitedly I showed him my discovery of a smiley-faced spider Theridion zebrinum. She has a smiley face pattern on her abdomen and was looking after her egg sac in her small leaf home. Her web design is unique to her species and works by exploiting the behaviour of many flies to land on leaves. Signal flies, for example, like to show off and wave their wings at females from a leaf platform. If the fly lands on the spider’s leaf, it will quickly become ensnared and eaten. The face itself is likely not crucial for scaring off predators and instead an amusing continuation of the spider’s stripes on the rest of her abdomen.
Zebra smiley spider, Theridion zebrinum
Almost missed as we walked passed was a middle sized longhorn beetle in the genus Coptops. I hadn’t found very many longhorn beetles at all so this was exciting. These beetles’ larvae live in deadwood and have large jaws for chomping their way through the tough wood. I don’t know any more about this pretty beetle but it does have nice hair fringes on its striped legs.
Coptops longhorn beetle
Shining like a dark jewel on the next leaf was a stunning nymph of a Scambophyllum species of katydid. Amazingly, as this katydid grows up it will slowly change to green. Each new moult bringing in more green from the top down. By the time it is an adult it will be an excellent leaf mimic but for the moment it relies on aposematic colouring to persuade predators that it isn’t good to eat! A cool example of different anti predator strategies (distinctively aposematic to camouflaged) in the same insect!
Scambophyllum katydid nymph
Returning to the lodge for some food and a cool down in the afternoon, we sat and recharged our own and the flash’s batteries ready for the evening’s walk – determined to find as much as we could on our last night.
We set off soon after tea while there was still light to scan for tree swifts. The reservoir was covered in wheeling birds and Ted was sure that this would be his day. However, after watching until the sun went down not a single tree swift was spotted amidst the swirling mass. When an anguished shout from Agus Din revealed that he had stepped in a fire ant colony we decided enough was enough and headed into the jungle.
Ted tree swift hunting
Walking along the boardwalk again, a small ruby caught my eye in the middle of a messy web. A closer look revealed it as a beautiful red Parasteatoda spider species. She was a member of the Theridiidae or comb-footed spider family on account of a comb of bristles on her back legs. Also included in this family are the harmless false widow spiders we have in the UK and the more exciting to handle black widow spider. This one is certainly one of the more beautiful ones with her dark abdominal mask and legs against her scarlet body.
Parasteatoda species of spider.
Interestingly, a fair few animals in the jungle seemed to be more elaborate versions of the things we may find at home. In the UK there is a species of shieldbug called the spiny shield bug, Picromerus bidens, which is a rusty brown with red legs and black tipped shoulder spines – beautiful in an understated way. However, turning over a leaf one of the spiny shieldbug’s more attractive cousins was revealed. I have no clue what species it was but with a shimmering brassy base layer, three large yellow spots in the middle and its shoulder spines were twice the length of its British cousin. Also, like many jungle creatures, this bug had huge eyes for seeing in the gloom of the understory.
Showy shieldbug.
A largeish orb web was on the edge of the trail at about hip level, shimmering slightly in our torch beams. Crouching down to look at the owner sat in the centre, as soon as I tried to take a photo she dropped to the floor and disappeared! Eventually finding her in the leaf litter we were amazed to see that she had tucked her legs under and was almost perfectly mimicking a piece of fallen leaf! Incredibly, this spider is Parawixia dehaani, the same as the black one with red horns from last night’s walk, but looked completely different and it was only under the eyes of experts I sent photos to later that she was identified. Her camouflage coupled with her behaviour of dropping off her web whenever she feels threatened must be a good strategy. It’s fascinating the intra-species differences in the Parawixia dehaani. The spider from a few days ago had a web above head height and didn’t drop off her web when threatened. P. dehaani is quite a chunky orb weaver and these spiders do not survive well from high falls (as I have found out handling large four-spotted orb weaver back home and still feel very guilty) and so to know to build her web much lower so as to effectively utilise her defensive tactics is quite extraordinary.
Amazing leaf-morph of Parawixia dehaani
Hopping around the forest floor as we wandered into a clearing was one of the common white lipped frogs we had been seeing regularly. This little one had the most amazing amber eyes.
White-lipped frog
The clearing contained a large shelter, its beams about 4m off the ground and we sat nearby to try and call for the elusive large frogmouth, Ted was getting quite good at mimicking its call at this point but we still used a tape just incase the frogmouth didn’t see Ted as a threat to his territory. Meanwhile, I wandered about with my camera trying to find more animals. Suddenly, a huge buzz filled the air and Ted’s hand shot out and batted it from the air. It turned out to be a huge Paragymnopleurus dung beetle. These beetles are vital for the jungle ecosystem as they take the dung of animals and bury it in the ground, speeding up the decomposition process a lot so it takes less time for the nutrients to get back into the living ecosystem.
Paragymnopleurus dung beetle
I decided to climb up on the shelter to see if anything was hiding in the rafters. Pulling myself up to look in the roof I came face to face with the largest spider I had ever seen. Almost as soon as she saw me, she jumped backwards and ran up a nearby beam. She was incredibly quick, fairly indicative of the huntsman spider family to which she belonged. She was a freshly moulted giant tree trunk huntsman (Heteropoda boiei) and extremely beautiful. Her body was a deep forest green with heavy russet radiating from her thorax and twin-spotting her especially long legs. I jumped down as she had run to the edge of the shelter and was on the outside. Calling Ted over I used a long stick to coax her into a better position for a photo. All of a sudden she jumped, copious legs outstretched and glided over our heads and onto the floor behind us. Bounding in a Michael Phelps style butterfly run, she covered the compacted floor near the shelter and made it to the thicker leaf litter at the edge before hunkering down where she hid. I don’t think that her jumping behaviour had ever been recorded before but a gliding spider makes perfect sense in a jungle environment. She hunts primarily on tree trunks and so being able to bounce between them without wasting time scurrying to the floor and back up would be of great use, not to mention catching her food in middair. It was certainly quite a shock to have this huge 30cm legspan spider bounce over us but Mr Garden Figure wasn’t as worried and went to have a closer look before we left her alone.
Giant tree-trunk huntsman, Heteropoda boiei
On a hollow in a trunk a Pholcus spider had spun her web. These cellar spiders may not look especially intimidating but are amazingly efficient hunters and I think have quite potent venom (although would not bite a human unless you were very small). In the UK these spiders are predators of other spiders as well as other things. Here we saw this one eating a small cricket but, more impressively there was the sucked-dry body of the only scorpion that we would see in the forests of Sungai Wain.
Pholcus spider with cricket and scorpion prey
Wandering back the way we had come, Ted spotted the most beautiful frog I think I have ever seen. Sat on a leaf near the path was a bright orange/red creature speckled with white, a cinnamon frog Nictixalus pictus. These frogs live in the lower branches of the forest and prefer to lay their eggs in water filled tree holes. Very sadly, this frog is close to being listed as vulnerable on the IUCN red list as its habitat is declining so rapidly.
Cinnamon frog
As we approached the boardwalk again, I noticed a strange looking stick poking just above the water’s surface. About five centimetres in diameter, looking closer this stick seemed to have eyes! Calling Ted over he got very excited and identified it as a puff-faced water snake Homalopsis buccata. Its head patterning is apparently distinctive and it hunts by hanging motionless in the water, monitoring movement for any prey.
Puff-faced watersnake pretending to be a log
I was hanging off the boardwalk, nose almost touching the water when something large and leggy darted out from under my chest. It seemed to have too many legs for a spider and it was only when I focused on it that I realised that it was more than one animal! A large Dolomedes raft spider (almost certainly a new species) had grabbed a frog (also of unknown identity) and was slowly eating it! The poor frog was still weakly alive as the spider’s large jaws and enzymes began to digest it. Amazing to see the range of prey these big spiders will go for.
Dolomedes spider eating a frog
As we left the jungle and crossed a bridge on the reservoir, an old friend was waiting for us. Curled up on the banister was what was likely the very same young reticulated python that had given me a welcoming hug on our first night. Mr Garden Figure and Ted both said hello to it and took some photos of the stunning snake.
Reticulated python
Trudging back, we were very sad to not have another night walk in the incredible sungai Wain forest. Although we felt quite adventurous living in the jungle, there was a part of us that was looking forward to a bedroom that wasn’t full of cockroaches, potentially malaria filled mozzies, separate beds and without a hole in the floor when we got to Balikpapan city tomorrow…
Before that, however, Agus Din had one last treat for us in the morning and told us to be up before dawn…