Will Hawkes
E N T O M O L O G Y
The morning was spent working on our field notebooks for most people but I was distracted trying to find pollinating beetles to film for our video project. Cosmodela aurulenta tiger beetles became green blurs as they flashed over the sand, nearly impossible to photograph. A large golden orb-weaver spider (Nephila pilipes) was sat in her web waiting for unsuspecting prey. These spiders have a very interesting method of catching their prey. Their golden thorax is thought to act as an attractant to pollinator species (such as bees or flies) as the pollinators think it is a flower! This is called aggressive pollinator deception and I found a few spiders (mostly in the previous forest (Sungai Wain)) that showed this hunting method. However, a distinct lack of pollinating beetles were found and so I decided to try my luck near the river. Happily I soon came across a click beetle (Elatidae? sp.) sat on a riverside flower. Flowers are quite hard to find near the forest floor as it is normally too dark for pollinators to be attracted to it. Interestingly the only low-level flowers I saw were white. This is because white has a very high achromatic contrast (shade difference) in low light environments which helps the flowers be as distinguishable as possible. The rest of the flowers in the jungle can be found high in the canopy where the majority of pollinators live. I haven’t seen them but I would presume they are more colourful up there.
Anyway, back to the beetle. This species seems to mimic a piece of bark and gets its name from an odd protrusion between its thorax and abdomen that allows it to click, throwing itself into the air. It generally uses this to escape predators but also to right itself if it lands on its back.
At 11 we were due to leave to check some of the many butterfly traps that had been set up along the river, running late because of this beetle I grabbed camera and followed on. The butterfly traps were baited with banana but had not been massively successful. Apparently having a bit of alcohol in the trap helps a lot and so Josh begrudgingly offered to give up some of his beer he had smuggled in. We did, however, catch a few butterflies, the most beautiful being the giant Saturn, Zeuxidia aurelius. This butterfly will be marked and join part of the survey which can show how far these butterflies will move along rivers in the jungle.
Rounding a meander, we squelched into a muddy waterfall camp. The previous group was still here and so it was nice to catch up to hear what they had seen. Apparently they have sampling French cuisine here having been served snails and frog’s legs the evening before. I wonder what we’ll get to try…
The camp itself is right next to a river and has more flat ground than Hornbill, a small stream at the back and slightly larger shelters.
After setting up mosquito nets (still haven’t been bit in the Tane’Olen, a far cry from the hordes in Sungai Wain!) we were thrown into our first task – catching spiders to determine their functional groups. I decided to determine the spider’s functional group by hunting strategy and so set off to find spiders that eat things in different ways. Apparently we have a couple of days to do this and so I will look harder tomorrow when there is more light!
The light had all gone within an hour and we settled down for a good tea – although nothing out of the ordinary tonight – before a night walk! I get so excited about night walks, there’s just so much potential to see amazing life!
On the beach tens of cockroach nymphs scuttled around us, we didn’t see any at all during the day and they are all quite grey like the majority of the rocks on the beach… I wonder if they know they are camouflaged?
No longer a green flash, a Cosmodela aurulenta tiger beetle has fallen asleep on a leaf at the back of the beach. This gives us a brilliant opportunity to get a close look. Her giant mandibles are used for eating her insect prey. Long legs which can propel these beetles very quickly (up to nearly 9km an hour!) and beautiful elytra (wing cases) which hide wings that are regularly used during the day. See cover photo.
Lots of different frog and toad species were sat on the river’s edge, using logs and rocks as places to sing to impress potential mates. One giant river frog however was itself being used as a courtship platform. Its flat back and head made the perfect stage for male mosquitos to dance. These little animals wave their middle legs (the last segments expanded and white – white to make them extra-noticeable in the gloom of the jungle) high in the air, back and forth until a girl mosquito thinks he is suitably handsome (and good at waving) and mates with him.
Walking slowly along at the back looking for animals, I suddenly felt a sharp pain in my shoulder. Looking down I couldn’t see anything but as soon as I rubbed it the pain came back. I quickly took my shirt off and found the culprit, an incredibly tiny but very cross jumping spider! She must have crawled into my shirt and then got understandably worried when her new house started pressing into her, I think I would have bitten too. Although it made my arm feel quite warm for a bit, due to her size it was not the really impressive spider bite I had been half hoping for and so, after taking her photo, I gently released her onto a leaf.
What happened next did not have a happy ending however. It is a bit graphic but it is what happened. One of our brilliant local guides, Pak Simin, suddenly hauled out one of the most amazing animals from under a rock. With a 45cm shell length and much more than a metre with its long snaking neck. The Malayan soft-shelled turtle is something we had never expected to see because, although common, they have amazing camouflage as their soft shell allows them to mould to the riverbed. The turtle has a very long neck to get under rocks to catch fish and other prey. There is a funny protrusion on its head where its nose pokes upward which the turtle uses it as a snorkel so it doesn’t have to raise its whole head out of the water. Their name is well earned also as the shell is very bendy to the touch.
The entire group were so excited to see this animal but this soon changed to concern as we realised the turtle wasn’t going to be let go. We watched as this poor turtle was dragged through the river and the forest for the next hour back to camp before being tied, still alive, to a stake to keep it fresh before being killed the next day for food.
This was desperately sad to watch and a lot of the group were very upset and almost angry about it. But thinking about it carefully it is such a sustainable way of getting protein in the jungle. Unlike in the UK where almost any food comes with a carbon footprint through food miles, this was an incredibly low impact way of eating. Pak Simin has lived in or on the edge of the forest all his life and is very in-tune with its ecosystem and so will know exactly how many animals to take to maintain a balance.
However, eating sustainable meat is not the positive here. If we were not present to see him catch this turtle for food, we would more than likely never have seen it and therefore not have the same interest in it! By being able to have a close look at this elusive animal we could learn about it, take photos and tell stories to further show other people the amazing diversity of the rainforests, hopefully getting more people interested and therefore more likely to help conserve them.
I do think that a hands on approach to wildlife is the best way of learning and becoming interested.
The turtle remained of interest posthumously too as it was quite tasty, if a little fatty.
Back to insect hunting and a small water stick insect was spotted scooting over the surface, remaining well camouflaged as a floating stick. However it is not closely related to its terrestrial counterparts and is infact a bug – hemiptera rather than a stick insect –phasmatodea. It is a predator and will hide in vegetation snatching prey such as tadpoles and small fish. It breathes through a tail snorkel so it can remain underwater.
A huge white-sided water spider (Nilus albocintus) was sat on the surface, her light body and wide lengths making sure she didn’t sink while waiting for her food. If she catches big prey like a fish or a prawn she will quickly snaffle it onto shore to eat. Apparently she can even jump into the air to catch unsuspecting moths!
Further ahead someone was shouting me. Splashing forward I arrived to find two big huntsman spiders were on the path leading us away from the river. They were definitely Heteropoda species but I am still not sure what species they are. The two spiders had been mating but now one of them was an ex-Heteropoda species however as he had begun to be eaten by the female. She was reluctant to leave her lover and so we carefully stepped around her and carried on.
Nearing the end of our walk a truly beautiful black spotted rock frog with its blue toes was sharing a bush with a heavily jawed Scolopendra centipede.
Briefly turning my torch off I noticed five or six glowing green lights floating up and down in the air, fireflies. Grabbing my net from camp I caught a few to get a closer look. Fireflies are not actually flies and are in fact beetles in the family Lampyridae! Both males and females create the light from a chemical reaction in their abdomen and this bioluminescence has a range of functions. A male will flash his light to attract females who will flash back if she is interested. If she wasn’t impressed by what she saw in his flash she will stay hidden. Aside from courtship, the green light can also be used to attract the beetle’s prey – small flies and moths. The beetles have huge eyes for seeing the small green light in the dark.
I briefly put a few in a clear pot and their light was plenty bright enough to read a book by.
Setting the magical beetles free, I pulled off my wet boots and crawled into bed. Excited for tomorrow.
The formidable jaws of a Cosmodela aurulenta Tiger beetle.
Pollinating click beetle feat. ants.
Golden Orb-weaver Nephila pilipes
Back at Base Camp for lunch before setting off in the rain to Camp Waterfall! I did enjoy Base Camp but do much prefer the sleeping without walls in the jungle aspect of the two satellite camps. The journey to waterfall was predominately through the river which meant we really got a good look at the jungle – something you don’t really see when you’re on a forest trail because the vegetation is so dense! Huge trees touching the sky, dripping with vines and epiphytes (plants which grow on trees rather than in the soil), the sound of cicadas incessantly searching for love and secretive birds calling in the canopy.