Will Hawkes
E N T O M O L O G Y
Day 4: Smelly fungi, hairy lacewings and especially flat beetles.
The beautiful washing spot at Camp Hornbill
Up at dawn to open mist nets in the hope of catching some birds. Promptly a bat flew into the net and so we rushed up with a glove (rabies is quite a real risk here) but it managed to chew a big hole in the net and escape. The morning passed with teams of two checking each net at regular intervals. Eventually a call came over the radio announcing two birds were caught in the top net. Racing up the muddy track, Alex and I began to extract the tangled birds from the mist net. The birds were a small blackbird size with yellow bellies, brown wings, black cap, white throat and amazing little whiskers around their beaks. While we were collecting data such as weight and wing-length on the two birds they were identified as Yellow Bellied Bulbuls. Their whiskers amazed me most and I’m not entirely sure what they are for. The birds are insect hunters and so some suggestions I have heard are that the whiskers can act as a sort of net to trap insects, or even protect the bird’s eyes from flying insects as it flies through swarms of midges or similar.
Sketch of the Yellow Bellied Bulbul because I failed to get a good photo!
After furling the nets, we headed on a walk to put out camera traps in the jungle. As we walked I hunted for insects of course and it wasn’t long before we found an amazing fungi. This was a bridal veil fungus with the amusing latin name of Phallus sp. due to its shape when fresh. This one however was passed its best and its veil had drooped. The fungus gives off a strong smell of rotting meat that attracts all sorts of carrion feeding insects. These insects spread the fungi’s spores around the forest. A huge array of insects were visiting from bees to beetles and flies. But the most amazing was a beautiful green and black grasshopper which I only saw feeding on these fungi suggesting a carrion heavy diet. They have long black wings and so must be good at flying around the forest after the smell of rotting flesh.
The bridal veil fungus and some insects that it attracts
One pretty spider was a suspected Cyclosa species who make these amazing web spirals. I don’t really know why they make these web decorations but potentially their shiny silk is highly visible to pollinating animals in the jungle and so lure these insects to their doom. In the jungle white has high chromatic contrast (difference between light and dark) and so is easily distinguished.
As we sat down for lunch a small cockroach nymph crawled over a stick in front of me bearing a striking resemblance to one of the velvet ant species we had seen (and failed to photograph) in Sungai Wain forest. I wonder whether this was intentional or just a coincidence as a result of both animals have aposematic colouration – the velvet ant’s truthful, the cockroach’s false.
The amazing web of a Cyclosa spider.
Cockroach nymph that is potentially mimicking a velvet ant.
We were sat under a very tall tree and one of its nuts was passed around. Hand sized the nut was huge with a very thick shell. I was puzzling over why this tree had evolved such defences for its fruit before coming to the sad realisation that the animals that posed a threat to it are probably long gone. Large animals such as the Bornean rhino would have loved to try and get into this nut for a good food source. But this animal no longer exists in almost all of the Bornean forests, with only 15 known individuals left wild in Borneo. Although those 15 are in East Kalimantan where we were and some of the forests are very big… I hope that this tree still protects its fruit for a reason and will continue to do so for years to come. In the meantime however, when I tried the nut I got told off.
Big nut that may be protected for the probably absent rhinos
We walked passed a large dipterocarp tree with a notch cut out of one of its buttresses. Although the taking of trees from the Tane’Olen is forbidden, the local people will take a small amount of wood to make the handles of their Parang knives.
Blenda (one of the Indonesian students) found a big earthworm in the leaf litter which was very exciting, these animals are so important in the forest (see Day 2).
Then someone noticed a small brown bush of hair clambering slowly over the leaves. A closer look revealed that it was an insect – a lacewing larvae with an amazing afro of hair! Lacewing larvae have very elaborate camouflage both for hiding from predators but also to disguise themselves from their prey which includes aphids in the UK and may be the same here. However, the UK’s lacewings will use the corpses of aphids as camouflage and so this hair is a nicer form.
Lacewing larvae with good hair and a big earthworm.
However, the most exciting animal on this walk for me was a Janula species of spider. These spiders eat termites and have an amazing hunting technique. Sitting next to termite runs they will catch them and wrap them in silk. Once they have a large amount (maybe up to 15) they will wrap the mass of dead termites up and haul it off the ground to enjoy the feast.
Winding back to camp we headed off to the river for a wash and to soak in the most picturesque jungle (see cover image).
An incredible Janula species of spider
At seven, we had a group frog hunt. We were looking at the differences in frog morphology and how that is adaptive to their distribution in the river. For example, the Kuhl’s creek frog is very streamlined to sit in fast moving currents, strong muscular legs for swimming, angular toes for gripping onto rocks, large upwards facing eyes to see any prey above it in the water and a warm brown colour to blend in with the riverbed. We were also hunting for everything else though. Amber found a very hairy Thelticopis species of huntsman, none of which have been yet described from Borneo, which was exciting. Ted found a Dusky Mock Viper while I found a tiny Therates sp. tiger beetle sat just in front of it. The beetle would probably have made good prey for the snake if it was fast enough to catch it.
The streamlined shape and muscular legs of the Kuhl's creek frog.
A hairy Thelticopis huntsman spider
Dusky mock viper
Therates species of tiger beetle feat. dusky mock viper
Poisonous rock frog
Swimming huntsman (Heteropoda natans) underwater! Note its air bubble!
I accidentally scared a large swimming huntsman (Heteropoda natans) into the water and it did the most amazing thing. Forming an air bubble around its abdomen (where its book lungs are found) it can hide underwater, safe from predators for many minutes! I watched it (from a distance) for five and it was still quite happy to be submerged for that long at least!
We continually heard the loud ‘honk’ of horned frogs further up the bank but consistently failed in our attempts to find them. Very frustrating.
We returned to camp and counted up our frog species from the night. 8 new species taking our total to 19 seen in just two nights. Somebody had caught the poisonous rockfrog which is a large green creature that has toxic skin to deter predators.
When we’d finished discussing the frogs Ted and I set off back up the river for another hunt for the horned frogs. One exciting moment happened when my torch picked out the eyeshine of a large frog high above us on a cliff. An excited scramble up ensued (and a more exciting one back down holding it) to reveal that it wasn’t a horned frog but in fact a very large river toad.
Ted and a big river toad
Pink Everettia sp. of snail.
Exploring up a side stream a beautiful pink snail was found which I think is an Everettia sp. (after a long internet trawl back home)! A shout from Ted on the other side of a tree and he emerged looking very pleased with himself holding a violin beetle (Mormolyce sp.)!! Something we had been really hoping to see on the trip but hadn’t held out much hope. This incredible beetle has extremely modified elytra (wing cases) which help it camouflage against jungle leaves when hiding during the day. At night these animals are predatory and feed on insects underneath black and white bracket fungi (although this one was found on a green leaf about 1.5 metres up!). The young are xylophagous meaning they eat dead wood and so are important decomposers in the jungle. These beetles also have one of the better claims to fame (as if they needed one): they are the world’s flattest insect (relatively)!!
Taking the beetle back to camp, and making it a house overnight to show people in the morning, we headed to bed happy.
