Highlights Week 2
13th May 2010
Yesterday we had lectures from Ain and Julie telling us in detail what their studies involve. It was interesting to see the preliminary results. I also found out Tigga is looking at the tropical bats are true endotherms or are heterothermic endotherms, meaning they can alter their body temperature. She’s recording the bats body temperature and then placing them in an icebox to see whether they drop into torpor and what their body temperature is. The average body temperature of the bats we caught last night was 37°C. From the preliminary results it seems as though they can drop into torpor, but a lot more study is required. The theory is that they will drop their body temperature to within 1-2°C of the ambient temperature in order to conserve energy, and then as the temperature rises so too will their body temperature, remaining within the 1-2°C range, until optimal temperature is reached at which point they’ll return to their normal body temperature.
During trapping last night we got 7 individuals including species H.diadema, Murina suilla, Murina cyclotis and H. ridleyi. When we tried to release one of the H. diadema she was having problems with flight and whenever she tried to fly, she’s land on the forest floor. Tigga had a look at her and it turns out she had a dislocated elbow. This means that she’ll have to be euthanised, and will subsequently become a specimen.
Big rain last night – it rained heavily for over 2½ hours. It was drizzling, thundering and lightning while we were trapping last night, but luckily the heavy rain held off until we got back to base.
Julie’s group set up the mist nets behind the house and close to the forest, however had to abandon it due to the weather. Being close to steel poles whilst lightning is going on is definitely not advisable! Plus the bats tend not to leave their roosts during rainfall as it’s hard to fly and the insects aren’t out either. She said they caught an endangered dragonfly though!
Morning bats saw 4-6 bats caught and they had hidden under the plastic sheet inside the harp trap. Probably to stay out of the rain! It’s likely that they flew into the traps last night and not during their dawn peak activity. The same species we caught last night were in the traps this morning.
We leave here tomorrow after morning bats. I can’t believe how quickly this whole thing has gone, and I’m certainly glad I’ve had the opportunity to experience it.
Today’s interesting fact: insectivorous bats need to eat 50-100% of their body weight each night.
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| Balionycterus maculata | Eonycteris spelaea |
Wednesday 12th May 2010
Yesterday we went to a couple of caves – Gua Kelawar and Gua Terang Bulan, meaning Bat Cave and Bright Moonlight Cave. While we were in Gua Kelawar we saw hundreds or thousands of bats hanging from the roof. As we disturbed them they started flying around. It was so awesome! Not once did they hit anyone despite it looking like a sea of bats. It was absolutely majestic to watch, especially towards the opening of the cave as the daylight really showed the bats and how many were actually flying. Gua Terang Bulan is part of the main cave system and was massive! Here we actually found some of the carrion eating beetles actually feeding on a dead bat. It was disgusting but interesting at the same time. On the way back from the caves, we stopped at Kuala Krau for a much needed cold drink and ice cream. We also saw a few long-tailed monkeys crossing the road!
We all in the forest last night as Julie wanted to rest the river site as bats will learn where nets are, just like the forest bats learn where harp traps are. We got a different species again – a Hipposiderus diadema, which is the largest Hipposiderus. We got two of these, a male and female. When we released the female she tried to bite me through the bag, but didn’t pierce the skin, which was good! The teeth on this species are impressive! When we band the H. diadema we have to put the ID tag around it's neck as it will chew through one put on its forearm. We also got H. bicolor, Myotis ater, K. intermedia, R. stheno and Murina suilla. One of the bats I processed had parasites on it, which seems to be common.
This morning there were 7 bats to process, with a mix of male and females. We got a H. ridleyi, which we haven’t seen since the beginning of the expedition, so that was quite exciting! Again this morning we had a bat with parasites on it. These we small brown insects and I’m not quite sure what role it played, but the bats don’t seem to care.
Today’s interesting fact: the lifespan of a bat can be anywhere from 7 to 30 years depending on the species.
 | Hipposiderus diadema |
 | Hipposiderus diadema with the ID tag around its neck |
 | One of the caves we visited |
Tuesday 11th May 2010
Sadly the echolocation recording device didn’t work as planned yesterday afternoon, however throwing the bat into the air to prompt flight was extremely fun!
It was interesting to learn that the Cheiromeles torquatus climbs backwards as the pelvic girdle is very strong. If they land on the ground for some reason, they will walk along until they find something suitable to climb and then launch from. They also have a pocket on the underside of their body, close to their wing, where they fold their wing and tuck it in.
At the river mist net last night we get four individuals – 2 Cheiromeles torquatus, a Mops mops and an Eonycteris spelaea. The first C. torquatus seemed to have ‘braked’ to avoid the mist net and fell onto the bridge. We had to chase it to actually bag it! E. spelaea is a fruit bat that we hadn’t caught yet and it’s face looked similar to that of a kangaroo joey. It was very cute! The Cheiromeles torquatus had earwigs on them. The earwigs were about 2cm long! They were disgusting!! I will have to get photos before we release them. They do actually serve a purpose – to eat the dead skin. The relationship is called ‘commensalism’ meaning both species benefit, but don’t actually rely on one another. The forest group only brought back one bat, as the others were lactating females which are done in the forest so they can look after their pups. They got 7 individuals in total consisting of Kerivoula intermedia, Kerivoula pellucida, Hipposiderus bicolor, Hipposiderus cervinus, Rhinolophus trifoliatus and Rhinolophus lepidus.
During morning bats we got four individuals, including a H. bicolor that was caught and banded last night! We also got one of R. trifoliatus, R. lepidus and R. stheno.
We’re off to see some caves today to see a different environment where bats roost. Julie also wants to find a carrion (dead animal) eating beetle, so she doesn’t have to boil the flesh off dead bats to study their skull and bone structures.
I can’t believe how quickly this trip has gone. Only three more days here before heading back into the Kuala Lumpur and then flying home. It’s been an absolute awesome experience being here, one I wouldn’t trade for anything! No photos today as it just won't work for me for some reason. Hopefully it'll work tomorrow.
Monday 10th May 2010
Last night we captured 20 bats in total! 10 from the river mist net and 10 in the rainforest. It was by far our most successful night! Rainforest species included: Kerivoula intermedia, Myotis ater, Murina cyclotis, Kerivoula papillose, Murina suilla, Rhinolophus stheno and Hipposideros cervinus. River species were: Mops mops, Chaerephon johorensis and Cheiromeles torquatus.
It seems as though the law of averages is at play as we only got one individual during morning bats – a Balionycterus maculata.
We’ve got a lecture on echolocation this evening, followed by using echolocation recording devices. It’ll be interesting to see how that works. Tigga said she hopes to use the equipment on the river bats when we release them later this evening.
It was much cooler this morning at around 29°C, and there is a tiny breeze. It’s a nice relief from the constant heat, regardless of how short lived it is.
Interesting fact for the day: female bats can delay gestation in three different ways to synchronise with food availability.
- Delaying fertilization/ovulation so sperm is stored
- Delaying implantation of blastula (fertilised egg) into the uterus
- Embryonic diapause – pause in the embryos development. The embryo is implanted into the uterus by is dormant.
 | Pregnant Balionycterus maculata |
 | Measuring the forarm of Cheiromeles torquatus. It was 77.9mm! |
 | Wing of Cheiromeles torquatus |
 | Feeding an elephant at the Elephant Conservation Park |
Sunday 9th May 2010
There was amazing rain last night. It’s a pity it didn’t last for longer though as an increase in rain = an increase in insects = increase in bats.
Five bats were captured during morning bats. Another Cynopterus brachyotis and a species we haven’t captured before - Rhinolophus stheno. The fruit bats are more likely to be edge dwellers, which accounts for the recent trend of capture – we’re currently trapping towards to edge of the rainforest.
The cat had her kittens!! There are four in total, with at least one being a male. They’re absolutely adorable!
Saturday 8th May 2010
No morning bats as we didn’t trap Friday night. We entered tapping data into Ain’s database, and we also placed faecal samples into vials so she can analyse them.
I was on river nets which meant getting into the river (fully clothed) and setting up mist nets across the water. Two mist nets were set up – one upstream and one a bit more downstream. The net which was upstream consisted of two nets ½ a meter apart with one higher than the other but with a bit of an overlap. This was to try and capture both the low and high flying species. We did see a couple of individuals flying just about the water’s surface, however that species can echolocate and therefore detects the mist net. We got two Mops mops though. The forest group caught 8 bats including two Cynopterus brachyotis, a Murina suilla, Hipposideros bicolour 142kz and Rhinolophus trifoliatus.