Earthwatch Australia Teach Live

Day 8 Saturday 8th May

Today we had a sleep in until around 8.30 because there were no morning bats to collect. At 10.00am we had a lecture on bat ecology. About every second day we have a lecture on something bat related which I always find interesting.

After spending some time doing our daily journal I had some spare time to do a bit of cleaning and washing. After lunch we learnt how to process bat faecal (poo) samples. The samples are kept to examine what type of insects the bats are eating.

Tonight we are trying to catch fruit eating bats (molossids) again so late in the afternoon we set up the mist nets across the river. This time at a completely different spot that involved wading through waist deep water. The nets stay up until about 9.30pm. Unfortunately the only thing we caught were three birds which we were able to release after some difficulty. I really enjoyed sitting on the river bank in the darkness listening to the sounds of the forest and watching the fireflies skimming along the surface. It was nice change.

Day 9 Sunday 9th May

Last night we had the first tropical downpour of the trip. At around 3.30am the thunder started and soon after it started absolutely pouring. It lasted for a fair while and as a result the river is noticeably higher this morning.

Sunday was a return to normal routine with morning bats needing to be collected. The morning catch was small so the morning was fairly short. After lunch we sorted the insects and as usual there were plenty of them. The process is getting easier as we get better and better at identifying them.

After dinner we went out to collect the evening bats which and had our best haul yet. The scientist feels it has something to do with the rain. Apart from the usual suspects we also collected a couple of species that we hadn’t collected yet on the trip. I had no idea how many different species of bats exist in the world. World wide there are over 1,200 different types of bats which accounts for nearly one-fifth of all mammal species. The particular the part of Malaysia I am in has around 125 different species. Around 25% of these are on the IUCN Red List which means they are at some risk of extinction.

Day 10 Monday 10th May

Monday was essentially a normal day. Morning bat collecting session was over very quickly as we only collected one bat out of the 12 traps. The rest of the day involved insect sorting and a lecture on echolocation which was interesting to learn how technical the whole process is. Each bat has a slightly different frequency and amplitude of sound that it emits and they are able it modify the sound as it approaches an insect. Humans hear at around 20kHz, bats can hear at around 120kHz. This allows them to detect the flutter of a butterflies wings. The bat is also able to determine the size of the insect and whether it is soft or hard, all from being able to process the sound they send out compared to the sound it receives back after it bounces off something. Amazing stuff.

We tried to record the sound emitted by some of the bats. The species that we were trying to record are some of the largest insect eating bats in the world (Cheiromeles torquatus – Greater Naked Bat). In fact they are so big that they are unable to generate enough life from their own wings to take off. They rely on gravity to give them a hand. What they do is reverse up to a tree and climb up it to a certain height, then will jump and as they fall they are able to start flying. They are also able to swim. To release the bats you just have to throw them which to start off with is quite strange but you get used to it.

After dinner we collected bats from the bridge over the river. We only caught four bats.

A new sport. Bat launching.	Insect sorting. Requires a lot of patience

Day 11 Tuesday 11th May.

The morning bat session was longer this morning as the amount of bats trapped increased. I continue to get better at identifying the species and more confident with the processing.

The main highlight of the day was heading to a local series of caves where some species of bats roost. Bats will tend to roost in almost anything. Trees, bridges, dead and fallen trees as well as caves. The cave we visited is well known as having a large colony of bats that roost there during the day. Caves are not limited to only one species and many different types of bats can inhabit the same cave.

After a short walk through a plantation of palm trees we entered some more familiar vegetation and not long after we were at the cave. The purpose of our visit was to try and get some beetles that tend to live in the cave with the bats and will eat any dead bats that fall to the ground. These bats are useful to scientist because they can be used to clean the flesh from specimens they want to keep, leaving just the intact skeleton. The sort of beetle you might see used on a Bones type TV program. The beetles are known as Dermestes ater.

The cave was large and dark and the ground was covered in a thick, spongy layer of bat guano (bat poo). To ensure you didn’t disturb the bats we were not allowed to use our head torches. Tigga showed us very quickly using her torch and I was amazed at how many were hanging upside down from the roof of the cave, there must have been thousands.

We set about searching through the guano to try and locate the beetle or the larvae of the beetle. It was quite difficult work. Especially with bats flying around your head. We seemed to disturb the bats too much and suddenly a large majority of them took off. You couldn’t see them but you could hear them flying all around you. Like something from a movie. I was quite glad that they have great navigation skills. Tigga told us to get out of the cave as so we gradually made away towards the exit. The light that filtered in from the outside gave you a good idea of how many were above our heads.

Afterwards we headed to a much larger cave and looked around in there. The roof of the cave was much higher which meant different bats used it. Right at the back of the cave there was once again a lot of guano and amongst it there were dead bats with beetles and all.

In the evening we went into the forest to collect the evening bats and had quite a large haul. Once again we had a species of bat we hadn’t seen yet on this trip.

Walking to the bat cave.	The entrance to the cave. Note the bats flying on the roof.	A scene from the movie Journey to the Centre of the Earth.

Day 12 Wednesday 12th May

The day followed our normal routine with morning bats followed by journal writing and insect sorting. In the afternoon we were given a lecture by Aine and Julie, who are Phd students currently at the field station, on what their research is about. It was interesting to hear how everything we have been doing fits together to assist their projects and how it all aims to learn how better to conserve bat populations.

Late in the afternoon the skies began to darken and shortly after the lightning started on the horizon. We headed into the forest to collect the bats, moving very quickly to ensure we avoided the rain. We captured a couple a Hipposideros diadema which are a very large insectivorous bat. The reason why we have caught so many is because they prefer more open spaces and for the last couple of days the traps have been set on the main trail which is much wider. There were lots of other bats to collect and as the lightning and thunder got closer we finished our processing of the bats and returned to the safety of the field station. Not long after the rain started and it poured for a few hours with a great sound and light show as well.

Measuring the temperature of the bats	Hipposideros diadema	The light trap. Used to collect the insects.