Malaysian Bat Education Adventure

The harp trap set at the entrance to Gua Samat

Hi Everybody
As I mentioned yesterday, last night we didn’t trap in the forest but went to a small cave about 8 km from the field station, Gua Samat (Gua means cave in Malay, and Samat is the owner of the land, so it translates as Samat’s Cave). Ain visits this cave every month to increase the numbers of Hipposideros bicolor 142kHz and H. cervinus that she catches for the breeding study. It’s a strange sort of cave — made up of very large boulders that have fallen on top of each other and created a network of spaces where the bats roost.

We left about 5 pm and had to hike through banana plantations up a slight hill to get to the cave, where we set a trap at the main entrance. The bats started to emerge (come out) at about 6.45 pm, and it wasn’t long before the trap was full of bats! I think by the time we took the trap down at 11 pm we must have captured over 300 individuals, mainly Hipposideros bicolor 142kHz, with a few Hipposideros cervinus, and one or two Hipposideros bicolor 131kHz. We didn’t keep all of the bats we caught — we let many go immediately at the trap, we just made sure we had enough for each of the projects we were doing that night.

We didn't have to wait long before the harp trap started to fill up with bats!

We split into three groups to do three different projects. Ain was continuing her research looking at the reproductive condition of the bats (whether they were pregnant or lactating). As we are finding in the forest, most of the adult females were lactating, and we caught alot of juveniles taking their first few flights! Not all the young were ready to fly though, as you can see from the picture below. When the pups are really young, the mother will carry them with her when she goes out to feed.

A Hipposideros cervinus female carrying her pup. The pup can't be more than a few days old, so she would rather take it with her when she is foraging that leave it in the cave.

Julie was taking photographs of the wings of the bats so that she can study the shape of their wings and investigate how that relates to where they can fly.

I have recently started a project looking at how bats control their body temperature. Most mammals keep their body at a constant temperature, if it increases or decreases it is usually an indication that you are sick! Some mammals however will drop their body temperature when there is not enough food available to save energy. This is why some smaller animals hibernate — there is no food in winter and to save energy they drop their temperature which slows down all the systems in the body (heart rate, use of energy, use of oxygen).

Hibernation usually lasts several months (because winter does), but some mammals are able to drop their temperatures for shorter periods, this is called torpor. We know that bats in the temperate zones hibernate, but we have much less information on whether bats in the tropical parts of the world, where it is much warmer, use torpor.

So I’ve been measuring the temperature of the bats we’ve been catching. I take the temperature when we first catch them, and then I’ve been putting them in an ice box at a much lower temperature (about 22 deg C) for two hours to see if they then drop their temperature. The results so far are really interesting — some of the forest bats, like Murina suilla and M. cyclotis will drop as much as 15 deg C in a couple of hours, but I’ve been finding that the Hipposideros and Rhinolophus only drop their temperature by a few degrees C.

So we were all pretty busy, and finished up by about midnight, and got to bed around 1 am. Fingers crossed we will be back in the forest tonight.

Taking a break! Dr Kingston with Jovic and Saveng. You can see the ice box in the foreground (no bats in it yet though).

Ain and the students hard at work!

Hi folks

Sadly we were rained off again last night, but although the rain was on and off all night at least it wasn’t especially heavy, so I don’t think we are in danger of flooding again (phew!). We are getting very frustrated though!!

I thought I would take this time to tell you a little bit about some of the other work on bats that is going on here. The long-term work that you have been tracking focuses on the bats that live and forage inside the forest itself. We call them forest interior bats. Julie’s main project also looks at bats that hunt for insects above the forest. We call them open space bats because they forage in the open spaces, and many belong to the family Molossidae, or free-tailed bats. This may sound familiar because the most common bat in Texas is the Mexican Free-tailed bat — Tadarida brasiliensis. In fact T. brasiliensis is one of our state mammals and is very important for cotton farmers because it eats tons of the insects that are a pest on cotton. It saves farmers in our state millions of dollars a year! If you have ever been to Carlsbad Caverns or the bridge in Austin to watch bats emerging at night — those are all Mexican Free-tailed bats.

The Mexican Free-tailed Bat, Tadarida brasiliensis - the farmers' friend!

Here in Malaysia, we don’t have Tadarida brasiliensis, but we do have related species. Unlike the forest interior bats, we don’t catch these guys with harp traps, but with mist nets. The molossids normally fly very high (over 30 m) above the ground, but they do fly lower over rivers, so we set up a system of nets over the rivers. The system has very long poles so that we can actually stack three nets on top of each other to make a “wall” of nets. We used the bridge over the Krau River to give us some additional height. See if you can spot the net in the picture below.

Spot the net -- three nets are stacked here to provide a "wall" of nets that the bats don't see.

A Mops mops caught in the net. The fun part is getting them out (Photo - Ben Logan)

Julie and the crew have set this a few times since we have been here and had good captures of three species of the Molossidae: Cheiromeles torquatus, Mops mops, and Chaerephon johorensis. Cheiromeles torquatus is also known as the Greater Naked Bat because it has no fur — just a few short hairs. It is a really cool bat and is also the largest bat (weighing up to 200g) in the world to feed on insects in the open skies. It is also incredibly smelly!! Mops mops and Chaerephon johorensis are much smaller, both between 16-25 g with FA 40-45 mm. They are actually quite hard to tell apart — you have to look for differences in the skin joining the ears, and at some of the back teeth. You will also notice they look pretty similar to our own Tadarida brasiliensis.

Mops mops. Individuals of this species are often bleached orange by the build up of ammonia in the caves they live in, but many individuals are a dark brown

Chaerephon johorensis

Cheiromeles torquatus - big, naked and smelly!!

Tonight we are off to a small cave to catch Hipposideros bicolor 142 kHz and Hipposideros cervinus for Ain’s project. Remember she is studying when the bats breed, and to give her enough individuals for these species she has been visiting a small cave about 8 km away every month to check their breeding status. I’ll tell you more about that in tomorrow’s post.

Best wishes
Dr Kingston

Heading off grid -- trails trapped on the 14th May shown in red

Hi Everyone
Now that things here have settled down a bit, I can bring you the data from Friday the 14th. As you can see from the map, we are actually heading beyond the original study grid, along the main trail. This makes the trap numbering system a little confusing. We had KL0038, KL0040, KL0042, KL0044 on the grid, and the traps beyond were KL0631, KL0632, KL0633, KL0634, K00635, KL0636 (these were on the side trail heading south), and KL0682 and KL0686 on the main trail but off the grid. One of my jobs this summer is to map these new positions. As you may remember, the weather was fine up until 11 pm, and then it rained most of the rest of the night. When Ain and the crew went in the next morning, the small stream they had to cross was so deep that they had to wade across it. This was fine for Saveng and Jovic, but poor Zie is pretty small, and the water came up to her chest!

We had some cool captures though, including our first Nycteris tragata and Myotis ridleyi of the season, and then our largest Rhinolophus, Rhinolophus luctus. Rhinolophus luctus is related to Rhinolophus sedulus and Rhinolophus trifoliatus, but quite a bit bigger; the forearm ranges from 60-60 mm and weight 29 – 30g. Like both R. sedulus and R. trifoliatus it has lateral lappets, and it is a dark brown like R. sedulus. We don’t know much about it because we catch it so rarely, but we do know it tends to roost singly or in pairs and not in colonies like many other Rhinolophus. Roosting sites include caves, rock shelters, hollow trees, fallen tree hollows, or under thick bark at subcanopy level.

Rhinolophus luctus

Here are the rest of the data:

Hopefully we will be able to trap again tonight,
Dr Kingston

Hi Everyone,
We got back to Kuala Lompat yesterday (Monday), and began the big clean up. It took about 4 hours to get all the mud out! Here are photos from Saturday, the day of the flood.

The field station at 7.30 am on Saturday (left), with big puddles left from the heavy rains. On the right you can see the mist rising from the edge of the forest

The frogs alerted me to the possibility of a flood, so I head to the river to check the water level. Eek!! Bottom left is the first stick I put at the edge of the river -- it was underwater completely in 2 hours.

The field station by 10.30 (top left). Time to evacuate (bottom left) but not before a final photo (right), from left to right: Julie, Zie, Ain, Zam, Saveng (with the cat and kittens) and Jovic.

Inside the house!

Our disaster is an opportunity for the local Orang Asli (aborigines). Left - fishing off the bridge. Right - a chance to clean your motorbike!

Hi Everyone,
We have had a rather hectic weekend. We set traps on Friday night, and everything was fine until 11 pm, and then we got some heavy rain again. It carried on for most of the night, and when we got up in the morning I started to get worried. The frogs were calling. Lots of them, very loudly, all around the houses. It is never a good sign when the frogs are calling during the day — it means the swamps are forming around you and the frogs are making the most of the wet conditions to breed.

The field station, Kuala Lompat, is situated where two rivers meet (the Lompat river and the Krau river), and at 7.30 am I went to check out the river levels. They were pretty high and I put a stick in the ground at the edge of the water to see if the river was still going up. Half an hour later the stick was completely covered. I put another stick in at the new edge, and again it was quickly covered by the rising water. Oh oh! Two hours later the Lompat river had started to come up along the drainage system and was fast approaching the house!

Our Australian teachers left us on Friday, so Ain was in the forest with just Jovic, Zie and Saveng. That left me, Zam and Julie to rush around all the buildings and try and get all our equipment and belongings stacked up high. It was all a bit of a panic. By the time Ain came out of the forest, you had to wade to the house. Everyone quickly packed up their possessions before the water got into the house, we finished securing all the equipment, grabbed the cats (all six of them!) and retreated to higher ground.

Once everyone was out we sat and stared at the rising water. By this time, both rivers had broken their banks and water was gushing into the station, filling the house with water. With nowhere else to go we came to the nearest town (about an hour away), called Temerloh, and checked into a hotel for the night.

We got an update this morning (Sunday); the river was going down quite fast, but I decided we should stay another night here in Temerloh to be safe. I didn’t like the idea of more rain tonight and having to repeat the whole process in the middle of the night! If the water continues to go down, tomorrow we will head back to Lompat and begin the big clean up — the flood leaves a thick coat of silty mud behind so it will probably take us all day to clean up.

There were bat data for Friday 14th, but we were too busy evacuating to bring it with us, so I’ll have to give your Friday’s data when we get settled back in. I also have lots of photos of the flood which I will post next time. I’m not sure if we will trap tomorrow night — I think we will be a bit busy getting organized.

Keep your fingers crossed for us! Oh, and “banjir” is the Malay word for flood!

Dr Kingston