Malaysian Bat Education Adventure

Hi Folks
Last night was not a good night, as we got caught out by very heavy rains. Normally, we close the traps ahead of time if we think it is going to rain. So from about 6 pm we start staring at the sky and trying to decide if its going to rain or not. Last night though, we had no warning; everything looked fine at 6 pm but at around 7.15 pm a storm started to blow in from nowhere! By that time it is too late to close the traps, especially when they are so far into the forest. By 8 pm when we left to check the traps it was raining, and we had thunder and lightning for most of the rest of the night.

So we had a very small evening catch (just four bats), and nothing this morning. The traps set were KL0715, KL0717, KL0719, KL0721, KL0723, KL0725, KL0727, KL0729, KL0731, KL0733, KL0735, KL0737. Fingers crossed for a better night tonight!

Kerivoula intermedia with one of the killer big ants still attached

Hi Folks
Last night was clear and dry and we set traps KL0739, KL0741, KL0743, KL0745, KL0747, KL0749, KL0751, KL0753, KL0755, KL0757, KL0759, KL0761. We closed trap KL0745 at 9 pm because of the presence of big ants. You may have wondered about these ants in the past, and unfortunately today I evidence for you of just how harmful they can be. When we checked the traps this morning, we found that one of the other traps had been over run by the ants. They weren’t there at the night check, but had obviously found the trap overnight. Sadly, at the bottom of the trap were two dead Kerivoula intermedia. . You can see just how big these ants are — in the photo is one of the soldier ants and its head is about the size of one of your fingernails. The ant itself is about 2.5 cm long, and the head and body of the bat is only about 3.5 cm, so it is a very sad way for the bats to die. That’s why we take the traps down if we see any sign of them at the evening check.

Although the loss of any of our batty friends is sad for us, we don’t let the animal die in vain. The body is brought back and preserved as a specimen, so that it can be used for other research projects. We take extra measurements, so in addition to forearm and weight, we will measure the tail, the tibia, the hind foot, the ears and the head and body length.

The specimen is stored in alcohol which will preserve it for decades or even longer, so that it is available to other researchers in the future, or for other parts of our own research. Julie will probably use these two herself to look at the skull in more detail. Just as bats have different wing shapes, they have different skull shapes, and this influences what they can eat. It’s hard to eat a big crunchy beetle if you have a small fragile skull! Beetle-eaters usually have strong jaws and teeth and wide areas for the jaw muscles to attach to, whereas moth-eaters tend to have more delicate skulls and smaller, sharper teeth.

Closer view of the big ant, you can see that even in death, the ant's mandibles (biting mouth parts) are still firmly buried in the dead K. intermedia

So on to the data, you will notice that under “band” the two intermedia that died have a “TK” number. This is a specimen number which indicates the date the bat was prepared as a specimen. TK100602.1 has “TK” for my initials, then 10 = 2010, 06 = June, 02 = 2nd and the .1 tells you which specimen for that date it was, just in case (as we did today) you have more than one.

Dr Kingston

Hi Folks
Well as I mentioned yesterday, we took last night off from trapping bats. This morning I took Diah and Mimi into the forest to start mapping the trails that are off the grid. I’ll explain that in detail another time.

Today I thought I’d tell you a little bit more about what Julie has been up to. If you remember, she has been taking pictures of the bats with their wings stretched out so that she can describe the shape of each species’ wings in detail. We want to know if there are differences between species and if that affects where and how they can fly.

To test their performance when flying, she (with quite a bit of help!) has been building a huge flight cage. The idea is that the bats will fly through an obstacle course inside the flight cage and we can score how well they do. We can then see how the scores relate to the shape of the wings. But first we had to build the cage…….

Everyone was needed to get the sides into position

Once the sides were up they could be nailed into place

The hardest part was getting the roof on!

The finished product -- now all that is needed are the banks of strings that will act as obstacles

The obstacle course is made up of six sets of strings (we call each set a “bank”). The distance between the banks can be changed to make it easier or harder for the bats, and the distances between the strings within in a bank can also changed (again to make it easier or harder). Julie will test each species at inter-string distances (distances between the strings) of 10, 20, 40 and 60 cm, matched with the same inter-bank distances. See the diagram below to get an idea.

A diagram of the obstacle course design, seen from above

We plan to video the bats when they are flying to see how well they do. Each string is connected to the base with a magnet. If a bat hits a string, the string will come loose and we will be able to score that as a “touch”. In theory, a bat that is very manoeuvrable will not “touch” any of the strings, even when they are very close together (say 10 cm inter-string distance). That kind of bat should be able to forage in the really dense parts of the forest understory, and we will see what kind of wing shapes match up with being able to forage in “clutter”.

Other bat species may not be so good, and will touch lots of strings or perhaps even refuse to go through the obstacles at all. Those bats probably fly in the more open parts of the forest and should have different wing shapes from the bats that do well with the obstacles.

So that’s the theory!! We have done a few test flights, but tonight she hopes to start collecting actual data!

Setting up the banks of strings that the bats have to fly through. It can be a hot job when the sun is on the flight cage, hence the big hats. I don't think its a very exciting job either, because the girls have been singing at the top of their voices all afternoon!

Julie and Zam getting the banks of strings ready for tonight

Hi Folks
If you remember, Ain’s project is all about trying to work out when the bats breed. Our hypothesis is that most females will time things so that they are lactating (producing milk), which is very costly for them in terms of energy, when there are most insects about. So to find out when most insects are about, you guessed it, we have to catch insects as well as bats!

Whenever we trap for bats we run two light traps. There are lots of different kinds of traps for insects, light traps exploit the fact that many insects are attracted to light (which is why they are always buzzing around the lights in the house here, and probably around any outside lights you have at home in the summer). The bulbs we use give out a blue-purple light which is particularly attractive to insects.

The light comes on at dusk (it has an automatic switch) and goes off in the morning. So after we have collected the bats, Ain has to stop by the two light traps we are running and collect the insects. That’s the easy part! The really hard work is then to sort out all the insects in the different orders. We can’t get the identifications to species, because there is too little known about insects here, and it would take years. Instead we identify to order (like dragonflies — Order Odonata, grasshoppers and crickets — Order Orthoptera).

Even sorting to order takes hours so its a good job Ain has some help from the USM students at the moment. Once all the insects have been sorted, the number of individuals caught in each order is recorded. They are then they dried in a toaster oven, before we weigh each order o give what’s called the dry biomass of the Order (the total dry weight of all the insects in that order). So for each night, we have two measures of the abundance of insects — the actual numbers in each order and the dry biomass of each order. These measures of abundance change through the year, and we are trying to match that up with the local weather and the bat breeding.

The next thing we want to know is whether the bats are eating the insects that are available in high numbers. Guess how you work out what a bat eats? Yep you have to look at the feces (poos!). You could look at stomach contents but then you’d have to kill the bat, so we are stuck with picking through poos. So whenever a bat is released back into the forest, we keep the bag it spent the night in, which most of the time will also contain fecal pellets. These also have to be dried in the toaster oven (the smell is AWFUL) before they are stored in small plastic tubes — one tube per bat. When Ain gets back to the US she will have a fun time trying to identify bits of chewed up insects that have passed through the bats.

It has to be said, that collecting insects and poos aren’t quite as much fun as just catching bats, but its all part of the research!

The light trap for catching insects. The white bar is the bulb, at night it glows a blue-purple color with which attracts the insects. They hit the metal panels which are set at right angles to one another and fall into the collecting bucket at the bottom

The light trap is powered by a car battery (top) which has to be recharged every day. Bottom: Ain at one of the traps, the tarpaulin keeps the worst of the rain out of the trap

Top: After sorting, the insects are dried in a toaster oven (yum!) before being weighed. Middle and bottom: sorting the insects into the major orders

The orders of insects that are caught in the light traps. Most of them are found around the world, and should be familiar from their common descriptions (in blue)

Hi Folks
Another quiet night. The traps set were KL0763, KL0765, KL0767, KL0769, KL0771, KL0773, KL0775, KL0777, KL0779, KL0781, KL0783, KL0785, and we are now slowly trapping back towards the grid. It was a clear night, with no rain.

In an effort to make up for the nights lost to rain we have been trapping non-stop for about a week now (with the break for Kota Gelanggi cave). Everyone is pretty exhausted, so we are taking a break from trapping tonight. There is still lots do though! We need to catch up on sorting out the insects collected every night we trap (which I’ll talk about next), and the faecal samples, so that’s tonight’s entertainment.

Here are last night’s data:

Best wishes
Dr Kingston