Amphibians of the Leuser Ecosystem
Brad Sivacoe
We have just returned from our second trip to the rain forest. The first time we went was November 4-6, 1996. This time we started our trip on April 14-16, 1997. On this trip we focused more on our topic. My project that I focused on was amphibians. I worked mainly in the wet swampy areas. I worked with Hari Dasraf and Jonathan Vea. Hari was the one that got me interested in working with amphibians. He got me interested by taking me down to the pond and telling me about amphibians.
Before I went to the rain forest I didn't know that much about amphibians. I did know that they breathe through their skin and I knew what they ate. Also one fact that I learned from my research was that some amphibians change color like a chameleon can. Now I know a lot more than before because I did a lot of research.
In addition to my research, I raised a tadpole that I found in a little trench that was built to drain water. I had to feed this tadpole a special food that came in a little kit. I thought that it was interesting to watch the frog change from a tadpole to a frog. The tadpole died when he was turning into a frog (this stage is called metamorphosis). Another part of my research is that I boiled the skin off of a dead frog and put some of it's bones back together.
I think that this trip was a good experience for me because I had never been in the rain forest before. This trip gave me a lot of knowledge on amphibians. It also taught me some important field techniques. It could help local Indonesians learn about the things that I find out. This does not just have an educational value, it also has scientific value.
The method used for capturing amphibians and reptiles is "pit trapping." The pit traps have to be put in the natural path of the animals so they will fall in. We put down four pit traps in three different places. The places that we put the traps in were 1) swamp, 2) clear open area with sparse grass, 3) and burnt flat area. We did not catch anything in our traps. We think that we didn't catch anything because we did not put plastic over the top. The animals can tell if there is a hole in the ground, if there is a hole they will not go there. So this is the purpose of putting the plastic down. To build a pit trap first you have to pick a spot. Then you have to dig a hole the same size as the bucket you are going to use. Once the hole is dug put the bucket in the hole. Fill in the holes around the bucket with the dirt you have. Cover the bucket with a plastic sheet then scatter leaves around it so it looks undisturbed and normal, so the animals will go near the bucket and also in the bucket.
Another field method used to locate amphibians is an "active search". To do an active search on the side of a path you have to turn over logs and lift up rocks, but if you do this in a pond you have to look on logs and look in reeds and deep grass and other places that amphibians will be most likely to hide.
In the pond we saw lots of frogs and lizards. We found them on logs in the water and hanging from trees and hiding in reeds. We saw a dark green frog, a light green frog, a yellow frog, a red toad, brown frog, a skink with a silver back and a dark-colored skink.
The dark green frog had a pointed nose and 2 stripes of yellow on either side. The light green frog had two brown stripes on either side and the green in the middle of the stripes. The yellow frog was plain yellow. The red toad was as small as a watch face and was a dark red color. If the frogs see a person, they skipped across the water like a rock. A lot of the frogs have similar markings. I do not know why though. I guess they could be related to each other but I really do not know.
I like working with amphibians because they are really neat. I think that the frogs that we saw on our trip were neat because they had lots of colors on them and they are not just plain. It is very hard to catch amphibians because they are so fast and collecting conditions can be very difficult. There are no checklists on amphibians that inhabit the Leuser ecosystem, I think that this is bad because a species could disappear and we would not even know it. This is why there needs to be a checklist.
The classification of frogs can be very difficult because the frog has to be measured and the colors looked at. The males in one species may be different than a female in the same species. So it can be very difficult to tell two frogs apart that are in the same species.
I think that it will be important for scientists to study the amphibians of the rain forests in Indonesia and all over the world where they are not being studied. I think that this should happen because amphibians are good monitors of the forest. They monitor the forest by changing if something is wrong. If the air, water or soil is bad they might change in a way. So we would like to keep them alive. In the future I'm planning to make a frog pond so I can observe how frogs act and monitor other things that they do. The little pond has to be the right depth and have the surrounding that frogs will come to. If you do not have the things that frogs like, then the frogs will not come to your habitat and then you cannot study them. I want to continue my study to the end of the year, and find out more about amphibians.