Gateway to natural treasures
Sunday, December 23, 2007
THERE are many caves in Malaysia that have the name Bat Cave or Gua Kelawar. Some still have bats in residency, others don't.
The one on Langkawi does. As our boat headed up a tributary of the Kilim River, we could see a wooden boardwalk running alongside a cliff face and disappearing into a cave entrance.
This was our destination, Gua Kelawar.
We stepped out of the boat onto the wooden jetty and walked to the shelter to read the information board which would tell us about the cave.
The cave is only accessible by boat and is surrounded by mangrove swamps. The cave is actually a tunnel through the hill, and despite the large numbers of human visitors, is still home to a sizeable colony of bats.
As soon as we entered the cave, we could hear the squeaks of the bats and the rustle of their wings. As far as I could see, the bats were all insect eating bats.
Contrary to popular belief, bats are not blind, and the fruit eating bats have quite large eyes. The insect bats have tiny eyes and navigate using echolocation.
Bats leave the cave at night to feed. The fruit eating bats are beneficial to man as they pollinate trees and crops such as banana and durian.
The insect eating bats are also useful as they keep the insect population under control. If one bat eats 10g of insects every night, you can imagine how many kilogrammes a few thousand bats will eat. And some caves do contain thousands of bats.
The population in Gua Kelawar wasn't so big, and according to the locals there are less now than in previous years. Maybe the human visitors have taken their toll after all and the bats have moved to other quieter caves.
Bats support the entire food chain in caves. As they are the only animals which go out to feed, it is their droppings or guano, which falls on the floor and indirectly feeds all the creatures in the caves.
Tiny bugs and small insects feed on the guano and these in turn are fed upon by larger animals such as crickets, spiders, whip spiders, scorpions, cockroaches, and maybe small mammals and amphibians.
There were actually few insects visible in this cave. However, I did see a forest gecko on the boardwalk inside the cave. It had lost its tail, but a new one was just starting to grow. I wondered if this gecko normally leaves the cave to feed or if there is enough food inside.
The cave was actually quite dry although I could see it would get wet in the rainy season. The boardwalk means visitors don't have to step into the mud or the guano on the floor. The locals used to collect the guano for fertiliser, but in caves which are protected, this practice has been stopped as it upsets the cave's ecosystem.
As all visitors are accompanied by a guide as part of a tour group, I was pleased to see most guides told the visitors not to smoke or make any noise inside the cave. Also it is important not to shine the torchlight directly onto the bats as they are sensitive to light.
The cave contains a few stalactites and stalagmites. The limestone rock forming the cave is actually some of the oldest in the country, from the Silurian period, and is about 400 million years old.
We walked through the cave and followed the boardwalk back to the boat, to continue our trip down the Kilim River. We passed many limestone cliffs with stalactites hanging down from the vertical walls. With a variety of boats moored in the river, it was quite a scenic site.
Our next destination was the floating fish farm nestled against a high cliff.
The farm is basically a series of "tanks" separated by netting and plastic, with a wooden platform and a boardwalk made of planks, all seated on top of oil drums to keep it afloat.
At the first tank, the owner demonstrated the spitting fish. He placed a piece of bread on the platform and the fish accurately spat a mouthful of bubbles at the bread, which is their way of catching insects.
Other tanks contained brown reef stingrays, and a variety of large and small fish. One tank had several horseshoe or king crabs (belankas) and large oysters, and some large eels which were hiding in plastic drainpipes.
On the way back we saw lots of eagles circling overhead. The Red Eagle has become the symbol of Langkawi and has a large statue in the town.
There are various types of eagles here but the Brahminy kites seem to be the most prevalent, they are chestnut brown in colour, with white on the head and breast.
The White-bellied Sea Eagle is the largest of the local species and generally flies higher.
Many tour guides feed the eagles with chicken meat. The circling birds have learnt that tourist boats mean food and swoop down with their sharp talons fully extended to pick the pieces of meat nimbly off the water surface.
However this practice should not be encouraged as it could change the feeding habits of the birds and ultimately affect their lifestyle. The Brunei Times
The one on Langkawi does. As our boat headed up a tributary of the Kilim River, we could see a wooden boardwalk running alongside a cliff face and disappearing into a cave entrance.
This was our destination, Gua Kelawar.
We stepped out of the boat onto the wooden jetty and walked to the shelter to read the information board which would tell us about the cave.
The cave is only accessible by boat and is surrounded by mangrove swamps. The cave is actually a tunnel through the hill, and despite the large numbers of human visitors, is still home to a sizeable colony of bats.
As soon as we entered the cave, we could hear the squeaks of the bats and the rustle of their wings. As far as I could see, the bats were all insect eating bats.
Contrary to popular belief, bats are not blind, and the fruit eating bats have quite large eyes. The insect bats have tiny eyes and navigate using echolocation.
Bats leave the cave at night to feed. The fruit eating bats are beneficial to man as they pollinate trees and crops such as banana and durian.
The insect eating bats are also useful as they keep the insect population under control. If one bat eats 10g of insects every night, you can imagine how many kilogrammes a few thousand bats will eat. And some caves do contain thousands of bats.
The population in Gua Kelawar wasn't so big, and according to the locals there are less now than in previous years. Maybe the human visitors have taken their toll after all and the bats have moved to other quieter caves.
Bats support the entire food chain in caves. As they are the only animals which go out to feed, it is their droppings or guano, which falls on the floor and indirectly feeds all the creatures in the caves.
Tiny bugs and small insects feed on the guano and these in turn are fed upon by larger animals such as crickets, spiders, whip spiders, scorpions, cockroaches, and maybe small mammals and amphibians.
There were actually few insects visible in this cave. However, I did see a forest gecko on the boardwalk inside the cave. It had lost its tail, but a new one was just starting to grow. I wondered if this gecko normally leaves the cave to feed or if there is enough food inside.
The cave was actually quite dry although I could see it would get wet in the rainy season. The boardwalk means visitors don't have to step into the mud or the guano on the floor. The locals used to collect the guano for fertiliser, but in caves which are protected, this practice has been stopped as it upsets the cave's ecosystem.
As all visitors are accompanied by a guide as part of a tour group, I was pleased to see most guides told the visitors not to smoke or make any noise inside the cave. Also it is important not to shine the torchlight directly onto the bats as they are sensitive to light.
The cave contains a few stalactites and stalagmites. The limestone rock forming the cave is actually some of the oldest in the country, from the Silurian period, and is about 400 million years old.
We walked through the cave and followed the boardwalk back to the boat, to continue our trip down the Kilim River. We passed many limestone cliffs with stalactites hanging down from the vertical walls. With a variety of boats moored in the river, it was quite a scenic site.
Our next destination was the floating fish farm nestled against a high cliff.
The farm is basically a series of "tanks" separated by netting and plastic, with a wooden platform and a boardwalk made of planks, all seated on top of oil drums to keep it afloat.
At the first tank, the owner demonstrated the spitting fish. He placed a piece of bread on the platform and the fish accurately spat a mouthful of bubbles at the bread, which is their way of catching insects.
Other tanks contained brown reef stingrays, and a variety of large and small fish. One tank had several horseshoe or king crabs (belankas) and large oysters, and some large eels which were hiding in plastic drainpipes.
On the way back we saw lots of eagles circling overhead. The Red Eagle has become the symbol of Langkawi and has a large statue in the town.
There are various types of eagles here but the Brahminy kites seem to be the most prevalent, they are chestnut brown in colour, with white on the head and breast.
The White-bellied Sea Eagle is the largest of the local species and generally flies higher.
Many tour guides feed the eagles with chicken meat. The circling birds have learnt that tourist boats mean food and swoop down with their sharp talons fully extended to pick the pieces of meat nimbly off the water surface.
However this practice should not be encouraged as it could change the feeding habits of the birds and ultimately affect their lifestyle. The Brunei Times