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This leech was found in a cave in NE Laos. I have never seen any in Malaysian caves. There is little documentation on cave leeches as they seem to be quite rare.
leech |
BIRDS NESTS
The demand for birds' nest products is still big, especially in Asia. Cave nests are still very popular. However within Malaysia many buildings are being converted into "swiftlet hotels". These can be old houses which are converted, or just normal shop houses where the upper floors are used for the birds. The windows and doors are removed and covered to prevent sunlight entering, leaving small holes for the birds to enter and exit. Recordings of the bird calls are played constantly through speakers to lure more birds. This is very noisy for human neigbours, who also have to put up with the stench of the bird droppings. In 2006 there were an estimated 1,500 bird’s nest farmers just in Perak, with a total estimate of 30,000 "swiftlet hotels" in the country. Even in KL there appear to be swiftlet houses. According to the NST in March 2008, Kelantan is the country's second largest producer of nests, after Perak, with over 300 farms. The report went on to say that there were more than 36,000 farms throughout the country by the end of 2006. Malaysia is currently the world's third largest producer of edible birds' nests with 7% of gross supply value behind Indonesia (60%) and Thailand (20%). I've even seen an ad for a seminar on swiftlet farming.
With the retail price of bird’s nest ranging from RM4,000 to RM5,900 a kilo (2007), depending on its quality, it is no wonder that entrepreneurs are willing to spend tens of thousands of ringgit to convert old, sometimes abandoned, buildings, into homes for swiftlets. The use of heritage buildings is detrimental to the building as in the closed environment moisture accumulates hastening up the decay of the building.
The nests are sold dried, or else they are made into products such as drinks. The latest use I have seen is bird nest essence face masks. And even spas are opening offering a variety of facials all containing birds' nest.
swiftlet house in Ipoh |
dried prepared nests |
birds nest drink |
swiftlet house in Sandakan |
Gomantong swiftlet |
skeleton of swifltet in Gomantong |
GUANO
Cave guano is the droppings of bats and swiftlets that accumulate on the floor of caves. The word guano comes from a Spanish word and was first used to define excrement from certain sea birds that had value to humans as a fertilizer. Now the word is also used to include the excrement of bats and swiftlets. Today guano is harvested from many caves in SE Asia, the USA, Cuba and S.America. It is a free source of nutrient rich fertilizer.
Cave guano is rich in nutrients as inside the cave there is no sunlight, wind or rain, and so the components don't break down as quickly as they would outside. As it is rich in nitrogen and phosphates, it is good for crops.
In caves with large populations of bats or swiftlets, the resulting guano piles can be many metres deep. The largest mound I have seen is in Gomantong Cave and was made famous by David Attenborough in the BBC film Caves in the Planet Earth series.
When manmade chemical fertilizers became readily available, guano was used less. However it has now regained its popularity as an organic fertilizer. There are many sites on the internet selling guano. But the indiscriminate harvesting of cave guano can upset the ecology of the caves, as the guano supports the whole cave food chain, and is home to many invertebrate species.
In Niah Caves, Sarawak, it is estimated that birds and bats have been producing guano for at least 100,000 years, and that 7-9m depth of guano has accumulated over that time. In fact this guano probably helped to preserve the famous ~40,000 year old human skull found in Niah. The thick sequences of guano have helped preserve many of the archaeological finds. At Niah the collecting of guano is allowed.
Today scientists are turning their attention to guano for other reasons. It is a source of palaeoenvironmental remains on glacial - interglacial timescales. This guano is now being studied to determine climatic changes over the past 10,000, even maybe 30,000 years.
guano pile made famous by David Attenborough |
cockroaches feeding on dying bat |
ADAPTATION
It is widely thought that animals have special adaptations to be able to live in the total darkness of a cave. The most obvious of these are loosing the pigments and the eyes, as mentioned earlier, with the famous example of the Proteus salamander in Slovenia. However in tropical caves of SE Asia, this doesn't seem to happen much. Virtually all the tropical cave fauna has retained eyes and pigment, it is rare to find blind, white creatures. However one white troglobite is the cave crab, which is eyeless, and found in Mulu. But the Bidi Cave crabs (also in Sarawak) still have eyes and pigments. Other white AND eyeless Crustacea found in Mulu include Armadillo solumcolus, an isopod Cyathura sp., Bogidiella sarawacensis. The blind crabs along with these other crustacea, as well as some millipedes and pseudoscorpions are apparently the only troglobites without eyes. All the others have reduced eyes and pigments.
The cave racer snake in Peninsula Malaysia is a creamy white colour, but in Borneo it is a much darker grey colour with a more defined pattern, and yet it is thought to be the same species.
In caves with large populations of cockroaches, it is common to see white or cream coloured roaches. However these are simply the normal brown cockroaches which are undergoing a moult.
white crabs in Mulu |
brown crab, Bidi. Photo taken from Nature Malaysiana 1990 15(3) Ng, P & Shaharin, Y. |
blind crab Mulu, photo from NM 15(3) 1990. |
moulting cockroach |
moulting cockroach |
© Liz Price 2007
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