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I've been a Canberran since moving here from Adelaide on the first day of 1980. I now live in suburban Duffy with my partner Louise Maher, ABC 666 radio and on-line journalist. Among my early memories is following Sleepy Lizards (Shinglebacks) around the paddocks north of Adelaide, guarded by the faithful bull terrier. I have always been passionate about the natural world, trying to understand how it works, how the nature of Australia came to be, and sharing those understandings. My especial passions are birds, orchids and mammals. For much of my life I have been a full-time naturalist, running bush tours, writing books etc, doing consultancies, presenting a regular radio slot on local ABC, chairing a government environment advisory committee and running adult education classes. Recently I have eased back somewhat, but am still writing, teaching, doing some radio work and running overseas tours - as part of my fascination with our Gondwanan origins I've been running tours to South America for the past decade. I was awarded the Australian Plants Society Award in 2001 and the Australian Natural History Medallion in 2006, both for services to education and conservation. In January 2018 I was awarded a Medal of the Order of Australia for 'service to conservation and the environment'.

Thursday, 6 April 2017

Gomantong Caves; full of life

Malaysian Borneo contains some massive limestone cave systems, the best known of which are probably Mulu in Sarawak, and Gomantong in far north-east Sabah. Gomantong is only an hour or so's drive south of Sepilok, a major tourist destination, primarily for its Orangutan and Sun Bear rehabilitation centres; this is an area full of wildlife and we'll visit it together at some stage too.
Gomantong Caves locality, at the end of the red arrow.
Gomantong Caves are known best for being a major and long-term site for collection of swiftlet nests from the walls of the huge caves, for human food. Some might find this a little odd, given that they comprise bird saliva, but to each their own.
Looking into Simud Hitam, the Black Cave; this is the one that is open to visitors.
The caves - there are two major ones - were first mapped as late as the 1930s, but local people have known and used them for centuries. The caves are nesting sites for large (though dwindling) numbers of swiftlets; the nests have been harvested and traded as delicacies for at least 1500 years. There are three species of swiftlet involved, all of which use echo-location to navigate in the dark; they are physically indistinguishable, except by their nests. The White-nest Swiftlet (Aerodramus fuciphagus) produces the most valuable nests, of pure bird spit. The Black-nest Swiftlet (Aerodramus maximus) mixes its saliva with feathers and moss, which reduces the value to about a fifth that of the white nests. The Mossy-nest Swiftlet uses moss only and as a result is left to breed in peace.
Black-nest Swiftlet on nest, Gomantong.

Part of the Black-nest Swiftlet colony in Gomantong.
Mossy-nest Swiftlet Aerodramus salangana, Bako NP.
Even the keenest nidivore would be challenged by this nest served as a meal!
The valuable White-nest Swiftlets nest in the higher and larger cave, Simud Putih, or White Cave, which is not accessible to casual visitors. Traditionally the rights to harvest the caves were inherited and harvesting was carried out on a rotational basis. These days licences are sold by the Wildlife Department; at a cost of 300,000 ringgits (~A$90,000) per season they are not accessible to local individuals. Companies employ local gatherers, who still use traditional rattan and bamboo ladders to climb 90 metres up to near the roof. The harvest is carefully managed; one collection is made at the beginning of the season, as soon as the nests are built but before eggs are laid. The cave is then closed to harvesting while the birds rebuild and breed (guards are posted to prevent poaching) and the nests are gathered again after the chicks have fledged. A worker is paid somewhere around 3,000 ringgits (~A$900) for the entire season’s work. 
Harvesters' huts on the hillside near the entrance to the White Cave.

Looking out the 'back door' of Black Cave; the objects in the foreground belong to the cave guards.
The caves are home to more than just swiftlets however. Colonies of bats are found near the ceiling of the caves.
Wrinkle-lipped Free-tailed Bats Chaerephon plicatus high up in Black Cave.
Huge numbers of bats stream out at dusk, and as a result there are always birds of prey in the vicinity of the cave exits.
Crested Serpent Eagle Spilornis cheela in a coconut palm just outside the cave entrance.
The amount of guano produced by both birds and bats is immense, and the ammonia smell is very strong indeed.

Huge mound of swiftlet and bat droppings on the floor of the cave.
There are huge numbers of cockroaches living on the guano, along with millipedes, other insects and their larvae, hunted by wood centipedes and spiders. 
Some of the millions of cockroaches which inhabit the caves (above and below),
doing an essential clean-up job.

Scutigeran, or Wood Centipede, hunting the cave walls.
There are even freshwater crabs on the cave floor – it is a bustling ecosystem.
Freshwater Crab; unfortunately my flash wasn't working on this occasion...
The rainforest around the caves - it is about a ten minute walk in, on well-maintained trails with boardwalks in the muddier sections - is of course full of life, of every sort. It can be a slow walk! All the following photos were taken along the walk and around the forest clearing outside the caves.
A magnificent millipede.
Carpenter Bee Xylocopa sp. (I think!).
Probably Great Eggfly Hypolimnas bolina, which has a huge distribution from Madagascar through
south-east Asia to Japan and the Pacific, including Australia and New Zealand.
(Thanks for the tip below Susan!)
Red Grasshawk Neurothemis fluctuans; this one I'm pretty sure of.
Freshwater snails in stream along the track.
I feel more confident in putting names to vertebrates!

Green Crested Lizard Bronchocela cristatella;
portrait below.

This lovely dragon is found throughout much of south-east Asia.
Sumatran Gliding Dragon Draco sumatranus; this little lizard glides
by means of flaps of skin along its sides, supported by highly extended ribs.
(The former name of D. volans was applied when it was believed that the same species occurred throughout
south-east Asia. That name is now used only for lizards on Java and Bali; Sumatran gliding dragons are
found in peninsular Malaysia, southern Thailand, Sumatra and Borneo.)
Asian Water Monitor Varanus salvator; a common monitor (goanna in Australia),
this one was lying on some bags outside the workers' accommodation.
Pied Fantail Rhipidura javanica; a very familiar genus in Australia, it extends through south-east Asia to India.
Rufous-backed (or Oriental Dwarf) Kingfisher Ceyx erithaca.A diminutive (only 12cm long) and gorgeous little forest kingfisher.

Maroon Leaf Monkeys Presbytis rubicunda, above and below.
This beautiful monkey is endemic to Borneo.

A family group of Maroon Leaf Monkeys.
Large male Southern Pig-tailed Macaque Macaca nemestrina.These are powerful and potentially dangerous monkeys.
The highlight of my second visit to Gomantong however was undoubtedly another primate, and one quite unexpected. Bornean Orangutans Pongo pygmaeus can potentially turn up anywhere there is an expanse of rainforest, but they are thin on the ground. This mother and boisterous youngster delighted us for a long time. (Actually the mother was much shyer and stayed high up and among foliage; the young one had no such inhibitions.)

The fact that this was an entirely wild animal, not one used to people like the rehabilitated animals
at Sepilok, just added to our pleasure.
I hope you do find your way to Sabah one day, it is a special destination. If you do you must of course go to Gomantong, but don't make the mistake of just hurrying along the track to the caves. You'd miss a lot if you did.

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Susan said...

We get a species of scutie here in France. We have a breeding colony in our downstairs toilet. Known in English as House Centipedes, they spend the night hunting all through our ground floor level.

The butterfly is probably a Great Eggfly Hypolimnas bolina.

The bee looks like Xylocopa to me too.

Fab orang sighting. I'm envious.

Ian Fraser said...

Firstly, thanks for the butterfly tip; now updated above. I'm a big fan of 'scuties' too; no idea how many are here, but more than one. As for your orang jealousy, well you'll just have to get out more! :-) Yes, we were very lucky.

Flabmeister said...

I wondered if that was a cockroach in the image of the Black-nest Swiftlet. All knowledge comes to one who waits!

Are the nests from the harvest before nesting more expensive than those from the second round? I would have thought the latter would have a few additions to the saliva (gauno, eggshell, remnants of food etc).

Is there a concession selling bird-nests soup on-site and if so how does it taste? I am quite happy to take such gustatory delights by proxy!

Ian Fraser said...

Ever a disappointment I'm afraid I can't answer your very pertinent first question. One might think so, especially given that the 'black' nests are only worth 20% of the white ones. As for the second, certainly not - I'm sure that the concession owners would have something harsh to say about that. (And of course it's seasonal.)