Bali beasts

The blogging has been a bit slow lately here at Lost in Science. This is primarily due to me jetting off to Bali, Indonesia for a winter holiday.

But never fear, there is science wherever you go! Click through after the cut to see some of the amazing creatures I encountered.

(The pictures, unfortunately, aren’t mine. I never claimed to be a wildlife photographer).

Female Atlas Moth (click to embiggen)
Female Atlas Moth (Photo by Quartl, via Wikimedia Commons)
The Atlas Moth, Attacus atlas, has the largest wings of any moth in the world (in terms of surface area). Their wingspan can reach up to 262 mm (26 cm), although the one I saw was not quite that big. It also seemed to be quite old, with its papery, slowly-beating wings full of holes.

Ant mimicking jumping spider (click to embiggen)
Ant mimicking jumping spider (Photo by by L. Shyamal)

Speaking of arthropods, there was also this curious creature. You might think it’s an ant, but if  you look closely you’ll see those things at the front aren’t antennae; they’re another pair of legs. And it actually has fangs and spider eyes.

Yes, it’s a spider pretending to be an ant; specifically, a type of jumping spider from the genus Myrmarachne. They most likely mimic ants to avoid predators; ants often don’t taste too good, or are very aggressive.  There are many species of Myrmarachne, so I cannot say for certain which one was found loitering outside the temple Pura Luhur Batukaru.

Common House Gecko in Australia (click to embiggen)
Common or Asian House Gecko (Photo by Vicki Nunn, via Wikimedia Commons)
Moving on to things that eat insects, there are many types of geckos in Bali. But the most common variety found in houses is the appropriately named Asian House Gecko, Hemidactylus frenatus. This species is relatively new to Australia, having appeared on Brisbane wharves around 1983 (although it had been seen in the Northern Territory before then).

But it has since spread rapidly, with its distinctive “chuck chuck chuck” call being heard throughout northern Australia, gradually moving south. These geckos are well-adapted to living alongside humans, and their insect-eating often makes them welcome, if noisy, house guests. However, they’re not so good for the many indigenous species of gecko, frequently out-competing or even eating the locals (read more at the Queensland Museum or Department of Primary Industries).

Of course, the other interesting thing about all geckos is their ability to stick to walls. Their toes are covered in tiny hairs called setae, and the setae themselves are covered in thousands of even tinier filaments, 200 nanometres in diameter. These filaments bind to surfaces using van der Waals forces, caused by uneven distribution of electric charges in neutral molecules.

A single seta can lift a weight of 20 mg, which means a typical gecko with mass about 100 g could support a weight of 40 kg. And yet geckos can easily unstick their setae by changing their angle, effectively peeling them off. To find out more, see the Gecko Labs at Lewis and Clark College, Oregon.

Finally there was this amazing creature, the Manta Ray, Manta birostris. They’re frequent visitors to the aptly named Manta Point, off Nusa Penida, a cleaning station where small fish swim through their gills and over their skin, removing parasites and other detritus.

They are enormous, gentle creatures, up to 7.6 metres across, and although they look like stingrays they have no sting. The only danger from touching them is to the rays themselves, whose mucus coating – which protects them from infection – can be rubbed off by a careless diver.

There were many other creatures too, like pheasants, monkeys, bats… Maybe next time I’ll get a bit closer to them, rather than focusing on the creepy-crawlies.


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