Monday, 9 April 2012

we all stand together

Frog he would a-wooing go,
“Heigh ho!” says Rowley,
Frog he would a-wooing go,
Whether his mother would let him or no.
With a roly-poly, gammon and spinach,
“Heigh ho!” says Anthony Rowley.

traditional folk song.
Paul McCartney has composed quite a few turkeys in his time—Mull of Kintyre and Give Ireland Back to the Irish spring immediately to mind—but perhaps the most turkish of the lot is We All Stand Together, allegedly by the Frog Chorus. If I’d written this horror I think that I’d want to hide behind a pseudonym too, so I shall not be providing a link, and if you haven’t heard this recording, you will have to take my word for it that it is as grim as I’m suggesting.

By way of compensation, I thought that some genuine frog choruses might make for an interesting diversion. It’s that time of year again, the breeding season, and a walk along our local river after dark reveals the frog population in full voice. There are 20 species of frog and three species of toad in Hong Kong, and they are found in a wide variety of habitats: rivers, mountain streams, ponds, swamps and flooded former paddy fields.

The concrete shafts that form part of the territory’s storm water drainage system can be regarded as a habitat sub-type, because Asiatic painted frogs (Kaloula pulchra pulchra), individually the loudest of the local species, are frequently heard at the bottom of them. The shafts, which are one metre square in cross-section, act as acoustic resonators to amplify their croaking; you can hear the effect in the first two audio clips. The booming sound that you can hear in the first clip, similar to and almost as loud as a mooing cow, is an Asiatic painted frog several feet away in a large storm drain, while the other types of croak in the recording belong to two other species, as yet unidentified.

This chorus is loud enough to drown out two barking dogs a mere 15 yards away (click to play):


The second recording also features an Asiatic painted frog, but in this case I held the recorder next to the entry drain to a shaft. You could say that the sound is like that of a euphonium fed through a Marshall amplifier. Paula was standing on the concrete cover of the shaft and said that she could feel the reverberations. You can certainly hear them. The third recording was made in an open field and features at least four frog species.

Feel the vibrations (click to play—be sure to turn the volume to maximum):


How many different ‘croak’ styles can you identify? (click to play):


At this point, you may be wondering why I chose to begin this post by quoting the well-known song about the courtship habits of Mr Frog. In fact, all this creaking, croaking, clicking, clacking, clucking, stuttering, muttering, rumbling, grumbling, groaning and moaning can loosely be described as a series of ‘love serenades’, although it isn’t obvious what sound qualities an amorous amphibian might be looking for in a prospective mate. Purity of tone? Musicality? Loudness?

Many years ago, when I lived in the Sai Kung area, I was walking home along a quiet country road late one night when my attention was attracted by a cacophonous racket emanating from the storm drain on the opposite side of the road. I discovered that the drain had been blocked by fallen leaves, and in the pool behind the dam a dozen frogs were floating lazily, their cheek pouches rhythmically inflating and deflating in a honking concerto of booming croaks. It all seemed very lackadaisical, a kind of ‘I’m here if you want me, take it or leave it’.

And what about the apparently cooperative nature of some croaking? The village where we lived between 2005 and 2008 still had its paddy fields intact, and a path led through them to the next village. To stand in the middle of that paddy and hear thousands of frogs, all of the same species, croaking together as if they were following the baton of some invisible conductor, was an unforgettable experience. Not surprisingly, it was also a happy hunting ground for the local snakes, and it was a common occurrence to hear a thrashing kind of commotion out in the darkness as yet another snake found its dinner, a meal that from the snake’s point of view would have been preferable to a wedding dish of gammon and spinach.

Mention of the darkness reminds me to point out that our frogs are nocturnal, and they are hard to spot during the day, when they are probably hiding in rock crevices, under the leaf litter or in the long grass, where their natural camouflage helps them to resist discovery. Unfortunately, it doesn’t appear to work against egrets, which are common hereabouts. I often see these voracious predators in the field opposite our house after heavy rain, walking stealthily through the grass, head bent low to the ground and every so often snatching at something I cannot see that is then swallowed immediately. I can only surmise that what the egret is eating is a frog, because a lot of croaking emanates from the field at night, and the main diet of an egret is fish. However, the easily caught frogs are a bounty the egrets cannot resist, and many perish in this way (an individual egret can gobble down a dozen or more). Roly-poly pudding is not provided!

I’ve not been able to take any pictures of frogs in their natural surroundings to date. This spotted narrow-mouthed frog (Kalophrynus interlineatus) was snapped as it attempted to cross the concrete access road that runs along the river, where its natural camouflage will not stop it being trodden underfoot by an unwary pedestrian or squashed by a passing cyclist.

8 comments:

  1. wonderful post, dennis. i think i heard 4 croaks, but can't be sure: a fluttering, a rhythmic squeaking, a honking, and what sounded like an old man burping. i definitely could identify three different croaks.

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  2. Actually Kris, there are probably five different croaks, but then I had the benefit of directional information while I was making the recording.

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  3. That was fascinating, Dennis, and fun. Thanks for thee music and the info.

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  4. I was able to distinguish 3 different croaks. But seriously, they weren't like 'croaking'. :)

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  5. I know it sounds nothing like croaking Sam. I was using the word generically because we always talk about frogs ‘croaking’. ‘Singing’ would probably be a more accurate term, but who talks about frogs singing?

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  6. I think what intrigues me the most is the picture below.
    It looks like fire in the sky.

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  7. Angie, that photo was taken from my balcony a couple of years ago just as the sun was coming up. A lot of mist was swirling along the ridge line and kept getting caught by the sun’s rays. I chose this one for the blog out of the many I took because I think it looks like a winged dragon.

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  8. It's a very interesting post. That second sound byte was incredible. Have my laptop resting on my legs and it actually vibrated through me! I heard 5 I think maybe 6 in the last one, not too sure
    - Karen

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