A walker remarked to his companion as they passed me on the trail, "There's hardly any insects here". Earlier, a troop of young men had howled and hooted their way through an imagined wilderness, with a mere one or two having just enough grip on his senses to spot a fowl crouching in the undergrowth. Others raced down the track at speeds that send a shiver up my timbers whenever I place my belly on the ground to see what life looks like from a lower point of view. There were also a few parents who squandered the school break on local adventures, leading a gaggle of playmates who had not yet gained the ability to overlook a flutter of wings.
One of the most commonly encountered damselflies along forest tracks in the region, apart from Sulawesi where the genus is curiously absent, is Vestalis, a group of calopterygids with metallic green flanks and clear wings, although there are brilliant blue exceptions in Java and the Philippines. Adults of both sexes haunt sunlit clearings created by treefalls or chase the slim beams of broken canopies as the rays trace a daily route through the woods. They are also fond of perching by well-worn paths, which may offer the space to hawk for prey that'd otherwise lurk below their line of sight.
Vestalis amethystina is not rare in local reserves, but it's possible that many fail to detect the insects' emerald sheen on a wallpaper of waxy leaves. What gives the game away is usually a gleam of iridescence as the flashwing rises to a higher plane. They seldom run far; after a few minutes the damselfly usually floats back down to resume its watch on a low perch.
Except during courtship displays, calopterygids, unlike nearly all other odonates which employ alternate or phased strokes in normal flight, flap all four wings in synchrony, shooting through the air with ballistic speed and generating enough momentum to pierce the songbird barrier. The downside of parallel strokes, however, is a shortfall of power that restricts these jungle jewels to continuous stands of trees or the banks of shaded streams. Two other Vestalis species are now known in Singapore, with one enjoying a tenacious hold on existence by a vulnerable track and the other confined to a guarded swamp. But with protection a mere contingency in thrall to more productive imperatives, there is no telling how much longer these demoiselles and their dark, dappled home will survive a national longing for cleaner parks and the bright green lights of unnatural destinations.
Oh. My. Goodness. That is stunning. The animal, the photos, the text --- absolutely grand!
Posted by: Snail | 16 June 2012 at 04:51 PM