Despite the specific threat of invasive cousins and a dim horizon of forests imperilled by floods of drought, local woods still resound with the songs of frogs that unleash a cacophony of honks, chirps and croaks in the damp of the dark, which reaches a deafening exuberance after a bout of heavy rain. Many of these amphibians grew up in streams that flow swift and clear, or grazed in ephemeral pools that last for less than a season and evict their inhabitants with dry and deadly haste. Tadpoles that survive the onslaught of native nymphs hop out to explore new perimeters and conquer the shifting layers of a jungle replete with niches for creatures at home both on land and in water.
Tree hollows, buttress pans, waterlogged terraces, furrows made by the hooves and snouts of untamed hogs – every unholey receptacle in the reserves is a chance for dalliances that never go all the way and remain forever skin-deep. Some cling to the armpits of their mates; others embrace the waists of their chosen ones. Both positions end in the expulsion of seed from orifices that never quite meet and leave no unseemly tails to tell.
As unlikely as it seems to those who limit their gaze to lilyponds and village wells, some frogs have overcome the trappings of grounded imaginations to forage in the canopy. One common rhacophorid has invaded suburban parks and gardens, aided no doubt by its catholic tastes in spawning sites. Another arboreal frog, clad in cinnamon and pearls, is restricted to the slopes of Bukit Timah, where there are still enough treetop cavities and abandoned vessels to support small clutches of high-rise eggs. Adults emerge at night to bask on low vegetation; the males emit bird-like peeps that barely break the din of amourous crickets and cower in silence when men and machine roll down trampled loops to break the truce between good sports and fair game.
Though not beasts of the branches, microhylid frogs have also made numerous attempts at severing ties with standing water. Representatives elsewhere in the archipelago have developed extreme measures to break out of amphibious life-cycles. But the locally rare black-spotted sticky frog is content to seek out nurseries in flooded logs and other phytotelmata, including the cups of terrestrial pitcher plants. The tadpoles are said to survive on their own fatty deposits before leaving their shallow creches to vanish into the deep brown folds of the forest floor. Like their larger, bellowing kin, these stout little frogs feed on ants. Their tapering profile, broken by a foliar line that separates back from flank, renders the frogs near-invisible amid fallen litter. But a second line of defense exists in dorsal glands that exude a sticky slime to discourage further bites of a body built to withstand just a little serious ribbing.
A frog with more conventional breeding habits but rather unusual larvae is Pulchrana/Hylarana laterimaculata, which inhabits swampy forests and disturbs the peace of nocturnal trails with high-pitched 'yips'. In contrast to the spermatozoan forms of typical tadpoles, the young of masked rough-sided frogs resemble those of a relative that frequents torrents. Eel-like and pink from the lack of pigment, the tadpoles live in slow-flowing streams and adjacent pools, where they burrow in the leaf litter or mud. Adults are similarly elusive, calling from the dirty feet of tall trees and leaping away at speeds and trajectories that escape duller eyes.
Malesian frogs, too, possess a disarming gift for evasion. Individuals who venture onto jungle paths easily retreat into the undergrowth with single, spectacular bounds. Though associated with peat swamps, this large carnivore has adapted to disturbed habitats and old plantations. Males bear fang-like processes on their lower jaw, which are thought to be used in territorial battles.
Other members of the family may use their 'teeth' on aquatic prey, and like the microhylids of New Guinea, dicroglossids on the nearby island of Sulawesi have succumbed to the rules that govern the recombinant fates of creatures at the brink of a bout of explosive radiation. Closer to home, these robust frogs have found their way into fields, swamps and country roads, and hunt on mangroves and mudflats, with the larger species apt to prey on smaller anurans and serving as game for rural cooks.
Atypical of their family, puddle frogs seldom stray far from water. These stocky animals occupy shallow pools, casting a suspicious eye at the world above and sliding under a blade or branch to avoid close calls from passing walkers. Both adults and young are predacious, the latter making sudden lunges at worms and insect larvae from the bottom of seeps. Somewhere in deep time, the tribe must have saw it fit to maintain this pace, turn their backs on terra firma and leave the heights of falls and dense foliage to frogs of bolder bent. There's place still in the tree of life for those who prefer to stay put and paddle in the soft beds that form between low ridges and the cool veins that course through lands of overheated passions and inflamed spirits.