Water is the life blood of the small island city state of Singapore; it is hot, it is very hot. Like all island nations, too little freshwater would present a real risk to people and wildlife. In the boom and bust tropics, the monsoon deluge brings life, but also the risk of severe floods. To manage the cycle of rainfall, the city has created a network of concrete veins and arteries that capture every drop of rainwater, passing it from small drain to larger drain until finally the water spills into the Singapore river and the vast reservoirs. These barren concrete drains captured my interest, as they seemed like a place where creatures could be found. I had read stories of huge pythons slithering through the dark damp pipes hunting sewer rats and feral cats, so I couldn’t resist grabbing a torch and walking alongside the local drain on a damp night.
When the heat of the day fades into the humid night, these drains become homes and highways for night crawlers. One such creature of the night is the Asian Common Toad (Duttaphrynus melanostictus). These abundant urban toads can be found almost anywhere that there is a patch of grass or a puddle of water. It is a surefire guarantee that a few of these warty wonders can be found in the drains after dark. Sure enough, I found several within a few minutes walk from home.
By day, the Asian toad makes a home in the dank, golf ball sized drainage holes, that allow water to to pass from the earth into the sub drains. Here they are well protected from the heat of the day in a cave of concrete. As day gives way to night and the street lamps splutter to life, the toads crawl through the concrete tubes, pausing to check for danger under the amber glow. The Asian toad’s skin is packed with a cocktail of toxins, but there is no need to take unnecessary chances in the land of the cobra.
Satisfied that the coast is clear, my local toad wriggles out of his home, dropping down into the drain below. Here he will spend the night hunting for insects and worms, of which there are plenty.The toad is not an active hunter, preferring instead to sit motionless until a morsel trundles by, which is mopped up in the blink of an eye by a pistol fast sticky tongue.
The adult urban Asian toad is also known as the Black-spined toad, due to the black dots often visible on the tip of each wart. The adult toads that I find in Singapore have chicken egg sized bodies, but larger specimens have been recorded across the continent. It is also common to find much smaller individuals in the drains. They are the only toad that is regularly seen in urban Singapore, so identification is straight forward.
Photographing these delightful creatures after dark is a challenge. All of the photos of toads in the drain were taken on an iPhone, with the addition of a small clip on phone “selfie light” to enable the focus to find the toad’s eye. Seeing a person kneeling in an urban space with their head in a drain is not a common sight anywhere, and certainly not in Singapore. On several occasions I was offered help to find something, or indeed help for my physical and mental health!
Drain life falls into a nightly routine. I found the same toads in the same position for several nights running. They are creatures of habit, but every now and then an event occurs that crashes into their world, demolishing the routine. It starts with a flash and earth-shaking rolls of thunder. Twice a year the monsoon arrives over the island. Singapore is a wet country with frequent heavy showers, but the monsoon brings new excitement and abundance to the natural world.
With the approaching rains, the toads haul themselves up the steep walls of the drain by their fingertips. They must risk their lives as they bounce through the legs of joggers, dodge the slicing wheels of cyclists and the unwelcome noses of overcurious dogs. The race is on to arrive at the park where they tumble into the dips and scrapes, where puddles will soon form.
The waterlogged fields quickly become spotted with puddles in the grass. These small vernal pools, just 4 or 5 centimeters deep, will hopefully last long enough for the toads to spawn and the tadpoles to develop, before the sun scorches them back to dry earth.
On dark wet nights the large open field behind my home bursts into life with the squeaks and squeals of croaking males. Puddles fizz as males battle for position and grab at anything that moves in the hope that it may be an arriving female.
Positions are claimed and held by angry looking males with bulging butter coloured vocal sacks, blown up like ping pong balls under the chin. The serenade can be heard from many meters away, as males compete with each other to be heard.
The Asian toad breeds year round in hot and wet Singapore. Pairs lay up to 40,000 eggs in long winding ribbons of spawn. The race against time begins as soon as toad’s spawn. Eggs must hatch fast, and do so within 48 hours. It will take around 5 weeks or more for metamorphosis to occur. Although this process can occur faster as vernal pools evaporate, many do not make it. I have observed many more toad breedings occurring in drains or more permanent pools than in the temporary puddles, suggesting that perhaps the females are a little smarter than their opportunistic mates.
The tadpoles in the photographs (above) were spotted in a drain. Another day or two without rain and this tadpole colony, that had gathered in a puddle in a pipe, would be doomed. A rumble of thunder drummed a familiar and long anticipated rhythm as the monsoon rains broke over the tiny island. A deluge in hours turned the puddle into a flowing stream of fresh water that guaranteed a future for the next generation of Asian toads.
Eventually the excitement of the rains dies and the urge to breed has been satisfied. The toads leave the puddles to head back to their homes, deep in the concrete drains. Here they will fatten up on worms, ants and cockroaches over the coming months, until the rains return to the island.
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