It’s late February and all over the Marches anurans awake from weeks of torpor. Better known as frogs their body clocks have marked the days past the winter solstice. Slotted into the earth their bodies are at one with nature, their cold moist skin sensitive to every perturbation of temperature and humidity, logging the patterns in a data base as old as the hills to the east. When threshold values are reached their metabolism subtly accelerates, their senses heighten and their skin tastes the air diffusing through the fabric of the soil.
What finally triggers their heart beats to quicken, their lungs inflate, their eyes open and their limbs move, is the scent of green. Microscopic green algae in ponds, some far way, have also reached a threshold, one dictated by the earth’s orbit. The day/night ratio has passed a significant point and as a result the net photosynthetic gain of these little green factory units teeming in water columns throughout the countryside is now sufficient to produce a surfeit of glycolic acid, the volatile nature of which is powerful enough to stimulate responses in sensitive bodies miles away at concentrations in parts per million.
Now, like salmon sensing their natal rivers, frogs follow their noses back to the ponds of their birth. They journey by night when cooler, moister air eases their way, heightening their senses and hiding their movements. Muscle blocks in their back limbs propel lithe bodies through tangles of winter-weary grass and scrub, overcoming all the impediments of nature and man implanted in their path, from rocks to roads. The latter criss-cross their ancient routes exposing them to alien smells and sounds, dazzling beams of light and fast kinetic forces extinguishing life as swiftly as the predatory owls, rats and stoats they instinctively fear.
Close-up the birth-pond vibrates to the purr of adult male frogs drawn instinctively to this pivotal point. Into the dream pool they plunge, in an instant swapping air for water, re-entering the world of their conception and metamorphosis. Every earthly sense is heightened as the medium that begat them once more gives buoyancy to their bodies, effortlessly stimulating their amphibious frames. Brimming with refreshing winter rain the pond is charged with oxygen, and oestrogen. Bodies slip and slide with wild, instinctive energy, the urge to grasp growing with every additional body entering the pond.
In the small hours past mid-night the females finally yield; fore-limbs press again bellies bloated with spawn and help eject masses of eggs. Males instantly respond, shedding sperm in diffusing clouds, engulfing the fresh spawn in an act of primeaval, external fertilisation which lasts but a moment. Flexing agents of gene flow are chemotactically drawn through a crowded, aqueous medium to eggs briefly exposed, receptive and charged with attractants. Minutes later a protective layer of jelly effectively seals their genetic fate as proteins on the eggs’ surface interact with oxygen and water to form a robust, impenetrable boundary layer.
The males release the spent females, their urges exhausted; the females drift, spent in every sense for they have not eaten since autumn, and for many this is their final act, their hollow bodies succumb to the mechanics of nature and they are returned in elemental form to the waters which delivered them in a previous spring.
Monies from the sale of each Poetry on Frogs ebook (Fair Acre Press, £2.99 from February 2016. Submissions open January 2016) will be donated to Froglife