How do our frogs survive as the reserve’s ponds and streams dry up in the drought?
If the pond dries out early in the summer, the tadpoles and froglets that are not yet sufficiently developed to leave the water, will die. This is not as bad a thing for a local frog population as you might think: the creatures that predate tadpoles, fish and great diving beetle larvae for instance, will have succumbed as well. If a drought it is a one-off event, the frog population will recover quickly in an environment newly devoid of predators.
Left: the drying pond. Right: tadpoles that are not yet developed enough to leave the water.
But if the summer’s drought is the beginning of a trend, the common frog will need to adapt as quickly as possible to survive the change: adaptation is the key to the long term survival of a species.
The loss of that part of a local frog population that habitually breeds late in the season might well be the driver of a successful adaptation. If this is the start of a period of long and very dry summers, the earlier our frogs mate and spawn, the more likely it will be that their tadpoles survive long enough to leave the drying ponds and hide in the woods.
Left: froglets leaving the water Right: frogs look for damp places to hide in times of drought
If they can leave before the ponds dry up, our frogs and froglets will search for damp, cool places in which to hide. They will head for the woodland beside the Lambrok’s tributary stream, and hide under the mosses that grow in the shade, or under fallen tree trunks and log piles close to the places where there are springs and the ground is nearly always moist. There will be holes in the stream banks around the roots of the willows, and in the structure of the two bridges, where a frog can hide safely and wait for rain.
Driven by human intervention, climate change is happening so fast that many species will struggle to adapt to new conditions. Amphibians, their lives divided between changing environments both in the water and on land will have a hard time of it. If we are lucky, those of our frogs that survive this drought, will be just a little bit better equipped to face the next one.