As if they all received the signal at the same time, the tadpoles in my pond are emerging from the frogspawn. The surface of the water is a-wriggle with tiny tails as they try to break free from the confiness of the jelly that’s held them for the past few weeks.
The membrane that surrounds each egg allows the water from the pond to pass through it – this means that the embryos develop at the same rate, and will all hatch at the same time. There is safety in numbers for such little creatures, who at this stage can be eaten by anything from dragonfly larvae to diving beetles to water boatmen. It also helps to prevent cannibalism, which tadpoles are not averse to once they develop legs and become carnivorous.
In the film, you can see that there are some water snails hanging about – these have probably helped by cleaning any algae that started to grow on the frogspawn. In the bottom right-hand corner, though, there is a pond-skater – although it can’t eat a whole tadpole, it is quite capable of puncturing one and injuring it. Life is hard for frogs, right from the start.
Good luck, tadpoles. Out of all of this seething mass, one in a thousand will return next year to breed. The rest will sustain a whole generation of dragonflies and other aquatic insects. Nature is abundant, but rarely wasteful.