Common frog Rana temporaria, resting on log, West Midlands

Tadpole tale

Soon it'll be time to start looking for frogspawn.

Where to find frog and toadspawn

The dramatic transformation of wriggling tadpoles into frogs or toads has to be one of nature’s most remarkable achievements. It sounds almost too incredible to be true; like something from a science fiction (or even horror) film. But it’s been happening for millions of years.

Frogspawn and toadspawn usually starts to appear in February and March. Look just below the surface of the water in ponds and streams, especially amongst reeds by the water’s edge.

What’s the difference between frogspawn and toadspawn? Frogs lay a cluster of jelly-like eggs, whereas toadspawn comes in long ribbons.

If you’re lucky enough to have spawn in your garden pond, keep coming back each day: you’ll see the tiny black dots turn into comma-shapes as the unhatched tadpoles develop.

Clip of frogspawn expanding

Time-lapse video of frogspawn expanding in water (Oxford Scientific Films).

Time-lapse video of frogspawn expanding in water (Oxford Scientific Films).

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Frogspawn expanding video screenshot

Growing pains

Once hatched, tadpoles take about 14 weeks to transform into tiny frogs.

Toad tadpoles take a little bit longer, becoming toadlets after about two months. They develop back legs first, then front legs, while the tadpole’s tail shrinks and its body becomes less rounded. They also develop lungs and eardrums. During the transformation process (known as metamorphosis), the tadpole switches from feeding on algae to becoming carnivorous.

The final stage of the process, when the mature tadpole morphs completely into adult frog form, is very quick, taking just 24 hours.

I'm a frog, get me out of here!

Amazingly enough, tadpoles can control the rate of their transformation, according to their environment. For instance, they may turn into frogs more quickly to escape a pond teeming with predators like fish. On the other hand, if there’s plenty of algae to munch through and limited predators – or if the weather is too cold – tadpoles can delay and remain in the water for up to a year.

 Common frog Rana temporaria, controlled conditions, Birmingham

Create a mini pond

Making a mini pond, puting plants and large stones in bowl, Potton lower schoo

Spring is a lovely time to create a mini-pond, because you'll see it quickly develop over the next few months. Why not create your own mini pond to attract all sorts of wildlife?

You don’t need water in your garden to encourage frogs and toads: they also love piles of old logs, stones and compost heaps where they’ll find shelter, as well as slugs and insects to feed on.