It's an unmistakable sign that spring's on the way that once filled every garden pond.

But while milder winters are seeing frogs spawn earlier in the year, there are fears climate change may mean the creatures use up more of their fat reserves, reducing the number of eggs they lay.

Conservation group Froglife is appealing for people to get in touch with any sightings of frog, toad or newt spawn via an app on its website.

Frogs lay their spawn in rafts of up to 2,000 eggs. Tadpoles hatch two to four weeks later, depending on the weather.

At first they feed on algae and water fleas. After a few weeks, they begin to grow back legs, followed by front legs. They then absorb their tails, ready to leave the water as tiny froglets.

They will have become adults by autumn, feeding on worms and insects. As winter arrives, they hibernate under rocks, compost heaps or on the bottom of ponds.