Dry winters are bad news for frogs

https://www.theguardian.com/environment/2017/jan/02/dry-winters-bad-news-frogs-rain-weatherwatch

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There are two types of ponds along the Greensand Ridge that runs across from Leighton Buzzard in Bedfordshire into South Cambridgeshire. They are either lined with clay, and fill with rainwater, or they are hollows in the ground that rely on rising groundwater in the winter.

Both provide breeding opportunities for the common frog. The tadpoles have time to mature before some of the ponds dry out in late summer.

This ridge is made of mixed clay and sand, the terminal moraine of the last great ice sheet that almost completely covered England 10,000 years ago. Some of the ponds are ancient, made and lined by our ancestors and surviving still, and others have been scooped out by modern machinery to provide drainage.

Either way, aside from garden ponds, they are the main breeding ground for the frog, which favours the ones that dry out late in the season. This is probably because there are no fish to eat the tadpoles. In good years they can produce thousands of tiny frogs.

But this can be a gamble. Three years ago after a dry winter some seasonal ponds had such a tiny depth of water that the frogspawn was heaped up in the middle and was rescued by wildlife enthusiasts with buckets.

The last three months have also been unusually dry and the ground water is a metre below normal, leaving many of these ponds still empty. If the frogs are going to enjoy a good season in 2017 they need a great deal of rain in the next two months to top up the ground water and restore their breeding grounds.