Stuart Rae

Frogs spawning in a mountain pool 

Common Frog Rana temporaria in a high hilltop spawning pool

It is now mid-May and frogs are spawning in the hill pools in the Highlands. Sadly, there have been many days of snow showers recently and there are lots of late lying snowbeds for the frogs to contend with.

Ben More Assynt from one of the frog pools on the summit ridge of Glas Bheinn

I was up on Glas Bheinn in Assynt yesterday surveying ptarmigan on the high rocky ground, and while walking past a small pool at about 700m I noticed some frogspawn in the margins. I counted about 75 separate clumps of spawn and some of the tadpoles had begun to hatch. Then I checked a second pool where there was still snow lying around the edge, and there was one massive accumulation of spawn in a corner. Some of it had been frosted and the embryos were dead. The spawn had a grey opaque appearance. Then I noticed that there were numerous dead frogs lying on the bottom of the pond, while others were still amplexed together and swimming in the near-freezing water.

Late-lying snow edged the pool and the grasses had not yet started to grow

Life for those frogs up on the high hills is so different from that of those in the warmer lowland waters. They must be so wonderfully well adapted to survive in such conditions. They are amphibians, cold blooded animals, yet they were getting on with life right on the margin of their physiological capabilities. Meanwhile, I was all wrapped up in windproof clothing and still felt cold in the northerly wind. Well done the frogs that managed to lay their eggs and their tadpoles that hatched. Well done.

A large clump of frogspawn lay in the shallows, and dead frogs lay in the depths