One recent morning, on my commute up the track to the Forvie Centre, a neighbour stopped me for a chat. The conversation took a familiar path, beginning with the incessant rain (July’s weather having been, for the most part, dismal), and moving on to what wildlife was about. My neighbour mentioned the the proliferation of tiny frogs – or are they toads? – emerging from the Coastguard’s Pool at the moment. They’d surely make a good blog post, I was told. OK, well here we go then!
Firstly let’s try and answer the frog-or-toad question. Here at Forvie we have just two species to choose from: the Common Frog Rana temporaria and the Common Toad Bufo bufo; no Natterjacks or Marsh Frogs here to confuse matters. Both species are widespread and abundant on the Reserve wherever you find fresh water (and as I type this, with the monsoon lashing the windows, that’s just about everywhere). With a bit of practice, the smooth-skinned and attractively-marked Common Frog can be quite easily separated from the warty-skinned, brown-toned Common Toad. Have a look at the following couple of photos and see if you can sort them out.
OK, so they’re easy enough to identify when they’re fully grown. But what about the dinky ones? Well, the same differences (sorry) apply, and if you look really closely you can still tell one from the other. Below is one of the tiddlers currently emerging from the Coastguard’s Pool.
Even at this diminutive size, we can still make out the brown ground colour, coarsely warty skin and short legs, safely identifying this little fella as a Common Toad.
It’s not always necessary to look quite so closely though. I recall once overhearing a conversation between two Buchan folk, with one lady informing her friend that “there’s twa types o’ puddock… een that hops and een that craals”. And this is absolutely true. The Common Frog, with its long powerful hind legs, hops. But the Common Toad, with its shorter legs, crawls. It’s a bit like the way that a Rabbit and a Hare, although superficially similar, have a noticeably different gait.
So that’s the ID side of things sorted then. We know that we’re dealing with Toads in this instance. In fact it turns out the the Coastguard’s Pool, along the cliff path between Collieston and Hackley Bay, is a major breeding site for toads.
Every spring, substantial numbers of Common Toads travel across the Reserve to the Coastguard’s Pool to mate and spawn. They are very site-faithful, returning to the same breeding site every year. Toadspawn is laid in distinctive long strings, often tangled around the submerged vegetation, and is quite different to frogspawn, which is laid in a shapeless mass at the surface. This done, the adult toads then leave the pool and return to a terrestrial existence, spending the rest of the year in the damp grassland of the Reserve, or the leafy gardens of Collieston where they are a familiar sight on summer evenings. They will repeat this feat of navigation and endurance once again the following spring. It’s not just geese, swallows and terns and the like that migrate – toads are migrants too.
After a variable period of time, dictated by water temperatures, the spawn hatches into tadpoles. These ‘toadpoles’ are very similar to Common Frog tadpoles, but tend to be blacker in appearance and form dense shoals in the shallows of the pool. Once again, their rate of development is variable, but eventually they begin to grow tiny legs, the tail shrinks and disappears, and they resemble a tiny version of an adult toad. At this point, it’s time to leave the pool and set out into the wider world. And that’s exactly what they’re doing right about now.
Having complained about the wet weather in my opening gambit here, it’s worth pointing out that it’s great news for these tiny toadlets. At this early stage in their lives, with their delicate skin and small body size, desiccation is a life-threatening risk. So the rain does them a huge favour in this respect. It allows them to disperse safely into the surrounding grassland, heath and wetlands, where they will quietly and unobtrusively make their living.
Of course, with so many toadlets emerging into the world, many of them do fall by the wayside. They’re all-too-easily trodden on, even by the most careful of walkers, and they’re also on the menu for the local crows and herons. Road traffic claims a huge number of casualties too, even on our relatively quiet roads. Only a small proportion of them will survive into adulthood; it’s thought that they take between three and seven years to reach maturity. But those that do may well return in future to the Coastguard’s Pool to breed, thus sustaining this timeless cycle of life, and giving the local folk something to muse over besides the weather.
I give you the Common Toad – not the flashiest species to occur at Forvie, but surely one of the most characterful.