More about Fish, Amphibians and Reptiles in Mid Wales
In small upland streams the water is clear, cold in summer and highly oxygenated but there are few plants or invertebrates and the only fish to venture up this far are Bullheads and Brown Trout. The upland streams join each other to become brooks and small rivers where Minnows, Brook Lamprey and Grayling live. The main rivers of Mid Wales, the Wye and Severn, are populated throughout the year by Brown Trout, Grayling, Minnow and occasional other course fish such as Chubb and Pike.
Many fish migrate, coming up rivers at different times of year to spawn, most famous of which is the Salmon. Watch from river bridges in late autumn to see the migrating Salmon or visit Gilfach Nature Reserve to watch the salmon leaping up waterfalls in the River Marteg. Other fish that migrate up the Wye are River Lamprey and Sea Lamprey, Shad and Eel.
There are six species of amphibians that you might encounter. Common Frog occurs almost anywhere in damp vegetation, the adults being most visible in the early spring when they are noisily spawning in ponds, pools and ditches while from July through to September the young of the year may be seen near to water where they have developed through the tadpole stage to become miniature versions of their parents.
The Common Toad spends most of its life out of water and in some quite dry environments under stones and logs, coming out at night to hunt invertebrates like worms and moths that being attracted to lights then become dazed and fall to the ground.
Around Llandrindod Wells there is a population of an introduced species – the Midwife Toad, creatures more easily heard than seen as the male toads call at night, repeating a single note at regular intervals.
All three species of newt occur in Mid Wales, the Palmate Newt which can tolerate the more acidic waters of the uplands, the Smooth Newt and more restricted in range, the Great Crested Newt, which prefer to live at lower altitude. Much like toads and frogs, newts migrate to lakes, ponds and ditches in spring where they mate and lay their eggs, while for the rest of the year the adult newts live in dark, damp habitats under stones and logs.
Mid Wales has just three species of reptiles, the most frequently encountered being Slow Worm (not worms or snakes but actually legless lizards), which are often seen in gardens. Common Lizard is widespread and may be seen in summer basking in sunshine on banks, logs, amongst heather and in rough pasture. Much more restricted in its distribution is the Grass Snake which has only been recorded in the southern and eastern borders of the region. Grass Snakes require lush and rank decomposing vegetation in which to lay their eggs, which hatch by the heat of the decomposition. There are no recent records of Adder in Mid Wales, perhaps its absence is to do with the erratic temperatures and rainfall of the area.