Fungi fanatics hate the phrase ‘toadstool’ because it is both laden with prejudice and deeply-misleading – when did you last see a toad on a mushroom?
Poor amphibians! A burst of bright sunshine a month ago filled my pond with frogs and toads and they merrily filled it with spawn, but the current Arctic conditions will mean few tadpoles will emerge. The good news is that this minor climactic genocide will have little effect on the local population. The creatures have an impressive reproductive potential – each female lays hundreds of eggs each spring – so it only takes one good year in three or four for numbers to stay steady. This is just as well for frogs and toads are incredibly important to both the gardeners and the environment. To begin with the adults’ diet is comprised largely of slugs and small snails, not to mention numerous insect pests, so if you are surprised by one lurking beneath the dense foliage of your hostas, count your blessings.
They are also a vital food for a huge range of predators. Foxes, badgers and buzzards all gratefully accept this natural bounty. They are particularly important now because they come at a time when other sources of protein – such as voles and shrews – are at their lowest ebb.
Fortunately they are so plentiful and prolific that natural predators have little impact on numbers. Even though only a tiny percentage of the spawn will emerge from the water as froglets in even a good year – and still fewer will live to breed – it doesn’t matter. Should they get to adulthood, their life expectancy is several years.
Most British frogs are of the ‘common’ variety (Rana temporaria), but two European frogs have been introduced. The edible species (Rana esculenta) arrived in 1837 thanks to an enthusiastic amateur naturalist and it can still be found in parts of the South East and there is also a healthy Kent population of marsh frogs (Rana ridibunda), introduced in the 1930s by another well-wisher. Fortunately neither has proved an environmental disaster which is more than can be said for the latest import, the bullfrog (Rana catesbeiana). This rapacious species from North America was sold during the 1980s by garden centres to stock ornamental ponds, but has developed a great taste for native frogs.
Unfortunately, this is the least of their problems. Many have suffered from secondary poisoning after eating slugs contaminated with slug pellets. Worse, a deadly disease, Ranavirus, was accidentally imported from America and is proving the amphibian’s equivalent of myxomatosis (sores erupt along the frogs’ legs and torsos, often leading to the loss of limbs, before death in 90% of cases). Habitat loss is one of the biggest threats, however, because around three quarters of village ponds and many wetlands disappeared during the 20th century. Ironically, currently their best chance for recovery is from modern gardeners. The fad for ponds and organic practices mean frogs are thriving in suburbia and working hard at controlling snails, slugs and pest insects – long may they remain!
All the more reason, therefore, to rejoice at the first croaks and groans from a nearby ditch or pond. Not only is this an early signs of new life, but an indication of environmental health. Frogs have delicate skins and this means they act as conservation canaries, being particularly susceptible to pollution.