Monday 24 May 2010

Frogs, toads and tadpoles



By the end of March – early April our pond was suddenly full of mating toads, leaving large amounts of toadspawn. Or frogspawn, as somebody mistakenly called it. They appeared after dark and were very active and noisy. The spawn they left –a jelly like substance- had clear little black cores in each egg, slowly growing into very small tadpoles, kept inside the membrane but wiggling their little tails trying to get out. When the eggs hatched the tadpoles appeared to stay together in a tight space, surrounded by the protective barrier of the spawn. No doubt a strategy to avoid predation. Since early May the pond has been full with little tadpoles – thousands of them- when they finally left the protection of the spawn and started swimming around.  They appear to ‘graze’ on algae from the side of the pond. The photograph with this post shows the shade of the author in the water of the pond, while taking the picture.
A toad is an amphibian characterized by dry, leathery skin, brown coloration, and wart-like parotoid glands. A distinction between frogs and toads is the characteristic feature of toads to adapt to living on dry land.
Toads cannot transmit warts to people through handling or skin contact. The bumps on a toad's skin help the animal blend into its environment visually by breaking up its outline. They are present on healthy specimens and are not a result of infection.
Common toads secrete an irritant from their skin that prevents most predators from wanting to eat them. Unfortunately for the toads however, a few predators, such as grass snakes and hedgehogs, don't seem to be deterred. If they avoid getting gobbled by a snake or hedgehog, toads can live for up to 40 years.
Common toads appear to be able to sense an impending earthquake and will flee their colony days before the seismic activity strikes.
When they are tadpoles their diet is vegetarian, but once grown up they switch to mainly insects. Therefore toads in the garden are considered very beneficial by gardeners.