While frogs have almost made the garden pond their own, the other British amphibians have generally fared less well faced with the rapidly dwindling availability of natural wetlands. The situation is particularly difficult for toads and Britain’s endangered Great Crested Newt – both of which tend to rely more heavily on ancestral breeding sites and have found making the transition to alternatives more difficult. Even so, neither newts not toads are strangers to the back garden water feature and their presence offers the pond-keeper an insight into a uniquely interesting group of creatures.
The Common Toad (Bufo bufo) can be told from its cousin the frog by its warty skin, though contrary to the Old Wives’ Tale, handling one will not make you catch warts. Their skin is, however, very bad-tasting as many a young puppy has discovered on its first encounter with Mr. Toad, so washing your hands after touching them is always a good idea.
In spring, the toads emerge from hibernation and head to the breeding ponds, spending all of their time in water throughout the breeding season. The males grasp the females around their armpits and cling on tightly – often having to fight off other males anxious to find a partner to breed. A pair of toads will remain permanently united in this way for about a fortnight, during which time she will lay 5,000 or more eggs, which he fertilises as they are produced. Unlike frogspawn, toadspawn is laid not in clumps but in long strings which are often wrapped around aquatic plants. The eggs hatch in a week to ten days and, although the adult toad is the largest tail-less amphibian in Europe, its tadpoles are amongst the smallest, measuring only around a quarter of an inch at hatching.
In June or July the young toads leave the water and will not return until they are mature adults four years later, though this is a long-lived species and they may well keep coming back for the next forty years or more. Since they are one of a gardener’s best friends in the constant battle against slugs and other pests, this long term relationship certainly has its benefits! However, they generally prefer deeper ponds than are commonly constructed in gardens, so not everyone will have the chance to benefit from the free and rather efficient service they can provide.
There are three kinds of newt in Britain, the Smooth Newt (Triturus vulgaris), the Palmate Newt (Triturus helveticus) and the largest of them, the Great Crested Newt (Triturus cristatus) a heavily protected, rare species. Newts emerge from hibernation in early spring, making their way to ponds at once. Mating usually takes place in April or May and once the breeding season is over, most of them leave for dry land, where they spend the rest of the year, lurking in damp places.
Unlike the rough and tumble approach of frogs and toads, male newts approach the mating game in a far more delicate way, growing crests of patterned skin along their backs and tails to attract the female and indulging in showy courtship dances to finally win her over. Mating itself is a gentle affair too, with the male rubbing and nuzzling the female, sometimes for hours, before producing a spermatophore – a sperm-containing parcel – which she then takes up to fertilise her eggs. She subsequently produces 2–300 eggs, laying them one at a time directly onto aquatic plants, often bending a leaf around each one to protect it. This habit often accounts for the unexpected arrival of newt “tadpoles” in a pond – having come in as unwitting hitch-hikers on newly acquired water plants.
The eggs hatch in around two or three weeks to produce small, almost transparent yellowish larvae with long, thread-like gills, which attach themselves to plants for the first few days of life, becoming free-swimming later. Feeding on algae and other water plants at first, they gradually become carnivorous, eating water-fleas and other small insects and grow their legs in reverse order to frogs and toads, their forelimbs appearing first. The young, now having grown fully developed lungs, leave the water in August or September and search out a suitable place to spend the winter, usually under moss or in holes in the ground.
Larvae which hatched late in the season may not undergo metamorphosis the change to adulthood and instead over-winter in the water to complete their development the following year. Depending on the species, young newts will not return to the water again until they are sexually mature in two or more year’s time if they survive. Life is not easy for newts they have many natural enemies both as adults and as tadpoles, including fish, water-beetles, dragonfly larvae, Grass snakes, ducks and herons.
Wildlife in general and amphibians in particular have been having a rather hard time of it, given the massive losses of ponds and lakes across the whole of Britain. While their inroads into our artificial ponds have been slower and less certain than their uniquely successful froggy relations, for those fortunate enough to have them visit, the garden pond provides them with a valuable lifeline and a rare stamp of appreciation for its owner.