WETLANDS - AMPHIBIANS AND REPTILES

All amphibians and one reptile are at home in water at some stage of their lives, though few live in it year-round.

The Smooth Newt (Triturus vulgaris, 9cm) is much commoner than the Palmate Newt (Triturus helvetica) and Great Crested Newt (Triturus cristatus) - the latter is the subject of a Biodiversity Action Plan. They can be found in almost any pond, including in gardens, and although the destruction of so many of these following World War II must have had an effect, they are thriving.

They breed in water and adults spend the summer months there before hibernating on land, often under logs, from October to March. Food consists of invertebrates, mostly aquatic but also some which happen to fall in, including earthworms.

Common Frogs (Rana temporaria, 8cm) and Common Toads (Bufo bufo, 10cm) have profited from the arrival of garden ponds en masse in the last 20 years. Though subject to bursts of the viral disease known as 'redleg', numbers of the former are pretty stable. Equally, given the devastation caused to amphibian populations in the Americas and Australia by the chytrid fungus in recent years there is no cause for complacency.

Common Frog spawning occurs in February or early March, before the Common Toad - the latter species has stringy, black-spotted spawn, quite distinct from that of frogs. Fortunately spawn is no longer seized by any passing schoolchild as used to happen but predation is considerable, including by newts, while tadpoles fall foul of all sorts of predators such as dragonfly nymphs.

One amphibian with a dubious background in Britain is the Marsh Frog (Rana ridibunda, 13cm), which was introduced to Kent (an action which would now be illegal) in 1935 and has spread quite widely in the southern Home Counties.

They are the biggest, and noisiest, frog we have, as anyone residing near a pond containing them in the breeding season will confirm. Given their size, they are unlikely to make the Common Frog welcome in any wetlands they inhabit, so while not so big a threat to our native wildlife as the American Bullfrog (Rana catesbeiana), they are not strictly good news.

Adult frogs and toads are the principal prey item of our longest snake, the Grass Snake (Natrix natrix, to 150cm), which swallows them whole. Six to eight of these are enough to last a Grass Snake a complete season. They do not prey on lizards, which explains the presence of the Common Lizard in the tree stump in the picture.

Grass Snakes, which hibernate from October to March, are non-poisonous and fairly common, found almost anywhere there is wet grass or standing water. They enjoy basking and are strong swimmers, leaving an s-shaped wake with the head just above the surface. However, they can be found in woodland and travel longish distances to forage. Breeding can occur in compost heaps, which provide an ideal micro-climate for the eggs and young.

Successive wafer-thin skins are shed or sloughed as the snake develops, before which the eye goes a milky white colour. They are at their most vulnerable when this process is occurring though natural predators are not numerous.

Images © Jeremy Early. All rights reserved.

In 2013 I published My Side of the Fence - the Natural History of a Surrey Garden. Details may be found, and orders placed, via this hyperlink My Side of the Fence. In November 2015 Surrey Wildlife Trust published the atlas Soldierflies, their allies and Conopidae of Surrey, jointly written by David Baldock and me. Details are on this web page: Atlas.