SHREWS OF BRITAIN

There are five species of shrew found in the British Isles, but only the Common, Pygmy and Water shrews are at all widespread. The other two species are not found on the British mainland at all: the Greater White-toothed shrew, Crocidura

russula, can be seen in Ireland and on the Channel Islands of Guernsey, Alderney and Herm, while the Lesser White-toothed shrew, C.

suaveolens, is found on the other Channel Islands of Jersey and Sark, and the Isles of Scilly, where it is known as the Scilly shrew. Both have shorter tails than the other species.

Water shrews, Neomys fodiens, and Common shrews can be told apart fairly easily. As well as being marginally larger at 4½-7in (11.5-18cm) including tail, and weighing up to 23g, Water shrews are black above and white below, with a small white spot by each ear. They are mostly found in, on or around bodies of water, such as ditches, ponds and streams, where they hunt for prey, such as shrimps, frogs and small fish underwater, paralysing their victims with venom from their saliva. They are also far less common, with fewer than 2 million individuals in Britain.

Common and Pygmy shrews, Sorex minutus, are much harder to tell apart, especially when catching more than a glimpse is difficult. But a close look reveals their differences: Pygmy shrews have just two colours; dark brown above and a dirty grey below. However, young Common shrews can be confused with these smaller relatives, especially as they may not show the contrasting patch of pale brown on their flanks. Pygmy shrews have longer tails relative to their head and body than Common shrews: the Pygmy’s tail is approximately 75-80 per cent of the head and body length, compared to 50 per cent in the Common shrew; the tail of which is also noticeably thinner. At just 2¾-4½in (7-11.5cm) long and weighing only 3.5-10g, Pygmy shrews are also, as their name suggests, considerably smaller.

The Water shrew lives in a small burrow on the banks of its habitat. Stiff hairs on its back feet and tail aid swimming.

Unlike the Common shrew, the Greater White-toothed shrew has unpigmented teeth, (top). The Scilly, or Lesser White-toothed, shrew is often found in coastal habitats, such as sand dunes (bottom).