Lesser Shrew

Like the greater white-toothed shrew, this species alternates bouts of activity with rest (2) throughout both the day and night (3), but activity peaks at dusk and dawn (3). It is typically a solitary species, but is not as aggressive as Sorex species (3). White-toothed shrews are also known as 'musk shrews' because they have a strong musky aroma. They are known to 'belly-mark' their home ranges by dragging their belly along the ground in order to scent-mark it (4). As home ranges overlap, it is likely that it is not very territorial (3). It feeds on a variety of invertebrates (2) including small crustaceans that live amongst rocks on the seashore (4). They nest under logs and stones or in burrows (2). The breeding season extends from March to September, and females become receptive and conceive whilst they are still suckling the previous litter (3). This species has a greater reproductive output than any of the British red-toothed shrews, producing 4-5 litters a year, each comprising of 1-6 young (5). The young exhibit 'caravanning' behaviour (2); if the nest is disturbed, the female leads the young to a new nest site; the young follow her in a line, each one grasping the tail of the shrew in front by the tail (4). The average life span of this shrew is up to 18 months (3).

All shrews are protected under the Wildlife and Countryside Act (6).

This shrew is the smallest of the 'white-toothed shrews' (2); it lacks the deposition of iron in the tips of the teeth seen in red-toothed shrews (4). The upper surface of the body is greyish or reddish brown in colour; and the underside is paler (3). The tail is covered in short bristly hairs (3), and long whisker-like (2) white hairs (3). Although smaller and lighter, this species is very similar in appearance to the greater white-toothed shrew (Crocidura russula) (2), so much so that the only truly reliable method to distinguish between the two species is by examination of the teeth, and the relative sizes of the tail and hind feet (measurements above) (3).

Occurs in a variety of habitats (2), favouring dry ground, and has even adapted to living on the seashore and grassy sand dunes in the Scilly Isles (4). Like the greater white-toothed shrew, it often occurs close to man, living around outbuildings (3).

This shrew has a wide distribution in Europe, extends eastwards to Japan and also occurs in North Africa (3). It does not occur on mainland Britain, but is present on Jersey and Sark in the Channel Islands and is also found on the Scilly Isles (3), where it is thought to be represented by a subspecies known as the Scilly shrew (C. s. cassiteridum, endemic to the Scilly Isles (6). It is believed to have originally been introduced to the Scilly Isles (4) and has since evolved into a new subspecies.

Protected under Schedule 6 of the Wildlife and Countryside Act, 1981 (6).

This species is not threatened at present, although like most shrews it is vulnerable to pesticide use, habitat loss and declines in prey availability (5).