Cornwall Mammal Group
Recognition:
The lesser white-toothed shrew is the only British member of the Crocidura genus, which are characterised by their un-pigmented teeth, in contrast to the red-tipped teeth of the other British shrews.
This shrew is at the western limit of its distribution and in the UK is found only in the Channel Isles and the Isles of Scilly. Presumably this reflects the spread of the shrew following the last Ice Age, when rising sea levels preventing the species getting as far as the mainland. If a shrew is seen on the Isles of Scilly, then it is a lesser white-toothed, as this is the only shrew species present. The shrew has a greyish or reddish-brown coat which fades to a paler belly, and a typical pointed snout and relatively prominent ears. The tail has a covering of short bristly hairs interspersed with long white hairs. Often found on the sea shore, they are more sociable than other British shrews and may share their nests with other
adults. They are active both day and night, but tend to be more nocturnal than their
mainland cousins.
Although too small to leave footprints on anything other than soft mud, the highpitched squeaking of shrews can often be heard as they engage in vigorous territorial disputes. Shrews build tightly woven nests of dry grass and vegetation in suitable cavities, there is normally a single chamber and multiple exits. Shrews can often be persuaded to set up home under sheets of corrugated metal and this is a useful method of surveying for the species. Their tiny droppings may be left in piles in prominent places.
© David Chapman
The lesser white-toothed shrew is an insectivore, usually searching for small crustaceans around the shore of the islands. Away from the seaside they will feed on a range of invertebrates including beetles, flies, worms and snails. It has been noticed that lesser white-toothed shrews can survive longer without food than the other British shrews.
Although less aggressive than mainland shrews, they are usually solitary animals and occupy overlapping territories of about 50 m of shoreline, which they mark with scent glands on their flanks.
They breed from May to September producing small litters (often only about 3 young) in their nests of grass and leaves. The young weigh only 0.5 g at birth but are weaned at about 4 weeks and the female may be pregnant whilst still feeding her last brood. Most animals breed in the year after their birth and typically have between 2 and 4 litters, but they rarely survive into a second year although they apparently live longer than other British shrews and have survived 4 years in captivity.
On the Isles of Scilly the most important predators are probably kestrels and domestic cats. On the European mainland owls, stoats and weasels, and foxes take large numbers.
Cornish Tales:
In 2010 a lesser white-toothed shrew made a bid for freedom and stowed away on the Scillonian III, the regular ferry service between the islands and Penzance, heading for the mainland. It was caught and repatriated via the Skybus, surely one of Cornwall’s best travelled shrews!
Distribution:
In Cornwall the lesser white-toothed shrew is found only on the Isles of Scilly, where it has been recorded on all the larger islands, being especially common on St Mary’s and Tresco. Otherwise in the UK it occurs on the Channel Islands. Elsewhere it occurs widely across Europe from Spain to the Far East.
Records:
2007-2012: 30
2002-2007: 7
Pre-2001: 62
Total: 99
Did you know?:
The lesser white-toothed shrew is also known as the ‘musk shrew’ because of the strong smell they produce to mark their territories. In the Isles of Scilly the shrew known as a teak or teke. In common with other shrew species, when moving its family the lesser white-toothed shrew will often form a ‘caravan’ - a line with each of the young hanging on to the tail of the animal in front.
Conservation:
Listed as a globally threatened/declining species and included in the Isles of Scilly
Biodiversity Audit 2008, the lesser white-toothed shrew appears to be quite common on the islands. It is protected under the Wildlife and Countryside Act 1981, Schedule 6, and a licence is required for any trapping.
Survey Methods:
Small mammal trapping. Plastic bait tubes. Incidental sightings. Cat kills and incidental records. Corrugated iron sheets.
