Habitat: In hedgerows, grassland, woodland, cultivated areas and woodland with a preference for human settlements and farm buildings during the colder months.
Description: A large shrew with a greyish-reddish brown upper surface and yellowish-grey underside. Prominent ears, bright white teeth and a tail with long white hairs. Known in some parts of Europe as the house shrew. The genus name crocidura is greek for woolly tail due to these white hairs, and russula translates from latin to ‘reddish’, referring to their dorsal fur.
Size: Head to body length 60-90mm, tail 33-46mm.
Lifespan: 18 months (30 months in captivity)
Origin and distribution: Found on islands including Guernsey, Alderney and Herm. Previously not thought to be found in Great Britain, but recently discovered in Sunderland, North-East England.
Diet: They are an insectivorous species, feeding on a wide range of invertebrates including woodlice; snails; slugs and spiders. Caterpillars and earthworms are eaten more frequently in the winter. They may occasionally eat small rodents, lizards and amphibians.
A semi-social species of shrew, they live in close proximity to each other, and will protect their home ranges. They have been found to sometimes nest together in groups. They are monogamous, and mated pairs will guard their territory together.
They construct open, saucer-shaped nests from dry grass, typically under stones, logs or inside abandoned burrows.
They are mostly active during the day, and exhibit a primitive form of echolocation as a way to communicate and interpret their environment. Very vocal, and will make high-pitched squeaks when threatened or alarmed, or twitters and snuffles when foraging.
Greater white-toothed shrew are predated by barn owls, stoats and domestic cats. Their dark colouring acts as a way to camouflage them under the leaf litter from predators.
Breeding: Greater white-toothed shrews are monogamous and show female-biased dispersal (meaning that females leave the site where they were born to breed), which is thought to help prevent inbreeding. Female-biased dispersal is uncommon in mammals. Individuals of this species of shrew typically live through one breeding season (March to September), and females will have litters of between 2-10 young, which are cared for by both parents. Females can have up to 4 litters in one season.
Shrewlets will remain in their parental territory until the following breeding season and will reach sexual maturity at around 50-78 days old.
Conservation Status: Found on islands such as Guernsey, as well as across Europe and North Africa. The species has a stable population and is deemed as least concern on IUCN Red List.
Unpigmented teeth – very white due to a lack of iron deposits in their teeth, which leaves other shrew species with red/brown/orange tips. Grey/red-brown upper coat with yellow-grey underside. Their tails have long, white hairs. More prominent ears than other shrew spp.
Common shrew (Sorex araneus)
Similar in size to the greater white-toothed shrew. Coat is tricoloured – dark brown back, pale brown sides and white underneath. Teeth are red, as opposed to bright white.