Cornwall Mammal Group
Recognition:
The pygmy shrew is the smallest native British mammal weighing a mere 2.4 to 6.1 g.
Like other shrews they have small eyes and ears and a long, pointed, mobile snout. The
pygmy shrew has a head and body length of 40 to 60 mm, with a tail of 32 to 46 mm. Its
short, velvet-like fur is light brown with a pale underside. They have red tips to their
teeth. On occasion they produce high-pitched squeaks which can be heard by the human ear. The pygmy shrew is smaller than the common shrew, has a more domed head, is a paler brown colour and has a
proportionally longer and hairier tail. The
white ear tufts occasionally seen in the
common shrew do not appear in the pygmy shrew.
© David Chapman
© Jenny Hobday
Shrews are active all day and night, but usually under cover. Their tiny black crumbly droppings are rarely found and they leave tracks in only the softest and finest mud. However they are very vocal and their high pitched bickering and squeals
can often be heard in hedgerows and dense grass. Unlike common shrews, pygmy shrews do not dig for food and spend little time underground. Placing corrugated sheets (known as refugia) in unkempt areas can attract shrews and other small
mammals, and they may be disturbed when clearing garden rubbish. They make small, loose nests of grass and other vegetation in tussocks and under cover.
Shrews occur in dense vegetation, often in cool, damp, shady areas. Although they are also found in drier areas such as deciduous woodlands, scrub, hedges, grasslands, gardens and even sand dunes. The pygmy shrew shows a preference for grassland and stone-wall habitats.
The main prey of pygmy shrews include small invertebrates such as beetles, spiders, woodlice, flies and bugs, found while foraging amongst vegetation on the ground. Unlike common shrews, they rarely eat earthworms. In order to sustain its high metabolic rate, the pygmy shrew must consume the equivalent of one and a quarter times its own body weight in food each day.
Shrews mature in spring and the breeding season lasts from April to September. The males search for females that are in oestrus and willing to mate. After a gestation period of around 22 days, litters of 3 to 9 young (weighing about 0.25 g) are born. However, the young grow quickly and within a week are able to crawl around the nest. Shrews remain active throughout the year and do not hibernate. They are generally solitary animals and aggressively territorial, and if shrews meet the result can be
many squeaks and scuffles. Pygmy shrews, despite their smaller size, have home ranges that are larger than common shrews, at between 500 and 1800 square metres.
Their main predators are owls, but they are also taken by kestrels, stoats, weasels, foxes and domestic cats. Shrews are rarely eaten by cats and other mammalian predators as they produce a foul-tasting oily secretion as a defensive mechanism. Other threats include general habitat destruction and indirect toxins from pollution and pesticides.
Did you know?:
The pygmy shrew is also known as the Eurasian pygmy shrew or lesser shrew.
Well into the 19th century it was often thought to be the young of the common
shrew. Pygmy shrews seem more likely than other shrew species to board boats
which may explain their appearance on many islands around the UK.
Conservation:
Like all shrews, the pygmy shrew is protected under Schedule 6 of the Wildlife andCountryside Act 1981 and the Wild Mammals (Protection) Act 1996. A licence isrequired for the trapping or killing of shrews. Shrews of all species suffer highmortality in traps unless adequate food and nesting material is provided and thetraps are checked regularly.
Distribution:
The pygmy shrew is widespread throughout Cornwall but probably under recorded because of its inconspicuous habits and its small size. The pygmy shrew is common andwidely distributed across Britain and it is the only shrewnative to Ireland. It occurs throughout Europe, with theexception of the Iberian peninsular and the Mediterranean islands.
Records:
2007-2012: 118
2002-2007: 365
Pre-2001: 168
Total: 651
Survey Methods:
Small mammal trapping. Cat kill records. Owl pellet analysis. Incidental sightings – bird feeders, mouse traps, and live sightings. Dead shrews are often found in abandoned bottles and cans. Hair tubes. Corrugated iron sheets.
