The pygmy shrew

How small is a pygmy shrew?

The pygmy shrew is Ireland’s smallest mammal. A big breeding adult may weigh 6g, but they lose weight in winter and their bones shrink. In winter they may only weigh 3g!

Where do pygmy shrews live?

Pygmy shrews live in woodlands, hedgerows, farmland, gardens, and even bogs. In fact, they will live anywhere that has dense ground cover. They are common and widespread throughout

Ireland.

Pygmy shrews are true Irish natives

Many of our Irish mammals arrived here with some help from Man, but Pygmy shrews are believed to have been here at least since the Ice Age.

Do pygmy shrews live in groups?

No. Pygmy shrews are solitary and are very aggressive to other shrews. Each shrew has its own territory and it defends it against all others. If two shrews meet, a fight will start. Only in the breeding season are territories relaxed as males wander to find females.

How big is a territory?

Depending on how good the habitat is, a territory may be as small as 200m² to as large as 1500m².  An area the size of a football pitch may have between 5 – 40 pygmy shrews.

What happens to a pygmy shrew that has no territory?

No territory means little or no food, so a shrew without a territory dies very quickly.

What do pygmy shrews eat?

Pygmy shrews eat bugs - lots of bugs! Beetles, woodlice, and flies are favoured , but they will eat almost any bug that they find – slugs, earwigs, spiders, etc. Large earthworms, however, are a little too big for most pygmy shrews to tackle.

How much do pygmy shrews eat?

Small animals have a very high metabolic rate and need to eat much more food per body weight than a larger animal. A pygmy shrew needs to eat every three hours or it will die of starvation! For this reason, pygmy shrews are active both day and night.

Do pygmy shrews hibernate?

No. They need to keep eating throughout the winter.

What kills pygmy shrews?

Pygmy shrews have strong scent glands and these deter most predators from killing them. Domestic cats will often kill a shrew, but they will rarely eat them due to the scent glands. Owls often eat shrews, and in bog lands, foxes will also eat shrews. Pesticides can kill shrews indirectly.

How long do pygmy shrews live?

Pygmy shrews live short, fast lives. Few live more than 13 months.

Do pygmy shrews make noises?

Oh yes! Pygmy shrews are constantly squeaking, but their squeaks are very high-pitched and most people cannot hear them. Children are better at hearing these high squeaks.

Can pygmy shrews climb?

Pygmy shrews usually stick to the ground running along ‘tunnels’ in the undergrowth. But they can climb if they need to, and they can also swim if necessary.

When are baby pygmy shrews born?

Most baby pygmy shrews are born in June or July, but the breeding season can extend from April to October. Males wander in search of females. Courtship is fast and furious, and the pair then resume solitary lives. The babies are born 22-25 days later in a nest. Blind and helpless and weighing a mere 0.25g, the mother tends them for only 21 days.

Young shrews must then leave and find a territory. Most will die quite quickly. The mother may have two or three litters in the summer before she herself dies. Some young will survive the winter to breed the following year.

Are pygmy shrews protected?

Yes. Pygmy shrews are totally protected in Ireland.