NATURE NOTES - The shrewd shrew?

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WANDERING in the woodland the other day I found a dead shrew by the side of the path.

I thought at first that it was a pygmy shrew due to how tiny it was but on closer examination it soon became evident that it was actually a very young common shrew.

That was somewhat of a relief as pygmy shrews are wonderful little critters and our smallest mammal by far.

In fact it comes a close second to the bumble bee bat as being the smallest mammal in the world! However, while the bumblebee bat (Craseonycteris thonglongyai) is the smallest mammal by skull size, the smallest by mass is the Pygmy Shrew, which weighs in at 1.3 grams.

There are five types of shrew in the UK. They are divided into two groups, the red-toothed and white-toothed shrews.

The red-toothed group is the common shrew, the tiny pygmy shrew, and the water shrew. Lesser and greater white-toothed shrews are not found in mainland Britain.

The lesser white-toothed shrew is found on the Isles of Scilly, Jersey and Sark, whilst the greater lives on Alderney, Guernsey and Herm.

Shrews must eat every 2-3 hours to survive (I know how they feel!) so they are often seen dashing around foraging for food.

They actually live in burrows which have often been used previously by another animal.

Their main food source is insects but they will also eat earthworms, small slugs and snails especially in damp areas.

Shrews are highly territorial animals and only ‘party’ with one another in the mating season. Mrs Shrew has one litter of 5-7 young anytime from May to September.

Young shrews (or shrewettes) can sometimes be seen following mom in a ‘caravan’.

Each shrew gets hold of the tail of the shrew in front so that the mother runs along with a line of young trailing behind.

This behaviour is often associated with disturbance of the nest and may also be used to encourage the young to explore their new world.

Shrews do not hibernate, but they do become less active in winter (don’t we all!).

Shrews have a number of predators and are most commonly killed by tawny owls and barn owls, although weasels, foxes, stoats and kestrels have all been known to prey on them.

But they are often found abandoned by the predator, particularly cats, since a liquid produced from glands on the skin is foul tasting.

Shrews are famous for providing a home for a large number of parasites, normally transmitted to the shrew from its prey.

In comparison with mice, shrews have a very short life-span and it is rare for a shrew to live for more than 12 months.

The common shrew is very widespread, the second most numerous British mammal.

Living at densities of up to 50 per hectare in many types of woodland and often over 20 per hectare in grasslands and other habitats, the most recent estimate puts the number of shrews in Britain at 41,700,000.