Water Shrews in Worcestershire

By Craig Baulderstone, at Worcestershire Wildlife Trust

Nationally there is a poor knowledge of the population status of the water shrew Neomys fodiens and the situation is no different here in Worcestershire. Information on the distribution and dynamics of populations is essential for production of good habitat management guidelines, which are instrumental in the survival of any species.

The Worcestershire Wildlife Trust is planning a survey using bait tubes to give valuable information about the distribution of water shrew populations. This will work in conjunction with a national survey being co-ordinated by the Mammal Society. A bait tube is simply a section of plastic pipe with one end covered and of a size that allows free entry and exit of small mammals. Frozen blowfly pupae are placed inside and hopefully will encourage visiting shrews to enter, linger to feed, defaecate and then merrily carry on their way. The scats can then be examined to determine which mammal has left them there. The presence of aquatic prey is the key to identify water shrew scats.

Of course live trapping is necessary if we are to attain valuable information about the dynamics of populations, however this survey is still being planned with advice from the national expert, Sara Churchfield. The intention is to establish long term monitoring sites for winter and summer surveys.

Water shrews sometimes co-exist with common and pygmy shrews, often several kilometres from water, however their preferred habitat is grassy banks of rivers, streams, ponds and drainage ditches. Their favourite habitat is watercress beds.

Few records are held by the BRC for Worcestershire and hopefully surveys will increase these records. However if any populations or locations of watercress beds are known to readers, this knowledge would be gratefully received.

For more information please contact Craig Baulderstone or Andy Graham at Worcestershire Wildlife Trust on 01905 754919.

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