Harvest Mouse Survey

Harvest mouse at night

Harvest mouse (Micromys minutus) captured on survey after dark

Last week I joined Surrey Wildlife Trust on a harvest mouse survey in wetland habitat beside the River Wey.

Harvest mice are tiny rodents 5cm in length. Their remarkable prehensile tails add an extra 6cm. They live in long tussocky grassland, reedbeds, hedgerows and around woodland edges, building a spherical nest of tightly woven grass, high up amongst the stems. We found several examples at this site:

Harvest mouse nest

Harvest mouse nests are woven from a mixture of living and cut grasses which provides excellent camouflage

Nests are the most obvious sign of harvest mouse activity since the animals are especially active around dawn and dusk and rarely spotted in the thick vegetation.

Dozens of rodent-friendly traps of different designs were set in the thick wetland reeds and grasses. Surrey Wildlife Trust staff and volunteers returned three times each day over the course of a week – at dawn, midday and dusk – to ensure that no trapped animals were left for any longer than necessary.

Rodent trap

Rodent trap baited with peanut butter, bird seed and dried blowfly larvae

After retrieval from the trap harvest mice are transferred to a transparent bag for weighing and sexing:

Harvest mouse in bag

Harvest mouse recovered from trap

Weighing harvest mouse

Harvest mice weigh only 5g on average

Once the details of each rodent have been recorded a small patch of fur is trimmed to identify any animals which are subsequently re-captured.

Harvest mouse being marked

Marking harvest mouse – a delicate operation!

The highest number of individuals captured was 12 one morning, making this the most abundant site for harvest mice in the county at present.

Harvest mouse in the hand

Harvest mice require very careful handling by trained experts

With thanks to Surrey Wildlife Trust staff and volunteers.

Related links:

Buglife: Glow Worm Survey

Buglife are using my image in their postcard campaign to publicise a glow worm survey in Scotland this summer:

Glow worm postcard

Scottish Glow Worm Survey postcard

Glow worms are widely distributed in the UK, with records from the south of England up to the north of Scotland, but there have been very few Scottish records in recent years.

Related links:

Talbot Heath Inquiry

Talbot Heath lies largely unnoticed on the outskirts of Poole in Dorset. Once upon a time it formed a seamless whole with the famous expanse of heathland familiar to Thomas Hardy and his contemporaries. Nowadays it’s sliced apart by bypass and railway to north and south, and nibbled away at by encroaching residential developments to the east and west. The sea of heathland has become an island here.

Most of the locals clearly love this precious green (and brown) open space, but its close proximity to human habitation regularly puts the heathland flora and fauna at risk from fire and other degradations. The effects of arson in particular, but also the predations of local cats, litter and path erosion present a considerable threat to this Ramsar and SSSI designated site.

The local borough council in their wisdom recently approved a planning application to extend a housing development in the north, onto farmland which currently serves as a buffer between urban and heathland areas. This decision was controversial for several reasons, but especially because it appeared to override a government directive which prevented new developments within 400m of heathland sites.

The RSPB and other conservation bodies became worried that this development might set a dangerous precedent and the decision eventually went to a Public Inquiry. As part of their submission to the Inquiry I was asked to document the site photographically for the RSPB and their partners at Natural England.

Following 3 visits to the site in late spring 2011 I delivered a library of 300+ images, depicting the Talbot Heath landscape, its flora & fauna, human visitors, and urban effects.

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Update: In February 2012 the proposed development was refused permission by the Secretary of State for Communities and Local Government.