Fen Management Handbook - Scottish Natural Heritage

Water shrews (Neomys fodiens), also present in England Wales and Scotland, but
not Ireland and harvest mice (Micromys minuta), restricted to southern England
and parts of Wales, are also found along the banks of watercourses and open
water, and in reedbeds, marsh and other fen habitats. As with so many wetland
specialists, the populations and distribution of all three of these species is patchy
having suffered significantly because of habitat loss and fragmentation, pollution
and disturbance.
Drier areas of ungrazed grassland and purple moor-grass (Molinia caerulea)
dominated fen with plenty of dense cover support populations of field vole
(Microtus agrestis), another species widespread in Britain which is absent from
Ireland.
Otters (Lutra lutra) were once widespread throughout the UK, but declined rapidly
in the late 20 th century, becoming increasingly restricted to the north and west of
the country at that time. The decline of otters across southern England and Wales
was primarily due to the build-up of persistent organo-chlorine pesticides which
affected their ability to breed. This decline has now largely been halted since
these chemicals were banned and otters are once more becoming widespread
throughout the UK. Otters are mainly found in still and running freshwater systems
and along the coast, especially in Scotland, but associated habitats including fens
and swamps are important for breeding, feeding and resting as the tall vegetation
provides cover.
Otters are often found in fens
and swamps (Lorne Gill).
Bat species associated with wetland habitats include pipistrelle bats (Pipistrellus
spp.) noctule bats (Nyctalus noctula), brown long-eared bat (Plecotus auritus) and
Daubenton’s bat (Motis daubentonii). Although the latter are particularly associated
with aquatic habitats and some of the other species noted may be more generic in
their habitat requirements, they all occur in fens and reflect the mosaic of habitats
within the wetland and its surroundings.
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