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Bibliography
Mitchell-Jones, A J and
McLeish, A P (eds),
1999, The Bat-worker’s
Manual, Joint Nature
Conservation
Committee

Page, C N, 1988, Ferns:
their habitats in the
British and Irish
landscape, Collins

Richardson, P, 1985,
Bats, Whittet

UK Government, 1981,
Wildhfe and Countryside
Act c69, Part I, S9 (1),
The Stationery Office

UK Government, 2000,
Countryside and Rights
ofWayActc37,Sch 12,
S5 The Stationery
Office

Contacts
Bat Conservation Trust,
15 Cloisters House,
Battersea Park Road,
London SW8 4BG.
Tel 020 7627 2629,
www.bats.org.uk

English Nature,
Northminster House,
Peterborough PE1 1UA.
Tel 01733 455000,
www.english-nature.org
uk
details of ferns’ peculiar sex lives, a thin film of water
on the wall surface is necessary for them to reproduce.
Along railways, the water film would have come from
condensed steam. With the demise of steam trains, our
railway fern colonies are probably not getting any
bigger, and each tiny plant may be 50 years old or
more. They are as much a part of steam railway history
as their viaducts, bridges and walls.
Canal walls in the Black Country are noted for their
ferns, especially in the cool, damp, retaining walls
below lock chambers and around tunnel portals. Seven
species are found in the lock walls at the Deiph near
Brierley Hill where the Dudley canal ascends a flight of
locks. The portal of the Dudley tunnel under Gorsty
Hill is particularly attractive with a curtain of
maidenhair spleenwort.
Ferns often seem to prefer the mortar courses in the
blue-brick walls which are typical of Victorian
engineering works. This is probably because these
walls are more resistant to weathering and need less
maintenance, rather than any chemical properties of
the bricks. Maintenance, especially repointing, is the
nemesis of many a fern colony. Sometimes the work
has to be done, for safety and conservation reasons,
but it often seems unnecessary. Ferns have small
compact root systems, unlike flowering plants, so they
do very little damage to a well-made wall. There is no
doubt that ferns also prefer the softer lime mortars of
the past to the hard Portland mortars used today.
To conserve ferns in walls, follow three principles:
•
Carry out maintenance on fern-rich walls only if it is
necessary for safety or conservation.
•
If maintenance is needed, try to retain at least part
of a fern colony in the structure so that the wall can be
recolonised.
•
Always use lime mortars to repair or maintain fern-
rich walls.
Ferns in walls are worth conserving, and not just
because they are becoming scarce in natural habitats.
Their appeal is due to their beautiful form and
structure, the contrast between their delicate fronds
and their chosen habitat, the softening effect they have,
especially on the massive engineering works of the
industrial age, and the welcome touch of green they
bring to dark and frequently ugly places. Fern spotting
adds to the attractions of a trip along the canal, and
can enliven many a railway journey. At least it is
something to do while trapped in a train in the abyss
outside Birmingham New Street Station.
Bats have also found a man made alternative to their
natural roosting habitat in trees, caves and rocky
places. They have also suffered from man’s activities.
Their decline is partly due to the loss of foraging
habitats, and partly due to the destruction of roost
sites and roosting bats.
It has always been an offence under the Wildlife and
Countryside Act (1981) intentionally to harm or
disturb a bat, but the Countryside and Rights of Way
Act (2000) closed a loophole in the law. It is now an
offence recklessly to harm or disturb as well. This
means that ignorance of the presence of bats is no
longer a defence. We should find out if bats are present
before any work which could harm them is done.
Bat surveying is a specialist job. The Bat Conservation
Trust is a good initial contact in the search for an expert.
Surveys must be done as early as possible in a project,
because bats are difficult to find at certain times of year,
and it can take time to sort out any licences which might
be needed. Any work that could harm a bat or its roost
will need to be licensed through DEFRA, who take
advice from English Nature. It is much easier to employ
a specialist bat ecologist to do this for you, since it is a
complicated process. The licensing system has just
changed and there are some teething problems.
Bats have a very complicated lifestyle, which varies
between species and individual colonies, and is
dependent on the prevailing weather conditions. Their
life cycle can be broken down roughly into four stages:
• November to March hibernating all day and night in
winter roost-sites (usually cool damp places with a
constant temperature).
• March to May waking up and coming out of
hibernation; roosting during the daytime and cold
nights.
• May to August having babies and caring for them in
nursery roost-sites (which are usually warmer and in
different places to winter roosts); babies live in the roost
day and night, females in the roost during the day.
• September to October eating a lot to build up energy
and fat reserves for mating and hibernation, roosting
during the day and cold nights.
Bats are especially vulnerable to harm during winter,
when they are hibernating, and during summer, when
they are having babies and rearing them. It is worth
bearing this in mind when programming work,
because a licence to do work near a bat roost often has
a condition specifying that the work should be done
outside these vulnerable times.
If bats are found, most building works will need a
licence. Anything that stops a bat getting in or out of
its roost site, frightens it away from its roost, or wakes
it up from hibernation, will need a licence. This will
include nearly everything you plan to do, as bats can
creep into crevices less than 1.5cm wide, such as the
gap left where mortar has dropped out.
Maidenhair Spleenwort
on the Ferny Bridge,
former Great Central
Railway, Leicester
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CONTEXT 73 : MARCH 2002

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