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:

necessary for safety or conservation.

of a fern colony in the structure so that the wall can be

recolonised.

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