Small Mammals and Road Verges. A National Survey

We have received the following request, from the Mammal Society and University of Bristol, for help in this survey. Its now too late for the autumn 1999 survey but you could take part in the Spring 2000 survey, and future surveys. If any reader has some experience in small mammal trapping and would like to take part in the survey or become a local organiser they should contact the organiser directly. If any work is undertaken please let us know and be sure that a copy of the results are sent to Worcs BRC. I have the original request and forms if you wish to contact me - Harry Green.

The Mammal Society is undertaking a nationwide survey of small mammals on road verges with the assistance of its members and other volunteers. As wildlife in the wider countryside comes under increasing pressure from farming and other developments, relatively undisturbed habitats such as road verges constitute an increasingly valuable nature conservation resource. Road verges support a rich diversity of wild flowers and insects; various species of reptile have been found to be abundant within the patchwork of rough grassland and scrub; and kestrels, which are often seen hunting over our motorways, testify to the value of verges for small mammals.

The aims of the national survey will be two fold:

  1. To identify the relationships between road verge habitat features and small mammal abundance and diversity.
  2. To help formulate management prescriptions for small mammals and other wildlife on road verges.

Volunteers are requested to survey for small mammals along as many transects as possible on suitable road verges close to their homes during autumn 1999 and spring 2000. Volunteers who have time to survey in only one season (autumn or spring) will also be welcome. We intend the survey to run for a second year and therefore will also be seeking volunteers for autumn 2000 and spring 2001. A limited number of Longworth traps will be available on loan, and priority will be given to those volunteering to survey a number of sites. Most volunteers, however, will need their own or have access to at least 20 Longworth traps or alternatively trip traps in order to participate. Trip traps are relatively cheap to purchase (5 for 8.30) and are available from the following address:

Procter Bros Ltd, Pantglas Industrial Estate, Bedwas, Newport, Gwent NP1 8XD.Tel 01222 882111.

An outline of the small mammal trapping guidelines follows below. Volunteers should ideally have basic experience in small mammal trapping or should be taught the necessary skills by somebody suitably experienced prior to undertaking the survey.

We would also like volunteers, if possible, to undertake a basic botanical survey during the summer along each of their transects. We hope to identify any relationships between small mammal abundance and botanical species composition.

Anyone interested in participating in our survey should fill in the enclosed form (or write/phone/email the organiser) stating the number of transects they would like to survey, whether they are able to survey in both of the two seasons and if they are able to undertake the botanical survey. They are also requested to state if they would provisionally like to volunteer for the second year of the survey.

National Road Verge Small Mammal Survey: Guildlines for Volunteers

Survey guidelines

1. Habitat selection
Small mammal trapping will be carried out along road verges within rough grassland habitat. The study aims to investigate the relationships between small mammal abundance and diversity and a variety of verge habitat characteristics.

2. Safety
Volunteers must be able to park safely and legally at their survey sites. They must not walk within the road to access their survey sites or stand on the road or its edge while undertaking the survey. Volunteers must not choose motorway verges for their survey sites.

3. Transect lines
Twenty Longworth traps will be positioned along each transect line extending along a section of road verge. A small number of Longworth traps may be available for loan. Most volunteers will be expected to provide their own traps. Volunteers who do not have access to Longworth traps may use trip traps which are cheap to purchase.

4. Recording information
Volunteers should have basic experience in small mammal trapping or should be taught the necessary skills by somebody suitably experienced prior to undertaking the survey. During each visit the following information will be recorded at each trapping grid:

Weather conditions.
Each species trapped and its grid location.
Whether the animal is marked. Every new individual will be given a unique fur clip.
Breeding Condition.
Weight (volunteers are expected to provide their own weighing balance).

5. Trapping period
Volunteers are requested to survey as many transects as possible during two survey periods which will coincide with small mammal peak abundance (September - November, 1999) and low abundance (March - May, 2000) periods. Each survey will be undertaken over two consecutive mornings, plus one evening / afternoon when the traps are first set. Volunteers who only have time to survey one transect within the year will also be welcome. Volunteers will also be sought to survey alternative grids during Autumn 2000 and Spring 2001.

6. Optional botanical survey
Volunteers will be encouraged to record information during the Summer on botanical species diversity and abundance along each transect using a relatively simple technique. Many volunteers will have friends and colleagues with botanical expertise who might be able to assist them with this task. All volunteers will be requested to make a subjective assessment of grassland cover following a basic scale (e.g. sparse, moderate, dense).

For more information contact Lincoln Garland at:
School of Biological Sciences, Mammal Research Unit, University of Bristol, Woodland Road, Bristol, BS8 lUG Telephone: 0117 928 7593 Facsimile: 0117 925 7374. email:

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