Wider Countryside Survey - Herts & Middx Butterfly Conservation

Butterflies of the Wider Countryside Recording Survey

Can you spare time on 2 days in July and August to visit a grid square and do two 1km walks to record butterflies? This method is intended to compliment, not replace transects, and enable records from a wide variety of habitats to be collected. Some squares will be rich in butterflies, others less so, but all results will be important.

This survey is done in 1km squares and selected at random by the national survey co-ordinator. The squares are:

Wider countryside map for Herts & Middx

1km square Location Volunteer
TL2316 Welwyn (not Garden City)
TL3212 Hertford
TQ2480 Ladbroke Grove
TL2722 Aston (SE of Stevenage)
TL1734 South of Henlow (N tip of Herts/Beds border)
TL2332 Eastern Letchworth
TL1031 North of Hexton (part in Beds)
TL1232 Apsley End (part in Beds)
TL2502 Swanley Bar/Little Heath
TL2804 Northaw Great Wood
TL2831 Between Clothall and Rushden
TL2904 Cuffley Camp
TL3000 West of Crews Hill
TL3128 South of Cottered
TL3207 Broxbourne Wood (south of Brickendon)
TL3618 High Cross
TL4135 North-east of Nuthampstead
TL4216 North of Widford
TL4421 West of Bury Green near Little Hadham
TL4717 Trimms Green west of Spellbrook, south of Bishops Stortford
TQ1492 Harrow Weald Common southern half
TQ1593 Bentley Priory/Stanmore Common
TQ2397 London Shire golf course west of Monken Hadley
TQ2688 East side of Hampstead Garden Suburb
TQ2782 Baker Street/Regents Park

How to plan the survey

If you are a surveying a square that has been allocated to you, it will be necessary to establish a fixed survey route through the square The survey route is two parallel 1-km long survey lines across your square (running N-S or E-W), that are subdivided into ten continuous 200m sections numbered 1-10.

  • Ideally, survey lines should be around 500m apart and 250m in from the edge of the square.
  • Because these squares may be re-surveyed in future years, it is important to note the starting points of each section either with the help of permanent landmarks (trees, hedges, boulders, houses etc) or by using temporary markers (coloured tape or cord etc).
  • In practice, your survey lines are likely to deviate from the 'ideal' because of problems with access, or barriers such as roads, rivers, and canals. In cases where the survey lines deviate considerably from the 'ideal', at no point should the two lines be closer together than 100m.
  • For each of the two survey lines, only record 1-km even if it means not reaching the edge of the square
  • Minor intrusions into adjacent squares are perfectly acceptable and may provide the only practical way to carry out the survey. Indeed the route will be acceptable as long as more of the survey line falls within the square rather than outside.
  • It is advisable to make an initial visit to your 1-km square to familiarise yourself with the route.
Obtaining access to the survey route within squares

A large number of 1-km squares have paths, roads, bridleways or open access across them. This information can be gathered from an OS map and the open access website (www.gov.uk/right-of-way-open-access-land/overview). Unless there is open access to your whole square then it is important that you contact the landowner to gain permission to carry out the survey visits. We advise contacting the nearest dwelling to your square either by telephoning to arrange a visit or by sending them a letter. A letter template is available which outlines the reasons why the surveys are being carried out and what they entail. Click here for a copy of the template

How to survey
  • For each square record butterflies along the two 1-km survey lines on the same day.
  • Walk each section at a slow, steady pace counting all butterflies seen within 2.5m either side of the survey line, 5m ahead and 5m from ground level up.
  • Try to avoid double counting where possible e.g. when an individual butterfly repeatedly flies in and out of your recording box. However, if you lose sight of an individual, and later regain sight of the same species do not assume this is the same individual.
  • Do not count butterflies behind you.
When to survey and recording criteria
  • A minimum of two visits to each square are required to take part in this survey and these should take place in July and August, with at least 10 days between the two visits.
  • In addition, one or two further visits can be made to the square during May, June, July or August with at least 10 days between visits.
  • If possible return visits to squares should be made at the same time of day.
  • Record the time at which you start and end each survey line (1-km) on the survey recording form.
  • Survey lines should generally be walked between 10.45am and 15.45pm and only when weather conditions are suitable for butterfly activity: dry conditions, wind speed less than Beaufort Scale 5 and temperature 13°C or greater if there is at least 60% sunshine, or more than 17°C if overcast.
  • If a distinct shadow is cast (bright cloud) then conditions may be classed as sunny.
  • If possible, sunshine should be estimated for each section to the nearest 10% of the time it was sunny while you were walking that section (shade cast by features such as trees does not count).
  • At the end of each survey visit, record shade temperature (e.g. with a portable thermometer placed in a shaded position at the beginning of the first survey line before you start), estimate average sunshine (based on section data), and average windspeed, using the following Beaufort Scale (see Table 1).
Exceptions to general recording rules:
  • It is also permissible to record from 09:30-10:45 and 15:45-16:30, if at these times the majority (>75%) of the survey area is unshaded and the standard (described above) weather criteria have been met.
Species identification

Try to identify and separate all species you encounter, including where possible similar species such as Small and Essex Skipper, and the 'cabbage' whites.

If you would like to volunteer to survey one of the vacant squares or have more information please contact Andrew Wood (details on Committee page)

To view the results of the Wider Countryside Butterfly Survey in the UK click WCBS results