Amphibian Surveys

Introduction

This method is based on the Amphibian pilot surveys carried out by the National Amphibian and Reptile Recording Scheme in 2006 (see references for NARRS website).

Personal Safety

Please read this safety information before carrying out a survey.

Seasonality

The best time to survey British amphibians is during the spring, when they visit ponds in order to breed. However, note from Halliday (1996) that ‘In some temperate amphibians breeding is ‘explosive’, with annual breeding activity being completed in one or two days. In such species, effective censusing can be achieved by intensive fieldwork over a limited period, provided that the censuser is alert to the climatic conditions that stimulate breeding.

Monitoring Frequency

The original survey forms are available online, and anyone wishing to take part in the NARRS survey should visit the NARRS website to download these.

For consistency purposes, the same number of visits should be undertaken each year, with the same survey techniques carried out annually.

Equipment

  • Pond net
  • Powerful survey torch (500,000 to 1,000,000 cp)
  • Safety torch (a smaller torch for use if your survey torch fails)
  • Thermometer
  • Mobile phone (for use in emergency)

Methodology

The recommended methodology (NARRS) is for three visits to be carried out with up to three survey techniques carried out on each visit.

The three methods are as follows: (1) visual search; (2) netting; (3) night time torchlight survey. These are all described below. Landowner permission Prior to visiting a pond, it is essential to get permission from the landowner. If the landowner does not agree to grant permission of access then you should not attempt to visit the site.

Even if the site has public access then it may still be appropriate to contact the owner to seek permission to undertake the survey. Your meeting with the landowner can be a useful opportunity to generate good relations, to gather information about the pond and to minimize hazards that may arise during the survey.

If a landowner is willing for you to survey ponds on his/her land then:

  • Ask about convenient car parking.
  • Ask about safety issues at ponds (e.g. steep banks, deep water, butyl-lined reservoirs).
  • Ask about the pond and its wildlife. Are fish present? Are ducks kept on the pond? How often does the pond dry out?

Visual search

A visual search involves walking once around the pond edge, searching for amphibians and especially their eggs. Before undertaking amphibian surveys, you should ensure you are familiar with the features of the amphibians and their eggs and where to look for them.

This can be attained by reading literature, or better still by receiving training from an experienced surveyor.

Netting

You should make another circuit of the pond, making sweeps of any beds of submerged vegetation you can reach, again searching for eggs and for amphibians. Night time torchlight survey After dark the pond should be searched again, by torchlight, making a single circuit of the accessible perimeter.

The torchlight survey may take place on a different day to the visual search and netting. However, a visit during daylight should always take place before a torchlight survey, so that any potential hazards can be identified. Therefore, in practise it will save time if all three techniques are carried out on the same day.

Additional recording

It is important to record a number of other pieces of information to help analyse population trends at the pond, and also so that the data can be usefully incorporated into regional and national surveys such as NARRS.

This includes:

  • Information about the habitat suitability of the pond.
  • Information about the timing and weather conditions during the survey and prior to the survey.
  • Details of the proportion of the pond that you were able to survey.

Full details of the suggested information can be found on the example form and notes.

References

Halliday, Timothy R. ‘Amphibians’ in Sutherland, William J. (Ed) ‘Ecological Census Techniques: A Handbook’, Cambridge University Press, 1996.

National Amphibian and Reptile Recording Scheme