Wildlife Recording Guidelines
Amphibians

Introduction

The following methodology is based on survey work normally required in the Northwest of England and north Midlands, i.e. Cheshire, Lancashire, Staffordshire and Shropshire – our main areas of employment. As such it deals with the species encountered in the region: common frog, common toad, smooth newt, palmate newt and great crested newt.

Survey Period

The key time period for the survey of amphibians is March through to July. April and May are the preferred months, when most breeding adult amphibians are in their breeding ponds. Surveys for common toad and common frog can be undertaken earlier in the year, but these periods may miss smooth, great crested and palmate newts.
Survery Methodology

Licence Requirements

A DISTURBANCE LICENCE IS REQUIRED IF IT IS INTENDED TO SURVEY FOR GREAT CRESTED NEWTS. LICENCES ARE ISSUED BY ENGLISH NATURE (ENGLAND), CCW (WALES) AND SCOTTISH HERITAGE (SCOTLAND)

Common Frog

Common frogs spawn communally in warm, shallow water close to the shoreline, often on the south-facing side. Spawn counts should be carried out in March or early April, earlier in the south of England and later in the north. If individual spawn clumps have coalesced to form an individual mat, the area of the mat should be noted and from this an approximation of the number of clumps can be made. As a female only spawns once, then this is a good indication of population size.

Common Toad

Like frogs, common toads are explosive breeders with the bulk of the population (about 75% of breeding males) occurring at a pond within 4 or 5 days of the first paired animals arriving. As the strings of spawn are more difficult to locate (they are intertwined around vegetation often at depth where they are not visible), then population estimates are best obtained by head counts made after dusk. Head counts should be made using a torch, capable of casting a beam at least half of the way across the water body where practicable.

Newts

All three species of newt can be surveyed for using the same methodologies. Four methods exist for their survey and a minimum of three
is usually employed to obtain adequate results on four separate occasions in April and May to confirm presence. If population assessments are to be made then two further visits should be made. Full details can be found in Great Crested Newt Mitigation Guidelines which can be downloaded here

Torch Counts

The perimeter of the water body is slowly walked at dusk and a torch shone on the water’s surface. A pretzel type halogen can be used or more effectively a 1million candle power lamp. The number (and sexes) of newts are recorded and a density calculated, i.e. number of newts per unit length of shoreline walked. The proportion of adults detected at peak season, late April to mid-May, can vary between 6% and 23% of the population.

Bottle Trapping

Bottle traps (made from 2 litre plastic drinks bottles) are set in the pond at 2 metre aggregate centres and left in position overnight. Traps should include an air supply or be open to the air via a ventilation hole to prevent asphyxiation.

Netting

Dip netting from the pond shoreline can be carried out by day or prior to setting bottle-traps. Netting prior to torch counting will disturb amphibians and affect the results obtained by ‘torching’.

Dip netting should be done by sweeping the net backwards and forwards swiftly through vegetation at the pond edge for 15 minutes per 50 metres of pond circumference. It is advisable if two people undertake the operation, one checking the net contents, whilst the other continues sweeping. This method detects a lower proportion of the population than either of the previous two methods and is best restricted to surveys where a basic presence or absence is required. Dip netting can also cause damage to aquatic vegetation and larva can be killed by netting. Netting should therefore be restricted to the early part of the survey season, i.e. April to June.

Egg Searches

These take the form of examining floating vegetation for the rolled egg cases of newts. The eggs of smooth and palmate newt are indistinguishable in the field, whereas those of the great crested newt are larger. This method can not be use to establish a population level, but can be used to confirm breeding of great crested newt and ‘common’ newts (smooth or palmate).

Each of the above methods produces different figures for estimated populations from any pond surveyed. The methods each their own advantages and disadvantages and best results are obtained by combining the methods. The actual method employed on any one site will be determined by the requirement of the survey and the condition of the pond

Terrestrial Searches

Terrestrial searches can be used to assess migration routes to and from breeding ponds, and to obtain an indication of the range of terrestrial habitat used. The most effective method of terrestrial survey is to erect a series of drift fences and pit fall buckets around the site and for these to be monitored on a daily basis. If a pond is totally surrounded by drift fencing, then virtually all amphibians using the pond can be counted if the fencing is kept in-situ during the migration periods. Pitfall buckets should be suitably furnished with damp vegetation and a means of escape for small mammals. This method is the most expensive and labour intensive of all the survey techniques.

Summary

Survey methods for amphibians depend upon the survey requirements (clients brief), site terrain and species involved. Most surveys should be undertaken in April or May, although surveys in June can provide adequate results. Surveys for great crested newts can only be undertaken by a suitably licensed amphibian handler.
It should be noted that any survey only records what is present at the time of the survey and not what is not present.

Further information on survey and recording of all amphibians (and reptiles) can be found in The Herpetofauna Workers’ Manual published by JNCC.