Ponds, Pools and Lochans

3.6 Assessment of the conservation value of ponds using other groups of animals


Techniques are available for assessing the conservation value of ponds in terms of amphibians, dragonflies or water beetles alone.

Amphibian survey methods

Methods for surveying amphibians, and assessing the conservation value of amphibian populations, are given in the Herpetofauna Workers Guide (Gibb and Foster, 2000) and in the advisory leaflet Surveying for amphibians published by the British Herpetological Society (BHS, 1996). Site quality can be assessed using the system developed for SSSI designation which is summarised in Table 11. For more detailed monitoring of amphibian populations (particularly newts), survey methods have been recommended by Griffiths, Raper and Brady (1996).

All exceptional great crested newt sites (which may comprise several ponds) are eligible for designation as SSSIs . For the other widespread species, exceptional populations with four out of the five native species are needed to qualify for SSSI status. Gibb and Foster (2000) describe the scoring system used by JNCC for identifying sites of high importance for amphibians. A simple identification guide to amphibians has been published by Froglife (1999).

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Figure 15. Frogs are widespread in Scotland: an exceptional population is one where more than 500 spawn clumps can be counted (see Table 11). Graham Burns

 

Table 11.
Assessment of pond conservation value based on amphibian population size
Standard survey methods described in BHS (1996) should be used to estimate the size of amphibian populations, allowing pond value to be assessed according to the criteria given below.
The survey method shown for each species is the optimum technique. The table indicates whether numbers pf animals recorded should be regarded as low, good or exceptional populations.
         
Species Survey method Low population Good population Exceptional population
         
Great crested newt Seen/netted in day Less than 5 5 to 50 More than 50
  Counted at night Less than 10 10 to 100 More than 100
         
Smooth newt Netted in day or Less than 10 10 to 100 More than 100
  counted at night      
         
Palmate newt Netted in day or Less than 10 10 to 100 More than 100
  counted at night      
         
Common toad Estimated Less than 500 500 to 5000 More than 5000
  Counted Less than 100 100 to 1000 More than 1000
         
Common frog Spawn clumps counted Less than 50 50 to 50 More than 500
Natterjack toads are excluded from Table11. All important and established colonies of natterjack toads are in sites with SSSI status where established means evidence of a viable colony over a period of 5 years or more and Important means: (1) all sites with more than 100 adults or 25 spawn strings for at least two of the previous 5 years; (2) all heathland sites; (3) the best or sole representative in a watsonian vice-county (Gibb and Foster, 2000) .
         

Water beetle survey methods

Field survey techniques for water beetles are given in Foster and Eyre (1992). The conservation value of water beetle assemblages in ponds and other habitats can be assessed using the Species Quality Score system (see Foster and Eyre, 1992). A large body of data on water beetles supporting this method has been collected by members of the Balfour-Browne Club (contact address: see Appendix 1).

Dragonfly survey methods

Standard dragonfly recording methods are described by Brooks (1993). The British Dragonfly Society (BDS) records dragonflies at a range of sites in Scotland (contact address: see Appendix 1).

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