national amphibian and reptile recording scheme – narrs amphibian surveys
Post on 29-Mar-2015
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National Amphibian and Reptile Recording Scheme NARRS Amphibian Surveys Slide 2 Aquatic habitat Survey Methods Egg searching Netting Torching Bottle trapping Refuge searching Pitfall trapping Slide 3 Egg Searching Submerged vegetation Great crested newt Smooth/palmate newt Slide 4 Slide 5 Slide 6 Slide 7 Focus on newly-laid eggs Harder to identify once larva takes shape Slide 8 Egg Searching AdvantagesDisadvantages Quick methodLittle value for determining population size Great crested newt eggs are distinctive No equipment is needed Low level disturbance Slide 9 Netting A good net with a rigid frame and a mesh of approximately 2-3mm costs around 50-60 including delivery Slide 10 Netting Effort Work around the pond perimeter Net along two-metre lengths of shoreline Agitate the net through aquatic vegetation in two- metre arc Netting open water is less effective than netting in vegetation Slide 11 Great crested newt larva Smooth newt larva Slide 12 Overwintering larva Slide 13 Netting AdvantagesDisadvantages Useful for catching great crested newt larvae and general sampling. Needs a sturdy net. Allows accurate identification.Often ineffective for adult great crested newts. Long season (March-October).Disturbance to pond. Can be carried out during the daytime. Risk of transfer of pest plants and possibly diseases. Slide 14 Torching Newts primarily nocturnal Detects presence and allows a count Best time March-May Warm, still evenings (Avoid wind, rain, or low temperatures) Larvae detected late summer, early autumn Slide 15 Torching Two- metre sections The torch should be moved away from the bank and back, to cover the area of the pond in the two- metre segment Repeat for all the accessible areas of the pond Record the percentage of the perimeter surveyed Daytime survey work should occur prior to torching, so that any potential hazards can be identified in the daylight Slide 16 Torching Size difference of GCN obvious, and male tail flash Count total newts seen Slide 17 Torching Brighter generally better. (e.g. 500,000 to 1,000,000 candlepower) Good torch can cost 40-120 e.g. Clubman CB1 or CB2 Slide 18 Torching AdvantagesDisadvantages Minimal disturbance to pond and newts Has to be done after dark (safety & access issues) Quick survey methodUnsuitable in rainy and windy weather Identification of species can be difficult from a distance Difficult in murky and turbid ponds (e.g. after netting) Slide 19 Bottle (or funnel) Trapping Typically used where torching is not possible Turbid water, too much vegetation, rain, wind More onerous and potentially dangerous than torching, netting etc. Slide 20 Bottle Trapping Welfare Issues March-April: 12 hours May: 10 hours June: 8 hours July-August: 7 hours Sept- October: 8 hours Slide 21 Bottle Trapping AdvantagesDisadvantages Reliable method to detect adults and larvae Risk of killing adults and larvae (and other species) Useful technique in weedy or turbid ponds Risk of vandalism/interference Allows accurate identificationLogistically onerous You MUST be trained and experienced to use bottle trapping! Keeps pond disturbance to a minimum Stakes can puncture pond liners Slide 22 Refuge searching Looking under rocks, logs, discarded debris where moisture is retained March-October A bit hit and miss Supplementary technique only Slide 23 Method JFMAMJJASOND Bottle + ++ L L Egg + + Torch + +++L Net + ++ L +L Pitfall + +++ + Refuge + + + = may be found/ less effective = optimal/ most effective L = larvae present Fdsfgdgggdg Slide 24 NARRS pond selection A NARRS amphibian survey is conducted on a pond in a randomly-chosen square, usually within 5 km of the surveyors post code Important to have representative sample Home Slide 25 Locating the pond within your square Starting at the south-west corner of the square, find the nearest pond Can locate on map, but need to confirm in the field Slide 26 Gaining access permission Unless there are public rights of way, you must get permission from the landowner to visit the site and carry out the survey. You need to check that your mapped pond is still present, and that there are no other ponds closer to the south-west corner of the square. Knock on doors and ask locally Use access request letter (see www.narrs.org.uk) Slide 27 Pond access If there are no ponds within the survey square then move to one of the immediately neighbouring squares start with the square to the north, then move clockwise If a landowner is unwilling to grant permission for you to access the site, either move to a neighbouring square as above or request another square from ARC Slide 28 Definition of pond Water body between one square metre and two hectares, which holds water for at least four months of the year Slide 29 How to carry out the pond survey Your contact with the landowner is a good opportunity to find out some information about the pond, for example: Has it been stocked with fish? How often does it dry out? Are there any safety issues, e.g. steep or slippery banks? Is it known to support amphibians? !Remember to prepare your risk assessment! Slide 30 How to carry out the pond survey NARRS amphibian surveys are conducted using the same methods we have practiced, but note also: Breeding frogs and toads can be detected most easily during their peak spawning time Frog- or toadspawn can be found Techniques used for newts can also spot frog and toad tadpoles Slide 31 Licensing Most widespread amphibians do NOT require a licence in order to carry out a survey - the exception is the great crested newt (and other EPS) If you are in an area where youre likely to find GCNs, you should be licenced or accredited As a guide, if you find GCNs and are not licensed or accredited, you should stop surveying that pond and gain accreditation ARC can accredit people trained by ARC staff and/or if recommended by trusted trainers You must submit licence returns/results. Slide 32 Filling in the Survey Form The survey form has been kept as simple as possible while allowing key information to be recorded Most information requested is self-explanatory e.g. Pond details Your details Landowner details Slide 33 Habitat suitability factors Developed for the Habitat Suitability Index (HSI) for the great crested newt. -the NARRS survey form contains space to record a simplified version of the HSI (see separate presentation). Slide 34 For each survey technique, record numbers of amphibians seen (indicate presence only for larvae and newt eggs). Visual search AduImmLarvaEgg Common frog 1 0 Common toad Great crested newt Palmate newt ? Smooth newt ? Other species Crassula grass snake Eggs of smaller newt species are not identifiable to species so indicate with question mark if not sure which one you have Slide 35 Survey conditions There are boxes to record the conditions under which the survey was conducted Date Time :to : Air temperature o C Water temperature o C Water clarity (score 1-3) Rain (score 0, 1, 2, 3) Wind disturbing water (tick) Bright moonlight (tick) % Shoreline surveyed% Number of traps used (IF APPROPRIATE/LICENSED ONLY!) Scoring for water clarity and rain given on survey form. Slide 36 How many times to visit the pond? Ideally, four survey visits but in practice, as many as a surveyor can make, up to four The survey form provides space to record information from up to four survey visits and the method/s used at each visit When to survey the pond? Ideally, an early survey in March and the rest mid- April to May (but later is still OK) Slide 37 REMEMBER your results are valuable and important to us however many methods you use or survey visits you are able to make! Even NEGATIVE results (i.e. where you dont find any species) are important! Slide 38 www.narrs.org.uk Slide 39 Photographs Photographs used in this presentation are by Fred Holmes, Phyl King, Will Watson, Steve Bolwell, Ben Driver and John Robinson Copyright of all photographs remains with the photographers and ARC These photographs should not be used for purposes other than NARRS training without the permission of the photographers.