REPTILE TRANSLOCATION REPORT. Hoggett s End, Bishop s Stortford, Hertfordshire

Transcription

1 REPTILE TRANSLOCATION REPORT Hoggett s End, Bishop s Stortford, Hertfordshire OCTOBER 2012 Surveyors: Peter Oakenfull AIEEM Date of Surveys: 30 th August 28 th September 2012 Report compiled by Graham Goodall BSc (Hons) CEnv MIEEM and Verity Roberts BA (Hons)

2 Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire Contents 1.0 Executive Summary Introduction Reptile Translocation Methodology Rationale. 3.2 Removal of reptiles from the development area Limitations and constraints Results Conclusions and Recommendations... 8 Appendix A. Grange Builders LPP Proposed Site Development Plan, March 2012 Appendix B. Appendix C. Appendix D. Reptile Refugia Positions Survey Map Reptile Exclusion Fencing Installation Map References

3 1.0 Executive Summary Maydencroft Land Advisory was commissioned by Grange Builders LLP to carry out a Reptile Population Index survey to determine the size of the reptile population within an area of land proposed for development at Hoggett s End, Bishops Stortford, Hertfordshire. The survey was carried out by Maydencroft ecologist Peter Oakenfull AIEEM between March and June It followed a presence/absence survey conducted in May 2011 that confirmed reptiles were present in the East Meadow but not in the West Meadow. Analysis of the 2012 Population Index survey data indicated that very low numbers of Slow Worm (considered to be a remnant population) and low numbers of Grass Snake were present on the site. It is the client s intention to develop the whole site and as a result, all existing suitable reptile habitat will be completely lost. Artificial refugia sheets were placed at a density of 100 per ha (twice the recommended quantity) following the installation of reptile fencing. The sheets were placed throughout the site with higher densities in areas identified during the Population Estimate Survey as offering suitable habitat for reptiles, and particularly in areas where reptiles had been previously found. The sheets were checked for a period of 30 days in suitable weather conditions during the period 30 th August to 28 th September, and until no animals had been found during five consecutive visits. Grass Snakes were encouraged to move off-site and Slow Worms were caught and translocated to a suitable receptor site at The Commons Local Nature Reserve in Welwyn Garden City, Hertfordshire, Grid Reference TL The translocation work was carried out in a timescale that avoided moving animals that were preparing to hibernate. Captured animals were handled carefully by an experienced ecologist, transferred to a holding container and then released into the receptor site within an hour, close to reptile hibernacula. Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 2

4 2.0 Introduction Maydencroft Land Advisory was commissioned by Grange Builders to carry out a Reptile Population Index survey to determine the size of the reptile population within the land proposed for development at Hoggett s End, Bishops Stortford, Hertfordshire. A comprehensive site description was given in the Extended Phase 1 Habitat Survey and European Protected Species report (Maydencroft Land Advisory, May 2011). The Population Index survey was carried out by Maydencroft ecologist Peter Oakenfull AIEEM between March and June It followed a Presence/Absence survey conducted in May 2011 that confirmed reptiles were present in the East Meadow but not in the West Meadow. Analysis of the survey data indicated very low numbers of Slow Worms and Grass Snakes. It is the client s intention to develop the whole site (as per the drawings sent to Maydencroft Land Advisory by Stuart Brown on 9 th March 2012; see Appendix A) and as a result, all existing suitable reptile habitat would be completely lost. Therefore, it would be necessary to encourage Grass Snakes to move off-site into suitable adjacent habitat, and Slow Worms would need to be caught and translocated to a suitable receptor site. A translocation strategy was used to ensure that all reptiles were moved safely off-site prior to development. 2.1 Legislation There are six species of reptile native to the UK: three snakes (Grass Snake, Adder and Smooth Snake) and three lizards (Common Lizard, Slow-Worm and Sand Lizard). The Sand Lizard and Smooth Snake have a restricted distribution in Britain and have a higher level of protection as European Protected Species. The other native species of reptile are generally common and widespread throughout the UK in suitable habitat, and are protected under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended). Under this legislation it is an offence to: Sell, offer or expose for sale or have in possession or transport for the purpose of sale any live or dead native reptile; Intentionally kill or injure any native reptile. Reptiles are likely to be killed or injured by activities such as: Clearing land, installing site offices or digging foundations; Cutting vegetation to ground level; Laying pipelines or installing other services; Driving machinery over sensitive areas; Removing rubble, wood piles and other debris. (List taken in part from the document Reptiles: Guidelines for Developers, English Nature 2004) All native reptile species are listed on the UK BAP Priority Species list published in 2007; they are also on the List of Species of Principal Importance under Section 41 of the NERC Act Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 3

5 3.0 Reptile Translocation Methodology 3.1 Rationale Natural England recommends that the best strategy is to keep reptiles on a development site by enhancing an area of existing habitat. However, in this instance this was not possible. It is the client s intention to develop the whole site as per the drawings sent to Maydencroft Land Advisory by Stuart Brown on 9 th March 2012 (see Appendix A). This was confirmed during a telephone conversation between Graham Goodall, Maydencroft Senior Ecologist, and Stuart Brown of Grange Builders LLP on Monday 9 th July As a result, reptiles had to be caught and moved (translocated) to suitable receptor sites. A programme of capture and release to an appropriate site was undertaken to avoid the killing or injuring of any Grass Snakes and Slow-Worms. The translocation followed the best practice guidance outlined in the Herpetofauna Groups of Britain and Ireland (HGBI) advisory note 'Evaluating Local Mitigation Translocation Programmes: Maintaining Best Practice and Lawful Standards of HGBI recommend the following practices should be adhered to during any translocation programme: a) Where low populations of Common Lizards, Slow-Worms and Grass Snakes are present, the use of refugia up to a density of 50 sheets per hectare is suggested, with trapping undertaken over a period of up to 60 days. b) A full report on the results of the exercise should be made available after completion of the translocation. c) A destructive search is undertaken whereby an area is carefully cleared under the watchful eye of a trained and experienced ecologist, to capture any remaining reptiles on the site Slow Worm Captured animals were translocated to The Commons Local Nature Reserve in Welwyn Garden City, Hertfordshire, Grid Reference TL257108, where there is an existing population of Slow Worms. The current population is considered to be medium in size and has been monitored over a period of 12 years during which annual habitat management for reptiles has been carried out. The site contains 5 hectares of rough grassland interspersed with coppice and fringe habitat with south-facing areas of bramble and grassland. The quality and amount of habitat available is sufficient to support a slight increase in population as a result of the planned translocation. Permission of the landowner was gained prior to the commencement of the translocation. The current programme of monitoring the reptile populations at The Commons will continue to monitor the results of this translocation Grass Snake Grass Snakes are not restricted to rough grassland; they are more mobile, moving through hedgerows and gardens. It is considered therefore that the existing low population of Grass Snakes at Hoggett s End will be able to survive following the development. A strategy to exclude this species from the development area included a programme of sequential habitat removal to render the site unsuitable for reptiles, to encourage the animals to move into the Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 4

6 surrounding habitats. Following the completion of the habitat removal, the grassland will be maintained at a height below 30mm. 3.2 Removal of reptiles from the development area Erection of exclusion fencing Reptile exclusion fencing was installed to published guidelines (Gent, T. and Gibson, S., 1998) by a suitably qualified ecologist along the northern boundary and down part of the eastern boundary of the site as per the drawing included in Appendix C. A 1000 gauge polythene material was buried to a depth of 200mm with an underlay facing away from the capture area to stop any re-entry. The material was set at a slight angle, facing out from the site; it was made taught with no folds so that lizards would not be able to climb up it. The material was attached to wooden stakes with a finished height of 600mm above ground. A destructive search for reptiles was carried out as the fencing was installed. The fence will be maintained throughout the development period, and will only be removed on completion of the development Translocation of Slow Worms Artificial refugia sheets were placed at a density of 100 per ha (twice the recommended quantity) following the installation of the fencing (see Appendix B). The sheets were placed throughout the site with higher densities in areas identified during the Population Estimate Survey as offering suitable habitat for reptiles, and where reptiles had been previously found. The sheets were checked for a period of 30 days in suitable weather conditions (temperatures between 9 C and 18 C) during the period 30 th August to 28 th September 2012, until no animals had been found over five consecutive visits. Suitable temperatures typically occur in the morning between 8a.m. and 11a.m. and in the afternoon between 4p.m. and 6p.m., depending on weather conditions. The translocation work was carried out in a timescale that avoided moving animals that were preparing to hibernate. Captured animals were handled carefully by an experienced ecologist, transferred to a holding container and then released into the receptor site within an hour, close to reptile hibernacula Habitat Removal As rates of captures began to decline, areas of reptile habitat were carefully reduced by sequential strimming, taking care that layers were removed over several days, thereby gradually reducing the suitability of the habitat for reptiles. The refugia sheets were concentrated within smaller areas; this increased trapping success. Habitat removal continued until no Slow Worms were seen or caught and trapping ceased once five suitable days had elapsed with no captures. This strategy ensured that as the habitat was removed, Grass Snakes would be forced off the site into the surrounding hedgerows. All habitats were then completely removed under the supervision of an experienced ecologist to ensure that no reptiles remained or were harmed during the removal of turf and top soil. Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 5

7 3.2.4 Recording throughout the translocation programme and monitoring The results of the capture programme were recorded (see section 4.0). The current programme of reptile monitoring at The Commons Local Nature Reserve will continue and the results will be made available. 3.3 Limitations and constraints The close proximity of the site to residential areas was considered as a potential limitation due to possible disturbance by human activity (dog walking and movement of refugia). However, it is considered that these factors did not have a significant negative impact on the outcome of the translocation work. Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 6

8 4.0 Results The results of the translocation work are shown in the table below. Date Species Notes Sixty additional artificial refugia were placed over the site. Natural refugia and sheets left from the previous surveys were checked. Zero Slow Worm 1 sub-adult under sheet Zero Zero Slow Worm 1 Adult male under sheet Slow Worm 1Adult female under sheet Zero Slow Worm 1 Adult female under sheet Zero Zero Zero Zero Zero Destructive search carried out Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 7

9 5.0 Conclusions and Recommendations The removal of habitats under the supervision of an experienced ecologist has ensured that no reptiles remained on the development site or were harmed during the removal of turf and/or top soil. It is considered that the translocation of Slow Worms to a suitable receptor site and the removal of Grass Snakes from the development site should be successful. It was recommended in Maydencroft Land Advisory s July 2012 report that a mature dying Oak tree should be soft felled. However, since this report was written this tree has blown down and no longer requires attention. 5.1 Building Control Measures The following controls should be applied on site at the start of the development: All site personnel should be given a talk to inform them of the legal protection afforded to reptiles and what to do in the unlikely event that an animal avoided capture during the pre-development translocation process. Should a reptile be found in the development area, a suitably qualified herpetologist will be contacted to remove the reptile to safety (for Slow Worms this will involve translocation to the identified receptor site, for Grass Snakes this will involve moving the animal beyond the exclusion fencing). If development does not take place within two years of the surveys recorded here, the data presented within this report will be considered out of date and further surveys and assessment of the habitat and reptile status will need to be carried out. Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 8

10 Ecological survey data Please note that all ecological data collected during the surveys will be supplied to Hertfordshire Biological Records Centre for entry into the county database. Disclaimer Every effort has been made to ensure that the content of this report accurately identifies and considers the potential ecological constraints to development, its overall ecological value, and the possibility of the presence or absence of all Protected Species and the need for further surveys or ecological works. External factors such as weather conditions, time of day, seasons, disturbance by others, can all affect the use of the site by such species, and this report should therefore not be viewed as definitive. The report has been prepared for the exclusive use of the commissioning party only, unless agreed in writing by the author. No other party may use, make use of, or rely on the contents of this report. Maydencroft Rural Limited accepts no duty or responsibility, including negligence, to any other party and disclaims all liability of any nature whatsoever to any such party in respect to this report. Copyright The copyright of this report, its text, images and intellectual content remain the sole ownership of Maydencroft Rural Limited. The report should be used for its original agreed use only and it is specifically prohibited to transmit the report to any third party, by paper or any electronic means, unless agreed to in writing by Maydencroft Rural Limited. 1 st October 2012 Reptile Translocation Report, Hoggett s End, Bishop s Stortford, Hertfordshire 9

11 Appendix A. Grange Builders Proposed Site Development, March 2012 Hoggett s End N

12 Hoggett s End Eastern Meadow Appendix B. Reptile Refugia postions Hoggett s End N Aerial photograph reproduced under Licence from Google Earth Pro

13 Hoggett s End Reptile exclusion fencing to be installed prior to any Slow Worm translocation. Eastern Meadow Appendix C. Reptile Exclusion Fencing Installation Hoggett s End N Aerial photograph reproduced under Licence from Google Earth Pro

14 Appendix D. References Clark, Michael (2001), Mammals, Amphibians and Reptiles of Hertfordshire. English Nature (2001), Great Crested Newt Mitigation Guidelines. English Nature (2004), Reptiles: Guidelines for Developers. English Nature (1998), Species Conservation Handbook: Translocation of Slow-Worms. Froglife, Herpetofauna Groups of Britain and Ireland (1998), Evaluating Local Mitigation/Translocation Programmes: Maintaining Best Practice and Lawful Standards. Froglife (1999), Reptile Survey: An Introduction to Planning, Conducting and Interpreting Surveys for Snake and Lizard Conservation. Gent, T. & Howarth, W. (1998), Amphibians & Reptiles & the Law, Herpetofauna Workers Manual. Natural England (2004), Standing Advice Species Sheet: Reptiles, Legislation The Conservation of Habitats and Species Regulations The Countryside and Rights of Way Act Government Circular 06/2005, Biodiversity and Geological Conservation. The Natural Environment and Rural Communities Act (NERC) Planning Policy Statement 9 (PPS9) The Protection of Badgers Act The Wildlife and Countryside Act 1981 (as amended).