Amphibian and reptile enhancement biodiversity specification
A hibernaculum is an underground structure used by amphibians and reptiles during the winter to protect themselves from cold temperatures.
A hibernaculum should be situated in a location among suitable habitat, which will not be disturbed and is not prone to flooding. Suitable habitat is considered to be rough or tussocky grassland, hedgerows or scrub and bracken. The best sites for hibernacula get both sun and shade.
Hibernacula for amphibians should be situated in the shade within 250m of a pond. Hibernacula for reptiles should be situated in a sunny, open area.
Site should be clear, or cleared under any required precautions/precautionary working method statements as per planning conditions.
- The hibernaculum should be at least 1.5 - 2m2 in size.
- Some hibernacula can be constructed on ground if a risk of flooding exists, whilst most construction methods involve digging to create the subterranean aspect of the hibernaculum.
- Materials used can be a combination of brash, logs, rubble and composting materials with plenty of gaps in between. The site/hole should be filled with the materials, with rubble placed at the bottom (maximum 20% of total material).
- Subterranean hibernacula generally include entrance tubes at ground level. Areas of exposed material can also be left to allow access.
- Soil, turf or suitable vegetation should then be put on top of the hibernaculum to encourage invertebrates, pollinator-friendly plant species and provide shade.
To maintain the hibernaculum, it should not be moved. Trimming or cutting of vegetation may be required, on a rotational basis when amphibians and reptiles are less likely to be using the hibernaculum (usually during dry weather between April and September, with vegetation cut to 150mm at most). Management of vegetation near to the hibernaculum should be undertaken using hand tools.
Egg laying heaps enable the incubation of grass snake eggs, by retaining heat and moisture from decomposing material. Egg laying heaps can also provide shelter and overwintering habitat for amphibians and slow-worms.
Egg laying heaps should be located in a sunny or partially sunny area, away from busy roads and ideally no further than 400m from a water body. Female grass snakes will use a successful heap for several years so the heap should remain in the same location when maintaining or refreshing it.
Site should be clear, or cleared under any required precautions/precautionary working method statements as per planning conditions.
- The egg laying pile should be at least 1m2 in size.
- Materials used should be fresh manure, sticks or brash, sawdust and vegetation (leaves or clippings) or compost. The heap should not be too compacted to ensure access to reptiles and to prevent it from overheating.
- To maintain, fresh vegetation, clippings or manure should be added once every two years in April, May or October
- Management of nearby vegetation including trees, shrubs and hedges may be required to ensure that the heap receives adequate sunlight.
- The pile should not be disturbed outside of April, May or October as reptiles may be in hibernation.
Habitat piles provide refuge from predators and weather and also provides valuable invertebrate habitat. Habitat piles can be dry or moist dead wood piles. Dry dead wood piles can attract invertebrates and act as insect hotels. Moist dead wood piles decay and accommodate fungi and lots of invertebrate species which thrive on decaying wood.
A habitat pile should be situated in a location among suitable habitat, which will not be disturbed and is not prone to flooding. Some habitat piles can be placed in shady areas which may attract different wildlife than piles which are placed in sunny areas.
Site should be clear, or cleared under any required precautions/precautionary working method statements as per planning conditions.
Habitat piles for amphibians should be situated in the shade within 250m of a pond. Habitat piles for reptiles should be situated in a sunny, open area.
- Dry dead wood piles can be constructed using dry wood, brash, straw and dead leaves. Heavier materials should be placed at the bottom of the pile, with other materials loosely placed on the outer edges to allow for crevices and access.
- Moist dead wood piles are constructed in a similar way to dry dead wood piles, but situated in damper areas which are more sheltered from sunlight. Moist habitat piles tend to attract a different assemblage of invertebrates and fungi.
- To maintain, the pile should remain in the same place with materials added every 1 – 2 years as necessary.
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Links to amphibian and reptile ID guides: https://www.arc-trust.org
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Information on legal protections: reptiles protected under the Wildlife and Countryside Act 1981 (as amended) and GCN are protected under the Conservation of Habitats and Species Regulations 2017 (as amended).
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Some amphibian and reptile species are species of Principal Importance under the Natural Environment and Rural Communities (NERC) Act 2006.
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Further resources: https://www.arc-trust.org/habitat-management-handbooks