Great crested newts: surveys and mitigation for development projects

Standing advice for local planning authorities who need to assess the impacts of development on great crested newts.

Survey reports and mitigation plans are required for development projects that could affect protected species, as part of getting planning permission or a mitigation licence. Surveys need to show whether protected species are present in the area or nearby, and how they use the site. Mitigation plans show how you’ll avoid, reduce or manage any negative effects to protected species.

This is Natural England’s species standing advice for local planning authorities who need to assess planning applications that affect great crested newts.

This information should be used to decide what is needed for surveys and planning mitigation measures for great crested newts.

Ecologists need to decide which survey and mitigation methods are right for the project they’re working on. If this standing advice isn’t followed, they’ll have to include a statement with the planning application explaining why.

Where this guide says ‘you’ it means the ecologist.

Get more detail on:

Decide if you need to survey

Survey for great crested newts if:

  • distribution and historical records suggest newts may be present
  • there’s a pond within 500 metres of the development, even if it only holds water some of the year
  • the development site includes refuges (eg log piles or rubble), grassland, scrub, woodland or hedgerows

Great crested newts may be present even if:

  • the site has been ploughed, soil stripped or had ponds filled in within the last 4 years
  • the breeding pond was destroyed several years ago
  • the pond is muddy, heavily shaded or vegetated
  • the pond contains fish
  • the pond is temporary

You may be able to exclude areas from the survey if:

  • the newts are highly unlikely to be present, eg because the habitat is unsuitable or records show no newts nearby
  • the planned activity or development wouldn’t affect the newt population, eg because the newts are separated from harmful activities by a barrier the newts can’t cross

Habitat suitability index

Use the habitat suitability index (HSI) to calculate habitat quality and likelihood of great crested newt presence. HSI is not a replacement for detailed survey and cannot confirm presence or absence.

Survey effort required

You’ll need to decide exactly how many survey visits to make according to the survey objective and local conditions.

You may be asked for more surveys if your planning application is based on poor data, unless you can show the area is of low importance to newts.

For presence/absence surveys, you only need to complete the full recommended number of visits if you don’t find evidence of newts during early visits.

When to survey

The times in the following table are based on typical newt activity in central England lowland. Adjust your survey timings according to your location and local weather conditions.

Survey method Best time to survey
Environmental DNA mid-April to late June
Egg search April to June
Pitfall traps March, April, May and September
Refuge search April to September
Bottle or funnel traps March to May
Netting mid-March to mid-June (August to find larvae)
Torch survey mid-March to mid-June (August to find larvae)

You’re unlikely to detect any eggs or larvae between November and January.

Survey methods

Acceptable methods for surveying great crested newts are:

  • environmental DNA (eDNA)
  • bottle or funnel trapping
  • egg search
  • torch survey – this isn’t recommended for turbid ponds
  • netting – this should only be used in addition to other methods and not to indicate population size
  • pitfall traps
  • refuge search – it’s best not to rely on this technique alone

Presence/absence surveys of ponds

You should:

  • use 3 methods per visit (preferably torch survey, bottle trapping and egg searching)
  • visit between mid-March and mid-June with at least 2 visits in peak season (usually mid-April to mid-May)
  • visit the site 4 times if you can’t establish presence on the first visit

You can:

  • stop surveying if you detect the presence of great crested newts before the 4th visit
  • assume great crested newts are absent if there’s no evidence of them after 4 visits

Presence surveys on land

You should:

  • use pitfall trapping with drift fencing (and refuges if possible)
  • trap on at least 60 nights in suitable weather conditions (above 5°C, no high winds or heavy rain)
  • visit between March and October

This method is less reliable than a pond survey and shouldn’t be used to establish the absence of great crested newts.

Population size class assessments in ponds

You should:

  • use torch surveys and bottle trapping on each visit
  • make at least 6 visits (if you found newts during the first 4 presence/absence visits)
  • visit between mid-March and mid-June with at least 3 visits in peak season (usually mid-April to mid-May)

Survey adult newts in spring to estimate whether the population is small, medium or large.

You can combine results from multiple ponds if the newts regularly move between them, but only for counts you got on the same visit.

Provide the following results:

  • maximum adult count per pond per night
  • peak counts per pond overall
  • total site count

Then class populations as:

  • small – maximum counts up to 10
  • medium – maximum counts between 11 and 100
  • large – maximum counts over 100

Environmental DNA surveys

You can use eDNA surveys to find out if newts are present and whether to conduct population size class surveys on ponds and other waterbodies.

Make one visit in the daytime, during the period when the newts are likely to be present (this depends on location and conditions like the weather). Natural England will only accept eDNA survey results from samples collected between 15 April and 30 June each year. Follow the methods in the technical report that accompanies Defra’s research project into eDNA, and use quantitative polymerase chain reaction testing.

Provide evidence with your planning application and licence application that:

  • a licensed great crested newt surveyor collected the eDNA sample
  • a suitably equipped laboratory undertook the laboratory work in strict adherence to the methods in the technical report above
  • shows all ponds on maps, including those ponds that were sampled for eDNA

Include the following as a separate document with your licence application:

  • which waterbodies you tested
  • the dates when you took the water samples
  • a table showing the results
  • a declaration that you’ve followed the methods in the technical report

Keep the records from the survey for at least 12 months after the first licence return.

Influences on survey results

Mention and explain the implications in both your ecological survey and your licence application if any of these factors affect your survey counts:

  • weather
  • water turbidity
  • density of aquatic vegetation
  • disturbance
  • torch power
  • surveyor’s experience
  • position of drift fence or pitfall traps on the site

Assess the impacts

Provide an assessment of the impacts this development will have on great crested newts before, during and after the planned work. Include qualitative and quantitative information with your planning application.

Use these factors to assess the site’s importance, and submit this with your planning application:

  • the number and size of newt populations
  • the nature of the habitats and population, eg whether it includes a breeding site
  • how significant the site is to the local population and the wider status of great crested newts

Before development

Things that can affect great crested newts, eg injure or kill them as well as lead to loss of habitat before development work begins include:

  • site clearance
  • topsoiling
  • regrading and drainage work
  • archaeological excavation (this can also create new waterbodies for the newts to colonise)

During development

Construction work can destroy habitats and kill newts. It can also create temporary habitats, like piles of rubble.

Long-term impacts

Habitat loss or fragmentation is the most common long-term impact of development. Major habitat loss can cause:

  • reduced breeding and recruitment, eg fewer young, maturing and adults joining the breeding population leading to fewer breeding adults.
  • fewer foraging opportunities
  • fewer refuges, leading to exposure to predators or harsh conditions
  • unsuccessful hibernation
  • population fragmentation

Other long-term impacts include:

  • changing habitats, eg by tidying up semi-natural habitats for recreational or aesthetic reasons
  • habitat fragmentation and isolation, eg creating physical barriers that newts can’t cross
  • the effects of introducing fish to breeding ponds, or invasive plants like Crassula helmsii
  • the effects of more people using the area, eg to dump rubbish
  • changes to the water table
  • increased siltation
  • increased shading
  • increased chemical run-off
  • less prey

You will need mitigation measures to reduce the negative effects.

Scale of impacts

Use the following tables to assess the scale of impacts on the newt populations. Mitigation measures are needed even for low impacts.

Effect on breeding ponds Impact
Destruction High
Isolation caused by fragmentation High
Partial destruction or modification Medium
Temporary disturbance Low
Post-development interference High
Effect on other ponds newts use Impact
Destruction Medium
Isolation caused by fragmentation Medium
Partial destruction or modification Low
Temporary disturbance Low
Post-development interference Low
Effect on terrestrial habitat less than 50 metres from breeding pond Impact
Destruction High
Isolation caused by fragmentation High
Partial destruction Medium
Modified management, resurfacing etc Medium
Temporary disturbance Low
Post-development interference Medium
Temporary destruction and reinstatement Low
Effect on terrestrial habitat 50 to 250 metres from breeding pond Impact
Destruction Medium
Isolation caused by fragmentation Medium
Partial destruction Low
Modified management, resurfacing etc Low
Temporary disturbance Low
Post-development interference Low
Temporary destruction and reinstatement Low
Effect on terrestrial habitat more than 250 metres from breeding pond Impact
Destruction Low
Isolation caused by fragmentation Low
Partial destruction Low
Modified management, resurfacing etc Low
Temporary disturbance Low
Post-development interference Low
Temporary destruction and reinstatement Low

Mitigation and compensation methods

Assess how the development will affect newt populations in neighbouring plots even if they’re owned by someone else. This might involve additional surveys. You’ll need to submit a masterplan if the neighbouring plots have been or are likely to be developed. Find out more about masterplans and other requirements for mitigation licence applications.

Address the potential impacts you’ve identified on great crested newts by creating mitigation plans.

First, aim to avoid negative effects, eg by redesigning the scheme. If this isn’t possible, mitigate and compensate by:

  • excluding and relocating the newts on a small scale
  • creating, restoring or improving habitats on the site or next to it

If you predict a major, unavoidable impact on the newts, translocate (capture and move) them away from the site less than 1 km away to an area with the same or better habitats. You’ll need to compensate for destroyed habitat as well.

Follow the approaches in this guide for your chosen mitigation or compensation methods. Justify in your planning application if you need to use different techniques or levels of effort for the site.

Roads and other hard surfaces

Include with your planning or licence application an assessment of impacts caused by hard surfaces such as:

  • roads
  • car parks
  • buildings

Avoid habitat fragmentation, for example by:

  • creating corridors or ‘stepping stones’ of habitat to join up populations
  • altering road routes
  • installing ‘green bridges’ or underpasses
  • creating new breeding and terrestrial habitats on one side of the road

Design new habitats to avoid trapping newts, for example by:

  • using sloping kerbs either side of gully pots
  • creating draining schemes without sumps
  • not using kerbs

Position mitigation ponds away from busy roads – use permanent amphibian fencing if that’s not possible.

Only use tunnels or culverts to help the newts reach habitat across a road if:

  • there’s no alternative way to maintain dispersal routes
  • there’s a fencing system to channel the newts in – this will need regular maintenance
  • you monitor the tunnel’s effectiveness

Capture and release methods

Follow these methods if your mitigation plans include capturing newts to reduce the chances of them being killed, disturbed or injured.

Capture newts in the active season (between February and October). Capture methods include:

  • using ring fencing and pitfall traps to catch newts as they move to a breeding pond in spring (but not every adult will migrate every year, so plan accordingly)
  • hand searching, including dismantling refuges
  • destructive searching (carefully stripping areas likely to have newts), but not in winter and only if you’ve tried all other methods
  • netting, bottle trapping or draining ponds

Release the newts in a sheltered area close to a suitable refuge or in a pond. Release the newts at night if possible, and don’t keep them in captivity longer than necessary. Exclude the newts from re-entering the area using fencing.

Pitfall trapping as part of compensation

Use this method to capture newts if there’s a genuine need to, for example if it’s not possible to survey the pond. Only use pitfall trapping when weather conditions allow it, never when there’s likely to be a frost.

Fencing as part of mitigation or compensation

You can use the following types of temporary fencing:

  • drift fencing to guide great crested newts into pitfall traps
  • exclusion fencing to prevent newts from entering an area

Only use one-way fencing as a precaution alongside other capture methods. You can use permanent amphibian fencing if you need to exclude newts from the area in the long term.

Restore or create aquatic habitats as compensation

You can restore ponds for mitigation if:

  • the development will only have small impacts on the newts
  • there’s an opportunity to improve a low quality pond to support great crested newts

Before restoring a pond check the plants and other animals it supports.

Otherwise create new ponds rather than restoring existing ones.

Restored or created ponds should be:

  • positioned to avoid human or animal disturbance and agricultural run-off
  • able to hold water throughout at least one summer in every 3 years

Restored or created ponds should also have:

  • a surface area between 100 and 800 square metres and be between 1 and 2 metres deep
  • substantial cover of submerged and marginal vegetation
  • open areas of waters and be clustered with other ponds
  • populations of invertebrates and other amphibians for prey
  • no fish and very few or no waterfowl
  • shallow sloping sides and not be shaded on the south side

You can also use wide ditches to support newt populations.

You’ll need to create 2 ponds for every breeding pond lost.

Creating several smaller ponds is often better than one very large pond. New ponds should be within 250 metres of each other with no barriers the newts can’t cross, like roads. Position new ponds within 250 metres of existing ponds.

Don’t damage other rare or protected species when creating or managing ponds.

Restore or create terrestrial habitats as compensation

Include the area up to 500 metres around a mitigation pond when creating terrestrial habitat. This includes:

  • scrub
  • woodland
  • hedgerows
  • banks and ditches
  • leaf litter
  • rough grassland
  • bare ground with fissures
  • disturbed ground
  • pasture

Don’t rely on private gardens as compensation for terrestrial habitat lost through development.

Receptor sites as compensation

Survey the receptor site to make sure it doesn’t currently support great crested newts. This doesn’t apply if:

  • the newts are moved or excluded within the same site
  • you’re moving 20 adults (plus associated immature stages) or fewer

You can introduce part populations to an existing population, but only if the habitat will be made suitable for the increased numbers.

The receptor site should:

  • be as close to the donor site as possible
  • include (or be capable of including) the same types and mix of habitats that will be lost
  • be at least the same size as the habitat due to be lost – if it’s smaller it should have better quality habitats
  • be selected based on good land survey data from the site assessment and characteristics like connectivity and quality
  • not be in a site of special scientific interest (SSSI) unless there’s no other suitable habitat nearby
  • have no or limited public access – if there’s a strong case for public access, you’ll need to address the interference this could cause
  • not be enclosed by permanent fencing (use exclosures to prevent newts accessing hazardous areas)
  • allow for ongoing habitat management, maintenance and monitoring after the development

Create refuges as compensation

You can create hibernation and refuge sites for great crested newts, including:

  • large piles of rubble
  • rock
  • log piles
  • earth banks with plenty of mammal burrows and ground fissures

You can also design new hibernacula (hibernation shelters). These should:

  • be at least 2 metres long, 1 metre wide and 1 metre high
  • be surrounded by rough vegetation
  • have exposed edges for access
  • be capped with topsoil, ideally covered with turf
  • be filled with inert, clean hardcore, brick rubble, logs, sleepers or similar materials plus loose topsoil
  • be above the floodline

Position hibernation and refuge sites:

  • so that some are close to the breeding pond, and some further away
  • in sheltered areas that are not too dry, or prone to flooding or freezing in winter

Discovering newts after development has started

Stop all work that’s likely to affect great crested newts and break the law if great crested newts are found after development has started.

If great crested newts have previously been surveyed and identified as a constraint, contact your ecologist to discuss whether you’ll need mitigation or additional licences.

Delays in development work

If development work is delayed after you’ve put up amphibian fencing, leave them in place until work can continue. Fencing needs to be maintained to keep newts outside. You’ll need extra trapping if vegetation grows over the fence, or holes appear in it.

Make sure great crested newts are fenced into small areas for as short a time as possible. You may need to to remove fencing if the delays are likely to be for some months.

You might need to change the mitigation plan and ask for a licence variation from Natural England. You can only get a licence for up to 2 years in an enclosed receptor site.

Management and site maintenance after development

Your post-development management plans should include:

  • managing the aquatic vegetation in ponds
  • clearing trees or scrub around ponds
  • desilting and clearing fallen leaves
  • mowing, cutting or grazing grassland
  • managing woodland and scrub

The local planning authority will need to agree maintenance plans with the developer and the landowner.

Problems you may need to deal with when setting up maintenance agreements include:

  • introduced fish
  • leaking ponds
  • dumped rubbish
  • fires, major pollution or similar damage
  • damaged fences
  • silted or blocked tunnels
  • damaged interpretation boards

Set out the timings and responsibilities in your management and maintenance plan.

The plan should be in place for at least 4 years after the development. For schemes that have a big impact on newts, management and maintenance may need to go on indefinitely.

Population monitoring

Unless the scheme is very small, put a monitoring plan in place to assess the great crested newt population after mitigation.

Use the same counting methods you used before the development so you can compare population trends.

Here’s a guide to minimum requirements for monitoring.

Population size/site importance Low impact monitoring requirements Medium impact monitoring requirements High impact monitoring requirements
Small/low No monitoring required Presence/absence – 2 years Presence/absence – 4 years
Medium No monitoring required Population size class – 4 years Population size class – 6 years
High Population size class – 2 years Population size class – 6 years Population size class – 10 years

The monitoring plan should state:

  • who is responsible for monitoring
  • when monitoring will happen
  • what methods will be used

Additional information if you need a mitigation licence

The following guidance is for ecologists and developers who might want to apply for mitigation licence where they can’t avoid harming great crested newts and their habitat. The above standing advice should be followed together with the additional licensing guidance below, otherwise your licence application may be refused. If you need planning permission, you must get it before you apply for a licence.

You can apply for a mitigation licence. You’ll need expert help from an ecologist:

Fencing as part of mitigation or compensation

Slope the fencing at an angle between 40 and 45 degrees to allow newts to climb into the receptor area but not escape.

When installing temporary fencing:

  • use an amphibian worker and a fencing contractor to instruct or supervise the work
  • search and clear the fence line of newts first – carefully cut back vegetation if necessary
  • use a membrane that won’t break down or become brittle, eg 1000 gauge transparent polythene sheeting, woven polypropylene or black polythene DPC
  • make the membrane as taut as possible so there are no creases or folds
  • make sure there’s a suitable underlap so the newts can’t pass underneath, and an overhang so they can’t climb over it
  • place the backfill turf downwards in the trench and compact it so the newts won’t use it for shelter
  • secure the fence to supporting posts with pads and nails or staples, not battens
  • position fence posts outside the receptor area fence (and for drift fencing, on the side least likely to encounter newts)
  • curl-join any joins in the membrane and secure them to a post with pads and nails – do this underground as well
  • avoid gaps the newts could pass through
  • use a stile if the fence crosses a footpath

Protect the area with security fencing in areas open to the public.

If you need to allow farm access through a fence, keep the gap as small as possible and turn back each end of the barrier 45 degrees to the fence. This deflects the newts away from the gap.

Exclusion fencing may need ongoing maintenance to make sure it’s still working. The licence holder should keep a record of inspections and repair work to fences.

When you take down the fencing, remove backfill carefully by hand if newts could be sheltering in it.

Pitfall trapping as part of compensation

Install more traps in areas where there are likely to be more newts, for example around breeding ponds and rough grassland. Include areas of short grass or bare ground in the fencing layout, especially close to breeding ponds.

When installing pitfall traps:

  • fit the traps flush to the barrier fence with their tops just below ground level – check they’re still in the right place especially after heavy rain
  • space the traps between 5 and 10 metres apart – but you can use a higher density near breeding ponds, rubble piles and other areas newts are likely to be
  • don’t use plastic buckets that have a lip – but you can use plastic tape to create a small overhang and stop the newts escaping

You can place refuges (eg carpet tiles) along the fence line, to increase the chances of capture.

When searching traps and moving the newts:

  • open the traps every day before 11am unless the weather indicates capture rates would be low or zero
  • record the location, species, sex and life stage of all newts captured
  • use a suitable container to release the newts in the receptor area as soon as possible

Breeding ponds

You should ring-fence breeding ponds for at least one spring migration. Put pitfall traps on both sides of the fence. Capture adult and immature newts away from the pond, even during the breeding season.

Trap from February to November, depending on local weather conditions, or until the data shows the site has been trapped successfully. To capture a significant proportion of the population, you’ll need to:

  • trap around a breeding pond for at least 3 years, along with extra trapping away from the pond
  • put considerable extra effort into trapping for one year, eg trapping over several months due to weather conditions changing from damp to cold

Terrestrial habitats

Use drift fencing and pitfall trapping for terrestrial habitats. Fence off the development area. You can use one-way fencing at the perimeter if the receptor and donor sites are next to each other.

It’s better to divide the area into compartments with drift fencing rather than using fence lines or crosses, especially for large sites.

This table shows the survey effort required – use the population size estimate from your surveys.

Population size estimate Minimum traps per hectare Minimum number of trapping nights
Small 50 30
Medium 80 60
Large 100 90

Trap on nights when:

  • the night-time air temperature is above 5°C
  • the ground is damp, eg if it’s raining or has rained in the last few days

Trap for longer than the minimum nights shown in the table if you’re still capturing newts at the end of the minimum period. It’s usually safe to stop trapping if you make no captures after 5 trapping nights.

Use other capture methods as well as pitfall trapping.

Hand searching and night searching on land

You can use hand searching and night searching as additional techniques alongside others.

Ponds: capture methods

Start with pitfall trapping and use a combination of other capture methods for ponds.

Netting works best in small ponds or those with hard substrates and little vegetation.

When using bottle trapping:

  • set one trap for every 2 metres of shoreline
  • trap over 90 nights of suitable weather conditions
  • trap between mid-February and mid-June to remove breeding adults
  • remove vegetation that supports eggs

When draining a pond to catch the remaining newts:

  • use screens with a mesh smaller than 1.5 millimeters fitted to pumps
  • catch newts by netting as the water drains away, and hand search through plants, debris and silt when it’s drained
  • use ring fencing with pitfall traps around the pond if draining overnight

You can dig a narrow trench connected to the pond rather than draining directly from the pond, or drain the water into a nearby ditch to avoid using pumps.

Create new ponds as part of compensation

Create new ponds at least 6 months before moving the newts if:

  • all the conditions are favourable
  • the donor population is a “small population size class”

Create new ponds at least one year before moving the newts for medium population size classes and 2 years for large population size classes.

You can transfer water and vegetation from ponds that will be destroyed on the development site. Don’t introduce artificial egg laying substrates.

On ground that drains easily, you can position refuges in an excavated dip.

You can also provide smaller refuges for daytime shelter. Make sure these are secure if the site will be used by the public, eg use fencing to restrict access.

It’s not acceptable to create a few hibernacula or daytime refuges as compensation for losing large areas of good quality terrestrial habitat.

Releasing land for development

When the capture programme has finished, remove fencing and pitfall traps carefully and capture any remaining newts in gaps or traps.

Only fill in great crested newt ponds when:

  • the capture records show there’s been a reasonable effort to trap the newts
  • you’ve moved aquatic and marginal vegetation to receptor ponds
  • you’ve extracted any pond water you’re going to put into new ponds
  • you’ve searched the pond bed and surroundings for any remaining newts

You can release land for development if the work won’t affect great crested newt habitats, for example by:

  • interfering with migration or ongoing mitigation
  • causing changes to the water level of breeding ponds
  • storing spoil or stockpiles close to amphibian fencing
  • the area has been trapped and great crested newts removed

Population monitoring

Include the qualitative checks you make in your monitoring report, for example presence of late-stage larvae.

Send the results to Natural England with your licence returns.

For more information please see:

Photo Credit: Chris H / Flickr

Ecology Jobs News, Protected Species

Leave a Reply