What do bat surveys involve ?

By May, the bat survey season is well and truly underway and at NWS surveys are taking place almost every day of the week.

Initial surveys are undertaken to look for evidence of bats and if found then typicaly three nocturnal surveys (dawn and dusk) may be required during the main survey season, i.e. May to September.

During a dusk survey, surveyors watch the building from 15 minutes before dusk and 2 hours after dusk to watch for any bats emerging from the building. A bat detector and a recording device are used to record any bat calls which are then analysed to confirm the sightings and to identify species. Target notes are also recorded on a map so any points of entry can be identified.

During a dawn survey, surveyors watch the building for the 2 hours before dawn (which means a very early start!). The same method is used as in a dusk survey but the surveyors are mainly watching for bats to return to roost.

These surveys can be really interesting and exciting if there is lots of activity at the site but they can also be a bit boring if there isn’t much going on (you are essentially staring at a building for 2 hours…. potentially at 2.30am!). It can be worth getting up super early though if you get a close encounter with a bat like at a recent site where Brown Long-eared bats were roosting just above our heads in a barn.

Brown long-eared bat

Brown long-eared bat

Mitigating for great crested newts

Since starting great crested newt surveys in mid-March 2015, about 20% of the 75 ponds surveyed across Norfolk contained newts. For these sites, their development may now require a “European Protected Species Mitigation” ( EPSM ) licence, granted by Natural England after planning permission is given.

Lemonade and great crested newts

Bottle Trap

Bottle trap used in great crested newt surveys

We devise the mitigation strategy for clients based on where and how many newts are present.

To estimate numbers, we make six nocturnal counts via netting, with “bottle traps” (1.5 litre lemonade bottles) and spotlights. This indication of population size is used to devise a proportional strategy, ensuring that your development does not adversely affect newt populations.

Compensatory habitat

The EPSM licence needs to provide “compensatory habitat” at least equal in extent to that lost by development.  Newt habitats include scrub, grassland and woodland, but also often brown field areas, especially near old gravel or brick pits.  Ideas to think about when designing “compensatory habitat” are:

  • Restoring existing ponds to make them more suitable for great crested newts by clearing out shading scrub or desilting.
  • Creating brand new ponds: often also an attractive landscape feature (but no fish please and balancing lagoons aren’t suitable!)
  • Making wildflower meadows: good foraging habitat for newts plus an attractive feature managed well;
  • Planting woodland belts and hedgerows makes excellent shaded habitat for newts with leaf litter and logs, plus good for site landscaping, and corridors for newts to travel along to safely get from one area to another.

The bucket stage

If work cannot avoid impacting great crested newts, the development will need fencing off and trapping out with “pitfall traps” (buckets) to capture them and move them to safety.   Trapping normally takes place in autumn or early spring as it requires both suitably wet weather, but reasonable temperatures for the newt activity.

The number of nights trapping depends on the population, varying between 30 and 90 nights with additional needs where breeding ponds are removed.  If the fencing fails during building, then retrapping may be required, so investment in a decent spec fence is worth some thought. Generally you will need to keep the perimeter up from start to finish.

To create the compensatory habitat for a site near Dereham, we cleared ornamental shrubs and seeded the bare banks with wetland wildflowers around an existing pond, creating excellent refuges and invertebrates to hunt. Enclaves of wildflowers and trees were connected via thick hedgerows running around the boundary of the development, linking to hedges and ponds in the landscape.  Post development, the 2015 recount of newts showed numbers of breeding newts have remained consistent at 85, and that the mitigation had been successful.

Creating a bespoke boudoir for bats

As part of the re-development of a small brownfield site within Norwich, NWS were commissioned by RGW Portugal Ltd to undertake bat surveys of two small buildings. One of these was found to support low numbers of brown long-eared bats Plecotus auritus and soprano pipistrelles Pipistrellus pygmaeus, which were using the building for roosting in summer. The buildings needed to be demolished in order to create space for two new residential homes, and so NWS prepared a European Protected Species Mitigation licence for bats which was granted by Natural England.

Brown long-eared bat captured during demolition work

Brown long-eared bat captured during demolition work

NWS licensed ecologists supervised the demolition of the buildings in August, removing a roosting brown long-eared bat which was found along the central ridge beam and relocating this within a bat box which had been placed on a mature oak tree in adjacent woodland.

RGW Portugal Ltd were keen for an environmentally sensitive development and had included bike stores within the design to encourage the use of green transport. These features provided the perfect opportunity to create a bespoke bat loft for both species of bats to use. The loft was constructed above the bike stores, using a lined and tiled pitched roof to generate warm internal temperatures. Two carefully-placed bat access points were installed along the ridge and at both gable ends, allowing a number of entry points whilst reducing potential for light ingress and draughts. The ridge beam was formed using rough-sawn timber to create a suitable surface for bats to cling to, and bat batons were also installed along the inner walls to provide additional perching points.

The last features of the bat loft have just been installed this winter and NWS are hopeful to see use of this loft by bats when they return to roost in April.


Getting stuck in the mud at Cley

With support from members, business and the Heritage Lottery Fund, Norfolk Wildlife Trust acquired 60 hectares of land at NWT Cley Marshes in 2014. Norfolk Wildlife Services carried out baseline studies of the plants and invertebrates with particular focus on the impacts of the January 2014 flooding on the site’s ecology.

We decided to get stuck into the project (literally) to survey the saline lagoons and freshwater dykes across the site for aquatic plants such as Phragmites australis, and aquatic invertebrates such as the water boatman Arctocorisa garmari.  Initial results showed that an increased proportion of the open water on the site was unsurprisingly either brackish or saline. The effect on invertebrate species was evident during surveying as several groups were under-represented such as dragonflies.

In early summer 2015, we will survey the terrestrial invertebrates when they are most active. Some of the terrestrial invertebrates sought for include the Red Data Book ground beetle Pogonus luridipennis, or more commonly found cross spider Araneus diadematus.  Invertebrates like these are key indicators of the habitat quality and conditions present.

NWS will be running a workshop in September next year, looking at how the invertebrate population at Cley supports birds such as bittern, avocet and godwit. Check our website for more details on this “Bittern’s Breakfast and Avocets Lunch” event.

New winter homes for great crested newts

Since 2000, NWS has worked on development sites that support great crested newts, and in 2014 successfully assisted Saffron Housing in obtaining a European Protected Species Mitigation (EPSM) licence for this species on a residential development in South Norfolk. Nationally great crested newts have suffered huge declines and so are protected by European and UK law. Norfolk is one of the species’ strongholds, with greatest numbers of breeding ponds found on heavy clay soils.

With great crested newts present in ponds around the area and using the grassland on site to move between these, the EPSM licence was required during construction to protect these amphibians and provide compensatory habitat.

NWS staff supervised the installation of “newt exclusion fencing” and carried out pitfall trapping to remove newts from harm’s way. Great crested newts only use ponds for breeding and spend the rest of the year on land. The team focussed the compensatory habitat on features suitable for use during this “terrestrial phase” and supervised the creation of what was dubbed “Newt Nirvana” by the developer:  a wildflower grassland with hedgerows and scrub.

A key feature was the creation of three earth and stone mounds, which newts will use

This hibernacula has a rubble/log base to provide crevices for overwintering newts

This hibernacula has a rubble/log base to provide crevices for overwintering newts and is covered with turf to create stable temperatures through winter

during winter, called hibernacula. Great crested newts hibernate when winter temperatures drop below 5oC, normally from October or November. They typically hibernate underneath logs, within mammal burrow or tree roots, and even in building foundations. The hibernacula on site were designed to provide a number of sheltered crevices using logs and rubble, topped with turf to prevent exposure, whilst also ensuring newts were safe from flooding. Here the newts can remain protected until they emerge in late February or March to begin breeding in ponds.

Great crested newts : surveys and assessment

Why are great crested newt surveys needed?

Great crested newt surveys are needed if they might be impacted by a development.  Normally this means where there are ponds within 250m of a site.

Great crested newt surveys help determine whether newts are present and what the state of the local populations and habitats are.

Great crested newts have suffered serious declines in numbers over the last century. For this reason, they and their habitat are protected both under both national and European law.

This great crested newt was found during pitfall trapping in 2014

Great crested newt found during pitfall trapping

Smooth newt found during bottle trapping

Smooth newt found during pitfall trapping








Where are they found ?

Although they can disperse long distances and are found in a range of places, they are typically within 250m of a suitable pond.

Adult great crested newts are dependant on high quality aquatic habitats in ponds for breeding.  The adults though spend much of their life on land using grassland, woodland, hedgerows. During winter they will hibernate underground and can even spend winter in building foundations.

This pond in South Norfolk was home to 120 great crested newts, 50 smooth newts and a number of frogs and toads

This pond in South Norfolk was home to 120 great crested newts, 50 smooth newts and a number of frogs and toads

The picture on the right shows a pond surveyed in 2014 that a total count of over 120 newts on one night, which is exceptional.




How is a survey carried out?

There are three stages :

1. A walkover to look at whether habitat is suitable

2. Surveys to identify local populations if habitat is suitable

3. Assessing if there is an impact on these populations from the development

Walkover surveys in daytime

The first stage of a great crested newt survey is normally to carry out a daytime assessment of ponds in the vicinity.  This uses a technique called a Habitat Suitability Index (HSI) assessment on any water bodies present.

Habitat Suitability Index (HSI) is a predictive tool which looks at the likelihood that great crested newts are present. It can be undertaken at any time of the year.

Low HSI scores are sometimes sufficient to conclude the likely absence of newts and are helpful in concluding abscence from a site. Where there are good quality ponds and higher scores, further surveys will be needed to say if newts are present.

Great crested newt captured by netting

Great crested newt captured by netting

Surveys for populations

There are two choices for searching for newts, “traditional” nocturnal surveys and the more recent “environmental DNA” technique ( “eDNA” ).

  • For “traditional” nocturnal surveys, these are carried out between mid-March and mid-June.
  • For eDNA surveys, these are carried out upto the end of June.

“Traditional” nocturnal surveys

Since great crested newts are nocturnal and difficult to find on land, surveys take place at night between mid-March to mid-June when they gather in ponds to breed.

Four visits are required to determine presence or likely absence, and two of these must take place between mid-April to mid-May which is the peak for breeding activity.

If great crested newts are found during these surveys, an additional two visits estimate the population size more accurately. These are also important if obtaining a licence from Natural England.

The survey will involve looking for eggs, searching for adults with a bright torch and netting for adults and larvae.  Where there is poor visibility or the site is unsafe to enter at night, then bottle trapping can be used.  This technique is more risky as it can potentially drown animals if the traps are not set correctly.

Using eDNA techniques

An alternative and new technique to work out if newts are present is to collect water samples from the pond and have them analysed for great crested newt eDNA. This technique can quickly rule out a number of ponds and avoids unnecessary night surveys.

However, if eDNA results come back positive, six nocturnal visits will be required to determine the population size.

Water samples can be collected between mid-April to end-June using a set methodology.  We have used this technique extensively and can advise you if it is suitable for your development.

Assessing impacts on great crested newts?

The Local Planning Authority needs to know that the development will not impact the species long-term.

When considering a planning application, generally they will request to know if great crested newts are present, and if so how the population will be affected, so they can consider as a “material consideration”. We can provide that assessment for you, based on years of experience.

Sometimes avoidance of impacts is possible, based on changing the timings of works or altering layouts or locations.  This avoids later needs for a licences and could be conditioned as a “method statement”.

What if there newts are impacted ?

Where there are newts AND an impact is likely, a European Protected Species Mitigation (EPSM) licence from Natural England will be required. The licence will detail how and when the work can take place, any trapping or use of protective fences, and any compensation measures like new ponds or meadows.

This will usually be conditioned on to any planning decision, but will need to be demonstrated as deliverable prior the planning stage.  The law in this area is complex, so we suggest you seek our advice on your options.

Who can do surveys ?

An experienced great crested newt surveyor is required to survey and make an assessment.  Our staff have the necessary licences and experience to do the surveys for you.

Having set out the above “rules” there are exceptions, but they are complex and we suggest you ring us to discuss.










Natural England – update on European licences delays : 16/2/15

We thought an update of statistics on our previous article might be of assistance.

Natural England are still unfortunately experiencing delays in reviewing European Protected Species Licence applications.  It looks like the situation with bats has slightly worsened, although the issues with great crested newts now appear to have improved.  They are training more staff, but our forecast is for no improvement in the immediate to near future.

Bat Update (as of 16th February 2015)

  • 355 ‘New’ Applications outstanding [ Up from 279 on 22 December ]
  • “New application processing time: Average delay of 18 days (48 days versus 30 working day decision deadline) [ Increase from 17 days on 22 December ]

Great Crested Newt Update (as of 16th February 2015)

  • 52 ‘New’ Applications outstanding [ Up from 19 on 22 December ]
  • “New” application processing time: Average delay of 2 days (32 days versus 30 working day decision deadline) [ Down from 7 days on 22 December ]

If you are concerned about gaining a licence, please contact us as soon as possible.

Invasive Non-Native Species Workshop

NWS organised a training workshop, well attended by 17 NWT/NWS staff and volunteers, at Bewick House in Norwich.  The workshop was led by Mike Sutton-Croft and Ed Stocker from Norfolk Non-native Species Initiative, who gave an informative talk on the risks and impacts associated with these species, as well as how to control them.  The Initiative, launched in 2008, monitors the spread of non-native species in the county and develops action plans for those priority species of most urgent concern.

Although not all non-native species could be covered, the morning focused on key species like Himalayan balsam, Japanese knotweed, giant hogweed, floating pennywort, mink and signal crayfish.  We looked at species identification, how they colonise and management options for their removal.  Case studies included the complete eradication of floating pennywort on the Waveney and the control of Himalyan balsam on the River Wensum.

Mike also talked about the European RINSE Project (= “Reducing the Impact of Non-Native Species in Europe”), a project area spanning parts of France, Belgium, the Netherlands and Britain, which aims to exchange experiences on how invasive non-native species are managed.   The project has developed a new phone app called “That’s Invasive!” http://www.rinse-europe.eu/smartphone-apps to identify invasive species and register findings, helping to control their spread in East Anglia.

Tony Leech, an attendee at the workshop commented “It’s been a good morning – the practical approach was good and news that action could be effective is encouraging, especially for Himalyan balsam and giant hogweed.  I was reminded of the importance of putting in records for invasive non-natives in Norfolk and intend to do so!”

Details of further training courses over the summer are posted on our website www.norfolkwildlifeservices.co.uk.  Upcoming events include Aquatic Plants on 23 July and Water Vole Ecology and Surveys on 27 August.

What planting mixes can I use for bees ?

Buff-tailed bumblebee on Hebe flower

Buff-tailed bumblebee on Hebe flower

Norfolk Wildlife Services have been asked by a number of clients how they can do more for bees on their sites, including several large solar farms.

There are over 250 species of bees living in the UK, including solitary bees, honey bees and bumble bees, all of which are an important component of Britain’s pollinating insects.

Recent research has shown a worrying decline in bee populations across the UK, thought to be linked to changes in farming practices in England over the past 50 years, which have resulted in much larger, intensively-farmed fields of monocultures.  Habitats once used by foraging bees have been reduced in this new landscape, with, for example, species-rich hay meadows declining by 97% since 1930.  Similarly, hedgerow networks have often become fragmented, removing links between bee feeding and nesting sites.

Providing good habitat for bees is easy if you pick the right species and doesn’t have to be specialist to look after or expensive to plant. The main thing to consider is having a range of plants that flower throughout the spring and summer to provide nectar and pollen for as long as possible throughout the bee’s lifecycle [ and grow well in East Anglia !], such as the following:

  • Spring flowers : bluebell, bugle, crocus and daffodil;
  • Early summer flowers : thymes, hardy geraniums, catmint and snapdragons;
  • Late summer flowers : sedums, heathers, lavender

You can also buy nectar-rich wildflower packet mixes, some of which suit bees very well  – look for mixes with species such as borages, red clover, and cornflower to create a bee-friendly mini-meadow.

To find out more information about the causes of the long term decline in bees, check out the Living With Environmental Change Policy and Practice Notes Note No. 09 April 2014. Norfolk Wildife Services can also advise you about landscaping plans and land management for bees and how to plant and cultivate suitable flower mixes.