Impact of lighting on bats

Here at NWS, we are often asked to advise on the ecological impact of lighting on bats. Generally we recommend keeping lighting to a minimum and directing it away from any potential bat roosts or foraging and commuting areas because bats can be very sensitive to both the light itself and its consequent effects.

Illuminating bat roosts may cause bats to abandon their roost as the light delays their emergence and shortens the time available to them for foraging. A peak in insect abundance occurs soon after dusk, so this delayed emergence means they miss out on important feeding. Many of these night-flying insects that constitute the bat’s diet swarm around street lighting. However, certain species of bat, notably the rarer species, avoid street lights, meaning they miss out on this abundant food source.

Lighting can also cause barriers to commuting bats therefore isolating populations. It can also make them more vulnerable to predation. Kestrels (an avian predator to bats) have been observed hunting at night under the artificial lighting along motorways.

We now use a lux meter to measure light intensity during bat surveys. The result from the lux meter can help us advise on the impacts of installing lighting to an area and from this we can offer recommendations on how best to limit the effects.

Dr Emma Stone, a researcher at the University of Bristol is conducting ongoing research into the effects of lighting on bats. From Emma’s research, an overview and guidelines surrounding this issue have been produced by both Emma and the Bat Conservation Trust. However, as part of their Bats and the built environment series, the BCT has produced a condensed, user-friendly version of these guidelines: Bats and lighting in the UK.

Lux chart showing impact of lighting on bats

Lux chart showing the emergence of different species at varying light levels.

Bat roosts and trees

Schwelger box in holly tree

Schwelger bat boxes like this one in a holly tree can provide excellent homes for bats.

Bats have been found roosting in variety of places and require different kinds of roosts throughout the year to meet their various needs. One of the most popular roost sites is in trees.

Native broad-leaf tree species, such as oak, beech and ash, are particularly suitable for bats, but nearly all woodlands and trees have the potential for bat roosts. The older the tree, the better!

Bats cannot dig or bore into trees meaning they use naturally occurring holes and crevices in the tree’s structure. Our native bats evolved to roost in trees however, due to the decline in trees of a suitable age, bats now prefer roosting in built structures.

According to Bat Conservation Trust guidelines, when carrying out any tree work you will need to consider if the tree in question has any bat roost features such as: cracks and splits in the bark, a hollow trunk, loose bark, cavities in the trunk, or dense ivy on the trunk. If the tree does possess one of these qualities, it is likely to have ‘bat potential’. Advice will need to be sought from an ecologist who can establish any impacts the works are likely to have. The ecologist should also be able to help with any European Protected Species licences that maybe required.

Jordans Farm Partnership to start

Pollen nectar strip and Sally

Sally McColl, Ecological Consultant, assessing a pollen nectar strip for her JFP environment plan

A new farming model known as the Jordans Farm Partnership has been created. This
is a unique partnership between the Wildlife Trusts, Jordans, Linking Environment and Farming (LEAF), and the Prince’s Countryside Fund, which will aim to promote wildlife-friendly farming.

Jordans get grain from  42 arable farms, three of which are in Norfolk. Under the new partnership, each farm will be working with an advisor from their local wildlife trust to compile a unique farm environment plan to complement the arable production on the farm.

In Norfolk our ecological consultancy, Norfolk Wildlife Services, will act as the advisor on behalf of Norfolk Wildlife Trust. Sally McColl, ecological consultant, will be working with the three farmers to write and implement  the environment plan for each site, advising on wildlife enhancements to their farms and assisting with Countryside Stewardship Scheme applications. Each plan will ensure that a tenth of the farm is used to support nature. This includes growing crops to provide food for farmland birds, and pollen and nectar for butterflies, bees and other pollinating insects, to create wildlife corridors around the farm and to have well-managed hedgerows and water courses.

Tony Juniper, the President of The Wildlife Trust welcomed the new partnership, commenting: “The Jordan’s Farm Partnership could not be more welcome. Finding ways to tread the common ground that already exists can help forge a new path toward more enlightened practices. That, in turn, will bring benefits right across the board, including for the farmers who are in a powerful position to make a huge positive difference.”

This new scheme is being trialled on five farms and will be rolled out across the other 37 farms over the next two years. Part of the scheme will involve field trials and knowledge sharing as well as help with implementing the farm environment plans.

Together the farms within the partnership manage over 44,500 acres of land, so once fully up and running, that will make at least 4,450 acres of land that will help wildlife.

New level 1 GCN licence

Ben Christie Assistant Ecologist

Ben preparing for the great crested newt season in 2017.

NWS is proud to announce that our assistant ecologist, Ben Christie, recently acquired his level 1 great crested newt (GCN) class licence. Great crested newts are European Protected Species, meaning a license is needed to work with the species. Ben has worked exceptionally hard to obtain his license which permits him to survey great crested newts by hand, net, torch, aquatic funnel traps and bottle traps.


Bat survey health and safety training

NWS staff have undertaken new bat survey health and safety training.

Health and safety training

Sally, Carolyn and Chris now know how to enter derelict buildings safely during initial inspections.

Members of the team have learnt how to safely survey a building during initial inspections. Ecologists often have to enter derelict buildings to get a feel for their bat roost potential. Following this training, NWS staff now knows how best to avoid hazards, such as inhalation of asbestos.

Successful Water Vole Course at Hickling Broad


© Alex McLennan

On the 29th June, members of the public, Norfolk Wildlife Trust staff and Broads Authority staff all attended a successful NWS-led water vole course at Hickling Broad. Sue Traer (course leader and water vole specialist) kicked off the day in the classroom, catching everyone up to speed with water vole ecology, covering their lifecycle, habitat, food, and predators.

With the water vole taking the unfortunate position of Britain’s fastest declining mammal, Sue also tackled the species’ conservation status, educating attendees on the problems the water vole faces, the reasons for their decline and current water vole legislation.

After lunch everyone whacked on their wellies and headed outside. John Blackburn gave attendees a tour of the reserve, introducing them to the general habitat of Hickling Broad. Then it was time to learn the all-important survey techniques, applying the lessons from the classroom to the field. Everyone got stuck in searching the ditches for classic water vole signs: latrines, droppings, burrows and footprints.

By the end of the day, after identifying numerous latrines, feeding signs and burrows, everybody headed home satisfied that they could distinguish ‘Ratty’ from their bog-standard rat.

Bittern’s Breakfast and Avocet’s Lunch

Ever wondered what Cley’s birds eat for brekkie and lunch ?

Find out by joining us at Cley Marshes on Thursday 17th September. On this full day workshop, we will be looking at what delicacies the bitterns, avocets and other waders, wildfowl and gulls dine on at Cley Marshes in restaurants such as saline pools, reedbed and mudflats, and how coastal ecology provides the menus.

After a morning classroom briefing on coastal ecology and birds, and some “here’s some we prepared earlier” tastings, we will be ‘grubbing’ about in the marshes in a “behind-the-scenes” practical session to look for delicacies on the menu for birds. We will test various sampling methods using nets, forks, spades, buckets and sieves.  Getting covered in mud optional – and sandwiches are available instead of eating the avocet’s lunch !

There will be an afternoon session to examine samples upclose in the lab for a gourmet –
session separating food into their main taxonomic groups and training in using keys to
identify as far as possible.

If you want to see the difference between a ragworm and a lugworm – and a goby and a blenny – and to know a bit more about what Cley’s bird eat, this is a course for you.

The workshop will be lead by Norfolk marine wildlife expert, Rob Spray, who is an enthusiastic and entertaining tutor, ably assisted by NWS invert expert Ben Christie.

STOP PRESS : Ben Moore will present a summary of his thesis on the changes to the marsh invert community due to the storm surge.

Workshop Tutors: Rob Spray, Ben Christie

Date and Time: Thursday 17th September 2015, 10:30 am – 4:00 pm

Location: Cley Nature Reserve

Cost: £75 plus V.A.T., or £45 plus V.A.T. for concessions, including lunch.

Booking: To book a place, contact Ben Christie at Norfolk Wildlife Services by emailing, or by telephoning 01603 625 540.

See also

New EPSLs – reduced paperwork

Natural England have updated their European Protected Species licence forms, reducing some of the paperwork burdens on applicants.

New application form for bats

There is a new EPSL application form, which we think makes a lot more sense.  We are not sure if it is editable in all versions of Adobe Reader, but you can certainly use Foxit.  There are seperate forms for <3 species and >3 species, with a lot of tick boxes replacing the need to repeat text in and squeeze stuff up. It should make it more accessible for clients and easier to complete, plus indicates that NE may be streaming licences into low and high impact schemes, which makes a lot of sense.

Applications for home improvements and small scale housing developments

The guidance on the need for a Reasoned Statement has changed, making it only necessary for more complicated applications.  This doesn’t imply that you don’t need a licence – simply that the paperwork is becoming more proportional to the situation.  You need to read the details, but this means no more 20 page documents justifying a loft conversion or putting in a dormer window from NPPF. It also may reduce the paperwork burden on barn conversions under Permitted Development rights.

The exemptions are below.

Exemptions for Bats

“The following categories of work for all bat species and their roosts*:
i. repairs and maintenance, roof replacements, loft conversions, extensions and renovations of existing domestic dwellings and associated structures (eg garages).
ii. small-scale housing developments, including those that may require the demolition of existing buildings (whether domestic dwellings or other types of building).
*Unless the population is of regional or national importance – in which case please contact Natural England (see below) to discuss whether a Reasoned Statement is required.”

Exemptions for Great crested newts
“The following categories of works:
i. repairs and maintenance, extensions and renovations of existing domestic dwellings and associated structures (e.g. garages).
ii. small-scale housing developments within the curtilage of developed or previously developed (brownfield) sites, including those that may require the demolition of existing buildings (whether domestic dwellings or other types of building).”

There are also similar improvements around applications to conserve and protect Listed Buildings, Scheduled Monuments and places of worship.

You will need to read the fine print to see if this applies to you or contact us for advice.

A very sensible development from Natural England.

The document from Natural England is attached below :

Does my application need supported by a Reasoned Statement April 2015

Bat and newt licence delays – April

We thought an update of European Protected Licence delays for bats and great crested newts on our previous February stats article might be of assistance.

Natural England are still unfortunately experiencing delays in reviewing European Protected Species Licence applications. If you need to gaining a licence and how it might affect your project, please contact us as soon as possible.

The Natural England FCS test are also now processed and signed off at a regional level, which may have lead to some teething issues.  It has helped by improving lines of communication once an advisor has been allocated.  Generally discussion on allocation dates are “vague”, but once the licence is allocated and processed this is generally quick. As a corollary, then it is difficult for clients to plan with certainty when a licence will arrive, except at short notice.

Delays with bat licences have not worsened, but remain steady at around three to four weeks.  Hopefully newly trained staff should be assisting now, but our forecast is for no improvement in the immediate to near future.

With respect to Great Crested Newts, we would forecast that there will be additional delays, which are shown by the lengthening queue, due to the normal “spring surge” of new applications.

The following are based on ‘New’ Application processing time during the four week period 2nd March 2015 to 3rd April 2015 :

Bat Update (as of 6th April 2015)

  • 368  ‘New’ Applications outstanding [ Up from 355 on 10 February, 279 on 22 December ]
  • “New application processing time: Average delay of 17 days (47 days versus 30 working day decision deadline) [ No change from 48 days on February and 47 days on 22 December ]

Similar processing times were reported for Modifications and Resubmissions.

Great Crested Newt Update (as of 6th April 2015 )

  • 162 ‘New’ Applications outstanding [ Up from 52 in February, 19 on 22 December ]
  • “New” application processing time: Average delay of 5 days (35 days versus 30 working day decision deadline) [ 32 days on February, 37 days on 22 December ]

There were similar processing times for Modifications and Resubmissions.


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.