Protected

Bats and Trees

Summary

  • All tree survey work should include an assessment of the potential a tree has to support bats, as even unoccupied bat roosts are protected by law.
  • Bat surveys must be conducted on trees due to be felled or pruned if there is any possibility of bats using them as roosts.
  • The best time of year to carry out work on trees with potential bat roosts is spring (mid-March to end of April) after the young are weaned and independent, or autumn (September to late October) before hibernation. However, these times are climate dependent and can vary from year to year.
  • If no bats are found but possible roost places have been identified best practice would be to lower the branches or trunk with possible roost cavities to the ground by rope and leave them for 48 hours for any bat to escape. After 48 hours carefully open up the cavities if you intend to remove the material from site.
  • If bats are discovered when branches are removed or trees felled (particularly in winter), work must stop immediately and you must contact Natural England and/or Ribble Valley Borough Council's Countryside Officer.

Background

A tree forms an essential part of an often complex ecosystem that provides a variety of habitats for a range of different species. Thirteen of the sixteen bat species in the UK are known to roost in trees. Some bat species rely exclusively on trees for roost sites, whilst others use them for part of the year. All sixteen species forage in woodland and along woodland edges.

Any tree can be used as a bat roost as long as it provides shelter in the form of splits, cracks, holes and/or cavities in the trunk and/or branches, loose bark and/or ivy cover. Roosts can be at any height in the tree.

Good Working Practice

  • Plan ahead
  • Establish procedures that consider the possible presence of bats in trees (including in an emergency) at all times of the year. 
  • Incorporate a bat check into tree surveys.
  • Consider how and when tree work will be undertaken.
  • Ensure that the work carried out is proportionate to the risk. It may be possible to make the tree safe without felling it by reducing the crown or individual limbs whilst retaining an important roost. You may also consider restricting public access by rerouting footpaths, moving benches, or installing a barrier.
  • Aim to limit the chances of a bat and/or roost being damaged or destroyed and minimise any adverse impacts by carrying out tree surgery sensitively. 
  • Try, wherever possible, to retain any tree used by bats.
  • If a bat roost is damaged it may be necessary to demonstrate to Natural England that good practice was implemented.
  • Remember - work that may disrupt a bat or a bat roost will most likely require a licence from Natural England.

Procedures

For all tree work: 

  1. Check Lancashire Environmental Records Network (LERN) database for any known bat roosts.
  2. Survey tree(s) for bat potential and evidence of bats.
  3. Consider the potential of the tree as a bat roost.
  4. Assess the outcome of the survey. Ensure recommended arboricultural work takes account of the findings.
  5. Ensure contractors are aware of the potential to damage or disturb bats and their habitat and that they have a copy of this document and emergency contact details.
  6. Wherever possible retain ancient, veteran, dead, dying, or ivy clad trees.
  7. Carry out work according to the outcome of the survey and Natural England licence.
  8. Leave wood on site wherever possible for 48 hours or indefinitely if the situation allows. Deadwood attracts insects which in turn provide food for bats and other wildlife.
  9. Consider the potential for habitat improvement and compensate for loss of bat habitat by installing bat boxes or creating new cracks and crevices in suitable trees.
  10. Keep Natural England's and the Ribble Valley Borough Council Countryside Officer's contact details on site in case of emergency.
  11. Carry thick gloves and a bat box in your vehicle in case you need to handle a bat. Do not handle a bat unless you are instructed to do so by Natural England or another qualified professional. 

Contact Natural England or Ribble Valley Borough Council at any stage of the procedure if you need advice.

Surveying for bats

     1. Assess tree for bat potential:

High potential

Medium potential

Low potential

Woodpecker holes

Few small cracks or crevices

No cracks/crevices

Cracks/crevices

Low ivy cover

No ivy cover

Loose or flaking bark

Deadwood in canopy or stem

No flaking bark

Medium/dense ivy cover

 

 

Deadwood in canopy or stem

 

 

Snagged branches

 

 

Hollow stem or limb

 

 

Hole between buttresses

 

 

Hollow core

 

 

     2. Look for evidence of bat presence:

  • Staining around a hole/crevice caused by natural oils in the fur.
  • Stains beneath a hole/crevice caused by urine.
  • Scratch marks around a hole/crevice caused by claws.
  • Droppings beneath a hole/crevice.
  • Audible squeaking from within a hole/crevice especially on hot days or at dusk.
  • Insects (especially flies) around a hole/crevice.
  • Bats emerging at dusk and returning at dawn (during the active season).

     3. Keep records of surveys and mark any trees with high bat potential or evidence of bats on a map to indicate that further survey work is required.

Finding bats

If bats are discovered when branches are removed or trees felled (particularly in winter), work must stop immediately and you must contact Natural England and/or the Countryside Officer. Advice will be given on how to proceed, possibly including collecting up any bats with gloved hands and putting them into a bat box.

If a bat is found in a tree, then the bat and the roost are protected under the Wildlife and Countryside Act 1981 and the Conservation of Habitats and Species Regulations 2010.  

Any bat roost found must be fully surveyed by a licensed bat worker and information about the roost must be sent to Natural England.

Emergency tree work

In the event that a tree is an imminent health and safety risk and there is no option other than to carry out work immediately advice should be sought from Natural England on how to proceed. It would be best to get written advice if possible. A qualified/licensed person may need to be present on site during the tree works.

Contact details 

 
 
 

Ribble Valley Borough Council Countryside Officer

 
Planning
Floor D
Council Offices
Church Walk
Clitheroe
BB7 2RA

Tel: 01200 414 505

planning@ribblevalley.gov.uk

 

Natural England

Natural England
Foundry House
3 Millsands
Riverside Exchange
Sheffield
S3 8NH

Tel: 0845 1300 228 or 0300 060 3900

enquiries@naturalengland.org.uk