Bats and trees: who does what, where?

Information and good practice for arborists

4.8
4.8

Bats and trees: who does what, where?

Information and good practice for arborists

All bat species and their roosts are protected under UK wildlife legislation. It is an offence to: 

  • Kill or injure bats

  • Damage or destroy a bat roost

  • Disturb bats in their roost 

Protection applies whether bats are present at the time or not. 

4.4 Portrait

Who is responsible for what?

Bats and their roosts are protected by law. However, training is required to identify suitable roosting features in trees. This training provides professional arboriculturists with the tools to undertake a pre-work bat assessment of trees.

Tree owners / clients 

  • Ensure legal compliance 
  • Commission appropriate surveys where required 

Arboricultural contractors 

  • Be alert to potential roost features 
  • Avoid damaging work 
  • Stop work and seek advice if bats are suspected 

Ecologists (licensed) 

  • Carry out bat surveys 
  • Advise on mitigation 
  • Apply for licences where necessary 
Find a professional

There are currently 18 species of bats resident in the UK, many of which use trees in their daily activities.

Just as people use trees for different purposes, different bat species use trees in different ways:

Food

The UK’s bats are all insectivorous. As trees encourage a variety of insects, bats will often feed on these insects either by ‘gleaning’ them from a surface such as a spider off a web or by ‘hawking’ and catching them mid-flight.

Navigation

Bats will use features of echolocation to find their way around. Large trees a line of trees in hedgerows provide landmarks along commuting routes that bats will use regularly when travelling from their roost to feed.

Temporary shelter

Bats will use trees as a feeding roost to eat their prey while foraging or to take cover if the weather gets bad.

Daytime roost

Bats rest in a roost during day. Some bats, such as pipistrelles and barbastelle bats, are crevice dwellers and will squeeze into small nooks and crannies within a tree such as in cracks, splits or behind loose bark. Other bats prefer a little more space, using woodpecker holes or rot holes to roost in.

Hibernation roost

Bats need a safe, humid roost with a fairly stable temperature in which to hibernate over winter. A hollow trunk can provide suitable conditions for many bats to hibernate and wait for the weather to improve.

Next Steps

The Bat Conservation Trust have a guide and downloadable leaflet on how bats use woodland

The Bat Conservation Trust (BCT) runs a course specifically for arborists entitled Arboriculture and Bats: Scoping Surveys for Arborists.

This one-day course is Lantra accredited, supported by the Arboricultural Association and run at various locations across the country.

You can find out more information about the course on the BCT website: www.bats.org.uk.

Page image credits: Jim Mullholland