Bats and Trees

Bats and Trees – 24–25 January 2022

Two-day event

De Vere Tortworth Court,

24 & 25 January 2022

Trees are an essential part of the environment, providing a wide range of ecosystem services. Trees also provide food and shelter for wildlife. Cavities, splits and hollows, which were historically described as ‘defects’, are now known to provide habitat for numerous wildlife species. Among the wildlife species which use trees for shelter are bats, with 14 of the 17 UK bat species known to roost in trees.

Despite the high level of legal protection, recent research has highlighted the difficulties of effectively surveying trees for bats. Bats frequently move roosts making it difficult to know if a tree is used by bats. As bat roosts are protected whether bats are present or not, this has serious implications for tree management.

There is a growing number of ecologists who climb trees to look for bats and also a growing number of arborists developing an increase in ecology. Whilst some cross-discipline working is taking place, there is scope for much more. By running a two-day event on the topic of Bats and Trees we hope to encourage more ecologists and arborists to work together, sharing knowledge and experience.

Bats and Trees has two main aims:

  1. Improving the quality of surveys undertaken, which in turn will improve the conservation of tree-roosting bat species; and
  2. Improving the safety of those involved with trees surveys for bats.

The two-day event will comprise a mix of presentations and workshops from experts from both ecology and arboriculture, themes will include:

  • Bat ecology and roosting behaviour
  • Advances in survey techniques
  • Practicalities of surveying trees for bats
  • Compliance with legislation and industry best practice

Early Bird Booking Closed 17 January 2022


1 day ticket:
£120 (Members) | £140 (Non-members)

2-day ticket:
£240 (Members) | £280 (Non-members)

Bats and Trees - Programme

Important: This programme is subject to change.

Day 1 Monday 24th January 2022





Arrival and registration



Welcome & introduction

Jim Mullholland (Arboricultural Association)

Morning sessions – Bat ecology and roosting behaviour





Never underestimate a Potential Roost Feature

Morgan Hughes (University of Wolverhampton) and Scott Brown (Coppice Ecology)


Refreshment break


New approaches to surveying trees for bats

Jim Mullholland (Arboricultural Association)


Can we create bat roosts in living trees?

Sean Shereston (Arbology)


Morning speaker Q&A



Afternoon sessions – Practicalities and legalities of surveying trees for bats



Jim Mullholland (Arboricultural Association)


Work at Height Regulations – the regulator’s perspective

Chris Maher (Health and Safety Executive)


Two rope working and new technical guides in arboriculture; climbing and aerial rescue (TG1)

Simon Richmond (Arboricultural Association)


Refreshment break


Managing bat roosts in trees; an arborist’s perspective

Lee Gwyther (Grounded Trees)


Discussion forum – how can ecologists and arboriculturists work together to improve tree surveys for bats?


Afternoon speaker Q&A



Day 2 Tuesday 25th January 2022




Tree climbing workshop – Alex Laver (Tree Logic)


Using the body language of trees to inform tree assessments - Jim Mullholland (Arboricultural Association)


Bat roost creation in living trees (outside, Hawkers Grove) – Lee Gwyther (Grounded Trees) and Sean Shereston (Arbology)


Ash dieback and tree risk management - John Parker (Arboricultural Association)


Using the Bat Tree Habitat Key data to inform survey design and effort - Louis Pearson (BTHK project) Only one or two sessions (not four).

Workshop rotation (sunrise 8am – sunset 4:43pm)

Workshop times

8:30 – 10:00

1st workshop

10:00 – 10:30

Refreshment break

10:30 – 12:00

2nd workshop

12:00 – 1:00


1:00 – 2:30

3rd workshop

2:30 – 3:00

Refreshment break

3:00 – 4:30

4th workshop

Bats and Trees - Speakers

Morgan Hughes

Morgan Hughes

University of Wolverhampton

Scott Brown

Scott Brown

Coppice Ecology

Never underestimate a Potential Roost Feature


During routine pre-parturition monitoring of a known large maternity roost of noctule (Nyctalus noctula) bats with a previous (post-parturition) peak count 68 individuals, we observed and recorded 28 individual noctule bats emerging from a feature. This emergence was followed by the subsequent emergence of 51 Daubenton’s bats (Myotis daubentonii). Shared maternity roosts of this size have not been previously recorded. Later in the season, the entire limb supporting the roost feature (a north-facing knothole) came down in a storm. This afforded us the opportunity to create a transverse section of the entire feature, providing detailed schematics of the dimensions of characteristics of the 6m feature, including roosting locations of each species. We present the data including infra-red and thermal footage of the emergence. While inter-species cohabitation in roosts has been recorded before in some species in small numbers, this is the first record of a shared roost of this type and size between these two species, and a unique insight into the structure of a significant roost feature at the time of use.

Lee Gwyther

Grounded Trees

Managing bat roosts in trees; an arborist’s perspective


Managing trees with bat roosts is a challenging activity, requiring close working between the ecologist and arborist. An detailed understanding of both bat roosting ecology and tree management are required if the work is to be planned and executed safely and without impacts on bats. But how effective is communication and partnership working at present, and what could be improved? Lee is a bat licensed arborist, specialising in habitat management. He will share some of his experiences managing trees with bats and share what works and where improvements are needed.

Jim Mullholland

Jim Mullholland

Arboricultural Association

New approaches to surveying trees for bats


Through recent research, standard survey techniques used to determine whether a bat roost is present in a tree have been shown to have significant limitations. Guidance provided in the seminal ‘Bat Roosts in Trees’ book requires a significant increase in survey effort compared to the Bat Conservation Trust’s ‘Bat Surveys for Professional Ecologists: Good Practice Guidelines’. How do we address these limitations whilst not increasing an excessive financial burden? Jim will share new the results of an on-going research project which aims to improve the quality of surveys whilst not breaking the bank.