Bats are the only mammals that have evolved powered flight. They are long-lived intelligent animals with a complex social life. Bats are active at night, finding their way around and catching their food using an ultrasonic method of navigation known as echolocation. British bats are insectivorous, taking a huge variety and number of different prey items - thus they are important pest controllers. Bats need safe summer roost sites for rearing their young, good feeding areas with plenty of insect food, and safe undisturbed sites for hibernation in winter. They rely to a greater or lesser extent on trees but some bats prefer to roost in buildings including houses, churches and barns. The complex life style of British bats and their insectivorous diet means that their presence in an area is indicative of a healthy and diverse environment.

Twelve of the eighteen species of British bat occur in Bromley, of which 8 are almost certainly breeding in the borough. Two Pipistrelle species (Pipistrellus pipistrellus and P. pygmaeus) are the most common and ubiquitous of bats in LBB.

Data from the National Bat Monitoring Programme suggests that the populations of most bat species in the UK are stable or increasing from the baseline data of 1999 when monitoring on a national scale commenced. Detailed surveys in London reveal that there has been a significant decline since the 1980s particularly for Serotine, Noctule and Leisler bats (Guest et al. 2002) Bats in Greater London. Unique evidence of a decline over 15 years. British Wildlife 14 1-5.

All bats and their roost sites are fully protected by UK law.

Threats to bats in London Borough of Bromley

  • Loss of maternity roost sites in buildings and/or trees
  • Ignorance or intolerance of the public to bats
  • Loss of and disturbance to other roost sites including winter hibernation sites (mines, ice houses), and other seasonal roost sites (buildings (roof spaces), bridges, trees, ivy-covered structures).
  • Loss of insects due to inappropriate management of insect-rich feeding habitats such as grassland, woodland and wetland.
  • Disturbance to commuting routes – may be due to loss of or inappropriate management of flightline features such as trees, hedges, river corridors
  • Predation especially by the domestic cat.

Conservation status

  • All bats and their roosts have full legal protection under Schedule 5 of the Wildlife and Countryside Act 1981 (as amended).
  • Whiskered/Brandt/Alcathoe, Noctule, Soprano Pipistrelle and Brown Long-eared bats are Section 41 species of principal importance under the NERC Act.
  • IUCN Red Listed species: Serotine - Vulnerable; Leisler - Near Threatened; Nathusius Pipistrelle – Near Threatened.
  • Noctule, Soprano Pipistrelle and Brown Long-eared bats are Priority Species under the UK Post-2010 Biodiversity Framework.
  • All bats present in Bromley are London and Bromley Priority Species.

Actions carried out 2015-2020

  • Several local surveys were carried out for the National Bat Monitoring Programme (NBMP) organised by Bat Conservation Trust (BCT) and Joint Nature Conservation Committee (JNCC).
  • Serotine roost counts (2015-2020) were carried out annually.
  • Surveys for the Woodland Small Myotis Project using harp traps (under licence) and static recorders were carried out in selected woodlands in the Borough in 2018-2020.
  • Surveys for the Nathusius Pipistrelle Project using harp traps and sonic lures (under licence) were carried out in Kelsey Park in 2017.
  • Hibernation surveys – three underground winter hibernation sites are monitored each winter as part of the NBMP (under licence).
  • Bat box checks – there are several bat box schemes in the Borough parks and green spaces with checks carried out in spring and autumn (bats handled under licence).
  • Bat walks and talks are led for Friends’ Groups, youth organisations, and the general public over the summer months.

Actions 2021-2026

Action by

Continue NBMP surveys (roost counts, hibernation surveys) and report findings to BCT and London Bat Group

London and Kent Bat Group members

Encourage small-scale developers to use the BCT toolkit to inform them whether a bat survey should be undertaken before submitting the P/A 

LBB planning department, developers

Ensure developers and planners take into account the possible impact on bats of any planning application. This especially applies to developments in areas of known bat activity/roosts but planners should also use a trigger list of potential bat impacts as published by BCT to activate a bat survey.

LBB planning department, developers

Ensure developers and planners uphold the legal requirements of protection of roost sites and put in place mitigation measures eg bitumen based roofing felt in known or potential bat roosts


LBB planning department, developers

Encourage installation of bat bricks in suitable new developments including refurbishment of houses, bridges and other built structures.


LBB planning department, developers

Protect known hibernation sites from disturbance and maintain safety features.

Land managers, London and Kent Bat Group members

Stop pesticide use (including herbicides & fungicides) except in exceptional circumstances to increase insect abundance and diversity

LBB, land managers, Bromley Biodiversity Partnership, allotment holders etc.

Encourage appropriate management of hedges, tree lines and river corridors to provide safe commuting routes for bats. Gap up to provide continuous feature particularly adjacent to known roosts.

LBB, land managers, Bromley Biodiversity Partnership, idverde, Friends Groups

Raise awareness of bats and the threats to their lifestyle among the general public, roost owners, youth groups and schools by talks and walks.


Bromley Biodiversity Partnership

Encourage the general public to share their knowledge of bat feeding areas with idverde staff at High Elms and encourage roost owners to notify London Bat Group of the presence of bats.

Bromley Biodiversity Partnership, idverde, Friends Groups, residents associations, allotment holders etc

Encouraging planting of native species-rich hedgerows wherever appropriate, in school grounds, parks, allotments, sports grounds, churchyards etc to increase insect diversity and abundance. See the Friends Forum website and  information on plants to improve biodiversity   

Bromley Biodiversity Partnership, idverde, Friends Groups, residents associations, allotment holders etc

Encourage appropriate management of river corridors, ponds and lakes to increase food source for bats

Land managers, Bromley Biodiversity Partnership

Floodlighting can seriously decrease the ability of some bats to feed. Do not allow lighting to spill on to river courses and do not floodlight churches with bat roosts

LBB planners

Before undergoing tree management undertake a Potential Roost Feature (PRF) survey so as to lower the risk of harming bats. Seek appropriate advice if necessary.

Land managers

Encourage gardeners to ‘rewild’ areas of gardens and to plant night-scented flowers to encourage night-flying insect prey for bats

Bromley Biodiversity Partnership, residents

Encourage home owners to put up bat boxes/bricks.

Bromley Biodiversity Partnership: all members, residents.

Encourage cat owners to keep them inside for 1.5 h around sunset particularly if the cat consistently catches bats.

Bromley Biodiversity Partnership: all members, residents.

Continue to monitor the use of bat boxes in the parks and green spaces.

London Bat Group

Encourage Friends Groups to put up bat boxes Bromley Biodiversity Partnership, Friends Groups,


For further information about bats see Bat Conservation Trust website