Here is the second part of our comment on planning application 20/00379/OUT.
The bats’ flight corridor
Of the 18 species of bats native to Britain, 13 have been identified in the past 2 years either in SCP Nature Reserve, at the WHSAP site (H2.4) at Church Lane or at Southwick Court; identifications were made by Gareth Harris, Wilts Bat recorder or Richard Green, Lead Ecologist for RPS; all have been reported to WSBRC. The 13 species are:
• Bechstein’s bat, one of the rarest bats in western Europe, listed as Near Threatened on the global IUCN Red List of Threatened Species, a Priority Species in the UK Biodiversity framework.
• brown long-eared bat, a Priority Species in the UK Post-2010 Biodiversity framework;
• common pipistrelle;
• Daubenton’s bat;
• greater horseshoe bat, a Priority Species under the UK Post-2010 Biodiversity Framework, European Protected Species under Annex IV of the European Habitats Directive;
• Leisler’s bat;
• Lesser horseshoe bat, a Priority Species in the UK Pst-2010 Biodiversity framework;
• Myotis bat;
• Nathusius’ pipistrelle;
• Natterer’s bat;
• noctule bat, a Priority Species in the UK Post-2010 Biodiversity framework;
• serotine bat;
• soprano pipistrelle, a Priority Species in the UK Biodiversity framework.
Many of the bats have roosts in Green Lane Woods and are known to use a flight corridor to the south of Trowbridge to reach their foraging grounds in and around Southwick Country Park Nature Reserve. WHSAP sites H2.1, H2.2, H2.4, H2.5 and H2.6, all allocated for residential development, are positioned in this flight corridor: a combined total of 665 additional houses. See map below.
Map showing flight corridor in black and sites allocated for development in yellow
Most bat species are low-fliers, they fly just 2-10 metres from the ground, therefore:
- if the planned 180 houses at site H2.6 are built, they will block almost entirely that part of the flight corridor that passes through the green gap between Bramble Farm and the southern edge of urban Trowbridge;
- the ONS records 16% of households as owning cats, and on average those households own 1.6 cats each; this means there will be almost 50 cats living on this residential estate, happy to hunt and kill low flying bats;
- the proposed removal or reduction in height of the tall hedges that line Firs Hill, which lift the bats’ flight corridor over the road at present, will put low-flying bats in danger of collision with passing vehicles; traffic collision is a significant cause of death among bats.
Bechstein’s bat and greater horseshoe bat
There will be light pollution along a large part of the flight corridor. While the developers will be required to control the light levels of street lighting by the Trowbridge Bat Mitigation Strategy, they will have no control over the lights that people use in their gardens or on the outside of their houses.
There will be an increase in road traffic along a significant length of the flight corridor: research from Sussex University has found that bats avoid traffic noise and catch less prey when it cannot be avoided.
Ultrasonic sounds, which impede some bat species’ high-frequency echo-location calls, are increasingly common in residential areas: car parking sensors, high frequency repellents of all kinds.
We cannot pretend that these developments, to the south of Trowbridge, will not damage the bats’ habitat. In particular, the 180 houses and their infrastructure proposed by planning application 20/00379/OUT for the land at Southwick Court (H2.6) will form a physical barrier between the bats’ roosts in the woods to the east and their foraging grounds around Southwick Country Park Nature Reserve.
Header picture: lesser horseshoe bat by jessicajil (CC BY-SA 2.0) flickr.com