Areas of Land

Bats use networks of dark habitats to commute through the landscape and to forage at night. Bat activity surveys are used to aid in understanding how bats use habitats at a given site for foraging and commuting purposes, and to build a picture of the species and abundance of bats present. This type of survey is also referred to as a transect survey or static detector survey

Surveyors walk transect routes at a site aided by bat detectors noting bat activity at dusk and/or dawn, which provides a snapshot of bat activity at that time. This is carried out in conjunction with a longer-term deployment of an automated bat detector on-site, the acoustic data from which is subsequently subject to office-based analysis and interpretation.

Buildings and Trees

For buildings and trees, nocturnal emergence/re-entry surveys are used to confirm the presence/likely absence of roosting bats, or to characterise a roost. This type of survey is also sometimes referred to as a presence/absence survey, dusk and/or dawn survey, activity survey, or bat detector survey.

The survey involves multiple surveyors aided by bat detectors viewing each aspect of a building or tree at dusk and/or dawn, recording any bats emerging from or re-entering bat roosts. Where necessary this survey type is aided by a night vision or thermal camera. Nocturnal bat surveys are seasonally constrained (see our Survey Calendar).