Bat Activity Surveys

A preliminary bat roost assessment may identify the requirement for bat activity surveys.

Presence/absence bat activity surveys include dusk and/or dawn vantage point visits to watch, listen for and record bats exiting or entering a structure or tree.

These surveys are required if:

• The preliminary roost assessment has not ruled out the reasonable likelihood of a roost being present
• A comprehensive inspection survey is not possible due to restricted access
• There is a risk that the evidence of bat use may have been removed

Activity surveys aim to identify the presence of roosting bats and the requirement for mitigation. The surveys may also highlight a feature which is of value to commuting and foraging bats.

The timings of bat activity surveys are highly seasonal; under current best practice guidelines, 1 of these surveys (on low and moderate suitability structures) should be undertaken between May and August inclusive, while 2 of the 3 surveys on high suitability structures need to be completed between May and August.

In addition to vantage point visits, bat activity surveys may also comprise bat activity transect surveys. This involves ecologists walking predetermined transect routes to observe, listen for and record bats in flight. The aim of this survey is to establish habitats or features of importance to roosting, commuting and foraging bats. Remote monitoring of bat activity can also be used to compliment transect surveys.

Bat activity transect surveys should be undertaken once a month between May and October.