2.7.1 Fire or fire suppression

Likely to be beneficial

Use prescribed burning

1Twelve studies evaluated the effects of prescribed burning on bat populations. Eleven studies were in the USA and one study was in Australia.

2COMMUNITY RESPONSE (1 STUDY)

3Community composition (1 study): One replicated, controlled, before-and-after, paired sites study in Australia found that the composition of bat species differed between burned and unburned woodland sites.

4POPULATION RESPONSE (8 STUDIES)

5Abundance (8 studies): Two replicated, site comparison studies (including one controlled study) in the USA found that the activity (relative abundance) of open habitat bat species and evening bats increased with the number of prescribed fires, but there was no effect on other bat species, including cluttered habitat bat species. Three replicated, before-and-after or site comparison studies (including two controlled studies) in the USA and Australia found that prescribed burning or prescribed burning along with thinning resulted in higher overall bat activity or activity of Florida bonneted bats. One site comparison study in the USA found that two of seven sites that had been burned alongside other restoration practices had higher bat activity than unrestored sites. One replicated, randomized, site comparison study in the USA found that three of four burning and thinning treatments resulted in higher overall bat activity. One replicated, controlled, site comparison study in the USA found similar activity of three bat species in burned and unburned tree stands.

6BEHAVIOUR (4 STUDIES)

7Use (4 studies): One replicated, controlled before-and-after study in the USA found that more female northern myotis bats roosted in burned than unburned forest. Two replicated, controlled, site comparison studies in the USA found that fewer female northern myotis bats and male Indiana bats roosted in burned than unburned forest. One replicated study in the USA found that evening bats roosted in burned but not unburned forest.

8Behaviour change (3studies): Two replicated, controlled, site comparison studies in the USA found no difference in roost switching frequency or the distance between roost trees for female northern myotis bats and male Indiana bats in burned and unburned forests. One replicated, controlled, before-and-after study in the USA found that female northern myotis home ranges and core areas did not differ in size between burned and unburned forests, but home ranges were closer to burned forest than unburned forest. Assessment: likely to be beneficial (effectiveness 60 %; certainty 50 %; harms 18 %).

9https://www.conservationevidence.com/actions/1006

2.7.2 Dams and water management/use

Unknown effectiveness

Create or maintain small dams to provide foraging and drinking habitat for bats

10One study evaluated the effects of maintaining small dams as foraging and drinking habitat for bats on bat populations. The study was in Portugal.

11COMMUNITY RESPONSE (0 STUDIES)

12POPULATION RESPONSE (1 STUDY)

13Abundance (1 study): One replicated, site comparison study in Portugal found that reservoirs created using small dams had greater activity (relative abundance) of four bat species than the streams feeding into them.

14BEHAVIOUR (0 STUDIES)

15Assessment: unknown effectiveness (effectiveness 51 %; certainty 20 %; harms 0 %).

16https://www.conservationevidence.com/actions/1997

Relocate bat colonies roosting inside dams

17One study evaluated the effects of relocating bat colonies inside dams on bat populations. The study was in Argentina.

18COMMUNITY RESPONSE (0 STUDIES)

19POPULATION RESPONSE (1 STUDY)

20Abundance (1 study): One study in Argentina found that almost two-thirds of a large colony of Brazilian free-tailed bats relocated to a different dam compartment five months after being displaced from six compartments where the colony originally roosted.

21BEHAVIOUR (0 STUDIES)

22Assessment: unknown effectiveness (effectiveness 5 %; certainty 5 %; harms 5 %).

23https://www.conservationevidence.com/actions/1998