Background information and definitions
Wetlands can support high numbers of aquatic insects and provide important foraging and drinking habitats for bats. Wetlands may be created in proximity to existing habitats or habitat corridors. Restoration of wetlands may involve a combination of interventions, such as removing invasive and emergent plants and maintaining bankside vegetation and trees.
A study that involves the restoration of wetlands alongside other habitats at ex-quarry sites is described in ‘Threat: Energy production and mining – Mining – Restore bat foraging habitat at ex-quarry sites’.
For evidence relating to managing water bodies in arid areas, see ‘Threat: Climate change and severe weather – Manage natural water bodies in arid areas to prevent desiccation’.
Supporting evidence from individual studies
A replicated, controlled, before-and-after study in 2000–2001 of six restored and six undisturbed wetlands in South Carolina, USA (Menzel et al. 2005) found that restoring wetlands increased overall bat activity, and restored wetlands had similar bat activity to undisturbed wetlands. Overall bat activity was higher over wetlands after restoration (average 7 bat passes/30 minutes) than before (2 bat passes/30 minutes). Before restoration, overall bat activity was lower at drained wetlands (average 2 bat passes/30 minutes) than undisturbed wetlands (17 bat passes/30 minutes). However, after restoration there was no significant difference (restored: 15 bat passes/30 minutes; undisturbed: 9 bat passes/30 minutes). Seven bat species were recorded in total (see original paper for data for individual species). Wetlands were Carolina bays (0.5–1.5 ha) that were either undisturbed (three sites) or had been drained >50 years previously and restored in 2000 (drainage and forest removed; three sites). At each of 12 sites, bat activity was recorded during a random 30 minute time interval between dusk and midnight with 1–2 bat detectors before restoration (in 2000) and after (in 2001).Study and other actions tested