Background information and definitions
Artificial water sources may be created to provide foraging and drinking resources for bats in arid areas, or in areas where natural wetlands have been lost.
For an intervention that relates to managing livestock water troughs for bats, see ‘Manage livestock water troughs as a drinking resource for bats’. For an intervention that involves using small dams to create water sources, see ‘Create or maintain small dams to provide foraging and drinking habitat for bats’.
Supporting evidence from individual studies
A replicated, controlled, site comparison study in 2006–2007 of 15 artificial water sources within a plantation and three natural wetland sites in North Carolina, USA (Vindigni et al 2009) found that artificial water sources of two types had higher bat activity than natural wetland sites. Bat activity was higher at heliponds (201 bat passes/site/night) and drainage ditches (ditch interior: 61 bat passes/site/night; ditch edge: 60 bat passes/site/night) than at natural wetland sites (21 bat passes/site/night). Seven bat species were recorded (see original paper for data for individual species). Heliponds were small ponds (12 m x 24 m x 2.5 m deep) used by helicopters for the suppression of forest fires. Drainage ditches (1–2.5 m wide and 0.6–1.2 m deep) were positioned every 80–100 m within and along the edge of tree stands. The natural wetland (350 ha) was adjacent to the plantation. On each of 116 nights in June–July 2006 and 2007, bat activity was sampled simultaneously with bat detectors at two of four sites rotated in a random order (five heliponds, five ditch interiors, five ditch edges, three natural wetlands).Study and other actions tested
A replicated, site comparison study in 2009 at seven ponds within vineyards in Landau, Germany (Stahlschmidt et al 2012) found that artificial retention ponds had similar or higher bat activity for three species groups than adjacent vineyards. Activity of Pipistrellus spp. and Myotis spp. was higher over retention ponds (Pipistrellus spp.: 1,421 bat passes/night; Myotis spp.: 65 bat passes/night) than in nearby vineyards (Pipistrellus spp.: 8 bat passes/night; Myotis spp.: 3 bat passes/night), but the activity of Eptesicus and Nyctalus spp. did not differ significantly (ponds: 55 bat passes/night; vineyards: 14 bat passes/night). All seven retention ponds (0.1–1.3 ha) had bankside vegetation. At each of seven sites, bat activity was recorded using bat detectors and thermal infrared imaging cameras simultaneously at the pond and at a vineyard site 80 m away for 8–9 full nights in June–August 2009.Study and other actions tested
A replicated, paired sites study in 2010–2011 of 30 pairs of farmland sites in the Western Cape, South Africa (Sirami et al 2013) found that farm dams and ponds had higher overall bat activity but a similar number of bat species when compared with open grassland/crops, trees, vineyards or orchards. Overall bat activity and the activity of all six bat species analysed was higher over farm dams and ponds than in open grassland/crops, trees, vineyards, or orchards (data reported as statistical model results). The activity of three bat species also increased with dam/pond size. The number of bat species recorded did not differ significantly between dams/ponds and other habitat types or with dam/pond size (data reported as statistical model results). Three sampling points were surveyed at each site including a farm dam or stock pond (0.1–172 ha in size) and two other habitats (open grassland/crops, trees, vineyards, or orchards). A bat detector was deployed for 4.5 h from sunset for two or more nights at each sampling point between November 2010 and April 2011.Study and other actions tested
A replicated, site comparison study in 2005 of 33 natural and artificial water sources in the Negev Desert, Israel (Korine et al 2015) found that artificial water sources had similar or higher activity for eight of 12 bat species than natural water sources. Six bat species had higher activity at artificial water sources (average 6–71 bat passes/night) than natural water sources (average 1–20 bat passes/night). The activity of two bat species was similar at artificial (average 39–208 bat passes/night) and natural water sources (average 38–189 bat passes/night). Three bat species had lower activity at artificial water sources (average 0.5–2 bat passes/night) than natural water sources (average 11–19 bat passes/night). One bat species was recorded only at natural water sources (0.4 bat passes/night). See original paper for data for individual species. Surveys were carried out at 17 artificial water sources (water reservoirs or waste water treatment pools) and 16 natural water sources (natural springs and pools). At each of 33 sites, one bat detector recorded bat activity at the waters edge for one full night in May–June 2005.Study and other actions tested
A replicated, site comparison study in 2005–2006 of six cattle ponds in a pine-oak forest reserve in Mexico (López-González et al 2016) found that three of six ponds had higher bat activity than surrounding habitats during the dry season, but activity was similar over ponds and surrounding forest and meadows in the rainy season. At three sites, bat activity was higher over ponds than along transects up to 500 m away during the dry season (data reported as statistical model results). However, during the rainy season, bat activity was similar over ponds and along transects. One other site had similar bat activity at ponds and transects in both dry and rainy seasons. Two other sites had variable or little bat activity with no obvious pattern. Nine bat species were recorded (see original paper for data for individual species). The ponds were constructed to provide water for cattle. They were naturally recharged during the rainy season and varied in size (dry season: 0–12,450 m2; rainy season: 600–19,790 m2). Bat detectors recorded bat activity for 3 h from sunset during two consecutive nights at each pond and along transects up to 500 m perpendicular to the ponds. Surveys were repeated in the dry spring and rainy summer seasons in 2005 and 2006.Study and other actions tested