Background information and definitions
National legislation for bats varies around the world. In some countries, bat roosts and important bat habitats are legally protected, but in others there is no protection at all.
Assessing the effectiveness of protected areas is particularly difficult. For example, protected and unprotected areas might start off with different quality habitats (protection being granted to the best quality habitat). Protected areas are also more likely to be in remote areas, so less accessible to threats such as harvesting (Joppa & Pfaff 2009). Finally, effectiveness is best monitored over long timescales, but this increases the chance that other factors influence the ecosystem. The most reliable studies would compare protected and unprotected areas over time, and possibly correct for some of the biases.
Joppa L.N. & Pfaff A. (2009) High and far: biases in the location of protected areas. PLoS ONE, 4, e8273.
Supporting evidence from individual studies
A replicated, site comparison study in 2009–2012 of 80 rivers on farms in Wales, UK (MacDonald et al 2012) found that rivers in protected areas had higher activity of Daubenton’s bats Myotis daubentonii than rivers in unprotected areas, but the activity of soprano pipistrelles Pipistrellus pygmaeus did not differ between protected and unprotected areas. The average number of bat passes/year for Daubenton’s bats was higher over rivers in protected areas on both agri-environment farms (2.3 bat passes) and conventional farms (3.3 bat passes) than rivers in unprotected areas on agri-environment scheme farms (1.6 bat passes) and conventional farms (2.3 bat passes). A similar number of bat passes/year were recorded over rivers in protected and unprotected areas for soprano pipistrelles (data not reported). Surveys were carried out at 46 protected rivers (26 on agri-environment scheme farms, 20 on conventional farms) and 34 unprotected rivers (14 on agri-environment scheme farms, 20 20 on conventional farms). Protected areas were designated as Sites of Special Scientific Interest. No details were reported about the origin of the rivers; water may have originated from outside the protected area. One transect was carried out along each river in August and September in 2009, 2010 and 2011.Study and other actions tested
Referenced paperMacDonald M.A., Morris A.J., Dodd S., Johnstone I., Beresford A., Angell R., Haysom K., Langton S., Tordoff G., Brereton T., Hobson R., Shellswell C., Hutchinson N., Dines T., Wilberforce E.M., Parry R. & Matthews V. (2012) Welsh Assembly Government Contract 183/2007/08 to Undertake Agri-environment Monitoring and Services. Lot 2 – Species Monitoring. Final report: October 2012.
A study in 2015 of protected areas in Spain (Lisón et al 2015) found that the distributions of 10 of 11 target bat species and 13 of 18 non-target bat species overlapped with protected ‘Special Conservation Areas’ (SACs) significantly more than expected by chance. The distributions of nine of 11 target bat species and 13 of 18 non-target bat species also overlapped with ‘Special Protection Areas’ (SPAs) designated to protect birds. The amount of overlap between bat species distributions and either of the protected area types did not differ significantly between target and non-target species. Both SPAs and SACs were part of the legally protected European Natura 2000 network. Target species were of highest conservation concern and listed in Annex II of the European Habitats Directive. All other (non-target) bat species were listed in Annex IV. The mean percentage overlap between species distributions (grid cells in which the species occurred) and the protected areas were calculated using an existing bat dataset for mainland Spain and the Balearic Islands.Study and other actions tested
A replicated, paired sites study in 2011–2012 in 11 managed beech Fagus sylvatica forests in Germany, Austria, France and the UK (Zehetmair et al 2015) found that legally protected forests had higher activity for one of 20 bat species than unprotected forests, but overall bat activity and the number of bat species was similar between protected and unprotected forests. The number of common noctule Nyctalus noctula calls was higher in protected (141 calls) than unprotected forests (18 calls). However, the difference was not significant for 19 other bat species (see original paper for detailed results) or the number of bat calls recorded overall (protected forests: 1,223 calls; unprotected forests: 1,995 calls). The same was true for species richness (17 bat species recorded in both protected and unprotected forests). Surveys were conducted in 11 pairs of forest (one protected, one unprotected) managed for timber production. Protected forests were part of the Natura 2000 network. All stands were >10 ha with trees 80–120 years old and had a similar number of roost trees and volume of snags. Bat activity was recorded with bat detectors at eight locations per stand during one full night in May or July in 2011 or 2012.Study and other actions tested
A replicated, site comparison study in 2006–2013 along 1,608 road transects in France (Kerbiriou et al 2018) found that legally protected sites had higher overall bat activity, more bat species, and higher activity of three of six bat species/species groups than unprotected sites. Overall bat activity was 24% higher within protected sites than outside them, and the number of bat species recorded was 14% higher (data reported as statistical model results). The activity of three bat species/species groups was also higher within protected sites than unprotected sites: common pipistrelle Pipistrellus pipistrellus (14% higher in protected sites), serotine bat Eptesicus serotinus (105% higher) and Myotis spp. (368% higher). For three other bat species (Kuhl’s pipistrelle Pipistrellus kuhlii, common noctule bat Nyctalus noctula, Leisler’s bat Nyctalus leisleri) activity did not differ between protected and unprotected sites. Legally protected sites were part of the Natura 2000 network. Data were collected as part of a citizen science programme. Volunteers recorded bat activity while driving along 1,608 x 2 km road transects (each repeated an average of 2.4 times) through different habitats in protected and unprotected areas (number of sites for each not reported) between June and July in 2006–2013.Study and other actions tested
A replicated, site comparison study in 2010–2013 of 10 rainforest sites in the Western Ghats, India (Wordley et al 2018) found that protected forest had a greater number of bats than unprotected forest fragments, but the number of bat species and species compositions were similar. The total number of bats captured and recorded was higher in protected forest (average 35 bats/site) than unprotected forest fragments (17 bats/site). However, the average number of bat species recorded did not differ significantly (protected forest: 8 bat species/site; unprotected forest fragments: 6 bat species/site), and nor did the composition of bat species (data reported as statistical model results). Seventeen bat species were recorded in total (see original paper for data for individual species). Five protected rainforest sites and five unprotected rainforest fragments (2–103 ha) were surveyed. At each of 10 sites, bats were captured with five mist nets and recorded with bat detectors at five sampling points during two nights between January and May in 2010–2013 and November–December 2014.Study and other actions tested