ESR 8:61-68 (2009)  -  DOI: https://doi.org/10.3354/esr00100

ABSTRACT: Large dams have had a major impact on  a number of botanical and faunal groups. Nevertheless, little is known about their effect on bat populations. As part of a multipurpose project, the Alqueva dam was constructed during 2001 in Alentejo (Southern Portugal) and has created the largest reservoir in Europe. Its construction caused major changes in the region, mainly due to the deforestation and submersion of an area of 250 km². A 2-stage survey was implemented in order to evaluate the impact of these landscape changes on bat populations present in the region, as well as to define minimization and compensation measures. Bat activity was surveyed prior to and after the deforestation and flooding of the area, mainly through the use of ultra-sound detectors. The results show a clear decline in bat activity over the area now submerged; islands within the reservoir seem to be the only remaining foraging areas. Furthermore, bat activity increased in the area surrounding the reservoir. In this area, bats used similar foraging habitat types during both stages of the survey, confirming the importance of riparian habitats as foraging areas. Bat populations of this region were thus affected simultaneously by the disappearance of around 200 km of riparian habitat, extensive loss of roosts and the creation of a vast homogeneous habitat that is rarely used for foraging. In projects of this dimension, the future of bat communities is clearly dependent on the preservation of roosts and the most important habitats surrounding the reservoir.

KEY WORDS: Large dams · Bats · Habitat use · Conservation · Ultra-sound survey

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Cite this article as: Rebelo H, Rainho A (2009) Bat conservation and large dams: spatial changes in habitat use caused by Europe’s largest reservoir. Endang Species Res 8:61-68. https://doi.org/10.3354/esr00100 Export citation Share:    Facebook - - linkedIn