EDP Baixo Sabor: Bat Roosts - Ecological Monitoring Program (PME) [Flooding and Exploration Phase] and Program of Mitigation/Compensation Measures (PMC) [Compensation Measure MC5 – “Use of Artificial Habitats by Bats”] (2015-2020)

Sampling was designed to cover all known and potential bat roosts in the study area that remained after the flooding, including caves, mines, wells and all sorts of buildings. A new set of constructed (1 artificial shelter, 160 bat boxes in trees, 7 bat boxes in bridges) and reconstructed/improved roosts (4 pigeon lofts, 4 natural shelters, 4 mine entrances), were added in this monitoring phase, to survey the effects of the Compensation Measure MC5 (“Use of Artificial Roosts by Bats”) implemented in 2014/2015. A place was considered to be a roost when the presence of bats was confirmed, either by direct observations or by indirect evidences (e.g., faeces, urine stains, etc.). Each roost was visited once or twice per season, depending on the year, in the hibernation (January-March) and reproduction (April-July) periods.
All roosts were searched for the presence of bats by two observers, which recorded all individuals seen, dead or alive. The time spent in each roost varied with the number of bats present and of the accessibility conditions. In some roosts associated to the MC5 (mine/mine entrances, buildings, pigeon lofts, artificial shelter) records of temperature and relative humidity were taken,
Species identification were usually made “in situ”, with the aid of head-torches, binoculars and field guides. Abundance data refers to the total number of adults, sub-adults and juveniles present, including the dead individuals, but not the cubs, which were counted separately.