EDP Foz Tua: Bat Roosts - Ecological Monitoring Program (PME) and Program of Mitigation/ Compensatory Measures (PMC): Exploration Phase (2018-2020)

Study Extent

The data were collected within a 15-km radius buffer around the lower valley of River Tua (Northeast Portugal), up to 36 km from the mouth, in the municipalities of Alijó, Carrazeda de Ansiães, Vila Flor, Mirandela, Sabrosa and Bragança. There were also two additional sites surveyed at >20 km from the river.

Sampling

Sampling was designed to cover all known and potential bat roosts in the study area, including railroad tunnels, caves, mines, wells, bridges and all sorts of buildings. 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, in the hibernation (January-February), reproduction (April-August) and pre-dispersion (September-October) periods, depending on the year (in 2020, due to the Covid-19 pandemics movement restrictions, there was no monitoring campaigns in the reproduction period). All roosts were searched for the presence of bats by two observers, which recorded all individuals seen. The time spent in each roost varied with the number of bats present and the accessibility conditions. Species identification were usually made “in loco”, with the aid of head-torches, binoculars and field guides. Some bats were photographed to allow a “a posteriori” identification of individuals that raised doubts, or to count large groups that could not be accurately counted in a suitable time in the field.

Quality Control

All individual identifications were performed by qualified technicians

Method steps

1. To be completed

The taxonomic coverage of this dataset spans 1 phylum, 1 class, 1 order, 4 families, 9 genus and 16 species positively identified.

1. Chordata
   rank: phylum
2. Mammalia
   rank: class
3. Chiroptera
   rank: order
4. Miniopteridae
   rank: family
5. Molossidae
   rank: family
6. Rhinolophidae
7. Vespertilionidae

Most data were collected within a 5-km radius buffer around the river Tua valley (Northeast Portugal), up to 36 km from the mouth. There were also several sites located up to 15 km and two at >20 km from the river. The sites were located in the municipalities of Alijó, Carrazeda de Ansiães, Vila Flor, Mirandela, Sabrosa and Bragança.