EDP Foz Tua: Bat Roosts - Baseline and Complementary Studies [2008-2010]

Study Extent

The data were collected within a 15-km buffer around the Tua lower valley (Northeast Portugal), up to 50 km from the mouth, in the municipalities of Carrazeda de Ansiães, Vila Flor, Alijó, Mirandela and Sabrosa.

Sampling

Sampling was designed to cover all known and presumed bat roosts in the study area, including railroad tunnels, caves, mines, wells and all sorts of abandoned or little used buildings. A place was considered to be a roost when the presence of bats was confirmed, either by direct observations or by indirect evidences (eg., faeces, urine stains, etc.). Each roost was visited once in winter (January-February, hibernation period) and once in spring (April, reproduction period) of 2010. In 2008-2009, only a subset of the sites (railroad tunnels) were visited. All potential roosts were searched for the presence of bat colonies by two observers, which recorded all individuals of each species detected. The time spent in each refuge varied according to 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. When the visual identification raised doubts, or the numbers present were too large to be identified in a suitable time, photographs were taken to be identified later. Sometimes, reliable counts were not possible (e.g. due to the packing of the groups), so only the presence of the species was recorded.

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, 3 families, 4 genus and 9 species positively identified.

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

The data were collected within a 15-km buffer around the valley of the River Tua (Northeast Portugal), up to 50 km from the mouth, in the municipalities of Carrazeda de Ansiães, Vila Flor, Mirandela and Sabrosa.