EDP Foz Tua Reptiles - Ecological Monitoring Program [2011-2017]

Study Extent

The data were collected within a 5-km buffer around the Tua lower valley (Northeast Portugal) located in the region of Trás-os-Montes e Alto Douro, up to 50 km from the mouth, in the municipalities of Carrazeda de Ansiães, Vila Flor, Alijó and Mirandela.

Sampling

Sampling was designed to cover potential areas of nocturnal occurrence of amphibians (roads, tracks) in a grid of 2x2 km squares in, and around, the lower Tua valley affected by the Foz-Tua dam, including the reservoir area. A representative sample of transects of variable length was set up (one transect per square), covering the area affected by the dam and a control area upstream. Each transect was visited once in spring (April-Jun) and in summer (July-August), of 2012 to 2016. The transects were performed by two observers simultaneously (one on each side of the transect), during which all evidence (e.g., skin shedding) and individuals observed in displacement or located in potential refuge sites (e.g., stones or logs) along the transect, were identified and recorded. Species identifications were made with appropriate field guides. Sampling was carried out on days with favorable weather conditions to reptilian activity, especially on sunny or cloudy days. On days with very high temperatures (above 30 ° C) monitoring was preferably conducted at warmer times of day, particularly during the first four hours after dawn and the last three hours before dusk.

Quality Control

All identifications were performed by qualified technicians.

Method steps

1. To be completed

The taxonomic coverage of this dataset spans 1 phylum, 1 class, 2 orders, 7 families, 13 genera and 13 species.

1. Reptilia
   rank: class
2. Squamata
   rank: order
3. Testudines
   rank: order
4. Anguidae
   rank: family
5. Colubridae
   rank: family
6. Lacertidae
   rank: family
7. Natricidae
   rank: family
8. Phyllodactylidae
   rank: family
9. Psammophiidae
   rank: family
10. Geoemydidae
    rank: family

The data were collected within a 5-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, Alijó, Murça and Mirandela.