EDP Baixo Sabor: Reservoir Filling and Exploitation Phases - Eagle Owl (Bubo bubo) Surveys - [2015-2020]

Study Extent

The study was conducted in part of the sub-basin of river Sabor affected by the Baixo Sabor and Feiticeiro Hydroelectric Dams, as well as in several areas upstream, in the river Sabor itself and in the Angueira and Maçãs rivers. The sampling was centered in suitable habitats for Bubo bubo in 37 sampling points, from the river mouth up to 42 km upstream.

Sampling

Playback surveys were carried out at 37 count points, located in high ground near areas of favourable habitat for the Eagle Owl. The calling stations were located along the lower Sabor river valley, and its main tributaries in the area affected by the AHBS, and in upstream areas in the Sabor, Angueira and Maçãs rivers, from the river mouth up to 42 km. Each sampling point was visited ± 3 hours around sunset, corresponding to the period of greatest daily vocal activity of the Eagle Owl. In each point, a period of spontaneous listening of vocal activity was performed ("SCP", 8 minutes), followed by the playback of the Eagle Owl call (3 minutes) and for a final period of listening to the potential response of the focal, and other species ("PPP", 10 minutes). The spontaneous calls identification was made in field by experienced observers.

Quality Control

All individual identifications were performed by qualified technicians

Method steps

1. To be completed

The taxonomic coverage of this dataset spans 1 class, 1 order, 1 family, 1 genera and 1 species.

1. Aves
   rank: class
2. Strigiformes
   rank: order
3. Strigidae
   rank: family

Data were collected in a 5-km buffer around the lower Sabor river valley and its main tributaries in the area affected by the AHBS, and in areas upstream (rivers Sabor, Angueira and Maçãs), from the river mouth up to 42 km, in the municipalities of Torre de Moncorvo, Alfândega da Fé, Mogadouro, Macedo de Cavaleiros. Bragança, Vimioso and Miranda do Douro.