EDP Foz-Tua: Large Mammals: river crossings - reference situation/early exploration phase. Compensatory Measures Monitoring Program (MC40B.1 and MC40B.2) [2017-2020]

Study Extent

The data were collected in two bridges over the Tua river, Abreiro and Brunheda up to 25 km from the mouth, in the municipalities of Alijó, Carrazeda de Ansiães, Murça, Vila Flor and Mirandela.

Sampling

The survey covered two of the three bridges in the river Tua lower valley: Abreiro (MC40B.1) and Brunheda (MC40B.1 and MC40B.2), using the same methodology for both sub-measures. Sampling was carried out using a combination of (a) daytime pedestrian transects along the bridge deck to look for evidences of presence (faeces and footprints) and/or the presence of animals (dead or alive), and (b) the use of stone powder on the side of the road, provided the ideal conditions (i.e., absence of rain or wind strong) were met, in order to detect the presence of footprints and tracks/trails at night. Stone dust was placed at both ends of the bridges (but inside the deck) and at both ends of the adapted passage, only on the sidewalk, on each side of the road. These methodologies could be complemented with camera-trapping, if the safety conditions for the use of these devices were met. Each bridge was visited once a day, preferably in the early morning, for five consecutive days. Whenever possible, all evidences were identified “in situ” to the species level or, when this was not possible (e.g. deformed/incomplete footprints or broken/incomplete fecal samples), up to top-most hierarchical taxonomic group. The cases where no positive identification was possible where also accounted for, being recorded as “undetermined species”. Additionally, all probable signs of actual crossing through the bridges and/or in the adapted passage were recorded. A probable crossing of an individual of a species was considered when the footprints or trails were found in at least two places where the stone dust was placed, one at each end of the bridge, with the same direction of travel on the same sampling day. In same cases, the quality of the evidences (e.g., very old, broken or incomplete faeces, or unclear footprints), or the similarity between the species remains, prevented a species-specific identification, but could be attributable to several competing species. Accordingly, the following “species complexes” were used: “wild cat/domestic cat/genet (Felis silvestris/F. catus/Genetta genetta)”, “wild cat/domestic cat (Felis silvestris/F. catus)” and “beach marten/European pine marten (Martes foina/M. Martes)”. In this context, it is important to mention that some canid footprints attributed to the domestic (or feral) dog, were large enough to be compatible with those of Iberian wolf (Canis lupus signatus), a species that could potentially occur in the area, since there were three confirmed packs in the region in the last Wolf National Census (Pimenta et al., 2005). However, as all canids directly observed included large dogs, in the absence of photographic records and/or other unequivocal evidence (e.g., faeces) of the presence of wolf, all Canid footprints not clearly identified as dogs, were attributed to the species complex “domestic/feral dog/Iberian wolf (Canis spp.)”

Quality Control

All identifications were performed by qualified technicians

Method steps

1. To be completed

The taxonomic coverage of this dataset spans 1 phylum, 2 classes, 4 orders, 5 families, 11 genera (8 of mammals) and 9 species (6 of mammals).

1. Animalia
   rank: kingdom
2. Chordata
   rank: phylum
3. Amphibia
   rank: class
4. Mammalia
   rank: class
5. Anura
   rank: order
6. Caudata
   rank: order
7. Carnivora
   rank: order
8. Bufonidae
   rank: family
9. Salamandridae
   rank: family
10. Canidae
    rank: family
11. Felidae
    rank: family
12. Mustelidae
    rank: family
13. Viverridae
    rank: family

The data were collected in three bridges over the Tua river, Abreiro (MC40B.1) and Brunheda (MC40B.1 and MC40B.2) up to 25 km from the mouth, in the municipalities of Alijó, Carrazeda de Ansiães, Murça, Vila Flor and Mirandela.