EDIA – Global Bird Monitoring Program of the Alqueva Dam (EFMA) Secondary Irrigation Network, Irrigation block D: Large steppe species: Little Bustard (Tetrax tetrax) [2021]

Study Extent

The data were collected in the area covered by the Secondary Irrigation Network of the Alqueva Dam project block D (irrigation blocks of Alvarrão, Brinches, Brinches-Enxoé, Caliços-Machado, Caliços-Moura, Orada-Amoreira, Pias and Serpa) covering a total area of 45084 ha, and in a control area with 9205 ha, respectively.

Sampling

Each sampling point was surveyed 1-2 times a year in April and May, in the first or last hours of the day (that is, around the sunrise or the sunset). The approach to the sampling points were made by car, at a low and constant speed, stopping the vehicle approximately one or two minutes before the start of the count (so that the birds can get used to the presence of the vehicle and resume their normal behavior). The count was then performed for a period of five minutes. All counts were made in good or acceptable weather conditions (ie, in the absence of heavy rain, wind and fog). All detections of the species were noted in a field form specifically made for this purpose. These forms included (a) the location (with geographic coordinates), time and number of individual males Additionally, the following metadata were included: (a) day of the visit, (b) start and ending time of the observation (c) observer identification and (d) weather conditions in qualitative scales (cloud cover, temperature wind and rainfall). The habitat for each sampling point was characterized in a 250 m radius around the focal point, by dividing this circle in eight quadrants (or octants) and calculating the percentage estimate of the coverage for each of the following classes: (a) fallow land < 10 cm; (b) fallow 10 cm < 30 cm, (c) fallow > 30 cm, (d) crops, (e) fallow/plowed land, (f) sunflower, (g) stubble and (I) open “montado”. In this dataset only the predominant habitat in the quadrant corresponding to the effective observations is presented in the column “habitat”. For each obnervation, a separate record was made for birds seen inside and outside the 250 radius circle. This information is presented in the “organismRemarks” column. The identity of each sub-block is indicated by the respective name in each sampling point: ALV: Alvarrão, BRE: Brinches-Enchoé, BRI: Brinches, CMA: Caliços-Machado, CMO: Caliços-Moura, ORA: Orada-Amoreiras, PIAS: Pias and SER: Serpa) and in “control” (“Controloxxx”, in the “locationID” column) zones.

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, 1 orders, 1 families, 1 genus and 1 species.

1. Chordata
   rank: phylum
2. Aves
   rank: class
3. Otidiformes
   rank: order
4. Animalia
   rank: kingdom
5. Otididae
   rank: family

The data were collected in the area covered by the Secondary Irrigation Network of the Alqueva Dam project, block D (irrigation blocks of Alvarrão, Brinches, Brinches-Enxoé, Caliços-Machado, Caliços-Moura, Orada-Amoreira, Pias and Serpa) covering in total 45084 ha, in the municipalities of Moura, Beja and Serpa, and in a nearby control area, covering 9205 ha in the municipalities of Castro Verde and Beja (all in the district of Beja).