Aranzadi Ringing Scheme (bird ring-recovery data)

Method steps

1. Data collection is carried out using the EURING code standards, i.e., controlled vocabularies as stated by EURING (Speek et al. 2001). There are more than 60 fields that, overall, fix the criteria to register data on the ringing scheme, ring code and the use of other marks, species, catching method, sex and age, date, time, geographical position (coordinates), several fields related with individual biological traits (morphology, moult, brood size, etc.), and the condition and circumstance of the encounter (e.g., ringed, shot, etc.). Specific comments to be highlighted regarding methodological questions: (1) Species. Currently, both EURING and the ARS use the IOC (International Ornithological Congress) taxonomy. (2) For the specific case of the ARS databank, we must notice that the data in the field are collected through different methods, depending on the nature and aims of each ringing project. Such methods include, among many other techniques (Bub et al. 1996), mist nets at constant effort sites working under standardized protocols (e.g., Arizaga et al. 2022), chicks captured by hand in their nests (e.g., in colonies of seabirds, raptors breeding either in cliffs or trees, etc.), spring traps baited with insects to capture some territorial small passerine birds, clap nets, etc. Overall, the data can belong to one of the following two main project type categories: (1) projects coordinated directly from the ARS, most of which are based on constant effort sites using standardized mist-netting (Ralph and Dunn 2004), or (2) specific projects, normally created and managed by individual ringers or groups of ringers, e.g. designed to monitor given species (e.g., long-term population dynamics survey protocols), to promote and enhance training capacities, to environmental education and formation, etc. (3) Currently, the coordinates are taken with great accuracy, but in the past the accuracy of a locality was normally of ±5 km. Since birds are very mobile beings, this low accuracy poses no major impact on quality of the data bank. Before inserting new data into the system, a series of filters are applied to guarantee a minimum quality of the data: (1) in all the fields having categorical nature (that is, values are chosen from a closed list of possible values), such as the species and catching method, the system automatically checks for the consistency of values; (2) the coordinates are examined to detect impossible values (e.g., offshore or at an impossible latitude or longitude); (3) in recoveries, it is checked whether recovery date was not before ringing date and whether the species identified when the bird was ringed was the same of that reported for the recovery. The ARS Databank contain a record for each ring set or recovered, that is, each record corresponds to an individual bird. The ARS Databank contains 1773910 records (December 2023) and it is continually updated with new ones. Up to the decade of 1990, the mean number of ringings per decade was around 20,000 (but note that many ringings for the period 1950-1970 remain to be digitalized; Fig. 3A). This pattern started to change in 2000, and definitively in 2010, with almost 1,000,000 ringings, due to the incorporation of many ringers that until then had been using the ‘Ministry of Environment’ rings from the Government of Spain. A similar pattern can be seen for recoveries (Fig 3B). Up to 1990, the mean number of recoveries per decade was around 500 recoveries. Note also that, in older times, ringers were obliged to register only long-distance (>10 km), long-temporal (>1 year) or foreign recoveries, so many within-site recoveries were simply non-recorded within the ARS databank. The summarised bird ring-recovery data set here described (i.e., the data set published in GBIF) derives from the ARS Databank through a data aggregation process. The ARS Databank records are combined in one record in the published dataset when they have the same values for the following parameters: 1. Date. Recorded under "day", "month", "year , and "verbatimEventDate" 2. Species. Recorded using the DwC terms for taxon. 3. Sampling protocol. Recorded under "samplingProtocol", following the EURING controlled vocabulary (Speek et al. 2001). 4. Whether the records correspond to a new ringing or to a recovery, provided under "dynamicProperties" 5. Condition (bird found alive, dead or sick or wounded), according to the EURING controlled vocabulary (Speek et al. 2001), provided under "dynamicProperties" 6. Circumstance of the encounter, according to the EURING controlled vocabulary (Speek et al. 2001), provided under "dynamicProperties". The number of records combined in each case is shown under the "dynamicProperties" field, as "Frequency".

1. Chordata
   rank: phylum
2. Aves
   rank: class
3. order
   rank: order
4. Accipitriformes
   rank: order
5. Anseriformes
   rank: order
6. Apodiformes
   rank: order
7. Charadriiformes
   rank: order
8. Ciconiiformes
   rank: order
9. Coliiformes
   rank: order
10. Columbiformes
    rank: order
11. Coraciiformes
    rank: order
12. Cuculiformes
    rank: order
13. Falconiformes
    rank: order
14. Galliformes
    rank: order
15. Gruiformes
    rank: order
16. Passeriformes
    rank: order
17. Pelecaniformes
    rank: order
18. Phoenicopteriformes
    rank: order
19. Piciformes
    rank: order
20. Podicipediformes
    rank: order
21. Procellariiformes
    rank: order
22. Psittaciformes
    rank: order
23. Strigiformes
    rank: order
24. Suliformes
    rank: order
25. Upupiformes
    rank: order