What does the "Breeding/Wintering" field mean?

This topic aims at reflecting the current condition displayed by a species within the area it has been recorded. Although it is an optional field to fill in, it may contribute with relevant information on the phenology of bird species.

When a bird species is recorded within its current residence area it will be of interest to confirm the breeding probability for this species in this area. To determine the signs indicative of breeding, criteria considered in the Atlas de aves nidificantes de España have been adopted, which are as follows:

- Possible reproduction: Species recorded in appropriate habitat and season.

- Probable reproduction: A male persistently singing, an individual with an established territory, courtship and/or mating behaviour, construction of nest.

- Confirmed reproduction: Deflection displays as anti-predator behaviour, nests showing signs of recent use, fledglings exhibiting an inexperienced flight, adults carrying food or faecal sacs, nests having eggs or hatchlings.

When a specimen is recorded in a location out of its residence area the observer should attempt to determine if that individual is in passage, marking one of these options:

- Migration: A bird occasionally recorded in an area in which it does not behave as resident.

- Wintering: A bird recorded in a different date and in an area where it is not considered as resident.



What does the "Category" field mean?

The ¿Category¿ column encompasses the category system employed by Grupo de Aves Exóticas and Comité de Rarezas, dependant from the Sociedad Española de Ornitología which, formerly developed by the British Ornithologists¿ Union for the British Isles, several countries have adopted, together with AERC for the European range. Distinct categories are as follows:

- A: Species that have been recorded in an apparently natural state at least once since 1 January 1950.

- B: Species that were recorded in an apparently natural state at least once until 31 December 1949, but have not been recorded subsequently.

- C: Species that, having been deliberately or accidentally introduced or re-introduced by humans, now derive from the resulting self-sustaining populations. 

- C1: Introduced species. Species that have occurred only as a result of an introduction.

- C2: Partially naturalized populations. Species with established populations resulting from introduction by humans, but which also occur in an apparently natural state.

- C3: Reintroductions. Species with populations successfully re-established by humans in areas of former occurrence.

- C4: Naturalized feral species. Domesticated species with populations established in the wild.

- C5: Vagrant naturalized species. Species from established naturalized populations abroad.

- D: Species that would otherwise appear in Category A or B, except that there is reasonable doubt that they have ever occurred in a natural state. They do not account for the global number of species and form no part of the list.

- E: Species that, having been deliberately or accidentally introduced or re-introduced by humans, have populations which are thought not to be self-sustaining. They form no part of the list.

- E1: Species that regularly breed, and are likely to establish in the wild. Species within this subcategory need to be specially monitored for an eventual inclusion in C category in the future.

- E2: Species that occasionally breed in the wild, despite no signs of establishment process are evident.

- E3: Species just recorded occasionally, no breeding events being confirmed.

The categories assigned to each species refer to their situation through the Spanish territory. The official list of birds is uniquely formed by those included in A, B and C categories. Species included in D category are listed for informative purposes only and to stimulate debate about its definitive categorization. E category is obviated in this list, yet available in the Sociedad Española de Ornitología website.



What does the "Rarity" field mean?

If a species breeds in one or several of the territories included in the Spanish State, the initial must be typed:

P, Iberian Peninsula;

B, Balearic Islands;

C, Canary Islands;

N, North African Autonomous cities of Ceuta and Melilla.

When the species assessed is a rarity, in the sense it still accounts for very few citations in Spain because it appears exceptionally (vagrant birds sensu lato), the whole pool of citations certified by the Comité de Rarezas until 2002 (de Juana et al., 2004) is available. This number is typed using two numerals separated by a comma, the first one corresponding to the records obtained for the Iberian Peninsula and the Balearic Islands, and the second one to those records just obtained for the Canary Islands.

Among these numbers, ¿0¿ indicates that there does not exist any certified citation on a bird species within that area, and a ¿x¿ means that a species do not currently own the rarity category there. Furthermore, whenever a species not only mismatches the rarity category for both sub-regions but also breeds there, the ¿x¿ symbol is substituted by the initial of the territory (or territories) where it breeds.

The publication or use of non-certified citations in scientific or mass publications is not recommended.