The category system used here has been borrowed from that employed in Lista de las aves de España (List of Birds in Spain) by the Exotic Bird Group and the Rarities Committee of the Sociedad Española de Ornitología (Spanish Ornithological Society ), originally developed by the British Ornithologists? Union for the British Isles and later adopted by several countries and regions in the European Union.
We have adopted this same system in the List of Birds in Navarre to describe the categories in our region.
Category A: Species that have been recorded in an apparently natural state at least once since the 1st of January 1950.
Category B: Species that were recorded in an apparently natural state at least once before the 31st of December 1949, but have not been recorded subsequently.
Category C: Species that, although introduced or reintroduced by man, deliberately or accidentally, now derive from the resulting self-sustaining populations.
Category 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. These appear in a separate list.
Category E: Species that have been recorded as introductions, human-assisted transportees or escapees from captivity, and whose breeding populations (if any) are thought not to be self-sustaining.
R ? Resident; species present all year round in greater or lesser number. Covers sedentary and migratory populations.
E ? Summer Visitor; species present in the spring and summer which normally come to Navarre to breed.
P ? Passage visitor; migratory species which mainly come to Navarre as part of their migratory journeys.
I ? Winter visitor; species which come in autumn and winter.
In some cases, several symbols are used together because it is considered that the populations justifying the symbols are of notable relevance and/or numerical significance.
* - Species whose breeding in Navarre is corroborated by the Atlas de Aves Reproductoras de España(Atlas of Breeding Birds in Spain) (1998-2002) (Martí y del Moral, 2003. Ministerio de Medio Ambiente and SEO-Birdlife) with modifications provided by the Coordinating Team for Navarre (Sociedad de Ciencias Gorosti).
A general degree of abundance is indicated as a means of estimating the difficulty involved in detecting each species.
A ? Abundant; practically everywhere, in large numbers and difficult to miss.
C ? Common; fairly well distributed and relatively easy to observe in the right habitat.
E ? Scarce; reduced numbers and located in specific places or habitats. Relatively difficult to see even in its ideal habitat.
ME ? Very scarce; very low numbers, highly localised and very difficult to see.
Two symbols are used for the same species in some cases, indicating that the situation is not very clear or may vary by year, habitat or area.
Those species included in the Catálogo de Especies Amenazadas de Navarra e(Catalogue of Endangered Species in Navarre) as established by Navarrese Decree 563/1995 (published in Official Gazette of Navarre No. 156 of 20/12/1995) are indicated together with the threat category attributed to them.
E ? In danger of extinction
H ? Sensitive to habitat change
V ? Vulnerable
I ? Of special interest
Those species which have only vagrant presence in Navarre are included here. Only those with approved recordings in Navarrese territory are considered when species included in the List of Rarities of the SEO-Birdlife Committee of Rarities are involved. These species are indicated with the letter ?r?.