During the last decades birds have been an important conservation driver in the modern and European Spain. In fact it is the only taxonomical group with an exclusive and pioneer conservation legal framework established by the European Union (EU). It is the Directive 79/409/CEE for the wild birds and their habitats conservation (DOCE, 1979). The implementation of that Ordinance in the Spanish Estate after its adhesion to the European Union in 1986, supposed the pronouncement of a lot of spaces as protected, which were denominated as Birds Special Protection Zone (SPA), aiming to preserve the catalogued birds populations and their habitats. The Spanish SPA network covers more than 300 zones, with a surface higher than 12% of the national territory.
In the National Park and its Peripheral Protection Zone more than 52.589 hectares are under the umbrella of that Environmental Status. Among them, 43.723 hectares correspond to the Sierra de Guadarrama SPA (ES0000010) in the province of Segovia, and 7.866 hectares correspond to the Alto Lozoya SPA (ES0000057) in the Madrid province. The last one has its full territory within the National Park or its Peripheral Protection Zone. The Sierra de Guadarrama SPA covers some territory which is not part of any of those last categories.
The Alto Lozoya SPA was pronounced in 1989 and it is constituted by the Lozoya River High Basin, featured by the isolated environment due to the close pair of mountain ridges: the northern, formed by the central nucleus of the Sierra de Guadarrama; and the southern with the remarkable Cabeza de Hierro Mayor and Cuerda Larga. That space presents a vegetal cover quite well preserved. The heights areas are populated by several pastures types, and as well by different saxicolous communities colonizing the crags and the scree. In a lower lever are developed other bushes communities such as the Alpine juniper (Juniperus communis subsp. alpina) and the Sierra brush (Cytisus oromediterraneus). Under that shrubs line, around the 1.900 m- 2.000 m altitude the forest zone spreads out. The trees vegetation with the highest altitude corresponds to the Scots pine forests (Pinus sylvestris).The Alto Lozoya SPA was pronounced due to the black vulture and the Iberian imperial eagle presence.
The Sierra de Guadarrama black vulture populations are distributed in both National Park SPA, with presence in Rascafría,Valsaín, River Moros, River Pirón and Navafría. If we consider the Sierra de Guadarrama black vulture several populations as a single one, it will be the fourth largest colony in Spain after the following ones: Sierra de San Pedro, Monfragüe (in Extremadura) and Cabañeros (in Castilla La Mancha). Other remarkable species in the Alto Lozoya SPA are the griffon vulture, the golden eagle, the booted eagle, the peregrine falcon, the Alpine accentor, the tree pipit, the honey buzzard, the white-throated dipper, the bluethroat, the whinchat and the citril finch.
The Alto Lozoya SPA is adjacent to the Sierra de Guadarrama SPA (ES0000010), located entirely in the province of Segovia. The characteristics of both SPA are very similar, because the Sierra de Guadarrama northern Segovia slope features also a quite diverse altitudinal gradient. Nevertheless, reaching in this case lower altitude levels, that SPA integrates other kinds of habitats such as holm-oak woods, and some sierra slope crops. At the Sierra de Guadarrama SPA highest zones are present crags, pastures and mountain shrubs; at the slopes extensive pinewoods and oak woods alternate with bushes zones and pastures; and as it has been mentioned in the lowest areas there are holm-oak woods not very developed, some crops and cattle meadows. Numerous rivers and streams cross the area, forming in certain cases abrupt gorges, and maintaining many of them good examples of riparian forests. Small reservoirs are also included with a poor interest for the aquatic birds.
The Sierra de Guadarrama SPA (coming from the union of two precedent SPAS pronounced in 1988: El Espinar (ES0000008) and Valsaín (ES0000010) was pronounced, as the Madrilenian one, due to the black vulture and the Iberian imperial eagle presence. Other remarkable species in the Sierra de Guadarrama SPA are the white stork, the short-toed eagle, the booted eagle, the red kite or the red-billed chough breeding population.