Friday, 27 August 2010


In 2008 SEO/BirdLife brokered a national Peregrine Falcon (Falco peregrinus) census. The census fell short of the overall objective, however, with nil or partial counts in 18 of Spain's provinces. Extremadura was one of the regions where the census was partial, coming up with a figure of 44 occupied territories, 7 of them rated as only probable. This is a bottom-line figure because the actual population is bound to be greater, though it is very difficult to pinpoint by how much; maybe the real figure is over 60-65 pairs. Almost the whole known population is in Cáceres (42 pairs, 95%; more than 55 estimated); Badajoz accounts for only two pairs (5-10 estimated). This makes Extremadura the nation's second least important region ahead of only Madrid, containing 1.6% of Spain's 2462 to 2804 pairs. By provinces, Cáceres ranks 25th, while Badajoz comes in last together with Seville. The density is the country's lowest, with only 0.11 territories per 100 km2, way below the national mean density of 0.56.

The Peregrine Falcon breeds in all Spain's provinces, recording its highest density in the Canary and Balearic archipelagos and the Canabrian and Mediterranean coastline. Inland the most important areas are the Cantabrian, Pyrenean and Iberian mountain ranges. In Extremadura its range takes in the mountain ranges of the north and east of Caceres, with scattered presence in the centre of Cáceres and northeast Badajoz. The most important areas are Ibores-Villuercas (17 pairs), Valle del Jerte (8), Las Hurdes (7) and Monfragüe (4), with odd breeding pairs in the Sierra de Gata (2), Valle del Alagón (2), La Vera (2), La Serena (1) and La Siberia (1). There are nonetheless thought to be several more pairs in the Sierra de Gata (1-2), Valle del Ambroz (2), La Vera (1) and Villuercas (3). In 1998-2002 its presence was recorded in sites with nil counts in 2008, such as the Sierra de San Pedro (4 pairs) and scattered points of the centre and south of Cáceres and the centre and east of Badajoz. In Extremadura, therefore, it can be said to favour areas of a higher altitude and less of a Mediterranean influence. Particular notable is its absence in the southern thirds of both provinces, a lacuna stretching to Huelva, Seville, Córdoba and the meseta sur (Southern Tableland). The reasons for this seem to be lack of nesting sites and competition with other raptors like the Eagle Owl (Bubo bubo).

In 2008 all Extremadura's Peregrine were ledge nesters. Most of these cliffs were quartzite, although nests are also built on granite cliff ledges in the Sistema Central (Central Mountain Ranges), with rarer recourse to rocks of slate and other material. There are no known nests on artificial structures (accounting for 4.3% of Peregrine nests nationwide), including power line pylons (2.8% in Spain, used especially in Valladolid and, to a lesser extent, in León, Córdoba et al). Curiously enough there was one tree-nesting pair in 2008, in Seville, using an old Black Kite's pinetree nest (there are other records of tree nests in Ávila). There are a score of nests in built-up areas in Spain as a whole but none in Extremadura; in any case many of these urban breeders are actually the result of reintroduction projects.

There is very little to go on in terms of the Peregrine's breeding performance in Extremadura, although 10 out of the 12 pairs that are known to have begun incubation in 2008 actually ended up breeding successfully (83%). There is also a recorded productivity figure of 1.79 young per pair in 2002, above the Spanish mean of 1.42 in 2008 and similar to the 1.74 figure of Andalucía and the 1.8 of Castilla-La Mancha.

The fact that no complete counts have ever been conducted in Extremadura makes it hard to ascertain the regional trend of the Peregrine Falcon. Partial information is available for the years 2000 (38-44 pairs), 2002 (49-60) and 2007 (50). The graph shows the maximum figures known in these years rather than the real population trend. Nonetheless, judging from the highest-density and best-surveyed areas, the trend seems to be stable, with traditional territories regularly occupied and few known cases of abandoned territories. Thus, the figures for these areas in the years 2000, 2002 and 2008, were, respectively 9, 8 and 9 pairs in Gata-Hurdes; 6, 10 and 10 in Gredos and 14, 18 and 17 in Ibores-Villuercas. Nonetheless the Peregrine's numbers are falling in nearly all the provinces bordering on Extremadura (Salamanca, Ávila, Toledo, Córdoba and Sevilla), especially in river valleys (only one territory remains in the Adaja valley in Ávila; the number of pairs along the Tagus as it runs through Toledo have fallen from 30 to 2 pairs and similar cases are recorded for Guadalajara and Madrid) and in western Sierra Morena (where it no longer breeds). Several reasons are put forward for this decline, though mention is always made of the Eagle Owl as competitor for nesting sites and predator of adult and young Peregrines. Closer attention will therefore have to be paid to Extremadura's population to pinpoint any possible decline.

Most of the figures on Peregrine Falcon in Extremadura in 2008 were furnished by the Dirección General del Medio Natural (Environment Board) of the Junta de Extremadura (Regional Council of Extremadura), with subsequent phasing in of additional information from SEO-Cáceres. The photographer is J. M. Domínguez Robledo.

Prieta, J. 2009. El halcón peregrino en Extremadura. Pp. 115-118.
Prieta, J. 2009. El halcón peregrino en Badajoz. Pp. 118-119.
Prieta, J. 2009. El halcón peregrino en Cáceres. Pp. 119-120.
En: Del Moral, J. C. (Ed). 2009. El halcón peregrino en España. Población reproductora en 2008 y método de censo. SEO/BirdLife. Madrid.