Monday 31 October 2011


Goshawk (Accipiter gentilis). José Gordillo.

The Goshawk (Accipiter gentilis) was another one of the target species in the SEO/BirdLife-brokered national woodland raptor survey 2009-2010 (Palomino and Valls, 2011). The estimated Extremadura population came out as 700 territories (range 650-750). This represents 6.2% of the Spanish total (11,350 territories), ranking seventh behind the regions of Castilla y León (2490), Castilla-La Mancha (2010), Andalucía (1370), Aragón (1280), Galicia (900) and Catalunya (760). Extremadura's mean density is 1.7 territories per 100 km2, below the national mean (2.2) and ranking a modest 12th in Spain.

Broken down by provinces, Cáceres accounts for 420 territories, and Badajoz 280. The densities (2.1 in Cáceres and 1.3 in Badajoz) are among the lowest in Spain. In all it was detected in 14% of the surveyed 10 k grids (18% in Badajoz and 6% in Cáceres).

The Goshawk has a somewhat patchy range in Extremadura; this also holds true for the whole of Spain and France. It is very scarce in the central and western sectors of both provinces, barring some zones of the central mountain range and southern Badajoz. Conversely it is exceptionally common in eastern districts (La Siberia, Las Villuercas y Los Ibores), which contain the lion's share of the regional population; in fact the likelihood of a Goshawk sighting is higher here than anywhere else in Spain. In the northern two thirds of Spain the Goshawk chooses hilly, low-insolation, inland areas with conifer woods (especially pine). At lower altitudes it prefers high-rainfall areas, unlike in the upland areas.
Predictive map of the Goshawk's range in Spain, taken from Palomino and Valls (2011). This shows the high likelihood of Goshawk sightings in the centre-east of Extremadura.

Car transects are not really a very suitable censusing method for this shy raptor so rarely seen outside the display season. In Extremadura only 3 birds were seen on average every 1000 k, an identical finding to the whole of Spain. It was detected in 13% of the surveyed 10 k grids (20% in Badajoz and 5% in Cáceres).

The Goshawk's trend in Spain is uncertain according to the breeding birds monitoring project SACRE; its trend within Extremadura is equally unsure.

The figures obtained for Spain as a whole were much higher than expected, even tripling the important French population. This has made even the survey authors chary of the results. The same goes for Extremadura, with figures way above forecasts and perhaps overstating the real case. Another striking finding is that the Goshawk's population should be just as big as the Sparrow Hawk's, a raptor of similar habits but more easily and regularly detected. Another apparent discrepancy arises between Cáceres and Badajoz. Contacts were higher in the latter but estimates were lower than for Cáceres. This might be due to the fact that best areas of Badajoz were surveyed more comprehensively than in Cáceres.

The fieldwork was coordinated and carried out by SEO volunteers and staff of the Environment Board of the Regional Council of Extremadura.

- Palomino, D., y Valls, J. 2011. Las rapaces forestales en España. Población reproductora en 2009-2010 y método de censo. SEO/BirdLife. Madrid. [PDF]