THE HOBBY IN EXTREMADURA (2009-2010)

Hobby (Falco subuteo). Adult. John A. Thompson (taken from IBC).

In 2009-2010 SEO/BirdLife organized the first ever survey of nine diurnal woodland raptors (Palomino and Valls, 2011), the Hobby (Falco subbuteo) being one of the target species. Its estimated Extremadura population came out as 170 territories (range 140-200). This represents only 3.9% of the Spanish total (4410 territories), way below the figures for Castilla y León (1460) Galicia (650), Castilla-La Mancha (590) and Aragón (530). Extremadura's mean density is 0.4 territories per 100 km2, below the national mean of 0.9.

Broken down by provinces, Badajoz holds 120 territories and Cáceres 50. The densities (0.55 in Badajoz and 0.26 in Cáceres) are among Spain's lowest. In all it was detected in 7% of the 10k grids surveyed by means of lookout points (6% in Badajoz and 10% in Cáceres).

The Hobby has a patchy range in Extremadura, with the highest likelihood of sightings, and ipso facto the greatest abundance, in the eastern half of Badajoz and the southeast corner of Cáceres. There are also smaller population clusters in the Vegas del Guadiana and the centre of Badajoz. The map hardly predicts Hobby presence in pinewoods of the central mountain range, though there is in fact known to be a small population there. In general, the Hobby chooses in Spain cooler, low-rainfall, low-altitude areas with varied farmland scenery and nearby wetlands.

Predictive map of the Hobby's range in Spain, taken from Palomino and Valls (2011).

Car transects are not really a very suitable censusing method for this shy, retiring raptor. In Extremadura only 2 Hobbies were seen on average every thousand kilometres, matching exactly the average figure for Spain as a whole. It was detected in 7% of the surveyed 10k grids (3% in Badajoz and 11% in Cáceres). Of all the nine species studied, this species shows the lowest bird-per-kilometre figure both in Extremadura and Spain as a whole.

The Hobby's trend in Spain is unknown. The Spanish breeding birds monitoring project SACRE is not really suitable for surveying such a scarce, low-profile species. It shows a decline of 56% from 1998 to 2010 but this needs to be taken with a pinch of salt.

Very little is known about the Hobby in Extremadura, so these findings are quite revealing. For example, this study threw up the first probable breeding record in such a heavily birded site as Monfragüe. Nonetheless the models obtained for this raptor in Spain are pretty inaccurate due to the low number of contacts. All the abovementioned information now needs to be confirmed in the field, especially in Badajoz, which records higher population figures than Cáceres even though the species has been observed 2-3 times less in the former province.

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

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

THE SPARROW HAWK IN EXTREMADURA (2009-2010)

Sparrow Hawk (Accipiter nisus). Adult female. Francis Martin.

The Sparrow Hawk (Accipiter nisus) 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 690 territories (range 630-750). This represents 5% of the Spanish total (13,810 territories), ranking eighth behind Andalucía (4270), Galicia (1470), Castilla y León (1450), Aragón (1330), Castilla-La Mancha (1280), Valencia (810) and Catalunya (700). Extremadura's mean density is 1.7 territories per 100 km2, below the national mean (2.7) and ranking a modest 11th in Spain.

Broken down by provinces, Cáceres accounts for 430 territories and Badajoz 260. The densities (2.2 in Cáceres and 1.2 in Badajoz) are among the lowest in Spain. In all it was detected in 25% of the surveyed 10 k grids (20% in Badajoz and 30% in Cáceres).

The Sparrow Hawk has a somewhat patchy range in Extremadura, preferring the more wooded and mountainous areas. As with the Goshawk, the likelihood of a sighting is high in La Siberia and Las Villuercas y Los Ibores. Unlike the Goshawk, however, it is also fairly abundant in other areas, like the Sistema Central, Monfragüe, Montánchez, centre of Badajoz, Tentudía and Vegas Bajas del Guadiana. In Spain the Sparrow Hawk picks out the rainier areas with conifer woods, diverse landscape and warm months of May.

Predictive map of the Sparrow Hawk's range in Spain, taken from Palomino and Valls (2011).

Car transects are not really a very suitable censusing method for this shy, low-profile raptor. In Extremadura only 3 birds were seen on average every 1000 k, a somewhat lower figure than the mean for the whole of Spain (0.4 per 100 km). It was detected in 17% of the surveyed 10k grids (19% in Badajoz and 15% in Cáceres).

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

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

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

THE BUZZARD IN EXTREMADURA (2009-2010)

Buzzard (Buteo buteo). By José Ledo.

The Buzzard (Buteo buteo) 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 2870 territories (range 2790-2960). This represents 9.3% of the Spanish total (31,000 territories), coming in fourth behind three bigger regions: Castilla y León (5530), Andalucía (5520) and Castilla-La Mancha (3900). Extremadura's average density is 6.9 territories per 100 km2, a little above the national mean (6.1) but behind the Canary Islands (16) and the Cantabrian coast (9.5).

Cáceres, with an estimated 1490 territories, boasts Spain's biggest provincial population, followed by Badajoz with 1380 territories. Since both provinces are so big, the density (7.5 and 6.3 respectively) is lower than many other provinces, ranking 12th and 22nd respectively.

The Buzzard's range takes in the whole of Extremadura. It is most frequent in the province of Cáceres and thins out only in the Sierra de Gata, Las Hurdes, Las Villuercas and the southeast corner of the province. In Badajoz the best areas are in the northern third, near the River Guadiana, numbers dying down towards the south of the province. In Extremadura it was detected in 60% of the surveyed grids. The Buzzard is a very versatile raptor that can take to many different types of habitat. In general it prefers low- or medium-altitude areas that are not too hot and with a patchwork mixture of farmland, deciduous woods and Holm-Oak woods. It prefers high rainfall in hotter climes and low rainfall in colder areas.

Predictive map of the Buzzard's range in Spain, taken from Palomino and Valls (2011).

The car transects in Extremadura threw up an average of 6.3 birds every 100 km (6.8 in Badajoz and 5.8 in Cáceres); it was observed in 85% of the surveyed grids. Spain's mean birds-per-kilometre figure was 6.8, with Salamanca (19.2), Cantabria (17.9) and Ávila (14.9) to the fore.

The Buzzard's trend in Spain is stable according to the breeding birds monitoring project SACRE, especially in the centre of the country, including Extremadura.

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

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

THE SHORT-TOED EAGLE IN EXTREMADURA (2009-2010)

Short-Toed Eagle (Circaetus gallicus). Eva Palacios.

The Short-Toed Eagle (Circaetus gallicus) 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 980 territories (range 940-1020). This represents 9.4% of the Spanish total (10,380 territories), ranking fifth behind the bigger regions of Castilla-La Mancha (1800), Castilla y León (1760), Andalucía (1620) and Aragón (1340). Extremadura's mean density is 2.4 territories per 100 km2, above the national average of 2.1 and behind only Aragón (2'8) and the Valencia Region (2.7).

Cáceres, with an estimated 570 territories, boasts Spain's biggest provincial population, albeit ranking fourth in density (2.87 territories per 100 km2) behind Castellón, Teruel and Guadalajara. Badajoz, for its part, accounts for 410 territories, 1.88 every 100 km2 (the 30th highest density in Spain).

The Short-Toed Eagle ranges widely over the whole of Extremadura. It is especially abundant in the eastern half of Cáceres and the northeast corner of Badajoz, the two areas with the highest sighting probability in the whole of Spain. Although it is less common in the province of Badajoz, especially in its western half, some parts of the province still throw up the highest one-off densities in the whole of Spain (2.5 territories in only 10 km2). In all it was detected in 41% of the surveyed 10k grids. In Spain the Short-Toed Eagle favours low-altitude, high insolation areas with extensive Holm Oak woods, warm but with a certain humidity and little farmland.

Predictive map of the Short-Toed Eagle's (Circaetus gallicus) range in Spain, taken from Palomino and Valls (2011). This clearly shows that the eastern half of Cáceres offers the highest likelihood of a Short-Toed Eagle sighting.

On the Extremadura car transects 2.5 birds were seen every 100 km; it tuned up in 65% of the sampled grids. The mean birds-per-kilometre figure for Spain as a whole was 1.6, led by Castellón (4.4), La Rioja (2.8), Ciudad Real (2.8), Badajoz (2.7), Segovia (2.7) and Cáceres (2.4).

The Short-Toed Eagle's trend in Spain is stable according to the breeding birds monitoring project SACRE, although migration figures across the Strait of Gibraltar increased at an annual rate of 6.6% over the 1998-2009 period. Given that Spain's population is the biggest in Europe, it is logical to conclude that it is on the increase; this is born out by comparing the birds-per-kilometre figure with previous studies.

Not much can be added to the SEO/BirdLife results. The apparent discrepancy between the different surveying methods (for example, Cáceres is the province with the highest sighting rate from lookout points but only the sixth in car transects) is only to be expected in samples where the zones visited might be different and there are also several factors that might muddy the subsequent analysis (low territoriality, territory overlaps and shared hunting grounds).

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

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

THE GOSHAWK IN EXTREMADURA (2009-2010)

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.

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

THE BOOTED EAGLE IN EXTREMADURA (2009-2010)

Booted Eagle (Hieraaetus pennatus), light phase. Portaje, Cáceres, 27-07-2010. By Eva Palacios.

The Booted Eagle (Hieraaetus pennatus) was 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 2210 territories (range 2150-2270). This represents 12% of the Spanish total (18,500 territories), ranking fourth after three bigger regions: Castilla y León (3820), Andalucía (3790) and Castilla-La Mancha (3020). Extremadura's mean density is 5.3 territories per 100 km2, the highest in the whole country and way above the national mean (3.7). Behind Extremadura come Andalucía, Aragón and Castilla y León (densities of from 4.1 to 4.3).

Badajoz, with an estimated 1200 territories, boasts Spain's biggest provincial population, followed by Cáceres with 1010 territories. The highest provincial density is recorded by Sevilla (5.8), followed by Badajoz (5.5), Huelva (5.11) and Cáceres (5.08), all in the southwest quadrant of mainland Spain.

The Booted Eagle's range takes in the whole of Extremadura; it seems to be commonest in the northern half of Cáceres and scarcest in the centre-west of Badajoz. In all it was recorded in 57% of the grids with lookout points (65% in Cáceres and 52% in Badajoz). The Booted Eagle is a very versatile raptor. In Spain it prefers inland areas with cool, sunny springs, moderate relief and not too much farmland.

Predictive map of the Booted Eagle's range in Spain, taken from Palomino and Valls (2011).

The car transects threw up an average of 4.4 birds every 100 km; it was observed in 77% of the sampled grids (83% in Cáceres and 71% in Badajoz). The mean birds-per-kilometre figure for Spain as a whole was 2.3, led by Salamanca (5.7), Valladolid (5.6), Segovia (4.8), Cáceres (4.5), Granada (4.5) y Badajoz (4.2).

The Booted Eagle's trend in Spain is a very sharp increase according to the breeding birds monitoring project SACRE, with a 43% rise from 1998 to 2010. In the central zone of Spain, including Extremadura, the increase is even higher: 53%. Gibraltar Strait counts of migrating birds have also multiplied fourfold since the 1990s, with almost 30,000 Booted Eagles being recorded nowadays (Fundación Migres).

As regards the figures thrown up by this survey, not much can be said because there is insufficient previous information to go on. Nonetheless some discrepancies are evident in the above paragraphs. The population estimates clearly bring out the importance of the southwest quadrant of mainland Spain (Extremadura and Western Andalucía), while the observation probability map (bound up with abundance) shows the highest probabilities in Cáceres and the south of the northern meseta. The same goes for the car transects, with highest bird-per-kilometre figures in the northern meseta. In both cases Salamanca comes out winning while Badajoz and Sevilla come out losing.

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

Source:
- Palomino, D., y Valls, J. 2011. Las rapaces forestales en España. Población reproductora en 2009-2010 y método de censo. SEO/BirdLife. Madrid. [PDF]
- Fundación Migres: http://www.fundacionmigres.org/Noticia_aumento_poblaciones_rapaces.html

THE HONEY BUZZARD IN EXTREMADURA (2009-2010)

Honey Buzzard (Pernis apivorus). Left: adult female with a honeycomb in its claws(Joel Brueziere, taken from Fat Birder). Right: adult male (Stephen Daly, taken from IberiaNature). Adults are distinguished by their yellow iris and tail with dark bars only at the base. Males have grey heads and lack the female's "tiger stripe" pattern running across the secondaries. The plumage of this species is very variable, ranging from very dark to very light forms through various reddish and brownish hues.

In 2009-2010 SEO/BirdLife brokered a national count of nine diurnal woodland raptors (Palomino and Valls, 2011). One of the species that came into this trawl was the Honey Buzzard (Pernis apivorus) [click for general survey aspects and methodology]. According to this survey Extremadura's population comes out as an estimated 43 territories (range 29-58), 36 in the province of Cáceres and 8 in the province of Badajoz. This represents only 2.3% of Spain's total population (1850 territories), way below the figures for Galicia (710), Castilla y León (510) and Asturias (280). The mean regional density was 0.10 territories per 100 km2, a long way below the national mean (0.37); the figure was much higher in Cáceres (0.18) than in Badajoz (0.04). As expected the highest densities were recorded in Atlantic Spain; the four Galician and Asturian provinces are the only ones clocking up a mean of 2 territories per 100 km2.

The Honey Buzzard has a local range in Extremadura, with at least 5 population clusters. The main one is in the Cáceres part of the Gredos mountain chain (La Vera and the valleys of Jerte and Ambroz), then stretching westwards to Tierras de Granadilla and Valle del Alagón. The second biggest nucleus occupies the Sierra de Gata and the third Villuercas. In Badajoz there are 2 small clusters, recently discovered, one in Cíjara and the other in Tentudía. In general, Honey Buzzards choose patchwork deciduous woodland and farming habitat in areas with rainy springs. Most of Extremadura's population nests in oakwoods (Quercus pyrenaica), although in marginal areas there are also territories occupied in Cork-Oak woods and pinewoods (Cíjara).
Predictive map of the Honey Buzzard's range in Spain (Pernis apivorus), taken from Palomino and Valls (2011). Notes: (1) The highest likelihood of a Honey Buzzard sighting in the whole country is in the Cáceres part of the Gredos mountain chain. (2) The five sites with proven nesting in Extremadura are marked in red. (3) The sectors marked in grey outside these areas have no known Honey Buzzard sightings in the breeding period. (4) The Tentudía site does not feature on the map.

The lookout counts showed Honey Buzzards to be especially common in the valleys of the Jerte and Ambroz rivers , where the likelihood of sightings is the highest in the whole of Spain. Densities sometimes build up to 9 territories per 100 km2. The vehicle transects were far less successful. In Extremadura as a whole an average of only 4 Honey Buzzards were seen every 1000 km, albeit with local sightings of 3 birds per 100 km in Jerte valley. Lastly, the Honey Buzzard population trend in Extremadura is unknown, although the trend is considered to be "possibly upwards" for Spain as a whole.

So much for the results thrown up by the SEO/BirdLife survey, carried out by volunteers and drawn from complex statistical calculations, all subject to a certain error. The survey authors themselves point out that the results are lower than previous estimates (in the cases of Madrid, Catalunya and Cantabria) and should be considered as minimum figures. The same goes for Extremadura, with previous estimates of 75 pairs. The actual population might well exceed 43 territories, for in Jerte valley alone the fieldwork showed up 25 possible territories plus 12 more in adjacent areas (J. Prieta, own figures). Such doubts are inevitable when dealing with a species so poorly studied in Spain as the Honey Buzzard, a highly idiosyncratic raptor because of its diet (bees and wasps) and its short stay among us (only from May to August). The sampling period was therefore very short and the sample itself was small (detected in Extremadura in only 10 of the ten-k grids with lookout points). Other aspects of the Honey Buzzard's behaviour makes them difficult to quantify: they pair off very quickly and their wing-clapping display flight period is also very brief; the significant non-breeding population (50-85%) is very visible sometimes with sizeable flocks; territories overlap; they range over large hunting areas (7-10 km from the nest) and they rarely betray their presence with any calls (Bijlsma, unpublished). Lastly, they are sometimes hard to tell apart from Buzzards (Buteo buteo), especially when a long way off.

The fieldwork was coordinated and carried out by SEO volunteers and personnel of the Environment Board (Dirección General del Medio Natural) of the Regional council of Extremadura (Junta de Extremadura).

Sources:
- Palomino, D., and Valls, J. 2011. Las rapaces forestales en España. Población reproductora en 2009-2010 y método de censo. SEO/BirdLife. Madrid. [download in PDF format]
- Bijlsma, R. B. Inédito. Abejero Pernis apivorus. Propuesta de método de censo. Informe inédito para SEO/BirdLife.

WOODLAND RAPTORS IN EXTREMADURA (2009-2010)

Short-Toed Eagle (Circaetus gallicus). Adult feeding its chick with a Horseshoe Whip Snake (Hemorrhois hippocrepis). Photo: Juan Tevar (taken from SEO/BirdLife).

The latest Spanish Bird Monitoring Report (No.36) brought out by SEO/BirdLife deals with woodland raptors (Palomino and Valls, 2011). In the springs of 2009 and 2010 the fieldwork was carried out to ascertain national populations of seven diurnal woodland (or at least tree-nesting) raptors for the first time: Honey Buzzard, Short-Toed Eagle, Goshawk, Sparrow Hawk, Buzzard, Booted Eagle and Hobby. The figures gleaned also helped to update information on Red Kite and Black Kite, both dealt with in recent national surveys, in 2004 and 2005.

The sampling method was twofold: (1) low-speed car transects and (2) lookout points with good views. The national coverage was good, with records for 1059 10-m2 grids, 27,440 km of vehicle transects and 2614 lookout points adding up to about 9000 viewing hours. The coverage in Extremadura was very good, with 4187 km of transects in 113 grids and lookout points in 81 grids. As a region it ranked first in the number of vehicle transects and second in lookout points. The transect results are expressed as birds per kilometre, a widely employed abundance measurement that allows for comparison with previous studies; it is especially useful for raptors that hunt over open-country (buzzard, short-toed eagle, booted eagle and the two kite species). In the lookout points a note was made of all birds seen in each 10-minute period, an objective, abundance-related value that measures the observation frequency. Observers also gave their subjective estimate of the number of territories existing within the viewpoint area. On the basis of these three values (birds per kilometre, frequency and territories) a distribution and abundance map was built up for each species in Spain together with an estimate of the population size (expressed in territories, not necessarily of breeding birds). The latter result is shown in the following table:
The set of these nine raptors make up a total of 108,340 territories in Spain and 10,843 in Extremadura; this means that Extremadura ranks fourth among Spanish regions behind Castilla y León, Andalucía and Castilla-La Mancha, all bigger regions. In terms of density, however (21.5 territories/100 km2 in Spain), the Atlantic regions of northern Spain come first, as might be expected: Basque Country (28.1), Asturias (27.4), Cantabria (26.6) and Galicia (26.2). Extremadura 26.0) comes fifth in terms of density, albeit clocking up the highest density among Mediterranean regions. Behind this group, at a median level(20-25 territories/100 km2) come Castilla y León, Navarra, Andalucía, Madrid, Aragón and La Rioja. The rest of the Spanish regions (in the Mediterranean arch, Castilla-La Mancha and the Balearic and Canary Isles) do not reach the figure of 18 territories/100 km2. In terms of birds per kilometre, Extremadura comes second (3.7 birds/10 km), behind Cantabria (4.3) and ahead of Castilla y León (3.5) and Madrid (2.7). Broken down by provinces, the highest densities are recorded by Salamanca (8 birds /10 km), Segovia (4.7), Ávila (4.5), Cantabria (4.3), Cáceres (4.2) and Badajoz (3.2).

The fieldwork was coordinated and carried out by SEO volunteers and personnel of the Environment Board (Dirección General del Medio Natural) of the Regional council of Extremadura (Junta de Extremadura).

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