SPANISH IMPERIAL EAGLE: FALSE ALARM

Spanish Imperial Eagle (Aquila adalberti). Adult perched next to its nest. Monfragüe, spring 2010. Photograph taken from 2.5 km away (Javier Prieta).

A previous blog entry expressed some alarm at the apparent fall of Extremadura's population of Spanish Imperial Eagle (Aquila adalberti) from 49 to 41 pairs in two years. These fears were based on the figures sent up by the Regional Government of Extremadura to the national Environment Ministry. At the time, given the unofficial nature of the information we published this bad news with all due caveats. Happily, this apparent decline turns out not to be true, since Extremadura's actual Spanish Imperial Eagle population in 2009 was 47 pairs. This more up-to-date information comes from regional press reports of a visit by EU officials to assess the results of the EU "LIFE Programme" initiative to help conserve this raptor in Spain [read more here]. While waiting with bated breath for the official 2010 figures, which might be somewhat brighter, at least we know that the species has been holding pretty steady in the region in recent years, with a medium term increase since reliable counts have been made. We publish below new graphs of the Spanish Imperial Eagle to correct the ones previously shown in this blog.

PREPARING THE WINTERING HERON COUNT: LOOKING FOR ROOSTS

Mixed heron roost on the River Alagón (Montehermoso, Cáceres). In winter 2007-2008 the count was 5281 Cattle Egrets (Bubulcus ibis), 150 Little Egrets (Egretta garzetta) and 8 Great White Egrets (Egretta alba). In October 2008 it was occupied anew before being abandoned in November and has never been used since (figures provided by César Clemente and Javier Mahillo).

Every year SEO/BirdLife organises one or more counts of particular bird species or families. In 2011 it's the heron family's turn. A count of wintering birds will be carried out in January before tackling a count of breeding colonies later on. A particular value of this winter count is that it will then be fed into the Spanish Atlas of Wintering Birds, just like the recent coordinated counts of Cranes (December 2007) and gulls (January 2009).

Although several members of the heron family winter in Extremadura, only roost-forming species really lend themselves to systematic counts. The most abundant species in Extremadura is the Cattle Egret (Bubulcus ibis), followed by the Little Egret (Egretta garzetta) and at some distance by the scarcer Great White Egret (Egretta alba). The other heron species have been ruled out of the count, for various reasons. The Grey Heron (Ardea cinerea), although quite numerous, does not form roosts and is not usually gregarious. The Night Heron (Nycticorax nycticorax), although it forms big roosts in Doñana, is basically a summer visitor in Extremadura (albeit with the odd wintering bird). Other summer visitors that sometimes linger on into winter are the Squacco Heron (Ardeola ralloides) and the Purple Heron (Ardea purpurea). Lastly, the Little Bittern (Ixobrychus minutus) and Bittern (Botaurus stellaris), both very shy, have also been left out of this count.

The first step in the project is to find the roosts where the herons congregate each evening. The aim is to sound out the situation before 10 January 2011 and, if possible, by 31 December 2010. The next step will then be to count the birds in all known roosts in January. The ideal situation, volunteers permitting, would be coordinate all counts in the weekend of 14 to 16 January 2011, otherwise the count would have to extended to other dates in January. We therefore need your help: first by communicating any Extremadura heron roosts you may know about and secondly by then taking part in the count (for both purposes send an email to seo.caceres@gmail.com).

The only previous info on wintering herons in Extremadura comes from the Iberian counts carried out in 1992 and 1993 (Fernández-Cruz and Farinha, 1992; Sarasa et al., 1993). The overall results of both counts threw up figures of about 160,000 Cattle Egrets, 10,000 Little Egrets and 1500 Night Herons, with a few Great White Herons, Squacco Herons and Purple Herons thrown in for good measure. The results were broken down by river-catchment areas, so no regional figures are available. Even so, we estimate ball-park figures of 42,000 (1993) and 53.000 (1992) Cattle Egrets in Extremadura, above all in irrigated farmland and more numerous in the Guadiana catchment area (30-35 thousand) than in the Tagus catchment area (13-17 thousand). The Extremadura population is therefore very important (one third of the Iberian total); in 1992 the region also boasted Iberia's biggest roosts (the biggest with 7820 birds in Arroyo Concejo, Cáceres). The Little Egret, with a more coastal range, is less common in the region, accounting for 10% of the Iberian total. Even so the estimated Extremadura winter population is about 1500 for 1992 and 700 for 1993. Once more the Guadiana catchment area comes out tops. The lower 1993 figures for both species can be put down to the drought that hit the area at that time. This information, quite old by now, is only a rough guide for tackling the 2011 count, because many variables might well have changed since then, such as the number and site of landfill sites, new reservoirs, new irrigated farmland and ricefields,...). Prima facie, there now seem to be fewer but bigger roosts than in 1992 and 1993. Anyway, enough chat and let's get down to it!

Distribution maps of Cattle Egret roosts (top) and Little Egret roosts (bottom) in January 1992 (Fernández-Cruz & Farinha, 1992).
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References:
- Fernández-Cruz, M. & Farinha, J. C. 1992. Primer censo de ardeidas invernantes en la penínsulas Ibérica y Baleares (1991-92). Airo 3:41-54. [PDF]
- Sarasa, C. G., Bartolomé, J., Fernández-Cruz, M. & Farinha, J. C. 1993. Segundo censo de ardeidas invernantes en la penínsulas Ibérica y Baleares (1992-93). Airo 4:41-50. [PDF]

NOVEMBER 2010: Notable bird sightings in Extremadura

Firecrest (Regulus ignicapilla). Valdesalor, Cáceres, 29-10-10 (Carlos Fernández Díaz).

A list of the most notable records sent to the GOCE forum in November 2010 (compiled by Sergio Mayordomo).

-Alpine Accentor: 3 at Monesterio (Badajoz) on 27/11 and 6 flocks with 40 birds on passage at Ladrillar, Las Hurdes (Cáceres) (A. Pacheco).
-Osprey: one at Arrocampo Reservoir (Cáceres) on 1/11 (Jaime Collado), at Mérida (Badajoz) on 21/11 (Á. Sánchez) and at Gabriel and Galán Reservoir (Cáceres) on 25/11 (A. Pacheco).
-Booted Eagle: pale phase bird seen at Plasencia (Cáceres) on 3/11, at Montehermoso (Cáceres) on 13/11 (J. Mahillo) and at Mérida landfill site (Badajoz) on 28/11 (Á. Sánchez).
-Egyptian Vulture: 2 adults and one juvenile in the centre of Cáceres province on 1/11 (E. Palacios and M. Á. Muñoz).
-Pink Footed Goose: 2nd record for Extremadura (pending acceptance): one bird on 27/11 feeding on rice stubble at Casas de Hitos (Cáceres/Badajoz) with about 500 Greylags (J. M. Salazar, J. Vilches, J. Arias and Fran).
-Little Bittern: wintering birds on the River Guadiana: one bird at Mérida (Badajoz) on 12/11 (Á. Sánchez) and 3 birds at Badajoz on 12/11 and 2 on 28/11 (J. C. Paniagua).
-House Martin: 15 at Valcorchero, Plasencia (Cáceres) on 11/11 (E. Palacios and S. Mayordomo) and on 12/11 (M. García del Rey).
-Avocet: 9 at La Albuera on 7/11 (J. C. Paniagua) and on 26/11 (J. P. Prieto). 6 birds on ricefields between Palazuelo (Badajoz) and Madrigalejo (Cáceres) on 14/11 (M. Kelsey). 10 on the River Alagón at Riomalo de Abajo (Cáceres) on 23/11 (A. Pacheco).
-Goshawk: one at Salto del Gitano, Monfragüe (Cáceres), on 10/11 (J. L. Rivero).
-Short-Eared Owl: one in the open countryside called Campiña Sur (Badajoz) on 21/11 (A. Núñez).
-Purple Swamphen: one at Valdefuentes gravel pit, Galisteo (Cáceres) on 12/11 (S. Mayordomo). Late breeding record: adult and fledgling on 14/11 at Arrocampo (Cáceres) (J. Briz).
-Garganey: one female at Valdefuentes gravel pit, Galisteo (Cáceres) from 1/11 to 15/11 (J. Prieta and S. Mayordomo).
-Kentish Plover: 3 on ricefields between Palazuelo (Badajoz) and Madrigalejo (Cáceres) on 14/11 (M. Kelsey).
-Dotterel: one juvenile at Guijo de Coria (Cáceres) on 2/11 (J. Prieta) and on 3/11 (S. Mayordomo).
-Red-Billed Chough: one at Mirabel landfill site (Cáceres) on 7/11 (S. Mayordomo) and at San Vicente de Alcántara on 28/11 (J. Gordillo).
-White Stork: first birds at nest on 18/11 zt Zafra (A. Núñez), on 27/11 at San Vicente del Alcántara (J. Gordillo) and on 28/11 at Badajoz (J. C. Paniagua).
-Black Stork: wintering birds at Oliva de Plasencia (Cáceres): one on 10/11 (R. Montero), three on 14/11 (R. Vicente) and six on 17/11 (J. Prieta). Two birds at Moheda Alta, Navalvillar de Pela (Badajoz) on 27/11 (Á. Sánchez).
-Quail: one bird in an olive grove at Mohedas de Granadilla (Cáceres) on 16/11 (A. Pacheco).
-Pin-Tailed Sandgrouse: three flocks with 250 birds at Santa Marta de Magasca (Cáceres) on 10/11 (M. Kelsey).
-Squacco Heron: one on ricefields at Palazuelo (Badajoz) on 14/11 (M. Kelsey).
-Mediterranean Gull: one at Mérida landfill site (Badajoz) on 4/11 and two on 7/11 (Á. Sánchez).
-Common Gull: one first-winter bird at Mérida landfill site (Badajoz) on 4/11 and two on 7/11 and 28/11 (Á. Sánchez).
-Yellow-Legged Gull: several at Mérida landfill site (Badajoz) on 7/11 and two on 28/11 (Á. Sánchez).
-Black Kite: two at Navalmoral de la Mata (Cáceres) on 1/11 (J. Briz, M. García del Rey and V. Risco) and a juvenile at Cáceres on 10/11 (M. Kelsey).
-Tufted Duck: 71 birds at Charca de Brozas (Cáceres) on 28/11 (E. Palacios and S. Mayordomo).
-Goldcrest: two in Mediterranean woodland at Monfragüe (Cáceres) on 6/11 (S. Mayordomo). Abundant in the pinewoods of Las Hurdes (Cáceres) during the 2nd week of November (A. Pacheco). Three at Cabezabellosa (Cáceres) on 9/11 (R. Montero).
-Shelduck: 3 at Valdecañas Reservoir (Cáceres) on 25/11 and 12 at Moheda Alta, Navalvillar de Pela (Badajoz) on 27/11 (Á. Sánchez).
-Black-Necked Grebe: 2 at Charca de Brozas (Cáceres) on 28/11 (E. Palacios and S. Mayordomo).

Lingering summer visitors
-Wheatear: One at Villanueva de la Vera (Cáceres) (Dave Langlois) and 5 at Acehúche (Cáceres) (E. Palacios and M. A. Muñoz) on 1/11. One at Guijo de Coria (Cáceres) on 2/11 (J. Prieta).
-Willow Warbler: two at Talaván Reservoir (Cáceres) on 1/11 (Antonio Ceballos).
-Alpine Swift: One at Mérida (Badajoz) on 12/11 (Á. Sánchez).

First wintering visitors
-Brambling: One female at Cornalvo (Badajoz) on 12/11 (José Ledo).
-Redwing: One at Villanueva de la Vera (Cáceres) on 1/11 (D. Langlois).

NORTH-AFRICAN LONG-LEGGED BUZZARD IN EXTREMADURA: THE TIP OF THE ICEBERG?

North-African Long-Legged Buzzard (Buteo rufinus cirtensis), adult in captivity. September 2010, Plasencia, Cáceres (J. Prieta). Typical adult with rufous plumage, pale breast and darker thighs ("trousers") and unbarred reddish tail.

The Long-Legged Buzzard (Buteo rufinus) lives in North Africa (cirtensis subspecies) and in Eastern Europe (rufinus subspecies); it is hard to tell apart from the Common Buzzard (Buteo buteo). Check out specialist guides and internet sites (e.g., , here, here and here) to find out more about its complex identification features. As a general rule, however, any particularly pale or rufous buzzards in the field should be checked carefully. The Buzzard is a notoriously variable species but the birds in Extremadura, where it is abundant, are usually dark and fairly uniform.

The Long-Legged Buzzard is classed as a rare vagrant in Spain and observations have to be vetted by SEO's Rarities Committee. Taking only officially accepted records into account, it comes out as extremely rare in Extremadura, where there has only been one confirmed observation: an adult of unknown subspecies seen on 06/12/05 in Regina, Badajoz (J. J. Ramos Encalado, Ardeola 54:419). Possibly the same bird was seen in the same site on 25 and 26/12/05 and in January 2006 (Javier Salcedo et al). The tip of the supposed iceberg is therefore tiny. And to give a good idea of the identification difficulties, this particular bird was considered by some observers to be a Steppe Buzzard (Buteo buteo vulpinus).

Long-Legged Buzzard (Buteo rufinus) dark adult. 1-5-2009. Regina, Badajoz (drawing and fieldnotes by Juan José Ramos Encalado). The uniformly red tail tells us it's an adult.

There are now at least three other observations up before the Rarities Committee. One from 01/05/09 in Palomas, Badajoz (Antonio Matador): a 2nd-year bird, possibly of the cirtensis subspecies, casually photographed without the least idea it could be a Long-Legged Buzzard and then confirmed by several experts (Andrea Corso, Ernest García, Javier Elorriaga). Curiously enough, on the same day and only 35 km away an immature was recorded between Usagre and Hinojosa (Xurxo Piñeiro), but we don't know if this record has been sent in to the Rarities Committee.

Buzzard (Buteo sp.). Possible Long-Legged Buzzard (B. rufinus) immature. 1-5-2009. Palomas, Badajoz (Antonio Matador). It shows rufous plumage, pale breast and dark "trousers". The lightly barred tail tells us it's an immature.

Another two were recorded in 2010, once more 2nd-year cirtensis, near Trujillo, which might be two birds or the same bird seen twice: on 11/06/10 in Belén, to the east of Trujillo (Ernest García; ex member of the Rarities Committee) and on 22-23/06/10 in Los Cerralbos, to the west of Trujillo (Martin Kelsey). In this same zone there were other tentative observations in April and May that have not been sent up for acceptance.

Buzzard (Buteo sp.). Possible Long-Legged Buzzard (B. rufinus cirtensis) immature. 11-6-2010. Belén, Trujillo, Cáceres (Ernest García).

Further west there are other uncertain records, including one on 10/4/10 between Cáceres and Santa Marta de Magasca of another possible immature (Godfried Schreur and Jan van Schaik).

Buzzard (Buteo sp.). Possible Long-Legged Buzzard (B. rufinus), immature. 10-4-2010. Between Santa Marta de Magasca and Cáceres (Jan van Schalk).

On 18/4/10 a different bird was again seen in Santa Marta de Magasca: an immature female with some rufinus features. This bird was accompanied by a male Common Buzzard, both giving out the characteristic Buzzard mew and showing similar behaviour (John Muddeman and John Cramer).

Buzzard (Buteo sp.). Possible Long-Legged Buzzard (B. rufinus), immature. 18-4-2010. Santa Marta de Magasca, Cáceres (John Cramer).

The Long-Legged Buzzard may well be more common in Extremadura than it seems, especially if we include in our trawl observations that were never sent in for ratification for one reason or another (identification doubts, groups of tourists pushed for time, lack of interest, etc.). Since 2005 there has been a series of possible Long-Legged Buzzard sightings. With all due caveats when working with unratified records, SEO-Cáceres has compiled the following list:

* 2005. At least 6 birds in April-May 2005 in Trujillo (3), Llanos de Cáceres (2) and Vegas Altas (1). In Belén, Trujillo, three birds, two light and one dark, recorded by at least 14 different observers between 17/04 and 29/05/05. First record of a light bird and another dark bird on 17/04/05 (S. Villa, T. Driscoll and B. Driscoll); the light bird was seen on 19/04/05 and 20/04/05 (J. Muddeman); on 20/04/05 a dark bird was seen hard by in Torrecillas de la Tiesa (J. J. Saiz); a bird on 22/04/05 and on 23/04/05 (M. Kelsey); a bird on 1/05/05 (Á. Molina and A. López; J. Portillo and J. Portillo) and on 5/05/05 (S. Villa); a bird was seen on 8/05/05 (A. López and J. Diego Acevedo); the bird was still present on 29/05/05 (K. Parker, G. Dodd); in May two light birds were seen (J Muddeman) and one dark (S. Villa). In Cáceres-Santa Marta de Magasca, 25 km west of Belén: two putative birds of the cirtensis race in late April 2005 (S. Villa, J. Boyes and J. Boyes) and a dark bird in May (S. Villa). In Vegas Altas: one light bird in May 2005 (J. Muddeman).
* 2006 and 2007. No information.
* 2008. One putative juvenile in Belén, Trujillo, on 4/05/08 (S. Villa)

Buzzard (Buteo sp.). Possible Long-Legged Buzzard (B. rufinus). April 2004. Belén, Trujillo, Cáceres (Santi Villa).

Let's hope the picture becomes clearer in the future. At present we have little to go on but the supposed presence of 2nd-year cirtensis birds in Spring in steppeland areas could reflect the dispersal of immature Long-Legged Buzzards from North Africa to southwest Iberia. The species has been breeding in Andalusia at least since 2009 (Elorriaga & Román, 2010), and in 2010 there were cases there of hydridisation with Common Buzzard (J. Elorriaga, pers. comm.); precedents of such crosses are known from Italy. Given the close genetic similarity of both species the hybrids might well be fertile. And if these crosses are occurring unbeknown to us there might be hybrids from more than one generation at large in the field, exacerbating the identification difficulties even more. Moreover, the taxonomy has not yet been well defined, since the morphologically different buzzards from the Western Palearctic are genetically very similar. Some authorities consider them to be subspecies rather than full species; on the other hand other pundits separate "B. cirtensis" as a full species in its own right. To complicate matters even more, a recent study moots the validity of the Iberian subspecies B. buteo hispaniae, morphologically different from other European forms (Kruckenhauser, et al., 2004) and sometimes showing a reddish tail.

Acknowledgements: thanks to Javier Elorriaga for his help in identifying the photos and his input of information. To Sergio Mayordomo for compiling the previous records (2005-2008). To the colleagues of GOCE forum who have swapped observations and opinions.

Sources:
- Elorriaga, J. & Román, A. 2010. Primeros casos de reproducción e invernada del busardo moro en la península ibérica. Quercus, 293:32-34. [read more]. Results on 2010, Quercus 298:15.
- Kruckenhauser, L., Haring, E., Pinsker, W., Riesing, M. J., Winkler, H., Wink, M. & Gamauf, A. 2004. Genetic vs. morphological differentiation of Old World buzzards (genus Buteo, Accipitridae). Zoologica Scripta, 33:197-211. [PDF]