jueves, 19 de febrero de 2009

Gaviota Rosada en la Mancha [Ross's Gull at La Mancha]

El adulto el 22.2 en la laguna de Veguilla
The adult as on 22.2 at Veguilla lagoon
(© Javier Gomez Aoiz)

El 19.2.2009 se ha observado un adulto en plumaje invernal de Gaviota Rosada (Rhodostethia rosea) en la laguna del Camino de Villafranca, Alcazar de San Juan, Ciudad Real (Rinse van de Vliet et al.).

La cita ha sido difundida por ornitólogos holandeses en las redes de notícias de internet y se ha comunicado a Rare Birds in Spain. A las 21h del 19.2 hay una foto del ave en la web Surfbirds que se puede ver aquí y que no deja dudas sobre la identificación de la especie. Se ha vuelto a ver cada día del 20 al 26.2 pero no el 27.2 para volverse a ver el 28.2 (ver foto arriba y video debajo © Delfín González). La última cita es del 1.3 por la mañana, cuando se vió salir volando alto (Pablo Gutierrez, Ignacio Torres, Raúl Bueno y Antonio Gutiérrez). La información se puede seguir en la web Rare Birds in Spain.


Gaviota de Ross, Ross Gull, Rhodostethia rosea from Delfin González on Vimeo
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Se trata de la tercera cita para España, las dos anteriores de abril de 1994 en Gipuzkoa (Txingudi, 6-11.4.1994, D.Calleja. M.Guereñu, J.Villanueva, G.Gorospe et al, Ardeola 43:113) y otra en Zumaia el 17-18.4.1994 (I.Odriozola, I.Etxabe, Ardeola 44:132), ambos ejemplares adultos mostrando diferencias de plumaje.



Ver mapa más grande

La laguna del Camino de Villafranca está al Oeste de la población (ver mapa) y ha acogido diferentes rarezas los últimos años. Se puede descargar un folleto sobre las lagunas en este enlace.

Abstract: Ross's Gull at La Mancha. The 3rd Ross's Gull for Spain was found on 19th February 2009 at Laguna del Camino de Villafranca, Ciudad Real by a team of Dutch Birders. An adult in winter plumage was photographed and its identification was straightforward. The bird remained in the area at least until 26.2 but not on 27.2 but relocated on 28.2 again. Last seen on 1.3 morning when seen circling and leaving the area. See a photo and a video from these days. Follow-ups here or in the Rare Birds in Spain website. The previous two records were in April 1994, both adults in Gipuzkoa, Euskadi. The lagoon complex, including others nearby (see map above) is part of the Mancha wetlands and a pdf leaflet (in Spanish) can be downloaded from the above link.

lunes, 9 de febrero de 2009

January 2009: unprecedented 'white gull influx' [Enero de 2009: entrada sin precedentes de 'gaviotas blancas']

Larus hyperboreus 2w. Camariñas, A Coruña. 1.2.2009 © Ricard Gutiérrez

January 2009 has totalled a minimum of 28 Iceland Gulls (Larus glaucoides) and 33 Glaucous Gulls (Larus hyperboreus) in Spain (Rare Birds In Spain, January 2009 reports page). These numbers clearly are above the average of the period 2001-2008 in which data from the RBS website has been analyzed: 3,75 birds/January for glaucoides and 2,375 birds/January for hyperboreus, with a peak in 2005 before this extraordinary year 2009 results (figure 1). A late record from 31.1 of a Kumlien's Gull Larus glaucoides kumlieni is not included in this analysis.


Records of both species were concentrated along the NW coast, particularly around A Coruña province that collected 11 glaucoides and 11 hyperboreus, a 39,29% and 34,28% respectively of the individuals recorded per species. Records, however, reached the Canary Islands, indicating an Atlantic bias in the sightings, with Glaucous gull reaching three islands (only three previous accepted records for the islands) and one sole record for Iceland, the 2nd for the archipielago (read more in the Aves Canarias blog here), see figures below.

On 24.1.2009 a heavy storm, named Klaus, brought heavy winds to the Atlantic seaboard of Spain, even reaching the Mediterranean, where human casualties were unfortunately produced by severe winds. This storm brought hundreds of Kittiwakes Rissa trydactyla overland from the Atlantic to the Mediterranean and across inland Spain, being also frequent in the Atlantic harbours (read more in the Birdspain blog here or here for the Canary Islands situation).

Given this situation it is interesting to learn if the 'white gulls' above average arrived before or after the storm: Iceland gulls arrived clearly before (see figure below) at least to Galicia, later widespreading West and South (and further more even into the Mediterranean in February 2009). Glaucous gulls, however, showed higher numbers after the storm of 24.1 (see figure below).

gca: Gran Canaria; lzt: Lanzarote; fue: Fuerteventura; pon: Pontevedra; aco: A Coruña; lug: Lugo; ast: Asturies; can: Cantabria
compiled from data in Rarebirdspain.net (January 2009 bird news) © Ricard Gutiérrez


Movements in adults of Kittiwake towards their breeding grounds have been exposed as an explanation after the large proportion of adults involved in inland sightings. Unlike Icelands (only 2 adults reported out of 28 birds: 21.1 Pontevedra and 24.1 Fuerteventura), Glaucous gulls showed a larger proportion of adults (6 out of 32 birds). It may be the case, therefore that the storm could have also affected 'white gulls' populations on the move northwards to their breeding grounds besides mid-Atlantic birds. An Nearctic origin cannot be discarded since on 31.1.2009 one and another on 1.2 plus 3.2 Kumlien's Gulls, all adults, were noted.

It will be interested to follow the situation into February 2009 to see the spread of the arrival and to attempt a quantification of the episode, a difficult task though.

Larus glaucoides 1w. Cariño, A Coruña. 31.1.2009 © Ricard Gutiérrez


Resumen: Enero de 2009: entrada sin precedentes de 'gaviotas blancas'. Se recogieron datos de 28 gaviotas groenlandesas y 32 gaviones hiperbóreos en España en enero de 2009, muy por encima de la media de los años anteriores (ver figura). Las citas se concentraron en Enero en el NW, con la provincia de A Coruña con un tercio de las citas totales. También se citaron en Canarias, siendo de las primeras citas para las especies allí. La llegada de glaucoides se produjo antes de la tormenta 'Klaus' del 24.1.2009, mientras que la de hyperboreus es claramente posterior (gráficos). Sobre el origen de los ejemplares no se puede descartar cierto componente neártico como prueban las citas de tres Gaviotas de Kumlien entre el 31.1 y el 3.2.2009. El análisis de las citas de febrero 2009 podrá explicar la expansión de la llegada de gaviotas por el resto de España.