Birds in Spain Blog

  En data 12.4.2012 vaig trobar un ocell de segon any calendari (Euring 5) de Gavina de Delaware ( Larus delawarensis ) al terme municipal de Deltebre, al Delta de l'Ebre, Baix Ebre. L'ocell, amb el plomatge força desgastat que podem atribuir a un primer estiu restava alimentant-se i descansant a un filtre verd de nova construcció a la zona, prop de gavians de potes grogues ( Larus michahellis ).   La Gavina de Delaware va ser considerada raresa al conjunt de l'estat espanyol fins el 2005 inclòs moment en el que es va descatalogar com a tal restant però amb aquesta consideració dins l'àmbit català i essent, a partir d'aquell moment, estudiada pel Comitè Avifaunístic Català. Amb tot sempre ha estat una veritable raresa a Catalunya i fins 2005 només hi havia tres cites homologades a casa nostra (De Juana 2006) mentre que les posteriors escassegen: una el 2006 homologada pel CAC (Pedrocchi en López & Clavell 2009) i al portal ornitho.cat hi figura una...

Larus delawarensis , Málaga 3.2.2011 © Adam Wilson Adam Wilson & Dominic Davidson saw a Ring-billed Gull ( Larus delawarensis ) at Guadalhorce river mouth, Málaga, on the 3rd of February 2011. In the report they sent to this blog and the rarities committe (despite the species is no longer a national rarity) they quote as follows: 'I picked up the bird preening and bathing at the edge of the river near the sea. I jogged within earshot of Dom, who was getting something from the car, and told him I had a Ring-billed Gull. We both then watched it for half an hour as it continued to bathe and preen. It was slightly bigger than the nearby Black-headed Gulls, and therefore clearly not one of the large white-headed gull species. The legs were pale green. The bill was broader than Common Gull. The basal two-thirds were yellow, sharply demarcated from the black distal part of the bill (almost a third), which was in turn sharply demarcated from the yellow tip. The bill wasn’t quite as ‘...

Delfín González, which contributes to Rare Birds in Spain since its very first day, photographed the enclosed gull, a possible hybrid Lesser Black-backed x Ring-billed Gull at Colmenar Viejo dump, Madrid, on 28 November 2010. The gull-watchers visiting the dump think that it is the same bird they saw in the area in October 2008 and 2009, having been seen the three years during the same day within a 15-day period. Any comment? Delfín González, que colabora con Rare Birds in Spain desde el primer día, fotografió la gaviota adjunta, posible híbrido de Sombría x Delaware en el VRSU de Colmenar Viejo, en Madrid, el 28.11.2010. El equipo de autores que observan gaviotas en la zona piensan que se trata del mismo ejemplar que observaron en la zona en Octubre de 2008 y 2009, habiéndose observado los tres años el mismo mes con un margen de 15 dias. ¿Algún comentario?