Ten different species of geese have been seen in Extremadura to date. Apart from the Greylag (Anser anser) these include four "grey geese" of the Anser genus and five "black geese" of the Branta genus. The best sites are those that also host the biggest wintering Greylag flocks, especially Vegas Altas (up to 15,000 geese), but also in reservoirs like Valdecañas (up to 4000), Portaje, El Borbollón, Arroyoconejos or Los Canchales.
The Bean Goose (Anser fabalis) was the most numerous goose in the northern meseta until the mid nineteenth century. But the huge contraction of its wintering range has turned it into an official rarity since 2006. In Extremadura there have been only five records (11 birds) in the years 1998-99, 2002, 2005, 2007 (accepted by the rarities committee) and January 2011 (pending acceptance). It has been seen between November and February and only in Vegas Altas (Sierra Brava and Navalvillar de Pela) and Los Canchales, with records of both subspecies, the Tundra Bean Goose (beak nearly all black) and Taiga Bean Goose.
By José María Salazar.
The fourth rare goose, the Bar-Headed Goose (Anser indicus) is in fact a feral bird that originally escaped from European wildfowl collections. There have been four records in Extremadura, always a single bird, in Valdecañas (January 1987), Arroyoconejos (February 1996), Saucedilla (March 2003) and Portaje (with ring, July to October 2009).
The rest of the black geese are really rare in the region. The Red-Breasted Goose (Branta ruficollis), a species "Endangered" on a world level, has been seen only once in the region: a juvenile on 12/01/2002 in Sierra Brava Reservoir (in a flock with six species of geese and a hybrid) and on the next day in a Madrigalejo ricefield (J. Muddeman). The Canada Goose (Branta canadensis) is originally from America but now has many feral populations in Europe. The four Extremadura records (seven birds) are very scattered in time: two in Valdecañas in 1977 and 1999 and two recent in Sierra Brava and Moheda Alta in December 2009 and 2010. The Brent Goose (Branta bernicla) accounts four records, in November 1993 (Arroyo de la Luz), November 1996 (Los Canchales) and April 2008 (reservoirs of Guadiloba and Charco Salado, maybe the same bird, reckoned to be the American hrota subspecies).
- Anuarios ornitológicos of Extremadura (1998 to 2008).
- Monthly summaries of this blog (May 2010 to November 2011).
- Base de datos de Aves de Extremadura. Sergio Mayordomo (2009 and 2010, unpublished).