Thursday 6 September 2012


A Spain-wide Cormorant (Phalacrocorax carbo) count was carried out in summer 2012. The provisional results for Extremadura, while awaiting publication of the overall data, are as follows.

Three colonies were found with a total of 651 occupied nests. The biggest colony, in La Serena reservoir, was visited twice. It comprises 619 nests in two clusters, the main one with 614 nests on half-sunken Holm Oaks and the other only 2 km away with 5 nests on Eucalyptus. The other two colonies found seem to be new, or at least unrecorded hitherto. One was at Alange reservoir, where a 23-nest Eucalyptus colony was found by chance on 12/07/12 (upper photograph; by Ángel Sánchez). The other new colony was at Alqueva reservoir, again on half-sunken Holm Oaks, with 9 nests counted on three visits from May to June. [Other post on Cormorant in Extremadura]

The Extremadura Cormorant trend is clearly upwards, with an exponential increase in only 10 years. Barring the one-off nest in Valuengo reservoir found in 1993 (Prieta and Mayordomo, 2012), the first Extremadura colony formed in La Serena reservoir in 2002. This colony grew from 10 pioneering pairs in 2002 to 102 in 2007 and 341 in 2011 (including 13 in Córdoba and one in Ciudad Real; Piñeiro, 2011) and 619 by 2012. Unless the final census results prove otherwise, this could well turn out to be Spain's biggest colony today. In 2007 there was a national breeding wildfowl count, including the Cormorant(Palomino and Molina, 2009). The published result included three Extremadura colonies, the abovementioned one in La Serena and another two at River Guadiana in Valdetorres and at Valuengo reservoir. There is however no trustworthy information on these two ostensible colonies, with no indications of actual or recent nesting in 2011 or 2012. The prudent option is therefore to rule them out. In 2012 two new colonies were found, once more on big reservoirs of the Badajoz basin, and regional figures have doubled in a single year. [Other blog entries on the Cormorant in Extremadura]

Collaborators. The La Serena and Alange colonies were found by the Junta de Extremadura: Ángel Sánchez, Domingo Rivera, Sergio Pérez, Miguel Ángel Sánchez, Fermín Sierra, Demetrio Vázquez, Irene Rodríguez, Sandra Blanco, José Manuel Rama and José María Castaño. The Alqueva colony was covered by Luis R. Hernández Díaz-Ambrona and Juan Carlos Panigua (SEO/BirdLife volunteers). 

- Piñeiro, X. 2011. Cormorán grande Phalacrocórax carbo (p. 487). In, Molina, B., Prieta, J., Lorenzo, J. A. and López-Jurado, C. Noticiario Ornitológico. Ardeola 58:481-516. 
- Palomino, D. and Molina, B. 2009. Aves acuáticas reproductoras en España. Población en 2007 y método de censo. SEO/BirdLife. Madrid. 
- Prieta, J. and Mayordomo, S. 2012. Aves de Extremadura, vol. 4. Años 2004-2008. Grupo Local SEO-Cáceres. Plasencia. [PDF]