MORE THAN 100,000 CRANES IN EXTREMADURA (December 2012)

In December 2012 was carried on a common crane (Grus grus) census in Extremadura. As result, 95,282 cranes was counted. The coverage was almost complete, except for the region of La Serena and some roosts of Badajoz province. Estimating 6,000 cranes for no census areas, the final figure reached 101,000 cranes. The breakdown by areas is as follows: Zona Centro 63,207 individuals (62%), 22,292 Tagus basin (22%) and Guadiana basin 15,783 cranes (16%). Since a census of this scope is necessarily incomplete, it is possible that 120,000 cranes were present in Extremadura during winter 2012-2013. If we also consider that in February 2013 200,000 cranes have stopped at Gallocanta lagoon (Aragón), the figure of 120,000 cranes in Extremadura makes sense.

Two different methods have been used, on the one hand the traditional counting roosting, when cranes meet in wetlands to spend the night, and day counts at foraging areas. The latter has been used in the Zona Centro (Vegas Altas), one open agricultural region, with good visibility and extensive road network.

The comparison by sectors over the previous census of December 2007 (Prieta and del Moral, 2008) is shown in the table. For the whole of the region is estimated an increase of 20%. The Zona Centro grows very substantially (+65%), being the sole responsibility of the total increase. The Tagus basin remains very stable (+0'1%), offsetting rising sectors (Alagón and Almonte) those that decrease (Navalmoral and Cáceres). By contrast, the rest of the Guadiana basin, excluding La Serena, shows a drop of nearly 6,000 birds (-23%), mainly in the southern sectors of Alange and Azuaga. However, a census is a still image on a certain date and in the case of the crane wintering numbers can vary greatly between weeks in one place. Thus, after the census presented here, some sectors decreased (the Zona Centro declines slightly to 56,000 birds in January and February 2013), others areas were stable (Alagón) and other increased remarkably (Navalmoral rose by more than 4,000 cranes on February), to give some examples.

The evolution of the common crane population in Extremadura, as shown in the graph, remains positive with continued increases from the first data available in the 1980s. For the first time it has been found a figure of over 100,000 birds in the region, a value that duplicates the censuses conducted two decades ago (about 50,000 birds on average in 1989-1993 and 60,000 in 2001). All in accordance with the increase in Western Europe, where the current population is at least 300,000 cranes.

Sources: 

- Román, J. A. y Gómez Calzado, M. 2013. Invernada de la grulla común (Grus grus). Resultados del censo de diciembre de 2012 en Extremadura. Published on 26-03-2013, blog "Grullas Veo".

- Prieta, J. and Del Moral, J. C. 2008. The common crane wintering in Spain. Population in 2007 and census method. SEO / BirdLife. Madrid. [Download] 

Acknowledgements: This work would not have been possible without the invaluable participation of dozens of people who have dedicated time and effort as volunteers. 

Coordinators: Jose Antonio Roman, Manuel Gómez Calzado and Javier Prieta. Collaborators: Samuel Langlois, Dave Langlois, Manuel Flores, Marcelino Tirado, José María Guerrero, Jorge Pedro Durán, Sergio Méndez, César Clemente, Javier Mahíllo, Goyo Naharro, Agustín Iglesias, Vicente Sánchez, Javier Prieta, Sergio Mayordomo, Iván Hernández, Carlos Fernández Diaz, José Carlos López Fuentes, Marcelino Cardalliaguet, Andrés Maestre, Carlos Luengo, Marta Gómez, Javier Esteban, Martin Kelsey, Jesús Porras, Vicente Risco, Santiago Cáceres, Javier Caballero, José Luis Caballero, Estela Herguido, Antonio Galán, Helios Dalmau, Agustín Martín Ruano, José Antonio Pérez Burón, Daniel Pérez, Luis Venancio, Pedro Schreur, Justo Tarriño, Godfried Schreur, Jacobo Hernández, Jerónimo Milán, Jesús Solana, Francisco Lopo, Elvira del Viejo, Lucas J. Navareño, Carolina Climent, Iván Sánchez, Antonia Cangas, José Antonio Román, José Ángel Sánchez, Luis Salguero, Antonio Núñez, Gustavo Gahete, Francisco Montaño, Miguel Corvillo, Alfonso Pérez del Barco, Esther Gañán, Chema Traverso, Carmen Galán, Yasmina Annichiarico, Natalia Franco, Amparo Sánchez, Agustín Santana, Víctor Manuel Quintana, Manuel Calderón, Teresa Tena, Gerardo Pizarro, Fernando Pizarro, Manuel Gómez Calzado, Antonio Torrijo, Fernando Salas, José Luis Ciudad, Emilio Peña, Marc Gálvez, José Guerra, Fernando Yuste, Juan Pablo Prieto, Manuel Iglesias, Marisa García, Juan Carlos Núñez Crespo, Juan Manuel Rodríguez, Juan Miguel Segador, Gabriel Vidal, Manuel Azabal, Amalia Sánchez, Javier Monforte, José Leonardo Baena, Raúl Calle, Taimar Domínguez, Luis Bernardo Flores, Juan Pablo García, Pablo Hernández, Jorge Jara, Jaime Jiménez, Pablo Jorge Díaz, Alberto León, Mario Martín, Daniel Martín, José Antonio Mateos, David Morón, Antonio Moyano, Abel Murillo, Álvaro Rodríguez, Andrés Rodríguez, Juan Sánchez, Alberto Sánchez, Blas Serrano, Janette Valhondo, Antonio Ávila, Francisco Javier Alba, Juan Gabriel Díaz, Jorge Domínguez Patricio Liberal, Rubén Marcos, Álvaro Martín, David Neila, Valentín Pérez, Carlos Pinos, Juan Carlos Recio Borja Retamal, Ángel Rodríguez, Francis Rodríguez, Cristian Salguero, Juan Marcos Simón, Saúl Torrescusa, Juan Carlos Velarde, Jesús Sánchez, Pedro Muñoz, Jaime Rodríguez, Luis Alberto López, Juan Pablo Resino, Azucena Díaz.