Informations : José Miguel Pueyo, Arkadiusz Broniarek, Javier Mañas, Antonio Torrijo
These are the Official census of cranes in Gallocanta lagoon (North East of Spain) in migration (realizated by SODEMASA company & Aragon Government)
The lake of Gallocanta is a shallow inland saline lake of 1,400 hectares.. It is situated at an altitude of 990 metres in the heart of the Iberian Chain, in the north-west of the Iberian Peninsula, between the provinces of Zaragoza and Teruel (Aragon community).
Underground water has an important influence on the lagoon water level. The Gallocanta Lagoon is the biggest inland brackish lagoon in Europe with 7 kilometers long and 2.5 kilometers wide in its central part. The climate of the area is Mediterranean-continental, with temperatures ranging between -21 °C in winter and 30°C in summer. Rain is uncommon and irregular (450 mm a year), but it snows in winter and there are storms in summer.
The lagoon is surrounded by halophytic vegetation. In some other more localized places, the vegetation is higher (sedge and reed). The surrounding landscape is open, with many corn fields and also a few sunflower fields. All of them are very productive. Maize production began a few years ago thanks to irrigation. Dryness has been extreme in the past years. The importance of floods is decreasing, especially in autumn and winter, and dryness is very strong in summer. The most important floods occurred in the 70s, when we counted the highest number of water birds.
The period 1989/1992 was the last period of important flooding in the lagoon. 260 species of birds have been noticed in this varied biotope, including 126 nesting species.
The lagoon is of a great ornithological interest for migratory species, especially in winter for Common Cranes (Grus grus) as it is situated on the migration lane, between the Pyrenees and the cranes wintering areas in Spain. The migration periods coincide with the corn production cycle: sowing in autumn and at the end of winter. Cranes visit us in big numbers during the whole winter (around 25,000 individuals winter here), with occasional peaks of up to 130,000 individuals at the time of the pre-breeding migration. Other migrating birds like storks and flamingos use the water body to rest.
The lagoon surroundings can thus supply cranes with much food, but this means direct consequences on the local agricultural activity.
Anatidae are very abundant on the Gallocanta Lake, especially on wet years when the number of aquatic birds can reach over 200,000 in addition to the breeders staying in spring and summer. During the winter it receives birds from northern latitudes increasing the numbers and variety of this group of birds.
The importance of the lagoon for water birds depends on its flooding level: winter is a very important season for the populations of Common Pochard (Aythya ferina) with a maximum of 80,000 individuals, of Red-crested Pochard (Netta rufina) with 35,000 and of Common Coot (Fulica atra) with 40,000.
On the shores and especially in the places where fresh water enters the lake, among rushes and reeds, we can find insectivorous birds like Sylviidae. Even though they are virtually absent in summer, some of them breed here, but with the post-breeding migration at the end of summer the numbers greatly increase, and it is possible to observe the rare Aquatic Warbler (Acrocephalus paludícola).
In the fields of cereals, it is easy to find Alaudidae and Fringillidae, which form big flocks during autumn and winter, and other steppe land birds: Great Bustard (Otis tarda), Little Bustard (Tetrax tetrax), Black-bellied Sandgrouse (Pterocles orientalis) and the Eurasian Stone Curlew (Burhinus oedicnemus) which usually gathers in small numbers at the end of summer and the beginning of autumn to travel further south where they winter. In the shrubbery no taller than 40 cm, the Dupon’t Lark (Chersophilus duponti), an elusive bird, scarce in the rest of the world, keeps here a healthy population; it is very difficult to see, even during the breeding season when it is really easy to hear its song.
The birds of prey inhabiting this territory are typical of open country with a few species characteristic of woodland. In 2014 there has been a substantial increase in the population of Common Vole (Microtus arvalis), and therefore, so this year was remarkably good to observe this kind of birds in the area, both because of the numbers (tripling that of a normal year) and the diversity: uncommon species for this place like Short-eared Owl (Asio flammeus), Black-winged Kite (Elanus caeruleus) and Bonelli’s Eagle (Hieraaetus fasciatus) were noted. Moving around the heaps of stones and old constructions in the country we can find the more and more unusual Little Owl (Athene noctua).
The Gallocanta Lagoon is listed as ZEPA, it is also listed as a wetland of international importance, according to the RAMSAR Convention. Hunting is forbidden in the lagoon except in August and September (Quail hunting -Coturnix coturnix). -
Friends of Gallocanta Association (AAG) is a naturalist entity created by a group of volunteers on 2002, coinciding with the World Bird Day. Its main objectives are the conservation of natural, cultural and environmental heritage of the Gallocanta lake and its basin, the spread of the economic, cultural and environmental values and respect for nature. AAG try to give support to local initiatives and they help with initiatives in the rural areas, and cooperation with other related entities.
Since its inception the AAG has promoted and carried out numerous activities that have somehow reversed in the Gallocanta lake and its people positively.
Similarly, it has taken part in various European Congresses on the Common Crane (Sweden, Hungary, Germany, Russia), and has even participated with the Swedish German associations in the ringing, in those countries, of one of the cranes groups which then visit our lands.
The last challenge AAG has developed is the organization of the VIII European Congress on the Common Crane in 2014.
In observing these ringed cranes we have been working on a voluntary basis since 1999.
Informations: Association des Amis de Gallocanta