Patronat de Turisme de la Diputació de TarragonaDiputació de Tarragona
Terres de l'Ebre 
© R. Zaffi
© Klaus Storsberg

EbroDelta

Winter census of water birds

The winter census of water birds at the Ebro Delta, has reached 315,343 birds, an all time high since the register was started in 1972, and this is almost 30% more than the average for the last 10 years.

The winter count of water birds at the Ebro Delta is included in the International Waterbird Census (IWC), whose aim is to annually evaluate the number of water birds (ducks, waders, herons, coots etc.) that hibernate in more than 80 countries in Europe, Asia and North Africa. The information obtained gives us knowledge on a global scale of the state of conservation of these species, and evaluate the carrying capacity of the Ebro Delta wetlands. This census at the Ebro Delta was carried out between the 7th and 30th January, thanks to the participation of 41 people, including technical staff at the nature park, officers from the Rural Force and volunteers. Completing this census at the Ebro Delta, the main wetland in Catalonia, is very complex, both for the diversity of species and habitats (rice fields, lagoons, river, salt flats, bays, marshes) and for the great quantity of birds.

Globally, 315,343 water birds have been counted, which is the greatest number registered since this type of census was begun in 1972, this figure is 29.1% higher than the average winter amount over the last 10 years. The largest group are the ducks (51% of the total) with the mallard Anas platyrhynchos, common teal A. crecca and the northern shoveler A. clypeata being the most prominent, with 85,576, 28,865 and 24,260 respectively. With the mallard and gadwall A. strepera reaching 6,428 specimens, which is the highest figure in the history of this census. As they are so rare in Catalonia, there is only 1 long-tailed duck Clangula hyemalis, 1 greater scaup Aythya marila, 5 ferruginous duck Aythya nyroca and 9 marbled teal Marmaronetta angustirostris.

Waders are the second largest group of water birds to be represented, with 80,830 specimens (26% of the total). This year, for the fifth year running they have reached the highest ever in recorded history. Other impressive birds due to their number are the dunlin Calidris alpina and Eurasian lapwing Vanellus vanellus, with 44,991 and 14,687 specimens respectively. However, the little stint Calidris minuta, a species which has reached over 9,000 specimens in recent years has fallen to less than 5,600.  Among the most unexpected species are 1 specimen of pacific golden plover Pluvialis fulva - a rare American visitor, 1 specimen of marsh sandpiper Tringa stagnatilis and 11 specimens of temmincks stint Calidris temminckii.

Herons have presented very contrasting results, depending on the species concerned, as some, like the great white egret Casmerodius albus and the black-crowned night heron Nycticorax nycticorax, have reached a historic maximum, whilst others, particularly the little egret  Egretta garzetta and the cattle egret Bubulcus ibis, have shown a drop of 30-40% in relation to the last 10 years.

Other species, belonging to different groups, which are also well represented in this census have been the 17,972 greater flamingos Phoenicopterus roseus (highest ever recorded), 3,889 glossy ibis Plegadis falcinellus and 100 eurasian spoonbill Platalea leucorodia.

Groups Number of specimens
Ducks 160.025
Loons 9
Grebes 2.167
Cormorants 3.951
Herons 9.838
Other Ciconiiformes and similar 21.996
Diurnal birds of prey 868
Coots, cranes and other rails 35.060
Waders 80.830
Terns and less common gulls 536
Others 63

Total

315.343

 

Table 1. Global results for the main taxonomic groups from the winter water birds census at the Ebro Delta (2014).

 

Figure 1. Development of number of winter water birds at the Ebro Delta during the period 1972-2014.