The Egyptian Goose (Alopochen aegyptiacus) is one of the most numerous of the African Anatidae. Mainly sedentary, it is native to Africa south of the Sahara and in the Nile valley. It also has thriving feral populations in some European countries, estimated to be about 2000 pairs at the end of the twentieth century. Most of these feral birds are in the UK (700 pp. in 2000) and Holland, with a growing number in Belgium and a scattering of birds in Germany and France. In 2009 it was officially declared to be a pest species in the UK.
In Spain it was considered to be a rare vagrant until 2006; it is currently listed as an introduced species breeding sporadically without established populations (Grupo de Aves Exóticas). A check of the records up to 2003 (De Juana, 2006) shows year-round presence with winter peaks. This is explained by the arrival of birds from Europe and escapes from wildfowl collections, plus the birds born in Spain from feral birds.
Egyptian Goose (Alopochen aegyptiacus), pair of adults with nine chicks (only eight seen in the photo). Ibahernando Reservoir, 5-10-10 (Genaro Sánchez Peña)
As with most introduced species the number of sightings in Extremadura has shown an upward trend since the first record in 1993, becoming almost regular after 2007 when the first proved breeding occurred near Trujillo. Up to 2008 there has been a total of 19 records involving 60 individuals, 49 of them in 2007 and 2008 and with peaks in October and September. Taken together the sightings tally with the three abovementioned hypotheses about their origin. Some are obviously escapes, such as the birds seen in Sierra Brava and Casas de Hitos, where there is a large wildfowl collection nearby. Other individuals seem to come from the European population, such as the pair of adults with two juveniles seen in Talaván (middle photo). Lastly, there are the birds that breed in Extremadura, though there is as yet only one known breeding pair in Ibahernando Reservoir, Cáceres, which bred at least in 2007 (6 young), 2009 (11 young) and 2010 (9 young; bottom photo) (Julián Panadero; Genaro Sánchez Peña; Steve Fletcher). But there are other birds whose origin is harder to track down (top photo).
- De Juana, E. (2006). Las aves raras de España. Lynx Edicions. Barcelona