The Chinese quail (Coturnix chinensis) is a common galliforme in South Asia, Sunda Islands, and Australia. Their easy breeding and obvious attraction makes them relatively common as an ornamental bird. A male of this species has was found ran over on July 12, 2012 on the A-5, near the Parque Natural de Cornalvo (Badajoz). Jesus Manuel Crespo, sent some photos to the Rarities Committee SEO/BirdLife. As is not an uncommon bird and did not arrive here by natural means, the description was sent to the Exotic Bird Group (GAE), which then came to our notice. It is probably an escapee, although the date it was found could mean it was released for hunting.
Unfortunately, this observation shows the risks arising from the introduction of exotic species. One of the biggest causes of extinction in recent times. Perhaps the Chinese quail is not among the most dangerous compared with the the Japanese quail (Coturnix japonica). Another species of eastern Asia itself much like our Common quail (Coturnix coturnix) and long considered a mere subspecies of this. Indeed, easily hybridized in captivity, it is then difficult to identify resulting hybrids (the song is slightly different) and genetic testing must be resorted to. Quail hunting is common in Extremadura, but the extent of the introduction of the Japanese quail and their hybrids is totally unknown . However, studies by Manuel Puigcerver's team between 1999 and 2005 detected that 4.4% of quails analyzed in Catalonia were hybrids (but if specimens are considered doubtful, the percentage then rises to 15%).
The release of Japanese quail for hunting is a recent practice, as studies started in 1983 did not detect hybrids until 1990. Currently all quail farms breed the Japanese quail (there are no Common Quail breeding farms), which are the then released as either pure or hybrids. At some well quoted sites in France, 75% of the quail hunted are Japanese quail. Numbers released in Catalonia are also increasing and official figures quote 2,430 Japanese quail released in 1991 and 153,600 in 2003, 60 times more, in 17 years releases total more than one million. For comparison, the wild Common Quail breeding population in Extremadura is estimated at only 15,600 birds (Carrascal and Palomino, 2008), although in summer many migratory birds arrive from other locations.
In Extremadura is certain releasing takes place from quail farms, but the presence of Japanese quail has not been confirmed and is not on any list. Elswhere it is not know what proportion are natural hybrids, if any. Despite the massive release performed in Spain, France and Italy, it seems that most Japanese quail die, or are hunted, shortly after their release. No study has been carried out to ascertain the proportion of hybrids. It is standard practice to release them in the midseason at the end of the summer and as poultry have lost their migratory instinct, they do not usually survive the winter. But, is has also been found that more Iberian quail are over-wintering and have less tendency to migrate. Maybe hybrids are responsible ... but this has yet to be proved.