ALIEN QUAILS: CHINESE AND JAPANESE

Chinese Quail (Coturnix chinensus). Male and female. Taken from Avikultura. 

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.

 Chinese Quail (Coturnix chinensus). Male hit in Cornalvo, Badajoz (Jesus Maria Crespo) 

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%).

 Japanese quail (Coturnix japonica). Taken from here.

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.

Sources: 

- Puigcerver, M., Vinyoles, D.& Rodriguez-Teijeiro, J. D. 2007. Restocking with Japanese quail Do hybrids affect the native population of common quail coturnix Cotunix? Biological Conservation 136:628-635. 

- Rodriguez-Teijeiro, J. D. & Puigcerver, M. 2006. Study of the degree of hybridization between Common Quail and Japanese quail in Catalonia. Report. Universitat de Barcelona and Generalitat de Catalunya. 

- Carrascal, L. M. & Palomino, D. 2008. Common birds breeding in Spain. Population in 2004-2006. SEO / BirdLife. Madrid

WINTERING QUAIL: A MUDDY PICTURE

The Common Quail (Coturnix coturnix) is a highly mobile species, especially the males, which move around at random in the breeding season in search of females. This mobility is the response to a complex reproduction system, without territory, and their particular breeding habitat, unirrigated cropland, which often changes its position from one season or year to another. Quails in fact may well breed more than once a year in Europe, first in the south and then further north. When the cereal crop is harvested they are forced to move anew; on the Iberian Peninsula they usually congregate in the meseta norte, where the crop is harvested latest in the year. Lastly, come autumn, they move off to Africa. Not all of them, however; a few wintering birds do stay behind. For example during the field work of the Atlas of Wintering Birds in Spain there were 112 contacts over three winters (2007-2010), 31 of them in Extremadura; Badajoz is the Spanish province with most wintering Quails (22 contacts). The provisional map below shows the places where these wintering Quails were found (sampled grids shown in red, grids with wintering quail shown in blue).

But a curious event begs new questions. On 04/12/2010 in Navalvillar de Pela (Badajoz) a hunter was seen carrying a shot Quail (S. Mayordomo, C. Clemente and J. Mahíllo). Nothing extraordinary about this because Quail are known to winter here sometimes. A few days later, on 20/12/2010, three people were seen releasing Quail in another part of the same area, three complete crates of birds; they then started shooting at them forthwith, killing at least six (Á. Sánchez). This unexpected event, perhaps a one-off, poses doubts about whether the wintering Quail are natural. We know for sure only about this one case of deliberate Quail release in winter and winter Quail observations are fairly widespread, so the logical conclusion to draw is that wild birds do winter. This is borne out by studies conducted in Portugal which show the presence of migratory birds from September to December and sedentary birds from December to March, when the first migrants return from Africa. The proportion of migrants, judging from body fat, peaks in October (40-50%) and there are always more migrants in the north than in the south, where up to 70% of the birds are non migrators. Autumn density is usually high, up to 130 Quails per km2. Sedentary birds start breeding very early in the year, singing as from November and pairing off as from December. They breed before the migratory birds and the first brood is itself able to breed after a few months in their first summer. This sedentary behaviour seems to be recent, as the result of changes in farming practices. Although Portuguese authors argue that the same thing happens in north Africa and part of Spain, including Extremadura, there is no actual information to confirm this. In fact there are no known records of singing Quail in Extremadura in December or January (the first are heard in February) and winter records, even allowing for the specie's retiring habits and low detectability, are still few and far between (only nine from 2005 to 2008).

Sources:
- Catry, P., Costa, H., Elias, G., and Matias, R. 2010. Aves de Portugal. Ornitologia do territorio continental. Assirio & Alvin. Lisbon.
- Anuarios Ornitológicos de Extremadura (Aves de Extremadura) 1998-2008.