The last known Andalusian Buttonquail population is declining and its suitable habitats are shrinking according to a study published recently in Global Ecology and Conservation.
The Common Buttonquail (Turnix sylvaticus) is widely distributed in Africa and South Asia and is currently categorized as ‘Least Concern’ in the IUCN Red List. However, the nominate subspecies – known as the Andalusian Hemipode – which was originally distributed in Northwest Africa and Southern Europe, is now almost entirely restricted to a small area in Morocco after it disappeared from the other Mediterranean regions (Sicily, Portugal, and Spain). The last individual seen in Europe was shot in southern Spain in 1981, and after years of search the species was officially declared as extinct in 2018 (Read: Andalusian Buttonquail declared extinct in Spain).
Read also: Andalusian Buttonquail observed in Algeria in 2019 after almost three decades without confirmed sightings.
The farmland refuge of the Andalusian Buttonquail
The paper by Gutiérrez-Expósito and his co-authors summurised the result of the systematic surveys carried out in 2011, 2014 and 2017 in Doukkala region, the only known area where the Andalusian Buttonquail occurs in Morocco. The systematic surveys were performed in 11 fixed sampling sites evenly distributed along the strip covering a total area of 86.9 hectares (1.8% of the cultivated strip, Fig. 1B). This study design was necessary in order to study the evolution over time of the Andalusian Buttonquail population as well as the evolution of farming practices (the already known crop rotation used in the region, possible agricultural intensification,…etc.).
Non-systematic surveys were also carried out in the framework of this study (between 2010 and 2015, 627 plots were surveyed within the cultivated strip, plus 40 agricultural sites outside this cultivated strip, where the species was suspected to be present). Some records obtained by birders since 2001 were also included.
The main results of the study
The Andalusian Buttonquail is restricted to the agricultural coastal strip between Sidi Abed and Oualidia (Fig. 1B, reproduced above). Non-systematic searches in other agricultural areas yielded no positive results (Fig. 1A).
No evidence of buttonquail presence in the remnant scrubland patches despite an important search effort. The only records in these natural habitats were obtained in May 2002 and April 2006 (by two known birders and ornithologists: P.A. Crochet and J.L. Copete respectively). The latter is considered the last record of the species found in natural or semi-natural habitats (This is clearly shown in the title of the paper: “The farmland refuge of the last Andalusian Buttonquail population”).
The suitable area for the Andalusian Buttonquails declined over the years, from 63.4% in 2011 to 38.2% in 2017, mostly due to an increase in the proportion of ploughed land. Proportion of suitable crops occupied by the buttonquails also decreased over the years, from 20.7% in 2011 to just 16.5% in 2017, with a minimum in 2014 with only 10.3%.
The estimated number of individuals decreased over the years from 1,890 (range: 360-6818) in 2011 to 492 (40- 4111) in 2014, and then slightly recovered in 2017, with 596 (59-3,584) birds.
The estimated number of breeding females showed a similar trend. It decreased from 270 (40-967) in summer 2011 to 70 (5-646) in 2014 before slightly increasing to 117 (10-727) in 2017.
So, currently the global known population of the Andalusian Buttonquail (117 breeding females and 596 individuals in 2017) is confined to a small intensively cultivated area (4,675 hectares).
The authors concluded their paper with this:
“Given the currently available information, our distribution and population estimates must be considered as the global estimation for this taxon, an endemism of the Western Mediterranean basin. Persistence of such a small and declining refugee population in a very small area with a high human use seems very unlikely. In this sense, although Andalusian buttonquail is classified as a taxon underneath species level, a proper conservation status assessment and conservation action plan are urgently needed to take conservation measures at both in-situ and ex-situ levels”.
Reference
Gutiérrez-Expósito, C., García-Gorria, R., Qninba, A., Clavero, M. & Revilla, E. 2019. The farmland refuge of the last Andalusian Buttonquail population. Global Ecology and Conservation 17: e00590.