African stonechat

The African stonechat or common stonechat^[1] (Saxicola torquatus) is a species of the Old World flycatcher family (Muscicapidae), inhabiting sub-Saharan Africa and adjacent regions. Like the other chats, it was long assigned to the thrush family (Turdidae), to which the chats are convergent. Its scientific name refer to its appearance and habitat and means "collared rock-dweller": Saxicola from Latinsaxum ("rock") + incola ("one who dwells in a place"), torquatus, Latin for "collared".

In the past S. torquatus usually referred to the entire "common stonechat" superspecies and some sources^[3] still keep it that way, but all available evidence strongly supports full species status for the European (S. rubicola) and the Siberian stonechat (S. maurus) of temperateEurasia, in addition to the island-endemicsFuerteventura chat (S. dacotiae) and Réunion stonechat (S. tectes) which were never unequivocally accepted into S. torquatus. The Madagascar stonechat (S. t. sibilla) has sometimes been considered distinct. In addition, the well-marked populations of the Horn of Africa uplands may well qualify for an additional species.^[4][5][6]

In 1760, the French zoologist Mathurin Jacques Brisson included a description of the African Stonechat in his Ornithologie based on a specimen collected from the Cape of Good Hope in South Africa. He used the French name Le gobe-mouche à collier du Cap de Bonne Espérance and the Latin Muscicapa Torquata Capitis Bonae Spei.^[7] Although Brisson coined Latin names, these do not conform to the binomial system and are not recognised by the International Commission on Zoological Nomenclature.^[8] When in 1766 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the twelfth edition, he added 240 species that had been previously described by Brisson.^[8] One of these was the African Stonechat. Linnaeus included a brief description, coined the binomial nameMuscicapa torquata and cited Brisson's work.^[9] The specific name is from Latin torquatus "collared".^[10] This species is now placed in the genus Saxicola that was introduced by the German naturalist Johann Matthäus Bechstein in 1802.^[11]

The closest relative of this species are apparently not the Eurasian populations but the Réunion stonechat (S. tectes), but still the "white-collared" Saxicola form a distinct group in the genus. S. torquatus and S. tectes form a sub-Saharan African lineage that diverged from the Eurasian one in the Late Pliocene, roughly 2.5 million years ago. Réunion was colonized shortly thereafter, indicating a rapid expansion along the Indian Ocean coast of Africa. With the Sahara drying out in the subsequent Quaternary glaciation, the African and Eurasian populations became isolated for good.^[6]

The recent separation as species was proposed after mtDNAcytochrome bsequence and nDNAmicrosatellitefingerprinting analysis of specimens of the subspecies Saxicola torquatus axillaris but not S. t. torquatus, and hence this species was briefly known as S. axillaris.^[6]

The males have a black head, a white half-collar, a black back, a white rump, and a black tail; the wings are black with a large white patch on the top side of the inner wing. The upper breast is usually dark orange-red, with a sharp or gradual transition to white or pale orange on the lower breast and belly depending on subspecies. In a few, black replaces the orange breast feathers in part or entirely.^[13]

Females have brown rather than black above and on the head with an indistinct paler eyebrow line, chestnut-buff rather than orange below, and less white on the wings. Both sexes' plumage is somewhat duller and streakier outside the breeding season.^[13]

It has a scattered distribution across much of sub-Saharan Africa, occurring locally as far north as Senegal and Ethiopia. Outlying populations are found the mountains of southwest Arabia and on Madagascar and Grande Comore. It is non-migratory, moving only locally if at all. As a result, it has developed much regional variation, being divided into 13 subspecies.^[13]

• Collalba africana - Texto de la especie en El Atlas de las aves del sur de África .
• Collalba africana: Guía estructurada de las especies en el sur de África.