Ornithologists describe a new taxon of Common Chaffinch based on morphology, genetics and song.
Recording the song of a Great Tit (Parus major) is nearly impossible when a Chaffinch (Fringilla coelebs) is singing nearby. During my Master in Antwerp, I ventured into the forest to record Great Tit songs. Several recordings were useless because a neighboring Chaffinch overpowered the Great Tits symphony. Male Chaffinches typically sing two or three different song types, and there are regional dialects too.
Apart from differences in song, Chaffinches can also differ in plumage color. The Eurasian subspecies (coelebs), for example, has a bright orange breast and a blue cap. On Madeira, birds of the subspecies maderensis are less orange but they have a beautiful yellow back. Currently, there are 15 to 18 subspecies (depending on who you ask). A recent study in the Journal of Avian Biology focused on the Macaronesian subspecies (Azores, Madeira and Canary Islands).
Three Archipelagos, Five subspecies
Macaronesia consists of three archipelagos: Azores, Madeira and the Canary Islands. You can find one subspecies on the Azores (moreletti) and on Madeira (maderensis). The Canary Islands, however, house three subspecies on different islands: palmae on La Palma, ombriosa on El Hierro, and canariensis on Gran Canaria, Tenerife and La Gomera.
Juan Carlos Illera (Oviedo University) and his colleagues collected specimens from all five subspecies and studied them morphologically and genetically. The analyses support the different subspecies. The researchers found that individuals from each archipelago grouped together. They were also able to reconstruct the colonization history of the Macaronesian islands. The finches probably started off on the European mainland and consequently discovered the Azores, Madeira and the Canary Islands. Essentially, they followed a stepping stone route from north to south. The birds reached the Canary Islands about 600,000 years ago.
A New Taxon
Within the Canary Islands, birds from Gran Canaria were clearly differentiated from the other islands. The researchers conclude that it differs to much that it should be considered a new taxon: bakeri. This conclusion is supported by previous studies on song and sperm morphology. Morphologically, the new taxon can be distinguished from its relatives by the color pattern on one of the tail feathers (R4). Males of bakeri show a tiny white edge or small white spot, while canariensis males have an conspicuous white spot. A small, but possibly significant difference.
Illera J Rando J Rodriguez‐Exposito E Hernández M Claramunt S Martín A. (2019) Acoustic, genetic, and morphological analyses of the Canarian common chaffinch complex Fringilla coelebs ssp. reveals cryptic diversification. Journal of Avian Biology, 49(12): jav.01885.