Colonisation and diversification of the blue tits (Parus caeruleus teneriffae-group) in the Canary Islands

The blue tit (Parus caeruleus teneriffae group) is proposed to have colonised the Canary Islands from North Africa according to an east-to-west stepping stone model, and today, the species group is divided into four subspecies, differing in morphological, acoustic, and ecological characters. This colonisation hypothesis was tested and the population structure between and within the islands studied using mitochondrial DNA sequences of the non-coding and relatively fast evolving control region. Our results suggest that one of the central islands, Tenerife, was colonised first and the other islands from there. Three of the presently recognised four subspecies are monophyletic, exception being the subspecies teneriffae, which consists of two monophyletic groups, the one including birds of Tenerife and La Gomera and the other birds of Gran Canaria. The Gran Canarian birds are well differentiated from birds of the other islands and should be given a subspecies status. In addition, the teneriffae subspecies group is clearly distinct from the European caeruleus group, and therefore the blue tit assemblage should be divided into two species.