BIOGEOGRAPHY, GEOGRAPHICAL VARIATION AND TAXONOMY OF THE ANDEAN HUMMINGBIRD GENUS METALLURA GOULD, 1847

Biogeography and taxonomy of the High-Andean hummingbird genus Metallu ra were analysed on the basis of geographical variation of morphometri c and plumage colour characters. The genus Metallura is considered to consist of nine species and 15 subspecies. Within the species Metallur a tyrianthina seven subspecies are recognized (smaragdinicollis [inclu ding peruviana], septentrionalis, quitensis, tyrianthina, districta, o reopola, chloropogon). M. tyrianthina and M. iracunda are considered t o be sister species and to be closely related to M. phoebe and to the members of the M. aeneocauda superspecies. The latter consists of six species as follows: M. aeneocauda (with subspecies aeneocauda and mala gae), M. eupogon, M. theresiae (with subspecies theresiae and parkeri) , M. odomae, M. baroni and M. williami (with subspecies williami, atri gularis, primolina, recisa). M. tyrianthina and M. iracunda exhibit pl esiomorphic character states (dimorphism, colour of throat feathers, s hea bill), that link the genus Metallura to its sister genus Chalcosti gma. The disjunct distribution of similar phenotypes, and the progress ion of morphological characters suggest fairly recent allopatric speci ation processes in all Metallura taxa High-Andean habitat fragmentatio ns due to climatic changes during Late-Pliocene and Pleistocene presum ably caused geographical isolation and differentiation of most Metallu ra populations. The south-north phenotype progression regarding chin a nd gorget coloration of M. tyrianthina females, paralleled by a transi tion from weak to strong sexual dimorphism, suggest for the genus Meta llura a centre of origin in the Andes of north-eastern Bolivia or sout h-eastern Peru.