Argentina, Buenos Aires: 1, Saladillo (59o 56 ′ W, 35o 30 ′ S). Numbers and circles indicate localities visited during this study (black circles where “uruguaya” has been recorded), letters and stars indicate localities not visited during this study where specimens of “uruguaya” have been collected. Geographic location of important sites for this study. Two nontrivial evolutionary paths can constitute precursors to speciation in the capuchinos: (1) differentiation in vocalizations and habitat use arises with little plumage change in more or less geographically isolated populations, and (2) differentiation in plumage proceeds without change in vocalizations and habitat use within some populations. We consider the tawny variant to be a color morph of S.
hypoxantha is the only breeding representative of the ruficollis group. hypoxantha, with many records from areas where S. Both forms breed syntopically, and the tawny variant is recorded only within the range of S. hypoxantha in vocalizations and habitat use, varying geographically in parallel. We tested four hypotheses to assess the status of the variant: that it represents a new species, a hybrid S. cinnamomea) but has a tawny rather than chestnut body. It is also identical in pattern to the Chestnut Seedeater (S. hypoxantha) but has a tawny, not gray, nape and back.
This variant resembles the Tawny-bellied Seedeater (S. We describe a distinctive variant that would have been considered a species by the traditional strictly phenotypical criteria for classification of species in the genus. The capuchinos, a subset of the genus Sporophila, represent a radiation of seedeaters characterized by little genetic differentiation, virtually no change in bill and body shape, marked plumage differences on a common theme, and notable differentiation in vocalizations and habitat use.
0 kommentar(er)
