CONICET | Buscador de Institutos y Recursos Humanos

The Amaurospiza seedeaters are bamboo-specialized mixed strategists, most often foundin bamboos in vegetative state, feeding on buds, shoots, petioles and insects. As bamboosdie after flowering, birds may wander in search of live vegetative bamboo. The threecurrently recognized species of Amaurospiza are allopatrically distributed: the Blackish-blue Seedeater Amaurospiza moesta in the Atlantic Forest of Argentina, Brazil and Para-guay, and in forest enclaves in the Cerrado; the recently described Carrizal SeedeaterAmaurospiza carrizalensis known from a few localities in southeastern Venezuela; andthe Blue Seedeater Amaurospiza concolor distributed patchily from Mexico to Peru.Three subspecies are recognized within A. concolor: relicta in southwest Mexico, concolorfrom southern Mexico to Panama and aequatorialis from southwest Colombia to nor-thwest Peru. Full species status has been advocated for relicta and aequatorialis but evi-dence supporting their recognition is weak, while relicta was described in themonospecific genus Amaurospizopsis. Here we (1) test the monophyly of Amaurospiza,(2) reconstruct the phylogenetic relationships of all its constituent taxa using mitochon-drial and nuclear markers, (3) re-assess species limits in Amaurospiza with the aid ofvocalizations and genetic and plumage data, and (4) discuss the link between bamboolife history, biogeographical patterns and extent of genetic differentiation. Amaurospizawas found to be monophyletic in both the ND2 and multilocus analyses. In the ND2tree A. moesta and A. carrizalensis were sister to each other, A. concolor was found to beparaphyletic because aequatorialis was placed as sister to moestacarrizalensis, and a cladeincluding nominate concolor and relicta was sister to all the other taxa. The multilocustree showed the same relationships, but lacked nuclear samples of relicta. Mean ND2pairwise distance between concolor and aequatorialis (8.3%) was greater than thatbetween moesta and carrizalensis (5.7%), while relicta diverged on average 1.0% fromnominate concolor. The South American clade has more slender bills and white unde-rwing coverts, while the Central American clade has thicker bills and bluish underwingcoverts. All taxa exhibited typical Amaurospiza songs with quickly delivered, warbled,pure and fairly high-pitched musical notes. Number of inflections/second exhibited a ste-pped pattern, with concolor and relicta on the lower end and carrizalensis, aequatorialis and moesta on the upper end. Similarly, moesta, carrizalensis and aequatorialis had overallmore inflections per note than concolor and relicta. Linear discriminant analysis using nineacoustic variables correctly assigned all 62 songs to the correct taxon. Morphology, plu-mage, vocalizations and phylogenetic data indicate that aequatorialis should be affordedfull species status as the Ecuadorian Seedeater (A. aequatorialis), suggest keeping relictaas a subspecies of A. concolor and support continued recognition of A. carrizalensis. Ourdata support merging Amaurospizopsis into Amaurospiza.

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