At regular intervals throughout 2001, a unit from the Phelps Ornithological Collection assisted a biological survey along the Río Caroni in Venezuela, north and downstream of the Embalse de Guri. One of the expeditions was to Isla Carrizal at 07°54'N, 63°04'W, a large uninhabited island thickly covered with groves of spiney Guadua latifolia and Ripidocladus sp. bamboos, mixed with semideciduous forest and patches of savanna. On two occasions, three specimens of an unknown blue seedeater (Amaurospiza) were collected. Those were the first records for an Amaurospiza for northern South America, and subsequent investigation showed it to be a hitherto undescribed species.