New species of seedeater

Blue seedeaters Amaurospiza are rare and little-known finches from Central and South America; two or three species have so far been recognized: Blue Seedeater A concolor (including Slate-blue Seedeater A (c) relicta) and Blackish-blue Seedeater A moesta. A new species has recently been described, Carrizal Blue-black Seedeater (or Carrizal Seedeater) A carrizalensis, named after the tiny islet where it was discovered (Lentino, M & Restall, R 2003. A new species of Amaurospiza blue seedeater from Venezuela. Auk 120: 600-606). Only three birds were found on Isla Carrizal in eastern Venezuela (07:54 N, 63:04 W) and it is unknown what size the population may be. The discovery was a surprise to the researchers, because the Caroni river area in the Orinoco basin has been relatively well-covered by surveys in the past and because no other Amaurospiza species have been recorded from Venezuela before. The reason the finch had not been discovered until now is probably because its habitat is impenetrable spiny bamboo vegetation and because Carrizal is an uninhabited islet in the middle of the Caroni river.

From examination of the three birds collected, Carrizal Blue-black Seedeater was identified as a separate species on basis of its larger bill compared with other finches and because of small differences in plumage. The male is dull greyish-blue, while the female is brownish. The blue seedeater group had never before been found in Venezuela - and northern South America - and the geographically closest member of the group, Blue Seedeater, lives on the other side of the Andes in Colombia and Ecuador. The new seedeater was only discovered because a Venezuelan electricity company, EDELCA, had commissioned a survey to assess local wildlife before commencing work on a dam across the nearby Caura river. Carrizal Island, as EDELCA property, was already scheduled for deforestation for development of the Tocoma Dam, part of a major hydro-electric project along the length of the Caroni river. Part of the reason for the survey was to see what could be done to compensate for the loss of spiny bamboo caused by razing the island, and, at that time, Carrizal Blue-black Seedeater had not been identified as a new species. As a result, the island was cleared before its ornithological importance was fully recognized. New surveys for the finch will now be undertaken in the vicinity where the same bamboo is also found.
Enno B Ebels