El ave Ramphocelus bresilius es una especie endémica de Brasil con dimorfismo sexual en el plumaje del adulto. Los machos jóvenes son similares a las hembras adultas y jóvenes hasta el segundo año de vida. Adultos y hembras jóvenes son indistinguibles por el plumaje. Evaluamos si el color del iris puede ser utilizado para distinguir hembras adultas de hembras inmaduras. Utilizamos por primera vez la técnica molecular de identificación de sexos basada en los genes CHD para confirmar el género de individuos clasificados como plumaje femenino con iris rojo, y para identificar el sexo de los individuos clasificados como plumaje femenino e iris marrón. Usamos machos adultos como control. Analizamos muestras de DNA de 190 individuos. Los tamaños de los productos del PCR fueron identificados como 350 pares de bases (pb) para CHD-Z y 388 pb para CHD-W. Pudimos confirmar que las hembras adultas presentan iris rojo y las hembras jóvenes iris marrón. También pudimos distinguir machos jóvenes de hembras, que presentan el mismo color de iris y plumaje.

The Brazilian tanager, Ramphocelus bresilius is an endemic species from Brazil that is sexually dimorphic in adult plumage. Young males are similar to adult and young females until their second year. Adults and young females are not distinguishable in plumage. We tested whether iris colour can be used to separate adult females from immature females. We used for the first time the molecular sexing technique based on CHD-genes to confirm the sex of the individuals classified as "female plumage with red iris", and to identify the sex of individuals classified as "female plumage and brown iris". The adult males were used as a positive control. DNA samples from 190 individuals were analysed. The sizes of the PCR products were identified as 350 base pairs (bp) for CHD-Z and 388 bp for CHD-W. We confirmed that adult females have a red iris and the young females a brown iris. We could also separate young males and females which present the same iris colour and plumage. Although there are indications that the iris colour can be used by birds to identify the adults in co-operative breeding species such as the Brazilian tanager, more behavioural data are required to understand the role of iris coloration in this species. Rev. Biol. Trop. 56 (4): 1629-1633. Epub 2008 December 12.

We used conventional chromosomal staining to describe the karyotype of the critically endangered Lear's macaw, Anodorhynchus leari Bonaparte 1856. A diploid number of 2n = 70 and a karyotype similar to that of its congener Anodorhynchus hyacinthinus suggests that chromosomal rearrangements were not the main evolutionary mechanism in the genus.

Foram estudados citogeneticamente vinte exemplares da espécie Oryzoborus maximiliani provenientes de criatórios do Estado do Rio de Janeiro. Foi aplicada a técnica de cultura de curta duração de polpa de penas jovens, permitindo a investigação nas aves vivas. O cariótipo da espécie foi estabelecido (2n = 72) com identificação do par sexual. Considerações evolutivas são abordadas.

The investigation of the karyotype of Oryzoborus maximiliani in living birds utilizing young feather pulp culture is described. The species karyotype was established as 2n = 72 with unequivocal identification of the sexual chromosome pair. Evolutionary considerations are raised.