some Neotropical ornithologists. Another such case is P. maranhaoensis: Some considered it invalid, believing it was the male plumage of P. nattereri. However, P. maranhaoensis only occurs in the northern part of the range of P. nattereri, and the two have different voices. Molecular work also confirms the validity of P. maranhaoensis, though details presently are lacking. Comparably, P. aethopyga has generally been considered invalid as believed to be a hybrid between P. ruber and P. rupurumii, but this assumption has recently been shown to be incorrect, leading to its revalidation as a distinct species. For the same authors, the taxa proposed as hybrids by Hinkelmann, could be valid taxa, especially P. longuemareus imatacae. Species in taxonomic order References Further reading ffrench, Richard; O'Neill, John Patton & Eckelberry, Don R. (1991): A guide to the birds of Trinidad and Tobago (2nd edition). Comstock Publishing, Ithaca, N.Y.. Hilty, Steven L. (2003): Birds of Venezuela. Christopher Helm, London. Stiles, F. Gary & Skutch, Alexander Frank (1989): A guide to the birds of Costa Rica. Comistock, Ithaca. Bird genera