Caribbean oriole taxonomy examined
An examination of the "Greater Antillean Oriole" complex has concluded that it may in fact consist of four distinct species found on different Caribbean islands.
Names proposed for the new splits are Bahamas Oriole Icterus northropi (Andros and Abaco, Bahamas), Cuban Oriole I. melanopsis (Cuba, Isla de Pinos), Hispaniolan Oriole I. dominicensis (Hispaniola) and Puerto Rican Oriole I. portoricensis (Puerto Rico).
The study, by Garrido, Wiley and Kirkonnell, published in the journal Ornitologia Neotropical (16: pp.449–470), found plumage differences between the four forms were more marked in immature birds, with vocal differences considered more significant in adults.
Within the group, Bahamian birds were considerably larger but appeared closest to Black-cowled Orioles I. prosthemelas of Central America in appearance, than to birds from the West Indies.
"Whether or not it is eventually regarded as a separate species, what is not in doubt is that the Bahamas Oriole is one of the Caribbean's rarest birds. Habitat loss and invasive species, two of the major scourges of the region's native wildlife, threaten its continued survival." —David Wege, BirdLife Caribbean Program Manager
If accepted, the splits have considerable conservation implications for the newly recognised endemic species. For example, Puerto Rican birds are frequently victims of brood parasitism following the recent arrival of Shiny Cowbirds Molothrus bonariensis on the island.
Shiny Cowbirds are also a very real threat to the Bahamas Oriole. The orioles are believed to have been extirpated on Abaco and a 1997 study estimates just 50–100 birds on North Andros and 100–200 remaining on South Andros. There is no estimate for the number of birds on Mangrove Cay between North and South Andros.