Baltimore Orioles Icterus galbula
Canada

The familiar and very vocal Baltimore Oriole Icterus galbula breeds commonly across North America eastward of the Rocky Mountains (from Alberta to Newfoundland, the Dakotas to Maine, southward to eastern Texas, Louisiana, and Georgia) and winters in Florida, the Caribbean, central Mexico and Central America to northern South America.

The taxonomy of the two commonest species of oriole in North America has been extremely fluid. In the 1980s the eastern Baltimore Oriole was lumped with the western Bullock’s Oriole Icterus bullockii as a single species, the Northern Oriole. Historically separated, populations of the two taxa had been able to meet after trees were planted on the Great Plains allowing them to extend their ranges towards each other. Despite some differences in their appearance it was found that they interbred, and that most birds in the central plains were hybrids. Further study showed though that in some places the birds were choosing mates assortatively (ie of their own type), and that they were in fact not particularly closely related on a genetic level: in the mid 1990s the decision to lump the forms was reversed and they were considered as two separate species again.

 

Male Baltimore Oriole, Point Pelee, Ontario. May 2005

 

 

 

 

Male Baltimore Orioles, Toronto, Ontario. May 2006

All photos copyright Charlie Moores