I was delighted to hear and then see the first Black-cowled orioles (Icterus prosthemelas) to appear in the garden since my return from California. Their soft call first drew my attention, but my delight at finding that it was a pair was muted somewhat when I saw that they were accompanied by a juvenile Giant cowbird (Molothrus oryzivorus). Not that I mind too much seeing the cowbird, all black but with an almost white bill. It has appeared here at the house just twice now in four years, but last week I did spot another accompanied by Montezuma oropendolas down at San Diego. The smaller but similar Bronzed cowbird is usually easier to find here. Several frequently perch with Great-tailed grackles (the much-despised zanates) down at the lawyer’s house, Las Musas. Just musing, perhaps. Like the European Cuckoo, these cowbirds lay their eggs in the nests of other species, much to the hosts’ detriment.
The Black-cowled is our only resident oriole in this area. It prefers lower locations and is pretty much at the limit of its range here at 1200 m on the Caribbean side. It is considered rare on the Pacific slope. Orioles are much more numerous further north than Costa Rica, say, in Mexico, where identification is a real problem. Here, if it’s black and yellow it’s this one, and if it’s black and orange it’s the Baltimore oriole (Icterus galbula), the very common northern migrant that appears at the banana feeders between September and May. The following photographs show that you should be careful, however!
As both photos here show, male Baltimore orioles frequently seem to be much less orange on the breast than in their guidebook illustrations. Females and juveniles can vary a good bit in plumage, and birds with a narrow black bib at the throat are often seen though not shown in all field guides.
I have seen the black and chestnut Orchard oriole (Icterus spurius) lower down at CATIE in Turrialba but it seems very infrequent and has not appeared here at the house. Geographic and seasonal distribution would suggest that it would be easy to find as a migrant and would even be a possibility as a winter resident.