Mystery Bird: Baltimore Oriole, Icterus galbula

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[Mystery bird Baltimore Oriole, Icterus galbula, photographed at the east end of Galveston Island, Texas. [I will identify this bird for you tomorrow]
Image: Joseph Kennedy, 16 April 2008 [larger view].
Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/320s f/8.0 at 1000.0mm iso400.

Please name at least one field mark that supports your identification.

Rick Wright, Managing Director of WINGS Birding Tours Worldwide, writes:
The computer screen and middle-aged eyes give an oddly warm cast to what I know must be the vivid orange of this oriole; but let’s take advantage of that anomaly — not so different, after all, from the sort of distortions we routinely encounter in the field when we see a bird from an odd angle or in poor light — let’s take advantage of that anomaly to focus more closely on the patterns than on the exact colors of this striking bird.
The completely black head rules out a great many Icterus species, but more eloquent still is the tail. Though shadow and an ever-so-slight lack of focus make it hard to tell exactly what color the outer rectrix is, we can see clearly that that feather is yellow or orange distally. For the sake of efficiency, we’ll limit ourselves to the orioles recorded in Texas; we can immediately eliminate from consideration Streak-backed, Bullock’s, Hooded, Orchard, Altamira, Scotts, Audubon’s, and (for good measure, though I don’t think there are any Texas records yet) Black-vented, all of which have black tail-tips in their colorful male plumages.
And that little bit of knowledge lands us right on the correct identification. To confirm our diagnosis of this male Baltimore Oriole, let’s consider the wing. The median coverts are yellow-orange, and the tips of the greater coverts from a discrete white wingbar; white edgings are conspicuous on the secondaries, forming a definite panel.
For a time after 1973, Baltimore and Bullock’s Orioles were treated as conspecific. Though it is true that they interbreed with some liberty (libertinage?) on the western Great Plains, biochemical research has determined that these two taxa are not each other’s closest relatives in the oriole lineage, and they are now considered distinct.
Review all mystery birds to date.


About GrrlScientist

grrlscientist is the pseudonym of an evolutionary biologist and ornithologist who writes about evolution, ethology, and ecology, especially in birds. After earning a degree in microbiology (thesis focus: virology) and working at the Fred Hutchinson Cancer Research Center in Seattle, she earned her PhD in zoology from the University of Washington in Seattle, where she studied the molecular correlates of testosterone and behaviour in white-crowned sparrows. She then worked a Chapman Postdoctoral Fellow at the American Museum of Natural History in New York City, where she studied the speciation and distribution of lories and other parrots throughout the South Pacific Islands. A discarded scientist, she returned to her roots: writing. Formerly hosted by The Guardian (UK), she now writes about science for Forbes and for the non-profit think tank, the Evolution Institute and she writes podcasts for BirdNote Radio. An avid lifelong birder and aviculturist, she lives with a flock of songbirds and parrots somewhere in Germany.
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0 Responses to Mystery Bird: Baltimore Oriole, Icterus galbula

  1. Baltimore Oriole? Or is that too easy?

  2. Steve Duncan says:

    I’m with David – Baltimore Oriole. It has an all black head with orange on the tail. Similar patterned Orchard Oriole has an all black tail and deeper red color.

  3. The Ridger says:

    Baltimore / Northern Oriole – black head, orange body, black & orange on tail, white on wings