FreeLists / tn-bird / [TN-Bird] Brown-eyed Vireos

[Bill Pulliam <bb551@xxxxxxxxxxxxx>]

This afternoon (8/19/07), I was treated to the best impression of a  
Bell's Vireo that I have ever seen a White-eyed Vireo pull off. Not  
only did this bird (presumably a juvenile male) have nice dark brown  
eyes and faintish whitish spectacles with no trace of yellow, but he  
was singing a song that, with only a little effort and selective  
listening, was easily interpreted as a mumbly version of the classic  
Bell's "wheedlewheeedlewhee wheedlewheedlewoo." So why wasn't this a  
Bell's Vireo, you might ponder? Well, because other than looking and  
sounding like a Bell's, it didn't look and sound like a Bell's. By  
this I mean its size, proportions, actions, "flickiness" or lack  
thereof, were all typical White-eyed Vireo. Its wingbars were a bit  
too crisp, its head, bill, and tail shape didn't look un-WEVIish in  
any way. Plus, if you listened more objectively, you had to admit  
that his mumbly song had a few chips and some "chickaparea" like  
phrases thrown in, and honestly, well, it was just the juvenile  
babblings of a baby boy who hadn't learned to form proper words yet.

I see these Brown-eyed Vireos every year in late summer and early  
fall, of course; anyone who lives amidst an abundance of nesting  
White-eyed Vireos does. Every year there are one or two like this  
bird that really tug on the temptations to make it into a BEVI not a  
WEVI. But I considered this bird noteworthy for one particular  
reason: I decided out of curiosity to see what the major North  
American field guides had to say about this particular ID problem. I  
was astounded and profoundly disapointed to discover that they do not  
address it at all! I grabbed the four guides I had handy, and here's  
a case-by-case breakdown:

Eastern Petersons: Illustrates the head of a young WEVI with a bold  
glowingly-yellow set of spectacles. No mention of jizz or behavioral  
differences. Dark eye and white eye-ring listed as marks for BEVI.

Robbins: Illustrates young WEVI looking exactly like adult except for  
dark eyes. Mentions that yellow spectacles will distinguish it from  
Bell's. No mention of jizz or behavior; indeed it references the two  
species as "counterparts" which could be taken to suggest there's  
little difference.

NGS (an older copy): Juvenile WEVI not illustrated. Text says only  
that is is duller with "gray or brown" eyes. BEVI not even compared  
with WEVI in text; but (finally!) the distinctive shape, jizz, and  
behavior of the BEVI are mentioned.

And finally, the current state of the art, Eastern Sibley: "First  
winter" WEVI is illustrated with dark eye but flaming yellow  
spectacles and flanks. "Bright yellow spectacles" are listed as a  
distinguishing mark "for all" WEVIs. No mention is even suggested of  
the white-spectacled juvies of late summer and fall. Entry for BEVI  
is extensive including behavior, jizz, shape, and several  
distinguishing marks that might eventually let a novice or overeager  
intermediate birder realize that their dark-eyed, white-spectacled  
WEVI is NOT actually a BEVI, but not very quickly.

So the gist is this: The popular American field guides would leave  
most any birder who relied on them thinking that any dark-eyed,  
whitish-spectacled, wingbarred, smallish vireo is a Bell's Vireo,  
unless they are very dilligent in investigating the subtler aspects  
of bird ID. Why no guide even bothers to mention that some Juvenile  
WEVIs can be very drab and appear to have whitish spectacles, hence  
other field marks must be examined, is a mystery to me. Just another  
argument for learning to bird primarly from other birders and then  
only secondarily from field guides, but not everyone has that luxury.

Bill Pulliam
Hohenwald, Lewis County TN
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