Monday, March 14, 2011

Quiz #390 (2011-1-11) Solution

Click on picture(s) for a larger view.

Answer by Tony Leukering

Raise your hand if you immediately identified this week's quiz bird on posture alone. Oh, perhaps you then had second thoughts about other species that might share this bird's posture, but I will bet that for most people looking at the quiz photo, their first thoughts were correct.

The take-home message of this quiz is that structure and posture can enable us to identify a large percentage of the birds we see on any given day, if only we know them intimately, like most of us know this week's quiz bird. Without resorting to field marks. That is, a skulking smallish sparrow with a raised crest is nearly always a Lincoln's Sparrow. A long, low-slung dabbling duck with its big head pulled into its shoulders is probably a Northern Shoveler. A tiny brown ball of fluff with nearly no tail is a Winter Wren. Or, now, a Pacific Wren. A largish passerine standing on the ground with head and back erect, tail slightly cocked, and long wings drooped to below the level of the tail is nearly always an American Robin.

Yes, other species of Turdus and Wood Thrush need to be considered (or the Catharus thrushes if we got the size estimation wrong), but given where birders live and how common American Robin is in the places where most of the ABA-area's birders live, it is quite correct to jump to the conclusion that such a bird is an American Robin. While we cannot see our quiz bird's underparts, we really do not need to see them to confirm our snap ID, but we ought to look at at least a few characters to be certain. The upperparts are dark gray. Check. The rump is the palest part of the upperparts plumage. Check. The tail is black. Check. The wings are plain and dark. Check. The crown is blacker than the nape and/or the back. Check. There are white eye arcs. Check. The bill is yellow. Check. Card-carrying American Robin; no red underparts seen. Nor black-and-white-striped throat. Nor white vent. Nor white tail corners.

Now, the real trick is becoming as familiar with as many of the other species one sees as one is with American Robin (or whatever one's local easy-to-watch, abundant species is). Yes, the clues are much more subtle with some (many?) than they are with American Robin, but they are there. There to be studied and learned.

I took this picture of a (male?) American Robin at the Fort Lupton cemetery, Weld Co., CO, on 6 May 2006.

Incorrect species provided as answers:

Congratulations to the 28 of 28 getting the quiz correct:
Devich Farbotnik
Tyler Bell
Thomas Hall
Robert McNab
Su Snyder
Nick Komar
Jim Nelson
Margaret Smith
Christopher Hinkle
Pam Myers
Peter Wilkinson
Julie Rouse
Christian Nunes
Margie Joy
Ben Coulter
Michael Speegle
Barbara Deneen
Adrian Hinkle
Kirk Huffstater
George Cresswell
Tom Wilberding
Matt Bristol
Al Guarente
Marcel Such
Joe Bens
Joel Such
Bryan Guarente
Chishun Kwong

Answer: American Robin