Monday, August 29, 2011

Quiz #414 (2011-3-09) Solution

Click on picture(s) for a larger view.
Respondents need identify only the flying birds; an extra bonus point will be given to those with the correct ID of the swimming bird; no penalty is attached to incorrect attempts at that ID.

Solution by Tony Leukering

Though I usually avoid such for this venue, the hidden bird in this week's quiz is right in the middle and not hiding at all. Of course, the posture of the bird does not allow much in the way of showing off ID characters, but there is enough to go on. So, before you read further, go ogle the picture to see if you can find the hidden bird.

Most of the birds in the picture are readily identifiable to a particular species, as they sport the distinct white wedge in the outer wing, black tips to the outer and middle primaries, and pale gray upperparts of Bonaparte's Gulls. Please note that though a bird here and there may seem to exhibit dark on the underwing, that is all an artifact of shading; none of the small gulls are Black-headed Gulls. At least seven of the birds show the black robber's mask, uncontrasting pale wingtip, and/or the narrower-winged look of basic-plumaged Forster's Terns, with all seven of those birds being in the left half of the photo. Note also that all of the terns are smaller and more pointier-winged than are the Bonaparte's Gulls.

Skipping ahead, the caveat with the quiz photo asks for the identity of the one swimming bird, but with no penalty for incorrect responses. That is because the bird is out of focus and large white-headed gulls are hard enough to ID without an out-of-focus and small image. However, I believe that the whitish head on an obviously immature bird in winter, the extensively black and large bill, and the fairly short wingtips all point to Great Black-backed Gull. In fact, I know that is the correct ID, as I took the picture in my back yard in Villas, Cape May Co., NJ, on 1 March 2011.

Now, on to the hidden bird right in the middle. Below, I have cropped and enlarged the middle section of the quiz that includes the swimming bird and the hidden bird. The hidden bird is not all that hidden. I have indicated three Forster's Terns (FOTE) in the left side. Note the bird smack dab in the middle that is small and pale like a Forster's Tern, but with wingtips that are even more rounded than on the Bonaparte's Gulls. Also note that there is no contrasting white wedge in the wingtip, as shown by the Bonaparte's Gulls, and the fairly short tail. This combination of features allows us to identify the beast as an adult Little Gull (LIGU). Ross's Gull is ruled out by the tail length and shape.

This picture points out one of the items that I stressed in the gull-ID workshops that I gave in Colorado: Identify every individual; don't assume that all birds in a flock are of the same species.

Ten respondents provided no incorrect species for the flying birds, but did not provide enough correct answers, with most of those missing the Little Gull. Interestingly enough, one of them missed the Forster's Terns, but I do congratulate that respondent for finding and correctly identifying the Little Gull! Excellent work, there! Five respondents got the extra-credit question correct.

Incorrect species provided as answers:
Black-headed Gull - 3
Gull-billed Tern - 1

Congratulations to the 1 of 15 getting the quiz correct:
Devich Farbotnik (who also got all fours species correct)

Answer: Bonaparte's Gull, Little Gull, Forster's Tern with Great Black-backed Gull