tags: birds, mystery bird, bird ID quiz
[Mystery birds] photographed at Bolivar East Beach, Galveston County, Texas. [I will identify this bird for you in 48 hours]
Image: Joseph Kennedy, 17 October 2007 [larger view].
Nikon D200, Kowa 883 telescope with TSN-PZ camera eyepiece 1/800s f/8.0 at 1000.0mm iso400.
Please name at least one field mark that supports your identification.
This image features a cluster of bird species; can you tell me how many species are present, what species they are, and how many individuals of each species you see?
Life Science
Education
Comments
The brown pelicans in the lower left are easy, pouched beak, recurved neck and color. The various terns and gulls are harder, I'd need my book for that and I'm at work.
Posted by: apikoros | November 24, 2009 4:09 PM
I think I see 6 species. 2 Brown Pelican, 5 Black Skimmer, 12 Royal Tern, 26 Gull-billed Tern, 4 Forster's Tern and it looks like the tail band of a first winter Ring-billed Gull disappearing top right
Posted by: Adrian | November 24, 2009 5:31 PM
Wow! Ok then... I agree with the Brown Pelicans, Black Skimmers, and Royal Terns, but because of the dark tips to the wings, what appear to be Gull-billed Terns I think are in fact immature Laughing Gulls, Leucophaeus atricilla!
immature Laughing Gull
Posted by: David | November 24, 2009 6:35 PM
Hello David. Yes you are right, Laughing Gulls. I had thought that they were too small and the heads were too unstreaked, but do you agree with the rest?
Posted by: Adrian | November 25, 2009 5:32 AM
I think that most of these Laughing Gulls are adults. Most of them don't show any black on the tail, the shoulder and upper breast are clean white instead of being washed with gray, and the primary coverts are gray, not black. There is one first-winter Laughing Gull (I think) in the upper left corner -- you can see a very brown head and neck. Adrian, I don't see anything that looks like a Ring-billed. In this mess, I could just be missing it, but since you only mentioned the black tail-tip, it seems just as likely you're looking at a second-year Laughing Gull.
Good call on the Forster's Tern. It took me awhile just to find the darn things, and I tried to call the first one a Sandwhich Tern.
Posted by: psweet | November 25, 2009 9:44 AM
Yes Adrian, a good catch on the Forster's Terns...
Paul, please correct me if I'm wrong- I understand that Laughing Gulls take about 3 years to reach adulthood, and so "1st Winter" and "2nd Winter" plumages are still therefore "immature"... in the photo above then it appears that there is a range throughout that 3-year span...
mixed-age group of Laughing Gulls
Posted by: David | November 25, 2009 10:59 AM
Hi, David, exactly right. "Immature" as a descriptor for gulls really isn't all that useful for ID issues, since the differences between years are considerable. Fortunately, they tend to parallel each other.
Laughing Gulls are a 3-year gull, which means we have 3 identifiable ages (all adults look alike). I can definitely find 1st year and adults here -- I'm less sure of 2nd year, but I'm probably just not looking hard enough.
Incidentally, the last year of 'immature' plumage is usually the hardest to find, since mortality affects each cohort, but when we get adults, we're combining 15 to 25 cohorts together, depending on the species.
Posted by: psweet | November 25, 2009 11:49 AM