The long pointed wings of this bird should immediately call to mind pelagic birds: shearwaters, albatross, petrels, gannets and boobies. The long pointed bill and relatively pointed tail quickly eliminate most possibilities other than gannets and boobies. Some shearwaters are vaguely similar to our bird in plumage, but none have the long pointed bill of this bird.
Narrowing our choices down to boobies and gannets is a good first step, but that's when things become somewhat complicated. In the ABA area, Northern Gannet is the most widespread and common species, so it's best to start there. Structurally our bird is similar to a gannet. Those who see lots of gannets may note that they typically appear longer-winged in proportion to the body. While quite useful in the field, its utility in this single photo is perhaps more limited—particularly for those without comparative experience with gannets and boobies (which I suspect includes most of us). The one thing that stands out on our bird is that the dark breast contrasts with the paler belly. There is a sharp line of demarcation between the breast and belly, and the upper breast does not become noticeably paler. Instead the breast and head are generally the same color. The pattern of the underparts really only fits one species—Brown Booby.
But what of this individual's reddish-colored feet? Those who spend even modest amounts of time looking at photos on the internet or magazines may simply attribute this to poor color reproduction. Such a hypothesis is well-reasoned, but wrong. This individual had feet that appeared quite pinkish. If anything they appear less pink in this photo due to the shady conditions. While many texts refer to Brown Boobies as having yellowish colored feet, it is not unusual to see young brewsteri Brown Boobies with pinkish colored feet. So if you see a brown booby off California or in the Interior West with pinkish-colored feet, you should look beyond foot color to identify the species. In addition to the difference in underparts (Red-footeds have dusky breast bands), note that Red-footed Booby also has all dark underwings.
I photographed this juvenile brewsteri Brown Booby in February 2005 off Manzanillo, Mexico.
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The following people (listed by submission date beginning with the earliest) submitted correct answers for the March Bird Photo Quiz—brewsteri Brown Booby:
As stated in the quiz rules, answers must consist simply of the Common or English name exactly as it appears in the ABA Checklist.
The following list shows the number of submissions for each species guessed.
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The photo and answer for this quiz were supplied by Chris Wood.