Mystery Bird: Flying Royal Tern, Sterna maxima

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[Mystery bird] Royal Tern, Sterna maxima, photographed flying over Frenchtown Road, Bolivar Peninsula, Texas. [I will identify this bird for you tomorrow]
Image: Joseph Kennedy, 22 August 2008 [larger view].
Nikon D200, Kowa 883 telescope TSN-PZ camera eyepiece 1/2000s f/8.0 at 1000.0mm iso400.

Below the fold is a detailed analysis for how to ID this species ..

Rick Wright, Managing Director of WINGS Birding Tours Worldwide, writes:
The taxonomically savvy will have noticed that these quizzes are proceeding in roughly checklist sequence: first a bunch of shorebirds, then a gull, now a…well, now a what?
Long-winged and white, this bird might at first glance be mistaken for another gull; but our quiz bird is “sharp” everywhere gulls are “blunt”: the bill is finely pointed, the wingtips acute, the tail feathers–particularly the outermost ones–noticeably attenuated. These are the characters of structure and shape that make terns, as Roger Tory Peterson quotably observed, “readily distinguishable” from their fatter, clunkier cousins, the gulls.
Lingering over this tern’s structural features will let us refine our identification even further. The bright orange-yellow bill is very heavy at the base, but fairly rapidly to the tip; though it’s hard to gauge from this angle, there’s no obvious droop. The wings are fairly narrow and long, as is the tail. This description eliminates both Caspian and Elegant Tern: the former is obviously heavy, the latter exaggeratedly slim.
We’re left with Royal Tern, and what we can see of this bird’s plumage fits that species perfectly. The outer primaries are dark above and pale below, with a smudgy blackish trailing edge. The head is almost entirely white, with a streaky “scarf” on the nape; that patch does not surround the eye. The dark upperwing coverts and secondaries identify this as a first-winter individual, a determination made easy in the field at any distance by the almost continuous whining whistles and bleats young Royal Terns utter.
Terns have wings and they fly; normally thought of as exclusively coastal, Royal Tern has occurred in such surprising inland localities as Arizona and Nebraska in the last few years. Other, even more outlandish outlanders have to be looked for wherever terns congregate, but fortunately, Royal Tern is a very distinctive species. Lesser Crested Tern is — to judge by photographs and paintings — smaller, stouter, and shorter-billed; just how difficult some of the large-to-medium terns can be was nicely demonstrated this spring by a bird at Bolivar Flats (!) this spring — variously identified as an Elegant, a Cayenne (Sandwich), and a Lesser Crested, and ultimately and sensibly let go as undiagnosable. Birding is all about the challenge.
Review all mystery birds to date.


About GrrlScientist

grrlscientist is the pseudonym of an evolutionary biologist and ornithologist who writes about evolution, ethology, and ecology, especially in birds. After earning a degree in microbiology (thesis focus: virology) and working at the Fred Hutchinson Cancer Research Center in Seattle, she earned her PhD in zoology from the University of Washington in Seattle, where she studied the molecular correlates of testosterone and behaviour in white-crowned sparrows. She then worked a Chapman Postdoctoral Fellow at the American Museum of Natural History in New York City, where she studied the speciation and distribution of lories and other parrots throughout the South Pacific Islands. A discarded scientist, she returned to her roots: writing. Formerly hosted by The Guardian (UK), she now writes about science for Forbes and for the non-profit think tank, the Evolution Institute and she writes podcasts for BirdNote Radio. An avid lifelong birder and aviculturist, she lives with a flock of songbirds and parrots somewhere in Germany.
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0 Responses to Mystery Bird: Flying Royal Tern, Sterna maxima

  1. Tegumai Bopsulai, FCD says:

    Sarah Palin’s U.N. meetings begin with media flapShe wanted to allow the photogs in to use it as a photo-op without allowing journalists to come along. They didn’t like this.

  2. Greg Laden says:

    One good tern deserves another: Sterna maxima

  3. Lloyd French says:

    Royal Tern, Sterna maxima

  4. Rick Wright says:

    Royal is now (again) in the genus Thalasseus, along with Great Crested, Elegant, Sandwich, and a couple more I can’t bring to mind right now. Very hard to keep up with generic classification in the Charadriiformes lately!

  5. Smilodon says:

    This tern is clearly a King Tern.
    Thalasseus consists of
    Royal, Great Crested, Elegant, Sandwich, Cayenne, Lesser Crested, Chinese Crested.

  6. bobk says:

    Thanks for your last account of the Mediterranean Gull.
    The information was concisely useful – high value in an increasingly jabbery world. And also insightful – what but weighty experience could recognize an unsnouty jizz.

  7. bobk says:

    Royal Tern.
    The bill is very Elegant but the extensive black on the wing tops speaks of a youthful yet Regal lineage.
    Long live the market.

  8. Hilary says:

    Royal Tern – darker wings and not enough black on the head for Elegant.

  9. JohnB says:

    Juvenile Royal Tern

  10. bobk says:

    Something just occurred to me. I assumed that the thread or hair that is trailing from its bill was to line a nest. I’ve often seen terns dip down to pluck things from the water top. But, if this is a juvenile, why would it be building a nest? Hopefully it is not fishing line.