Roseate Terns

Adult Roseate Tern on Eastern Egg Rock, Maine, in June 2011.

From Oak Harbor, Ohio, Kenn writes: Terns may be the ultimate summer birds. They are related to gulls, but gulls thrive in cold weather, some even spending the winter north of the Arctic Circle. Terns, by contrast, love warm climates. In much of North America, they are most prevalent during the summer.

About ten days ago, thanks to the generosity of Dr. Steve Kress and his highly successful Project Puffin, Kimberly and I were able to visit Eastern Egg Rock, in the Gulf of Maine. We did see puffins there, and many other birds as well; maybe Kim will blog about the puffins (hint, hint). But I was most pleased by the opportunity to look closely at Roseate Terns.


Some treatments of tern identification focus on bill color. The mostly-blackish bill of Roseate Tern can be useful for quick ID, but it’s tricky, too: other terns have blackish bills for part of the year, and in transitional stages they can show color patterns much like that of the Roseate’s bill. The SHAPE of the bill is a better confirming point. It’s relatively long, thick at the base and tapered to a fine tip, with the gonydeal angle on the lower mandible located fairly close to the base of the bill.

Wing pattern is one of the best ID points.  Summer adults typically have dark outer vanes on only the outer three primaries.  When the wing is folded, this shows up as a limited dark area on the wingtip.

Here’s a closeup of the wingtip from the previous photo.  Looking at the top of the near wing (the one on this side of the bird!), we can see dark gray on the three longest feathers, while the rest of the primaries (stacked up toward the left) are paler silvery gray.

The wing pattern can be even more obvious when the wings are spread.  In this photo, on the far wing, the dark gray is clearly limited to only the three longest primaries.  On the nearer wing, we can see that there is no dark trailing edge to the wing at all.

Compare that underwing pattern to the one shown by this Common Tern, photographed at the same place and date.  The black trailing edge to the outer primaries is obvious at a glance.



Adult Common Tern in flight, Eastern Egg Rock, Maine, in June 2011.

Roseate Tern also has a noticeably long tail, and lacks any black or gray on the tail (Common and Arctic terns both have narrow black outer vanes on the outer tail feathers, and Forster’s Tern shows some gray on the inner vanes).   The faint rosy blush on the breast feathers, the source of the bird’s name, is a fleeting phenomenon of spring, and barely a hint of it shows in our photos from late June.  Regardless, Roseate Tern is still a beautiful bird, and well worth the effort to find and identify!  For those with a keen interest in the subject, more information on identifying terns can be found in two chapters of my new Kaufman Field Guide to Advanced Birding. 

Roseate Tern is a widespread species, found from the North Atlantic to the Indian Ocean, but it is not abundant anywhere.  Its North American populations have declined seriously, so it is now listed as Endangered in the northeastern USA and eastern Canada, and as Threatened in the southeastern USA.   The nesting Roseates on Eastern Egg Rock (along with about equal numbers of Arctic Terns, and many more Common Terns) are closely monitored and protected by Project Puffin, a great program that deserves the support of birders everywhere.

That Time of Year

From Oak Harbor, Ohio, Kenn writes: For several years now I've been very interested in the whole subject of molt. This is the process wherein birds develop a new coat of feathers, generally by dropping a few feathers at a time, with new feathers growing in their place. Birders may not notice the molt unless they look closely, but it's a universal phenomenon among birds. Especially among smaller birds, it's generally true that a healthy wild bird will replace every one of its feathers at least once a year. Birders may not notice, though, unless the new feathers are strikingly different in color from the old ones.

The timing of the molt for most species is quite predictable. Right now, for example, here in northern Ohio, the American Goldfinches are starting their spring ("prealternate") molt. It's most noticeable on the adult males, who molt from very dull to very bright colors. This bird was outside the windows at the Black Swamp Bird Observatory yesterday, the last day of March. The occurrence of molt is one of the reasons why we have to look at the calendar when we're considering the identification of an unknown bird: it may be some familiar species in the process of going through a change.

People sometimes ask us why this bird is called the "American" Goldfinch, when it also occurs in Canada and locally in Mexico. Why not just "Common" Goldfinch, or "Yellow" Goldfinch, or something like that? Well, there's a good reason. Remember, I said that the bird shown above was just starting to molt. When it finishes the process of molting into its full summer plumage, usually around July 4, it will look like this:

As I said, we have to look at the calendar when we're considering an unknown bird; for some reason, April 1 produces more than its share of weird reports.

All seriousness aside (as the saying goes), the molt really IS going on right now, and it's affecting the appearance of many birds. The American Goldfinch is a great example to watch because it may come to feeders right outside your window and because the change of color on the males is so striking. But a high percentage of our small songbirds are going through some kind of molt of their head and body feathers at this season, and with a close study, you may be able to see the contrast between the crisp new feathers and the slightly older, worn, faded feathers. It's a part of the survival strategy of the birds and it's something we can witness for ourselves with just a little extra attention.

I'll Sleep When I'm Dead

It's spring, the Red-winged Blackbirds are all pumped up and making music, and so are we.

From Oak Harbor, Ohio, Kenn writes: In my most recent book, Flights Against the Sunset (published by Houghton Mifflin in 2008), there was a whole chapter ("Nightland") that was an extended essay on sleep deprivation. None of our friends were surprised about that. For Kim and me, sleep is usually pretty far down the list of priorities. There are always too many other interesting things to be doing.

Right now we're a little more crazed than usual. This weekend is the big annual banquet / celebration of the Black Swamp Bird Observatory (BSBO), and we've been swamped with trying to prepare for it. The observatory has a great staff and a lot of wonderful volunteers, without whom nothing would ever happen (come to think of it, I'm a volunteer). But still, Kim has been going like crazy all week, like a hummingbird on overdrive, dealing with a zillion details relating to the weekend. I never move as fast as she does, but I've been preoccupied with prep for the weekend as well.

Most of the action is taking place in Port Clinton, on Ohio's North Coast. It kicks off tonight (Friday night) with a show by our band, 6-7-8-OH, playing classic rock from 8 to 11 in a benefit concert for the observatory. Tomorrow morning (Saturday) I'm teaching a workshop on field identification of ducks, geese, and swans, a two-hour intensive course (and no, I'm not finished preparing for it yet). Saturday afternoon there's a tour of local businesses in Port Clinton, focusing on the many who have offered support to BSBO. Then in the evening we have the annual banquet, with awards, silent auction, etc., and a featured presentation by Norm Smith from Massachusetts Audubon, showing pictures and talking about his amazing research on Snowy Owls. Then Sunday morning we have field trips followed by a celebratory brunch.

And then maybe we sleep, or at least lie around on the floor with our tongues hanging out.

Ah, Spring! It's such an exciting time of year, the birds are all jazzed up, and so are we! But if you've called or written to us recently and haven't heard back, this is my attempt to explain why!