Texas - Terns in Context

Recently mentioned that the Black Tern is one of the smallest of the terns, but I didn't really place that in context. A photo from Rollover Pass on the Bolivar Peninsula may give you a better idea. Here 3 small molting Black Terns are in the center, dwarfed by 3 large Royal Terns to the right with their orange bills, and 2 medium-sized Sandwich Terns on the left, with yellow-tipped black bills. The Royal Tern at 20" is almost as large as the 21" Caspian Tern.

At Bolivar Flats the Black Terns were seen with the slightly smaller Least Terns. I thoughtlessly tried to frame the Black Terns by themselves, but did find the 2 small tern species together. The bill of the Least is yellow in breeding plumage, with a touch of black at the tip. No other terns seen in the U.S. have yellow bills.

Terns were once grouped with the Gulls in the family Laridae but DNA analysis convinced the taxonomists to give terns their own family, Sternidae. There are about 44 species of birds in the tern family, including 5 species with the name noddy.

We did get to see a few distant Gull-billed Terns on the Bolivar Peninsula along Yacht Basin Road, a new species for us. They have relatively longer legs that most terns, as well as thick black bills, and are not usually seen along the shore with other terns.

Black Tern - Chlidonias niger

The timing of our Texas birding trip in early April preceded the peak of spring migration for the songbirds and others, but we did get to see a strong pulse of Black Terns passing through, with many present at both Rollover Pass and Bolivar Flats. Most birds we saw were in the middle of their pre-alternate molt, presenting interesting mixtures of black and white. This one apparently has a long way to go....

The birds at Bolivar Flats (a sanctuary managed by Houston Audubon) were pretty oblivious to our presence, so we had prolonged opportunity for viewing. This second bird has developed more black, but still far from the beautiful sleek finery it will obtain over the next month.

The Black Tern is a small tern, less that 10" long including those long wings. Compare to the Least Tern, 9" long. Overcast sky added to the pleasing monochromatic composition. 

Last shot shows one of the birds stretching. The black "band" is simply the tips of the secondaries on the trailing edge of the right wing. 

All birds we saw were simply resting on the beach or shoreline. Our only previous experience with the Black Tern was on a Rich Stallcup outing to Moonglow Dairy about 10 years ago, where we watched several of them flying like swallows over a marshy area and deftly snatching insects from the water's surface.