by Jim Stevenson

This essay is on the loons of Offat’s Bayou and a few other birds photographed out there recently. Many thanks to David Hanson who took Liz and I out there, along with his sweet wife, Jan.

From late fall through spring Common Loons fill up the shallows of the Gulf of Mexico with their gray plumage. They have huge, almost reptilian lungs and dive deep after fish, out-swimming their piscine prey with warm-blooded stamina and a wicked dagger beak. And in the Gulf, almost all our loons are Commons. Here’s one below just beginning to change, attaining white spots on its back.

Loons do a lot of funny things, like bathing regularly. They splash like crazy, creating a noisy scene with water going everywhere. This individual is gaining its breeding plumage with the dark head and neck stripes. They ride low in the water, not just because of their weight, but also the stones they ingest to help digest the fish bones.

Loons lose the power of flight for a time and Offat’s Bayou is a great place to go through this stage, with a steady supply of fish. This bird is close to getting his new feathers and I imagine can already fly. However, these exercises strengthen the flight muscles and ensure they can get airborne, depart and make it “home.”

As you can see, this individual has fully-formed flight feathers (say that ffffffast) and is probably just waiting for the right winds. Note the dagger bill and large body. Breeding plumage loons are strikingly beautiful, regardless of which of the five species. Common Loons are widely distributed in the Old World, too, where they are called “Divers.”

This is about as close to full breeding plumage as our loons get before they take off at dawn one morning. The same gene that controls plumage development also tell the birds when to leave, and also encourages vocalizations with those species whose notes are tied to courtship. Isn’t that a lovely bird?

Sometimes loons turn on their side to preen and observers can get confused. Arctic Loons, for instance, show more white on the flanks than the very similar Pacific Loons, so preening Pacifics are sometimes called Arctic Loons! [I know, I did it once north of Nome and caught myself in the error.] BTW, check out the size of the foot on loons!

This is another good example of how closely related green and purple are in their iridescence. You can see both appearing on the sheen of this bird’s head, and Pacifics have green throats while Arctic has purple. There are many other examples of green and purple, such as goldeneye and scaup heads, for instance.

There were other birds around the loons, such as this smartly-plumaged Forster’s Tern, In a bit of a surprise, it was flying around with a fish hook it its breastbone (curious how their genus name is sterna). These are quite similar to Common Terns, but the orange would be replaced with red, Commons have a shorter tail and are grayer underneath (and rarely have fish hooks). In some plumages, though, especially intermediate ones, those two can be a buggerbear.

There are few things in ornithology more lovely than the wings of a Bonaparte’s Gull. These immatures are quite different from adults, having dark-tipped wings without the light on the leading edge. Bonies are winter residents and most this late are birds that wintered further south, headed for Canada.

Eared Grebes are the western counterpart to the Horned back East. Their thin, erect neck is a great field mark when their changing colors might otherwise be confusing. Red eyes are great for seeing in dark water and the fish-eating bill is shared with most grebes. This species is common out West, but it is the Horned that reaches Alaska, a common theme for many pairs of species, where the eastern bird’s range is diagonal, and extends to Alaska.

Hooded Mergansers are the “other” merganser, a beautiful duck normally of tidal creeks and quiet lakes. These have paired off, a common sight for many ducks in spring. They may likely make the trip up North together but males wander off after mating. This is due to their bright colors, which could otherwise attract predators. Another duck often seen in Offat’s Bayou is the Northern Shoveler, also pair in spring.

The larger cousin of the Hooded Merganser is the Red-breasted, though their bill and legs are a lot redder than their chest! They feed in Offat’s Bayou with other piscine, diving birds like loons and grebes (and probably taste about like them). [They are not game birds.] All mergansers have toothy, serrate bills designed to catch fish, and that structure (and food) separates them from other ducks.

Sandwich Terns join Royals as deep-water feeders and Offat’s Bayou offers them that experience. Note the yellow tip on the otherwise-black beak, a sure sign it stuck its bill into a sandwich. Deep-water terns are sleek and slender for flying out into the Gulf for much of their food, allowing the sandwich to really move its buns.

Caspian Terns feed around the edges of Offat’s Bayou in shallows where fingerling mullet school. They leave the deeper water for the above Sandwich, as well as Royals. They have a thicker, redder bill than the latter, are bulkier and have less of a forked tail. Caspians wander inland across much of the country while Royals and Sandwich are confined to the marine realm.

The best time to scope out Offat’s Bayou is early morning with favorable light and calm seas.