Here is an abbreviated list of birds mostly commonly seen along the mid-Atlantic coast in summer. Many nest in our latitudes early in the season.

All birds look alike t first. The best way to distinguish them is to positively identify one member of a family, then learn its close relatives by comparison of size and distinguishing features. It may be frustrating to read that a Caspian tern is larger than a Royal, but until you start noticing the differences, they're all just swallow-tailed birds that aren't gulls, which is redundant.

Gulls are fairly large with webbed feet, slightly hooked bills and squarish tails. Gregarious, omnivorous and very adaptable scavengers, they are particularly common on the shore while some species forage inland as well. Typically they have white bodies and black or gray mantle (plumage on the tops of the wings from tip to tip and the section of back in between). Young birds are usually mottled brown and white.

The largest, with a five-fot wingspread, is the great black-backed gull which has a black mantle and white head. Its sixe is distinctive.

The herring gull - the prototype "seagull" - is somewhat smaller. It has a red spot near the end of the bill, the visual trigger which prompts nestlings to peck and feed. Adults have white bodies with gray mantle and black wingtips. The pigeons of seashores, they eat carrion (preferably fish), haunt garbage dumps, packing plants and piers.

The ring-billed, only slightly smaller and similarly feathered, has a black ring around its bill instead of the red spot. Its legs and feet are yellow instead of pink.

Laughing gulls are somewhat smaller still. They have distinctive black heads and black mantles.

Terns , nearly as common as gulls along the shore, are white birds with forked tails and slender, sharply pointed wings. Very fast flyers, they dive for fish beyond the surf. All have short straight bills, which are red or orange, and black caps; these two characteristics distinguish the separate species.

The common tern, one of the smaller ones, has a deepley forked tail. Its cap is smooth, its dark orange bill tipped with black. Particularly agile, even for its kind, it is called the "sea swallow."

Royal terns are larger. Their bills are distinctly orange and their caps rather tufted in back.

The Caspian tern is the largest of the lot with a clearly red bill and smooth cap.

Sandpipers are the small hunters of the tidal wash, the fast-footed little birds that run close to the waves and fly low over them in flocks. The least and the semi-palmated are the mot common, the least being browner and smaller. A close and common relative is the sanderling, which is larger and has broader white wing stripes than the others.

There is a tribe of much larger wash waders which also probe the wet sands for small crustacea and the like. The largest is the willet, a rather drab-looking bird when walking on its slender gray legs. In the air the bright white chevrons on the wings are distinctive.

Oyster catcher: Feathered somewhat like a horizontal penguin, they have straight vividly orange-red bills which they use with great efficiency. They chisel some mollusks from rocks and can stab inside a clam shell to snip its muscle faster than the critter can close. They can also eat a sea urchin without breaking it.

The osprey is the large hawk that lives entirely on fish it snatches from the water with its talons. Several smaller birds (the bald eagle may try, too) will mob it for its prey, which is carried head-forward through the air. They nest in trees or on man-made platforms like wrecked boats, navigation markers, even barnyards where farmers used to welcome thm as avian watchdogs.

The double-crested cormorant is a dark bird that typically flies low over the water or swims around on it. They are great divers from the surface and remain submerged for long periods. Resting on offshore rocks, they half-spread their wings out to dry.

Herons. These long-legged waders live in marshes, feeding on fish, small marine animals, snakes and frogs. They have long slender necks and straight bills. Several species were nearly annihilated for their plumes, which were turned into ladies' hats around the turn of the century. The biggest, the great white, is rarely seen in our range.

The common or American egret is the next largest white one and is commonly seen here. It has a yellow bill and black legs and feet.

Slightly smaller is the red-dish egret in its white phase, a shaggier bird with black on the end of its yellow bill. (It may be confused with the immature little blue heron, which has a black tail.)

The snowy egret is smaller still, with notably shaggy plumage and characteristically yellow feet, which one can't see, of courst, when he's standing in the water. Wait until he flies.

The cattle egret, an Old World species, is rapidly spreading into the northeastern states.It has a shorter neck than the others and some tan plumage on the chest and head. It follows livestock in pastures, snaring the insects they stir up from the grass.

The great blues heron is an enormous bird with a six-foot wingspread - unmistakably large. A fish-eater, it will stalk its prey or stand in slow-moving water and wait for it. Quite shy of humans, it utters a loud quawk when disturbed and flies with slow ponderous beats. It has a white face iwith black plumes.

The blue Louisiana heron is smaller, with dark face and white plumes. Also, its white belly is characteristic.

The mature little blue heron has a dark reddish head and neck. It body is dark blue.

The aptly named black-crowned night heron normally seems to have no neck at all. It has ablack cap with white plumes andis usually not seen until dusk.

Reddish egrets in their red phase are shaggy-chested rust-colored birds with long necks.