tri

Louisiana Birds – Water birds and Wetlands

A special report from birdcentral.net

Glossary

Themes

The birds listed in the table below at some point in their life-cycle spend time in the wetlands, bays, estuaries of Louisiana. This table shows some of the food items that each species depend on, either while wintering, migrating, breeding, or being residents. The food items are from the Life Histories of North American Birds, edited by A.C. Bent. Bent compiled the 26 volumes of material by communicating with a variety of naturalists and referencing their material. As noted below, John James Audubon was one of the sources. The language used in this table came from the Life Histories so can be a bit dated at times. Some of the naturalists comment about the value of many of the species (for example the Marbled Godwit, White Ibis, and the American Golden Plover) in terms of the contribution they make by eating animals that could be pest, like Mosquitoes, or contributing in other ways.

It is important to realize the diversity of life that can be found in the wetlands. That diversity depends on unique food webs, but all those food webs depend on the small stuff, like plankton, minnows, larvae. The oil that has spilled into the water, in the mud, makes it very difficult, or impossible, for the plankton and the minnows to live. Without the foundation, the minnows and the plankton, the rest of the food webs don't happen.

As this is written, in late June of 2010, many of the birds listed below are finishing up their nesting in Northern Canada, and other places, and will soon be migrating down to Central and South America. Millions of birds will be expecting to stop-over in the Gulf so they can refuel for the rest of their journey. One can only wonder what food webs will be operating in August and September when they stop by.

An example of the depth of the food web problem can be seen in this portion of a NYTimes article from June 24, 2010, Impact Feared on Gulf's Deep-Water Fish by Andrew W. Lehren and Justin Gillis

"Fearing that the oil spill in the Gulf of Mexico will deal a severe blow to the bluefin tuna, an environmental group is demanding that the government declare the fish an endangered species, setting off extensive new protections under federal law. Scientists agree that the Deepwater Horizon spill poses at least some risk to the bluefin, one of the majestic - and valuable - fishes in the sea. Its numbers already severely depleted from record levels, the bluefin is also the subject of a global controversy regarding overfishing. In fact, scientists say, it is virtually certain that billons of fish eggs and larvae have died in this spill, which came at the worst possible time of the year. Spawning season for many fish in the gulf begins in April and runs into the summer. The drilling rig exploded on April 20, and the spill has since covered thousands of square miles with patches of oil."

Florida shore birds

Shorebirds
Willet	“The favorite feeding grounds of the eastern Willet are on the broad mud flats in the bayous, bays, and estuaries on the coast; it also feeds along the muddy banks of creeks and ditches or about the pond holes and spaces on the salt marshes.” Their food consists of aquatic insects, marine worms, small crabs, fiddlers, small mollusks, fish fry and small fish. Some vegetable matter is eaten, such as grasses, tender roots, seeds, and even cultivated rice.
Greater Yellowlegs	Small minnows, water insects; insects and larvae, dragon fly naiads, aquatic Hemiptera,
Lesser Yellowlegs	Gleans most of its food from the surface of the water around the tall grass; small grasshoppers, other small insects; water boatman, various crustaceans; Dytiscid larvae, Dydrophilld larvae;
Spotted Sandpiper	Flying insects, locusts, grasshoppers and caterpillars (cut worms, cabbage worms, army worms) beetles, grubs and other pests; also trout fry (very young trout)
Whimbrel	Earthworms, sandworms, insects, larvae of Diptera, beetles, slugs, small crustacean such as shrimp, crabs, marine mollusks,
Long billed Curlew	Mollusks, crawfish, small crabs, snails, periwinkles, toads, worms, larvae, grasshoppers, crickets, beetles, caterpillars spiders, flies, butterflies, berries, worms.
Marbled Godwit	Snails, crustaceans, insects and their larvae, worms, leeches, “These big birds, when they were as abundant as they once were, must have been an important factor in keeping in check the dangerous insect hordes of our State.” (1919)
Ruddy Turnstone	Coon oysters, fiddler crabs, grasshoppers and other insects, mollusks, small fish, vegetables
Red Knot	On migration the Knots feed mainly on the sandy and stony beaches probing in the sand for minute mollusks and small crustaceans, grasshoppers, marine worms (Nereis)
Sanderling	Sand fleas, marine worms, shrimp, small crustaceans, fly larvae, flies,
Dunlin	Mostly animal: mollusks, worms, crustaceans, insects and spiders
Western Sandpiper	Fly larvae, aquatic beetles and bugs, marine worms, small snails,
Least Sandpiper	Small crustaceans, worms, insect larvae such as green-head flies, mosquitoes, small beetles
White-rumped Sandpiper	Marine worms (Nereis) 70% animal, 30% plant
Pectoral Sandpiper	55% flies (Diptera); amphipods (22%), vegetable matter (algae) 10%,beetles (8%); also – mites, spiders, caddis fly larvae, and grass seeds; during spring – crickets
Buff Breasted Sandpiper	40% consisted of coleopteran, adults and larvae; 50% diptera, chiefly larvae and pupae. seeds of Polygonum, Potamogeton and Elcocharis.
Long-billed Dowitcher	Larvae of midges (Chironomidae)
Short-billed Dowitcher	Grasshoppers, beetles, flies, maggots, marine worms, oyster worms, leeches, water bugs, fish eggs, small mollusks, seeds of aquatic plants
Stilt Sandpiper	70% animal, 30% plant. Blood worms, Dytiscid larvae, Planorbis snails, mosquito larvae
Wilson's Snipe	Earthworms, cutworms, wireworms, leaches, grasshoppers, locusts, beetles, mosquitoes, other insects
Woodcock	Earthworms are primary food

Long-legged Wading Birds (Bitterns, Night Herons, Herons, Egrets)
American Bittern	Fish, frogs, meadow mice, lizards, small snakes, eels, crayfish, mollusks, dragon flies, grasshoppers.
Least Bittern	Small fish, tadpole, small frogs, lizards, snails, leeches, beetles, and other insects.
Yellow-crowned Night Heron	Land crabs, black crab, birds, crawfish, fiddlers
Black-crowned Night Heron	80% of food is fish; whiting (Merlucceus bilinearis), herring (Clupea harengus), cunners (Tantogolabrus adspersus). Dr. Coues noted: “The remains of animals in the food which could be identified comprised marine annelids, chiefly Nereis virens, crustaceans (shrimp, sand-hoppers, and a few small crabs); insects, chiefly beetles, flies and dragon-fly nymphs."
Green Heron	Minnows, earthworms, crickets, grasshopper, snakes, small mammals, lizards, crabs, crayfish, frogs
Tricolored Heron	Minnows, water insects, worms, slugs, and snails, as well as leeches, tadpoles, and aquatic insects
Little Blue Heron	“The little blue heron feeds to some extent in salt or brackish waters in estuaries and coastal marshes, where it catches minnows, fiddler crabs, and other crustaceans.”
Reddish Egret	“The food consists of a small fish and frogs, tadpoles, and an occasional crustacean, which are probably caught in the marshes of the mainland coast.”
Cattle Egret	The Cattle Egret was not in the US when A.C. Bent put together the Life Histories. It feeds on fish and insects primarily.
Snowy Egret	Small fish, grasshoppers, cut-worms, small lizards, crayfish, dragonfly nymphs, small crabs
Great Egret	“Their food consists only partially of small fishes and it includes frogs, lizards, small snakes, mice, moles, fiddlers, snails, grasshoppers and other insects.”
Great Blue Heron	Principal food of the Gt. Blue Heron is fishes of various kinds. Also, frogs, eels, pickerel, suckers, shiners, chubs, black bass, herrings, water puppies, salamanders, and tadpoles.

Ibis, Spoonbill
White Ibis	Small crabs, slugs, and snails, insects, crawfish, cutworms, grasshoppers, crayfish. Ibis eat great deal of crayfish and as was noted in 1913, “… but with thousands of ibis and herons that use the lake as a reservation, have kept the crayfish down to such an extent that there are more fish … than in many years. … As young fish eat millions of mosquitoes it stands to reason that with ibis and herons we have more fish and less mosquitoes, and any bird that does so much good to a State is of very great value and should be protected for that reason alone.”
White-faced Ibis	“Its food also consists largely of crawfish, various small mollusks, insects and their larvae, small fish and frogs, newts, leeches, and various other form of low animal life.”
Glossy Ibis	Cutworms, grasshoppers, crayfish, snakes, insects,
Roseate Spoonbill	Audubon (1840) wrote about the Spoonbill’s feeding habits: “They move their partially opened mandibles laterally to and fro with a considerable degree of elegance, munching the fry, insects, or small shellfish which they can secure.” Also would feed on prawns, fish, shrimps and beetles.

Plovers
Black-bellied Plover	Marine worms, small mollusks, crustaceans, and marine insects, grasshopper, snails,
American Golden Plover	“The large numbers of grasshoppers, locusts, crickets, and other insects that they destroy make them very beneficial birds to the farmers of the west, where they also do much good by eating the grubs cutworms, and wireworms only freshly plowed lands, their favorite resorts in spring.”
Snowy Plover	Small crustaceans, marine worms, small insects
Piping Plover	Federally listed as Endangered. Marine worms, fly larvae, beetles, insects, crustaceans, mollusks,
Wilson's Plover	Audubon, (1840) “They feed fully as much by night as by day, and the large eyes of this, as of other species of the genus seem to fit them for nocturnal searchings. Their food consists principally of small marine insects, minute shellfish and sand worms with which they mix particles of sand.”
Semipalmated Plover	“The semipalmated plover is an active feeder and in this way is sometimes beneficial to man. … small mollusks, various crustaceans, and insects.”
Killdeer	(1912) “In all 97.72 percent of the killdeer’s food is composed of insects and other animal matter. The bird preys upon many of the worst crop pests and is a valuable economic factor.” Beetles – 37%, other insects 39%, other invertebrates (centipedes, spiders, ticks, oyster worms, earthworms, snails, crabs, crawfish, and other crustaceans, 21%.

Oystercatchers, Stilts, Avocets
American Oystercatcher	Audubon, (1840) “I have seen it probe the sand to the full length of its bill, knock off limpets from the rocks on the coast of Labrador, using its weapon sideways and insinuating it between the rock and the shell like a chisel, seize the bodies of gaping oysters …”
American Avocet	Wetmore (1925) Animal food – 65%, plant food – 34%. Among the animal food were found phyllopods, dragonfly nymphs, back swimmers, water boatmen, various beetles and flies and their larvae. Vegetable matter consisting mostly of seeds.
Black-necked Stilt	Animal food – 98.9% vegetable – 1.1% . The animal food consisted mainly of insects, aquatic bugs, and beetles making up the largest items; dragonfly nymphs, caddis flies, mayfly nymphs, flies, billbugs, mosquito larvae and grasshoppers. Also crawfish, snails, tiny fish.

Gulls and Terns
Laughing Gull	Consists largely of fish. Sometimes it steals the fish that the Brown Pelican catches. Laughing Gull also gathers other food as it is available.
Bonaparte’s Gull	Eats primarily insects, especially winged insects. On the seacoast they live on small fish, shrimps, and other surface-swimming crustaceans, marine worms, and other small aquatic animals.
Ring-billed Gull	Gathers agricultural pests such as worms, grubs, grasshoppers, and other insects. Also gathers food at garbage dumps. Will also invade colonies of nesting birds to take eggs and chicks.
American Herring Gull	Scavenger of almost any type of food available such as garbage, dead fish, fish that another animal caught, etc.
Sandwich Tern	The food of the Sandwich Tern consists almost entirely of small fish such as small mullets, sand launces, and young garfish.
Royal Tern	Fish up to 4 inches long
Caspian Tern	Small fish and other small surface swimming food such as shrimp. Sometimes will invade a nesting area and steals eggs.
Forster’s Tern	Eats winged insects and sometimes small fish
Gull-billed Tern	Eats primarily insects.
Least Tern	Federally Listed Endangered Species. Mostly small fish.
Black Skimmer	Small fish, shrimp, and other crustacean that are on the surface of the water.

Cormorants, Pelicans, Anhinga
Double-crested Cormorant	Fish
Anhinga	Various type of fish, aquatic insects, crays, leeches, shrimps, tadpoles, eggs of frogs, water-lizards, young alligators, water snakes, and small turtles
Brown Pelican	Fish

Rails, Gallinules, Coots
King Rail	Insects, slugs, leeches, tadpoles, small crayfish, and seeds.
Clapper Rail	Small crabs, salt-water snail, fry, aquatic insects, and plants.
Virginia Rail	Earthworms, insect larvae, slugs, snails, small fish, caterpillars, beetles and other insects
Sora	Small mollusks, dragon flies, other insects
Yellow Rail	Very little is known about the food of this species. Insects, snails
Purple Gallinule	Very little has been published about the food of the purple gallinule. Baird, Brewer and Ridgway say, “Worms, mollusks, and the fruit of various kinds of aquatic plants are its food.”
Common Moorhen	“Their food consists of seeds, roots, and soft parts of succulent water plants, snails, and other small mollusks, grasshoppers and various outer insects and worms.”
American Coot	Coots eat whatever they can find. They feed largely on leaves, fronds, seeds, and roots of aquatic vegetation, such as pond weed, wild celery.

Ducks, Geese, Swans
Greater White-fronted Goose	Vegetarian. Eats aquatic insect larvae probably as it gathers various vegetations. Feeds often in farm fields to obtain grain.
Snow Goose	Feeds primarily on grain; also sea cabbage
Fulvous-Whistling-Duck	Seeds, grasses, weeds, acorns.
Black-bellied Whistling-Duck	Corn fed duck.
Wood Duck	Primarily a surface feeder. A large part of its food is insects. Also small fish, minnows, frogs, tadpoles, snails, and small salamanders; acorns, chestnuts, and beechnut.
Mallard	Vegetable matter such as seeds, and roots, wheat, barley and corn.
Mottled Duck	No food listed, but food would be similar to Mallard.
Green-winged Teal	Food is 90% vegetable matter. Sedges, pondweeds, grasses, smartweed, water milfoils, arrow grasses.
Gadwall	“Like the Mallard, the gadwall is a clean feeder, which makes its flesh delicious for the table. … It’s vegetable food consists of tender grasses, the blades, buds, seeds, leaves and roots of various aquatic plants, nuts, and acorns; it visits the grain fields to some extent, where it picks up barley, wheat, buckwheat and corn."
American Widgeon	Food is mostly vegetable, consisting mainly of the seeds and roots of grasses and various water plants. Pondweed, grasses, algae, sedges, wild celery, waterweed
Northern Pintail	Surface feeder. Vegetable matter makes up 87% of food. Pondweed, sedges, grasses, smartweeds, arrow grass, musk grass, and other algae.
Northern Shoveler	The food of the shoveler consists of grasses, the buds and young shoots of rushes, and other water plants, small fishes, small frogs, tadpoles, shrimps, leeches, aquatic worms, crustaceans, small mollusks, particularly snails, water insects, and other insects as well as their larvae, and pupae.
Blue-winged Teal	Surface feeder; likes rice, wheat, barley. Animal food includes tadpoles, worms, snails, other small mollusks, water insects and larvae.
Canvasback	Principal food of the canvasback is wild celery (Vallismeria spiralis); also wild oaks, blue flag, water chinquapin, tuber-bearing water lily, yellow pond lily, water milfoil.
Redhead	“The favorite feeding grounds of the redhead during the summer are in the open lakes of the interior where it dives in deep water or in shallower places to obtain the roots and bulbs of aquatic plants or almost any green shoots which it can find; it is not at all particular about its food and is a gluttonous feeder."
Ring-necked Duck	Mostly vegetation such as aquatic roots, various seeds, and grains, plus minnows, small frogs, tadpoles, crawfish, snails, insects.
Lesser Scaup	Feeding habits are much like the Greater Scaup.
Greater Scaup	The Scaup dives below the surface of the water to obtain food, such as fish fry, tadpoles, small fishes, small snails and other mollusks, flies and water insects. They also eat some vegetable matter such as buds, stems, roots, and seeds.
Surf Scoter	Mussels, small mollusks, crawfish, slugs, snails, frogs, small fish, tadpoles, fish spawn, and the larvae of insects. They also eat vegetable food such as duckweed, pondweed, and pickerel weed.
White-winged Scoter	Mussels, small mollusks, crawfish, slugs, snails, frogs, small fish, tadpoles, fish spawn, and the larvae of insects. They also eat vegetable food such as duckweed, pondweed, and pickerel weed.
Black Scoter	Mussels, small mollusks, crawfish, slugs, snails, frogs, small fish, tadpoles, fish spawn, and the larvae of insects. They also eat vegetable food such as duckweed, pondweed, and pickerel weed.
Bufflehead	Dives for food. They feed on chubs, shiners, small trout fry, and other small fish. They also eat small mollusks, crustaceans, beetles, locusts, grasshoppers,, and other insects.
Red-breasted Merganser	Primarily a fish eater, but will also eat crustaceans and mollusks.
Hooded Merganser	Mostly insects, but will also chase fish under water, eat crawfish, caddis fly larvae, dragon-fly nymphs, sand eels, crustacean; will also eat plants such as seeds, roots, and grain.
Ruddy Duck	Diving duck. Eats primarily vegetation but also small fish, slugs, snails, mussels, larvae, fish spawn, worms, and creeping insects.