Identifying Ducks.

It’s 20 minutes before sunrise. The light is dim, but it’s legal shooting time. Your decoys bob gently on the water in front you as you hunker in your blind. Suddenly, the dog starts to quiver as a flight of ducks set their wings, about to land in front of you, but you aren’t sure what kind they are. Rather than miss an opportunity, says Scott Yaich, chief scientist for Ducks Unlimited, use the duck’s size, shape, and color as clues to its species.

Atlantic Flyway: Two duck species that are commonly confused in the Atlantic Flyway are black ducks and hen mallards, which can often be found together, says Yaich. He offers a few tell-tale clues: "Black ducks stand out in flight due to the contrast between their dark breast and their stark, light underwing. If you’re close and can see the top of the wing spread out, mallards have white bars on the leading and trailing edge of the speculum [iridescent patch on the upper wing]. Black ducks have no white bars."

On the water, bill color is another clue. Black duck bills are olive green whereas hen mallard bills have an orange tone. Black ducks, which are really not black but dark brown, also look much darker than mallards when they are mixed together.

Mississippi/Central Flyways: Waterfowlers in the mid-continent flyways often mistake widgeons and gadwalls in flight, even though they look quite different close up. The birds are similar in size, and both have prominent white patches on their wings. The location of those white marks is the key to telling them apart.

"In flight, you know it’s a gadwall if the patch on the rear of the wing is close to the body, where the speculum would be on a mallard," says Yaich. "On widgeons, that patch is on the front portion of the wing away from body — what you might say is the bird’s elbow (though it’s really its wrist)."

Pacific Flyway: Even though blue wing teal are smaller, hunters sometimes mix up shovelers and blue wing teal, especially during the early teal seasons when the male blue wings are not in their full plumage and are missing the obvious white crescent on their faces. "Both have blue patches on the leading edge of their wings, but the shoveler has a prominent, spoon-shaped, and larger bill," says Yaich. "If you’re teal hunting, cue on the bill — otherwise, they look very similar during much of the hunting season."

Other Look-Alikes: Bill shape is also diagnostic when differentiating between redhead and canvasback ducks in flight or in low light. A canvasback has a long, wedge-shaped bill that slopes from its forehead to the point, whereas a redhead has a more typical duck-shaped bill.

Scaup and ring-necked ducks, which are similar in size and color, are two other potential look-alikes. Yaich says to look for white on the trailing inside edge of the wing, indicating a scaup. If it’s gray, it’s a ring-necked duck. Ring-necks also have a bulge of feathers on the back of the head and a distinctive ring on the bill, whereas scaup have a traditional duck-shaped head and no ring on the bill.

"As a rule of thumb, never shoot something you can’t identify if it risks putting you over your bag limit," says Yaich. "It’s always best to positively ID what you shoot."

Bolstering Your Bird Feeder.

According to the U.S. Fish and Wildlife Service, more than 52 million Americans feed birds — that’s more than the number of hunters and anglers in the U.S. combined. These self-appointed avian caregivers spend up to $20 billion each year on bird feed and backyard bird paraphernalia.

The practice is not without its detractors, who accuse bird feeders of creating dependency on human food sources and spreading disease. But Emma Greig, project leader of Project FeederWatch for the Cornell Lab of Ornithology, debunks both of these theories.

"No studies suggest birds become dependent on feeders, and it doesn’t make sense that they would," says Greig. "It would be a poor adaptation. Feeders are one of many food sources. They supplement the diets of billions of birds, but even during a severe winter when you see lots more birds at feeders, the birds are probably still not dependent on the feeder."

According to Greig, the reputation for spreading disease stems from a blinding conjunctivitis called Mycoplasma gallisepticum that caused a troubling decline in house finches during the 1990s. "Though other birds can carry the disease, only house finches were affected by it," explains Greig. "House finches now have immune systems to cope with it."

If you do see a sick bird at your feeder, it’s a cue to clean the feeder, which will cause the birds to disperse. "The sick one will likely get eaten by a hawk," says Greig. "The feeder may have extended [the bird’s] life a little, but birds live in complex environments. By hanging or taking down a bird feeder, you are not changing the evolutionary trajectory of a species. . . . The benefit is bringing the forest, savannah, or desert to your window. You can enjoy nature in your backyard."

To help you get better at bird feeding, Greig clarifies several feeder fallacies.

Myth: The best place for a bird feeder is by a window. You can see it better, and it discourages predators.

Fact: The best location for a bird feeder is near vegetation, shrubs, or trees, which give birds nearby perches from which to assess the safety of the feeder and dive for cover if a predator appears. It might or might not be near a window.

Myth: My housecat can’t reach the feeder so it’s not a threat to birds.

Fact: Cats are one of the biggest causes of backyard bird mortality, killing more than 1 billion birds per year. Keep your pet indoors if you want birds at your feeders.

Myth: Peanut butter (which some people mix with birdseed then smear on pinecones) is unsafe for birds to eat.

Fact: No studies show peanut butter as harmful. During the winter, peanut butter is a good source of protein and fat, and it’s a small percentage of a bird’s diet. Use brands that are free of preservatives and chemicals.

Myth: Because my neighbor has so many birds at his feeder, none will come to mine.

Fact: Birds are always looking for food sources. They’ll visit your feeder, too.

Why aren’t there any birds at your feeder? Greig says to check the food inside it. If the birdseed is old or has turned rancid, the feeder tube might be full but the birds won’t show up. "Other than that, you can’t make any real mistakes."