Diverse Divers

By Jim Low | November 2, 2008
From Missouri Conservationist: Nov 2008

Fleeing before a wild north wind, they materialize like wraiths. Scimitar wings slice through the air with a sound like a huge curtain tearing. The spectacle always sends a chill down my spine.

Say “duck” and most Missourians automatically conjure the image of an emerald-headed drake mallard. But if you spend enough time around big water, you will encounter several different types of ducks.

These ducks dive 40 feet or more for food instead of tipping bottom-up or dabbling for seeds in shallow water. Consequently, they are commonly known as “diving ducks,” in contrast to their shallow-water cousins, the “puddle ducks.” You are most likely to see diving ducks along the Mississippi River or a big lake.

Diving requires a streamlined shape and legs far back on the body. A denser body helps these birds get down to food. It also causes them to ride lower in the water on the surface, giving diving ducks a distinctive, low profile.

Dense bodies are harder to launch into flight, and so most diving ducks must run along the surface of the water to achieve flying speed with their relatively short, pointed wings. Once in the air, they must move faster than other ducks to remain aloft. If giant Canada geese are B-52s of the waterfowl world, diving ducks are the fighter jets.

Exactly how fast they fly depends on conditions. Puddle ducks routinely cruise at 40 mph, while teal swoop and wheel at 60 mph. Canvasbacks have been clocked at 70 mph. With a stiff north wind at their backs, divers make challenging targets. A hunter who can hit them consistently is not someone to bet against in a shooting contest.

Any duck with fast wing-beats and plumage that looks distinctly black and white is a likely suspect for the moniker “diver.” However, several diving ducks flout this rule, and hens of most species tend to be gray or brown.

Diving ducks are further divided into bay ducks, sea ducks, mergansers and stiff-tails.

Immigrants noticed the similarity of North America’s bay ducks to the common pochard of Europe, and you still hear this term applied to some, especially the canvasback and redhead.

The canvasback (Aythya valisineria) is our most imposing pochard. It is the largest, with adults averaging 21 inches from head to tail. Drake canvasbacks’ coloration is very similar to redheads’, but the canvasback’s black, chisel-shape bill is unmistakable, even at a distance.

You see canvasbacks mostly in bigger, deeper waters than other diving ducks. In Missouri they seldom stray far from the Mississippi River. During the migratory peak, canvasbacks sometimes gather in rafts of hundreds of birds.

The redhead (Aythya americana) is the spitting image of the European pochard. At 19 inches, it is only slightly smaller than the canvasback, but its head has a rounded profile, and the bill is more like those of other ducks. Both male and female redheads have bluish-gray bills with black tips.

The ring-necked duck (Aythya collaris) is one of the smallest and most common bay ducks in Missouri. Ringnecks cruise big rivers and lakes, but they also frequent ponds, marshes and managed wetlands. Their small size, together with typical diving-duck plumage and speed, make ring-necks fairly easy to recognize on the wing.

Don’t be confused if you shoot what you think is a ring-necked duck but are unable to find the ring. The name refers to an indistinct band of chestnut-colored feathers at the base of the drake’s neck. A better identifying characteristic is the white ring near the tip of the gray bill. It might have been better named the ring-billed duck.

Greater and lesser scaup (Aythya marila and affinis) look as if they were dressed for a black-tie affair. The drakes’ bold black-and-white markings and their tight flying formations make scaup easy to recognize in the air. Scaup lack the black end and white ring that ringnecks have around their bills, but they do have a black fingernail-like scale at the tip.

Telling the two species apart is more difficult, but not impossible once you see enough of them to recognize the greater scaup’s longer wing patches. These light markings run nearly to the tips on the upper side of greater scaup wings, but only about halfway out on the lesser. Both have the bluish-gray bill that accounts for the nickname “bluebill.”

Unfortunately, most hunters don’t see enough scaup to become proficient at telling the two species apart. For that reason, the bag limit includes both greater and lesser scaup.

Once you have a scaup in hand, you can tell the greater scaup by the rounded profile of its head, or the lesser by a slightly peaked, angular shape. On drakes, look for a subtle green iridescence that marks the head of the greater scaup or the purple sheen of the lesser. Also, greater scaup seldom are seen in Missouri and almost never on wetlands.

Sea ducks—as their name implies—are creatures of large, open waters. Many sea duck species are rare visitors to Missouri. Weeks after puddle ducks have deserted Missouri, two species of sea ducks—the common goldeneye (Bucephala clangula) and the bufflehead (Bucephala albeola)—continue to ply Missouri’s large reservoirs. Drakes of both species have dark heads with white spots. However, the placement of the spots makes each species fairly easy to distinguish. On the goldeneye, the spots are on the cheeks, whereas the bufflehead has a large white spot on the back of its head. At 14 inches long, the bufflehead is the runt of the divers.

My nominee for cutest diving duck is the ruddy duck (Oxyura jamaicensis), a member of a group known as stiff-tailed ducks. Drakes engaged in their mating display are so perky even an avid hunter might be tempted to pinch their little white cheeks. Ruddy ducks are only slightly larger than buffleheads. They are uncommon in most of Missouri, but you are more likely to see them the closer you get to the Arkansas state line.

That leaves the hooded merganser (Lophodytes cucullatus) and the common merganser (Mergus merganser), large fish-eating ducks with narrow, serrated bills ideally suited for holding slippery food. Mergansers superficially resemble pintails in flight, due to their sleek, graceful bodies and pointy tails. The shapes of their heads and bills are distinctive, however. Mergansers also tend to arrive and stay later in Missouri than pintails.

It’s a good thing mergansers are so distinctive, because the main reason to shoot one is to have it turned into a taxidermy mount. The merganser’s diet gives it an unpleasant fishy taste.

Diving ducks in general are less esteemed as table fare because their diets are long on fish, snails and other invertebrates, while puddle ducks tend to eat more grain, weed seeds and other plant foods. The canvasback is a notable exception. Though relatively uncommon, it is highly sought after by hunter epicures.

A handful of other divers have been seen in the Show-Me State, but they are too rare for the average hunter to worry about. For help identifying these and other waterfowl, write to MDC, Ducks at a Distance, PO Box 180, Jefferson City, MO 65102-0180 or e-mail pubstaff@mdc.mo.gov. Before you go afield, make sure you know all current regulations and limits. Pick up a Waterfowl Hunting Digest where permits are sold or online.

More detailed information is found in Birds in Missouri, a 375-page, softbound, large-format book covering more than 350 species. It is available for $30 plus shipping and handling and sales tax (where applicable) by calling (800) 521-8632 or visiting online.

Also In This Issue

A Boy Scout field trip molded a generation of conservationists.
An engineer’s methodical mindset and his passion for conservation meld into a plantation for quail.

This Issue's Staff

Editor In Chief - Ara Clark
Managing Editor - Nichole LeClair
Art Director - Cliff White
Writer/Editor - Tom Cwynar
Staff Writer - Bonnie Chasteen
Staff Writer - Jim Low
Photographer - Noppadol Paothong
Photographer - David Stonner
Designer - Stephanie Thurber
Artist - Dave Besenger
Artist - Mark Raithel
Circulation - Laura Scheuler