With the scientific name of Pelecanus erythrorhyncos (from Greek for “pelican” and “yolk-colored beak,” referring to its orange bill), the American White Pelican is an unmistakable bird, whether you see it floating lazily on a lake or soaring majestically overhead. It is a massive white bird with a large black stripe on the back edge of its wings (seen only when flying) and equipped with an enormous bill. Here’s a lovely photo that clearly shows the black trailing edge. Hanging from the lower bill is a pouch that can extend 6-8 inches when filled, allowing the pelican to hold 2-3 gallons of water and fish. With a wingspan of 8-9 feet and a bill-tip-to-tail length of more than 60 inches, each bird weighs between 12 and 20 pounds.
White pelicans feed on a variety of fish that occur in shallow freshwater lakes and wetlands. (The other pelican species found in the United States—the Brown Pelican—is seen only in saltwater areas.) Dragging their open pouches sideways through the water and dipping for fish, they drain water by pointing their bills downwards; they then raise their bills to swallow the fish. American White Pelicans often forage in large groups, driving prey toward shallower water, where they can be more easily caught. Seen from afar, their wonderfully synchronized movements look like a water ballet danced by gigantic floating marshmallows.
The American White Pelican is found mainly in western and southern portions of North America. These large birds don’t breed until they’re at least two years old and only breeding adults remain at the breeding sites—primarily on islands in huge lakes. In Colorado, they have historically bred in only three colonies: one in Riverside Reservoir on the northeastern plains, one at Arapaho National Wildlife Refuge in North Park, and one at Antero Reservoir in Park County. (Antero Reservoir was drained in recent years; although it has been refilled, it is not clear if a breeding colony has returned to that location yet.) Only about 2.5% of the total population of American White Pelicans breed in Colorado. Instead, most of the pelicans we see in Colorado during the spring and summer months are non-breeding birds, wandering widely throughout the state.
“The Pelican” by Dixon Lanier Merritt (1910); often misattributed to Ogden Nash
The Snowy Egret is one of North America’s most familiar herons—a group of long-legged wading birds that can be seen hunting for fish and small crustaceans in the shallow waters of rivers and lakes. Standing around 2 feet tall, a “snowy” has an all-white body, with a black beak that has yellow skin at the base. It is often most easily identified by its “golden slippers”—bright yellow feet set off startlingly from black legs. During breeding season, long delicate plumes develop off its breast and back, with a short, craggy crop of longer feathers at the nape of its neck. These beautiful feathers caused serious problems for them in the late 19th century, though. Snowies were slaughtered nearly to extinction to obtain these plumes for women’s hats. At the height of the millinery (women’s hats) feather trade in the 1880s, the plumes sold at $32/ounce—twice the price of gold at that time! Thankfully, legislation passed in the early 1900s put an end to this devastating practice. Their scientific name is Egretta thula: egretta from Old French “aigrette,” which is a diminutive form of “aigron” (heron); thula possibly from a Chilean Indian word that described a black-necked swan, but which non-native speakers misunderstood and misapplied to this bird in 1782.
Equally at home in saltwater or freshwater, a Snowy Egret’s diet is made up of roughly 75% fish and 25% small crustaceans such as crayfish. They often catch their meals by scurrying about rather frantically in short bursts in shallow water, stirring up critters in the water and the mud below. Colorado has a few small breeding colonies in the San Luis Valley, at Barr Lake in Adams County, and in the Walden area. Primarily, though, we see snowies in the eastern third of the state in late summer and fall, as they disperse from their main breeding grounds in northern Nevada and Utah, along the Gulf Coast, and in the southern portions of the Arkansas and Mississippi Rivers. So if you happen to be driving by a lake and you spot a 2-foot tall white figure dashing about in shallow water, take a second look—you might witness a Snowy Egret catch some delicacy for dinner!
Canada Geese are common in Colorado’s metropolitan areas. Their scientific name is Branta canadensis. “Branta” probably derives from an Anglo-Saxon or Old Norse word meaning “dark or burnt-appearing,” referring to its plumage; “canadensis” reflects the fact that they historically bred primarily in northern Canada and Alaska. (And impress your friends, family, and neighbors by knowing that the common name is Canada Goose, not Canadian Goose.) Presently there are 10 subspecies of Canada Geese. An 11th subspecies was separated into its own species in 2004—the small Cackling Goose. (In the winter, if you see a goose that is not much bigger than a Mallard and colored like a Canada Goose, you are looking at a Cackling Goose.) The subspecies we see year-round in Colorado is the “Giant” Canada Goose, on average weighing 11-12 pounds with a 6-foot wingspan. Here’s a photo from Weld County where you can see the dramatic size difference between a Cackling Goose (in front) and a Canada Goose (behind).
Breeding adults form long-time pair bonds, but they may form new pairs with the loss of a mate. Goslings are precocial and leave the nest within 24 hours of hatching. By this time they can walk, swim, feed, and dive, following the parents wherever they go. While the parents don’t directly feed their young, they defend an appropriate feeding territory and protect their goslings. The young can fly about 7-9 weeks after hatching. Young geese stay with their families through their first winter and typically don’t reproduce until their 2nd or 3rd years.
Almost exclusively herbivorous, Canada Geese have readily adapted to eat agricultural crops as well as grasses, when they are available—favorites include corn, millet, and oats. If you’ve ever worked in one of Greenwood’s goose enclosures, you’ve surely noted all of the poop. In the wild, a single Canada Goose can consume up to 4 pounds of grass in a day, creating as much as 3 pounds of feces each day. One study reported that, on average, an adult Canada Goose poops every 7 minutes. You know what that means—hose down those floors and pads every day!
It may be hard to believe today, but at the end of the 19th century, over-hunting had reduced the Canada Goose population to near extinction. In the early 1960s, a concerted effort to rebuild populations began across the nation. Primarily to provide waterfowl hunting opportunities in the state, the Colorado Division of Wildlife began its restoration project in 1955 in the San Luis Valley with a few pairs; in 1957, 40 geese were released near Fort Collins. As numbers increased, geese were captured and moved into new areas. Eggs were taken and incubated to encourage second clutches. The project started slowly, but eventually ballooned—out of control, some might say today. The principal problem has been that relocated geese never learned their species’ migratory pathways. Instead they have remained year-round in urban and suburban areas where groomed lawns, parks, golf courses, and artificial lakes provide ideal habitat. Ironically, since a large portion of the Canada Geese live in metropolitan areas, they face very little pressure from hunting—the original purpose of the restoration efforts. Add the influx of the smaller subspecies of migratory Canada Geese from the north in the winter, and the numbers of Canada Geese can seem overwhelming in our area. For better or for worse, the Canada Goose population has indeed been pulled back from the brink of extinction.
The Mallard is the most familiar and widely distributed duck in North America. Ducks are generally classified in two ways, based how they forage for food in the water. “Dabbling” ducks, such as the Mallard, feed on the surface or “tip up,” with their tails in the air and their heads under water, to grab vegetation below the surface. “Diving” ducks such as mergansers dive and chase food—typically fish and crustaceans—under water. Except for the Muscovy Duck, all domestic ducks can trace their ancestries to the Mallard. Its scientific name (Anas platyrhynchos) reflects its prominent, broad bill—from Latin for “duck” (anas) and Greek for “broad” (platus) and “snout or beak” (rugkhos). The common name derives from the old French “maslard,” meaning a wild drake. And speaking of drakes—did you know that a male duck is called a “drake;” a female, a “hen;” and the young (no surprise here), “ducklings”?
Pairs generally form in the winter, so migratory Mallards arrive on their breeding grounds early and ready to breed. Hens lay 1-13 eggs (typically, 8-9); the incubation period is 23-30 days. Ducklings are precocial, hatching fully covered with down. They are moving competently around the nest in about 12 hours. Ducklings usually leave the nest as a group on the morning after hatching, if the weather is decent—13 -16 hours after hatching—with the hen leading the way. Only the hen cares for the ducklings, brooding them for about two weeks. They begin pecking at dark spots and small objects as soon as they leave the nest. In the first month, ducklings eat mostly animal foods (e.g., invertebrates, small crustaceans, mollusks, fish eggs), catching these morsels on the water’s surface or on land. In the second month, they move to feeding below the surface, dabbling and tipping up. In Colorado, the peak time for laying eggs is in mid-May. So the ducklings that Greenwood has this late in the summer most likely reflect pairs that renested after losing a clutch to rising water levels or depredation.
This time of year, the Mallard drakes undergo a dramatic, rapid, and complete molt, which lasts only briefly in late summer. They lose all of their feathers and, as a result, are extremely vulnerable to predators because they can’t fly without their flight feathers. As a result, they seem to have evolved to do what the females do for most of the year, merging safely into the background with drab brown feathers. But even in this “eclipse” plumage, as it’s called, you can differentiate males from females by their bills. Females have orange bills with dark gray or black spotting while males have yellow or yellow-green bills. Here’s a photo of the familiar Mallard drake and hen in breeding plumage. Compare this—especially the bills—with a drake in eclipse plumage. So if you spot a flock of drab-looking Mallards in late July or August, take a moment to check their bills. You may find an “impostor” drake or two mingling among the ladies.
© 2009 Tina Mitchell