A Plethora of Pelicans

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A white pelican in mid-flap. (Paul A. Johnsgard)

By Paul A. Johnsgard

Of all the birds of the Great Plains, probably none is more widely recognized by the general public than is the American white pelican. Its almost cartoon-like profile, with a impossibly long pouched bill and a waddling gait on land that reminds one of an overweight uncle, is impossible to mistake. Yet, when swimming, a group of pelicans has the appearance of a slow but regal procession, with each bird maintaining a decorous distance behind the leader. In flight the birds produce a mesmerizing slow-motion aerial ballet. With their great wing areas providing lift for their relatively heavy bodies, pelicans can soar effortlessly in the slightest updraft, and during normal flight nearly a third of their time is spent in restful gliding. To maximize flying efficiency, the birds often assume an echelon formation, with the lead bird setting the flap-glide rhythm. As it shifts from flapping to gliding, the bird just behind does the same, and the rest follow in rapid progression. The result is a wave-like, almost hypnotizing, visual effect, which reduces the energy cost of flying for all of the birds using the slipstream of the one just ahead.

White pelicans have long been a prominent part of the Great Plains scene. When traveling up the Missouri River in August 1804, along what is now the Iowa-Nebraska border, Lewis and Clark came upon a flock of perhaps as many as 5,000 to 6,000 pelicans. One was shot, and, as if to prove Dixon Merrit’s familiar limerick about pelican beak capacity, its pouch was found to hold up to five gallons of water!

Pelicans use their huge beak pouches to capture fish by an open-mouth stabbing movement, taking in both water and prey. They then shut the beak, forcing water out its sides and trapping any animals inside. Pelicans often feed alone by this method, but like some other fish-eating birds such as cormorants, coordinated group fishing is a more efficient way of foraging. Working in groups of two to six birds, pelicans will typically use a semicircular formation to drive any fish into fairly shallow water, and, as if on command, all will suddenly thrust their beaks into the water in unison. The groups that are the most coordinated in this regard are the most efficient in catching fish.

Most pelican prey consists of fairly slow-moving fish, such as bullheads, carp and suckers, but salamanders have been found to be an important food item in North Dakota, and crayfish are sometimes also captured. In spite of their huge pouches, the tongues of pelicans are extremely small, and they seem to eat almost anything they can capture and swallow.

In spite of their catholic diet, fishermen have long despised pelicans, and up until the mid-20th century their continental population was in decline. Even in Yellowstone National Park, the unofficial (and illegal) policy was to raid the Yellowstone region’s only nesting pelican colony and destroy their eggs, in a senseless effort to try to protect the park’s cutthroat trout population for exclusive use by fishermen. Luckily, that policy has been rescinded, and since the 1960s the pelican’s continental population has been increasing at an estimated average annual rate of 3
percent.

Although the closely related brown pelican is a coastal species, the American white pelican breeds only in the continental interior and reaches its highest breeding abundance in the northern Great Plains, especially in the shallow lakes and “pothole” marshes of Canada’s prairie provinces. No recent nationwide population surveys are available, but in the 1980s the U.S supported an estimated 22,000 nesting pairs and Canada over 50,000. Given the estimated recent population trend, by now these numbers have probably doubled.

Persons wanting to see pelicans in Nebraska have many opportunities. Pelicans are fairly regular migrants on the wider rivers, just as they were in Lewis & Clark’s time. The central Platte Valley, where the river channel is widest and where there are few shoreline trees to obscure the view, is especially attractive. In a 1990 study John Sidle and others found that pelicans occurred there most commonly during migration where the river channel was at least 800 feet wide.

Lakes and reservoirs, especially their shallower portions, are equally attractive to pelicans. During May, I have seen as many as 700 to 800 along the western end of Calamus Reservoir, and comparable numbers occur near the western end of Harlan County Reservoir. Pelicans are also common at Crescent Lake and DeSoto national wildlife refuges during migration. I have seen pelicans on Lake Ogallala and Lake McConaughy on almost every visit from spring to fall. Some nonbreeders remain there through the summer breeding season, often “hanging out” below Kingsley Dam, waiting for stunned fish to come through the dam’s outlet and provide an easy meal.

White pelicans. (Paul A. Johnsgard)

Some locations near Nebraska that support breeding pelicans include LaCreek National Wildlife Refuge, at the northern edge of the Nebraska Sandhills near Martin, South Dakota, and there are other locations in northeastern South Dakota (in Roberts, Marshall, Day and Coddington counties) that often have colonies. Pelicans also breed locally or periodically in southeastern Wyoming and southwestern Minnesota, where Marsh Lake (Lac qui Parle County) had 1,450 nests in 1983. North Dakota has a single but very large breeding colony at Chase Lake, in Stutsman County. Breeding records there go back at least to 1905, and as many as 4,100 nests were present during the early 1960s.

Pelicans become sexually mature when they are three-year-olds, so many yearling birds and some two-year-olds often spend their summers at points between their Gulf Coast wintering grounds and their Great Plains breeding grounds, from South Dakota to central Canada. Most of these birds lack the horny enlargement present on the top of the upper bill that is typical of breeding birds. This curious structure, resembling an inverted keel, is chemically like the keratin in human fingernails, and varies considerably in shape. It develops every spring on adults of both sexes and drops off near the end of the nesting period. Like driving a red sports car, it is evidently a visual signal of breeding readiness and relative social status but seems to have no other apparent function. Visual signals might be especially important to pelicans, as they are nearly mute, and in several species the beak and pouch coloration becomes more colorful during the breeding season.

Spring migration begins shortly after rivers and lakes thaw, and is aided by the warming spring atmosphere and the associated thermals that provide strong updrafts. Pelicans are slow fliers, averaging about 30 miles per hour, and may not arrive at their northern breeding grounds until early May. They typically fly in flocks of up to about 250 birds, possibly covering up to a hundred miles or more in a day. Once on the breeding grounds, adults may make daily trips to feeding areas as much as 40 miles away, or rarely even as far as 60 miles!

Shortly after arrival on the breeding area the birds begin courting and looking for nesting spots. Pelicans typically nest on low, flat islands that can easily be flooded during storms. They are not known to maintain their pair bonds over winter, but monogamous pair bonds are quickly formed that last until the young have fledged. Two eggs are laid, and thereafter both sexes take turns in incubation, which lasts about 30 days. Since incubation starts with the laying of the first egg, the second-laid egg produces a chick that is hatched a day or two after the first.

The young are hatched naked and blind, and initially more closely remind one of reptiles rather than birds. The first-hatched chick grows rapidly, being provided with a nearly continuous supply of half-digested fish from both parents. Its sibling, however, is less fortunate, and as a result of parental neglect and aggression on the part of the older chick is likely to starve to death in less than two weeks. Typically fewer than 10 percent of successful broods still contain two chicks at the time of fledging, which occurs at 10 to 11 weeks of age.

The fall migration is a leisurely one. Migrant birds typically arrive in Nebraska by late September, and historically were gone from the state by early November. The warming climate trend of recent years may soon lead to later fall migrations and earlier spring appearances, even as early as late February.

Since 2011 a celebration of the pelicans’ spring return to southern Nebraska has developed at Harlan County Reservoir, with a White Pelican Homecoming Celebration at Alma during late March. In 2013 it will be held from March 22 to March 30, with a Harlan County White Pelican Watch extending from March 1 to April 15.

There is something uniquely relaxing about watching a flock of pelicans in flight. At times they might circle slowly, safely within the grasp of an invisible thermal, perhaps gaining a thousand feet or more of altitude in the manner of cranes, until they almost disappear from sight. At other times pelicans resemble nothing so much as a regatta of sailboats on royal parade, silently riding on the wind in measured procession. Unlike the excited clamoring of cranes, or the incessant dog-like yelping of snow geese, the pelicans simply fly silently on, as if they were aware that to add sound to their presence would in some way only lessen its impact.

 

Image Credits: Paul A. Johnsgard

Immigration in Nebraska