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St. Croix Creature Feature: Pelicans use the river as a north-south highway

Flocks of the huge white birds have been spotted on and above the St. Croix River during both spring and fall migration this year.

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Wednesday evening near Marine on St. Croix, the afternoon’s stiff south wind finally slackened. It had been like a summer day, warm and with a steady breeze blowing upstream. Now, September’s calm returned.

As the sun hung a couple degrees above the Minnesota bluff, a cloud of birds appeared to the north, flying down the river high in the sky. They were big and white and glided on broad wings.

It took a moment to determine they were not trumpeter swans, the other big white bird seen in these parts. Two things gave away the fact they were American white pelicans (Pelecanus erythrorhynchos): their big scoop-like beaks, and their particular way of soaring and gliding along between flaps of their wings.

A couple weeks ago, friends around Stillwater and Bayport also reported a huge flock of pelicans flying down the river in the evening. Photos and videos had failed to do it justice.

The St. Croix River last saw pelicans in the spring, when late ice-out on the shallow lakes to our northwest that they use for nesting were still frozen, and a plethora of pelicans spent a week or so on the open water around Hudson and Stillwater.

Range of American white pelican

This week, there were probably hundreds of them organized loosely in ever-shifting clumps that sometimes managed to briefly make the shape of a V. 

When they were directly overhead, they seemed to lose forward momentum, and the flock spun around directionless, vanishing into the sun and then reappearing against the brilliant blue sky. They spiraled like that for a minute, and then found

I wondered if they too had been waiting out the strong headwind during the afternoon, and had taken to the sky again when it subsided.

A pelican eats a fish on the St. Croix River in Hudson in April 2018. (Greg Seitz, St. Croix 360)

Pelicans may lack the grace of swans, and their vast numbers and diet of rough fish might make them seem somehow less special. But that’s human-centered thinking, and they are an amazing part of the ecosystem.

The big birds also have a big story to tell about conservation and restoring threatened species. Pelicans were almost wiped out by habitat loss, pesticides, and other human activities by the 1960s. Now there are dozens of nesting colonies across the western United States that are each home to 60,000 breeding pairs.

Seeing a few of them soaring down the St. Croix toward their winter homes on the Gulf of Mexico was awe-inspiring, and a reminder that we can in fact improve humanity’s environmental impact, when we try.

More about pelicans:

The American white pelican (Pelecanus erythrorhynchos) is a large aquatic soaring bird from the order Pelecaniformes. It breeds in interior North America, moving south and to the coasts, as far as Central America and South America, in winter.

The German naturalist Johann Friedrich Gmelin described the American white pelican in 1789. The scientific name means “red-billed pelican”, from the Latin term for a pelican, Pelecanus, and erythrorhynchos, derived from the Ancient Greek words erythros (ἐρυθρός, “red”) + rhynchos (ῥύγχος, “bill”).

The American white pelican rivals the trumpeter swan, with a similar overall length, as the longest bird native to North America.

Both very large and plump, it has an overall length of about 50–70 in, courtesy of the huge beak which measures 11.3–15.2 in in males and 10.3–14.2 in in females. It has a wingspan of about 95–120 in. The species also has the second largest average wingspan of any North American bird, after the California condor. This large wingspan allows the bird to easily use soaring flight for migration.

Body weight can range between 7.7 and 30 lb, although typically these birds average between 11 and 20 lb.

The plumage is almost entirely bright white, except the black primary and secondary remiges, which are hardly visible except in flight. From early spring until after breeding has finished in mid-late summer, the breast feathers have a yellowish hue. After moulting into the eclipse plumage, the upper head often has a grey hue, as blackish feathers grow between the small wispy white crest.

The bill is huge and flat on the top, with a large throat sac below, and, in the breeding season, is vivid orange in color as are the iris, the bare skin around the eye, and the feet. In the breeding season, there is a laterally flattened “horn” on the upper bill, located about one-third the bill’s length behind the tip. This is the only one of the eight species of pelican to have a bill “horn”. The horn is shed after the birds have mated and laid their eggs. Outside the breeding season the bare parts become duller in color, with the naked facial skin yellow and the bill, pouch, and feet an orangy-flesh color.

Apart from the difference in size, males and females look exactly alike. Immature birds have light grey plumage with darker brownish nape and remiges. Their bare parts are dull grey. Chicks are naked at first, then grow white down feathers all over, before moulting to the immature plumage.

American white pelicans nest in colonies of several hundred pairs on islands in remote brackish and freshwater lakes of inland North America. The most northerly nesting colony can be found on islands in the rapids of the Slave River between Fort Fitzgerald, Alberta, and Fort Smith, Northwest Territories.

They winter on the Pacific and Gulf of Mexico coasts from central California and Florida south to Panama, and along the Mississippi River at least as far north as St. Louis, Missouri. In winter quarters, they are rarely found on the open seashore, preferring estuaries and lakes. They cross deserts and mountains but avoid the open ocean on migration. But stray birds, often blown off course by hurricanes, have been seen in the Caribbean.

Wild American white pelicans may live for more than 16 years. In captivity, the record lifespan stands at over 34 years.

Occasionally, these pelicans may nest in colonies on isolated islands, which is believed to significantly reduce the likelihood of mammalian predation. Red foxes and coyotes readily predate colonies that they can access, the later being the only known species to hunt adult pelicans (which are too large for most bird predators to subdue).

Several gulls have been known to predate pelican eggs and nestlings (including herring, ring-billed and California gull), as well as common ravens. Young pelicans may be hunted by great horned owls, red-tailed hawks, bald eagles, and golden eagles.

The pelicans react to mammalian threats differently from avian threats. Though fairly approachable while feeding, the pelicans may temporarily abandon their nests if a human or other large mammal closely approaches the colony. If the threat is another bird, however, the pelicans do not abandon the nest and may fight off the interloper by jabbing at them with their considerable bills.

This species is protected by the Migratory Bird Treaty Act of 1918. On a global scale, the species is common enough to qualify as a Species of Least Concern according to the IUCN.

Habitat loss is the largest known cause of nesting failure, with flooding and drought being recurrent problems. Human-related losses include entanglement in fishing gear, boating disturbance and poaching as well as additional habitat degradation.

There was a pronounced decline in American white pelican numbers in the mid-20th century, attributable to the excessive spraying of DDT, endrin and other organochlorides in agriculture as well as widespread draining and pollution of wetlands. But populations have recovered well after stricter environmental protection laws came into effect.

Above information via an excellent Wikipedia article with quality references and editor-review.