[5] By 1933, fewer than 70 wild individuals were known to exist; extinction seemed imminent until aerial surveys discovered a Pacific population of several thousand trumpeter swans around Alaska's Copper River.

[6] Careful reintroductions by wildlife agencies and the Trumpeter Swan Society gradually restored the North American wild population to over 46,000 birds by 2010.

[7] The trumpeter swan was formally described in 1831 by the Scottish naturalist John Richardson in the fourth volume of American Ornithology; or, The Natural History of Birds Inhabiting the United States by Alexander Wilson and Charles Bonaparte.

[12] The trumpeter swan is the largest extant species of waterfowl, and both the heaviest and longest native bird of North America.

Alongside the mute swan (Cygnus olor), Dalmatian pelican (Pelecanus crispus), kori bustard (Ardeotis kori), and Andean condor (Vultur gryphus), it is one of a handful to weigh in excess of 10 kg (22 lb) between the sexes, and one survey of wintering trumpeters found it averaged second only to the condor in mean mass.

The trumpeter swan has a large, wedge-shaped black bill that can be minimally lined with salmon-pink coloration around the mouth.

However, it can easily be distinguished by its orange bill and different physical structure (particularly the neck, which is typically held curved as opposed to straight in the trumpeter).

[7] The breeding habitat of trumpeter swans includes large and shallow ponds, undisturbed lakes, pristine wetlands, wide and slow rivers, and marshes in northwestern and central North America.

In the winter, trumpeter swans migrate to the southern tier of Canada, the eastern part of the northwest United States (especially to the Red Rock Lakes area of Montana), and the northern area of the Puget Sound region of Washington state;[26] migratory populations have even been observed as far south as Pagosa Springs, Colorado.

[28] In addition, the collection of the Museum of Comparative Zoology in Cambridge, Massachusetts, includes a specimen that was shot by F. B. Armstrong in 1909 at Matamoros, Tamaulipas, Mexico.

In early 2017, a juvenile trumpeter swan took up residence in the French Broad River in Asheville, North Carolina, marking the first such sighting in that part of the state.

[31] Occasional sightings of trumpeter swans have occurred in the United Kingdom;[32] while some of these are believed to be vagrants, most are presumed escapes into the wild.

[36] Predators of trumpeter swan eggs include common ravens (Corvus corax), common raccoons (Procyon lotor), wolverines (Gulo gulo), American black bears (Ursus americanus), grizzly bears (Ursus arctos horribilis), coyotes (Canis latrans), gray wolves (Canis lupus), pumas (Puma concolor), and North American river otters (Lontra canadensis).

[38][40][44][45][46][47] Larger cygnets and, rarely, nesting adults may be ambushed by golden eagles (Aquila chrysaetos), bobcats (Lynx rufus), and probably coyotes, wolves and pumas.

[49] Predation of adults, when they are not nesting, is extremely rare; golden and bald eagles, and coyotes can pose a threat, but substantiated cases are very few.

Young trumpeter swans may have as little as 40% chance of survival due variously to disturbance and destruction by humans, predation, nest flooding, and starvation.

[54] Trumpeter swans have a strong tendency to avoid interactions with conspecifics, therefore it is implied that at first contact of a potential mating pair there is some unwillingness in the male and female to make this connection.

[58][59] The fabrication of a nest is an incredibly precise process that takes place over a series of 11 to 35 days and typically breeding pairs will begin construction in late April.

This is advantageous to the parents because it can reduce the risk of predation, provide optimal foraging sources such as aquatic vegetation, as well as ensure there is nearby water for when the cygnets are hatched.

During nest construction, female trumpeter swans feed significantly more frequently than males in order to fuel up for laying the eggs.

[67] It can be inferred that this behaviour is used to ensure the eggs are kept an appropriate temperature on all sides; this is crucial because exposure to the elements leads to high mortality rates in cygnets.

[70] It is rare for both members of a mating pair to be absent from the nest at the same time, and there is generally always a male or a female present guarding the eggs.

[62] After the meeting of the pair prior to mating or nest building, the male will often initiate courting calls which result in the duet mentioned above.

With this in mind, he does continue to be territorial and protective of the newly developing cygnets as well as allowing the female to replenish her nutrient reserves.

The increased care and attention of the male to the young allows for the female to feed more frequently and exert more energy toward the protection and overall health of the developing cygnets.

[71] Young cygnets have a very close relationship with their parents in the first part of their lives, spending most of their first few weeks with the female in the nest or in the water.

[71] In the 19th and early 20th centuries, the trumpeter swan was hunted heavily, for game or meat, for the soft swanskins used in powder puffs, and for their quills and feathers.

In 1918 Joseph Grinnell wrote that trumpeter swans once bred in North America from northwestern Indiana west to Oregon in the U.S., and in Canada from James Bay to the Yukon, and they migrated as far south as Texas and southern California.

[40] In 1984, Harry G. Lumsden posited that trumpeter swans may have been extirpated from eastern Canada by native people armed with firearms prior to the arrival of European explorers and noted archaeological remains of trumpeter swans as far east as Port au Choix, Newfoundland, dating to 2,000 BCE.

[79][80] There is an effort by local foundations, Idaho Department of Fish and Game, and the United States Environmental Protection Agency to clean up the area and help limit lead exposure of swans migrating through.