The trumpeter swan (Cygnus buccinator), also called the trumpeter, is a type of swan found in North America. It is the heaviest bird naturally living in North America and the largest living species of waterfowl. These swans have wingspans between 185 and 304.8 centimeters (6 feet 2 inches to 10 feet 2 inches). They are closely related to the whooper swan (Cygnus cygnus) found in Europe and Asia, and some scientists once thought they were the same species. By 1933, fewer than 70 wild trumpeter swans remained, and their survival seemed unlikely. However, airplane surveys later found a large group of thousands of swans near Alaska’s Copper River. Through careful efforts by wildlife groups and the Trumpeter Swan Society, the number of wild trumpeter swans in North America grew to over 46,000 by 2010.
Taxonomy
In 1831, the trumpeter swan was first named by John Richardson, a Scottish naturalist. This name was included in the fourth volume of a book called American Ornithology; or, The Natural History of Birds Inhabiting the United States, written by Alexander Wilson and Charles Bonaparte. Richardson gave the swan its scientific name, Cygnus buccinator. Richardson also described the swan in a book titled Fauna Boreali-Americana; or, The Zoology of the Northern Parts of British America, co-authored by William Swainson and Richardson. Although the book's title page shows 1831, it was actually published in 1832. The name buccinator comes from the Latin word bucina, which refers to a type of military trumpet. The trumpeter swan has no subspecies.
Description
The trumpeter swan is the largest living species of waterfowl and the heaviest and longest bird native to North America. Adult swans are usually 138–165 cm (4 ft 6 in – 5 ft 5 in) long, though large males can grow longer than 180 cm (5 ft 11 in). Adult swans typically weigh between 7–13.6 kg (15–30 lb). Males usually weigh between 10.9–12.7 kg (24–28 lb), and females usually weigh between 9.4–10.3 kg (21–23 lb). These weight ranges may vary based on food availability and age.
The trumpeter swan is one of the heaviest animals that can fly and is the heaviest flying bird on average. Along with the mute swan, wild turkey, great bustard, Kori bustard, Dalmatian pelican, and Andean condor, it is among a few birds that weigh more than 10 kg (22 lb) in both males and females. One study found that trumpeter swans average the second-highest weight among these birds, behind the Andean condor. The wingspan of trumpeter swans ranges from 185–304.8 cm (6 ft 0.8 in to 10 ft 0 in), and their wing chord measures 60–68 cm (24–27 in). The largest recorded male trumpeter swan was 183 cm (6 ft 0 in) long, had a wingspan of 3.1 m (10 ft 2 in), and weighed 17.2 kg (38 lb). It is the second heaviest wild waterfowl ever recorded, after a mute swan that weighed 23 kg (51 lb), though it was unclear if that swan could still fly.
Adult trumpeter swans have all-white feathers. Baby swans, or cygnets, have light gray feathers and pinkish legs, and they turn white after about a year. Trumpeter swans stand upright and swim with straight necks, like whooper swans. They have large, wedge-shaped black bills that may have a slight pink line near the mouth. Their bills are 10.5–12 cm (4.1–4.7 in) long, twice as long as a Canada goose’s bill, and are the largest of any waterfowl. Their legs are gray-pink, though some may appear yellowish gray or black. The tarsus (the part of the leg between the foot and knee) is 10.5–12 cm (4.1–4.7 in) long.
The mute swan, which was brought to North America, is slightly smaller. It can be distinguished by its orange bill and curved neck, unlike the trumpeter’s straight neck. Mute swans are often found near human areas year-round, while trumpeters live in untouched wetlands, especially during breeding.
The tundra swan is more similar to the trumpeter but is much smaller. A male trumpeter’s neck may be twice as long as a tundra swan’s. Tundra swans can be identified by their yellow lores (the area around the eyes). Some trumpeter swans also have yellow lores, and these swans may have paler legs than others. Distinguishing tundra and trumpeter swans from a distance can be difficult, but the trumpeter’s longer neck and larger, wedge-shaped bill make it easier to tell them apart.
Trumpeter swans have calls similar to whooper swans and Bewick’s swans. They make loud, musical sounds that resemble a trumpet, which is how the bird got its name.
Range and habitat
Cooperative surveys of trumpeter swans have been done regularly since 1968. These surveys were repeated in 1975 and then every 5 years after that. The most recent survey took place in 2015. The survey measures the number of trumpeter swans and how many young swans are born across the breeding areas of three groups of swans in North America: the Pacific Coast population, the Rocky Mountain population, and the Interior population. From 1968 to 2010, the swan population grew from 3,722 to about 46,225 birds. This increase was largely because swans were reintroduced to areas where they once lived.
Trumpeter swans breed in large, shallow ponds, undisturbed lakes, wetlands, slow rivers, and marshes in northwestern and central North America. The most breeding pairs are found in Alaska. Swans choose nesting areas with enough water to take off, food that is easy to reach, clean water, and little human activity. Natural swan groups travel in V-shaped flocks between the Pacific coast and parts of the United States. Swans that were released by humans usually do not migrate.
In winter, trumpeter swans move to southern Canada, the eastern part of the northwest United States (especially near Red Rock Lakes in Montana), and the northern part of Puget Sound in Washington state. Some swans have been seen as far south as Pagosa Springs, Colorado. In the past, swans lived as far south as Texas and southern California. Since 1992, swans have been spotted in Arkansas each November through February near Magness Lake, outside Heber Springs. A swan specimen shot in 1909 in Mexico is kept in the Museum of Comparative Zoology in Massachusetts. Trumpeter swans are no longer found in Mexico. In early 2017, a young swan was seen living in the French Broad River in Asheville, North Carolina, the first recorded sighting in that area.
Non-migratory swans have been introduced to some parts of Oregon. These swans are popular with bird watchers and wildlife fans because of their beauty. Programs that introduce swans to new areas, like the Oregon Trumpeter Swan Program, have faced criticism. However, the program says that the beauty of natural areas is more important than the original range of the swans.
Trumpeter swans have been seen occasionally in the United Kingdom. Some of these sightings are believed to be swans that wandered far from their homes, while others are swans that escaped from captivity. In 1997, two swans that had escaped from a collection at Apethorpe Palace in England raised a baby swan on the River Nene.
Diet
These birds eat while swimming, sometimes turning upside down or dipping their heads underwater to reach food. Their diet mainly includes aquatic plants, and they also eat insects from time to time. They consume the leaves and stems of plants that grow underwater and those that grow above the water's surface. They dig into muddy areas under the water to find roots and tubers. During winter, they may also eat grasses and grains found in fields. These birds feed both at night and during the day. Their feeding activity and body weight often increase in the spring as they prepare to breed. Young birds start with a diet that includes insects, small fish, fish eggs, and small crustaceans for extra protein, and later switch to eating mostly plants over the first few months.
Predators and mortality
Trumpeter swan eggs are hunted by several animals, including 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). Nests in certain places, like islands or floating plants in deep water, can help protect eggs from some predators. The same animals that hunt eggs may also attack young cygnets. Additional predators of young swans include common snapping turtles (Chelydra serpentina), California gulls (Larus californicus), great horned owls (Bubo virginianus), red foxes (Vulpes vulpes), and American mink (Neogale vison). Larger cygnets and, rarely, nesting adults may be attacked by golden eagles (Aquila chrysaetos), bobcats (Lynx rufus), and possibly coyotes, wolves, and pumas.
When their eggs or young are in danger, adult swans may act aggressively. They may start by bobbing their heads and hissing. If this does not stop the predator, they may attack it with their strong wings. Adult swans have been known to fight off predators of similar size, such as coyotes. Adult swans are rarely hunted by predators when they are not nesting. Golden eagles, bald eagles (Haliaeetus leucocephalus), and coyotes may pose a threat, but there are very few confirmed cases. In 2008, photos were taken of a bald eagle attacking an adult trumpeter swan in flight, but the swan survived. In another case, a coyote killed an injured adult swan.
In captivity, trumpeter swans can live up to 33 years. In the wild, they may live at least 24 years. Young swans have a low chance of survival, with as few as 40% surviving due to human activities, predation, flooded nests, and lack of food. In some areas, more young swans survive, and sometimes all cygnets reach maturity. Adult swans have a high survival rate, usually 80–100% each year, unless they are hunted by humans.
Breeding behaviour
Trumpeter swans, like other swans, often form lifelong pairs. Both parents help care for their young, but the female mainly keeps the eggs warm. Most swans find mates when they are 5 to 7 years old, though some may not find a mate until they are nearly 20 years old. If a pair separates, the swans may mate with different partners in different seasons. Sometimes, if a male’s mate dies, he may not find another mate for the rest of his life.
In late April, breeding pairs begin building their nests, a process that can take 11 to 35 days. Before this, swans perform courtship rituals to attract mates. Trumpeter swans usually avoid interacting with other swans, so the first meeting between a potential pair may involve some hesitation from both the male and female.
To build trust, males may gently approach females and touch their breast to the female’s side, causing both to touch their breasts together. At this point, the male’s neck feathers stand up, and both swans lower their heads to show calmness. Another display involves the male swimming toward a female and turning his head side to side to catch her attention. Other behaviors include spreading wings, flapping them rapidly, bobbing their heads, and making loud trumpet-like calls, which is where the swan’s name comes from.
Trumpeter swans use many sounds to communicate, including loud trumpet calls. These calls can be heard from far away and are used to warn others of danger or to signal during mating. When a pair is together near breeding season, they often make a “duet,” where both swans call together in a way that sounds similar. This duet is linked to their courtship displays and may also help them work together to protect their nest from predators.
Trumpeter swans often return to the same mate and nesting areas if their previous offspring were successful. Though they do not share the same range as whooper swans, trumpeter swans can sometimes mate with them in the wild.
Building a nest takes 11 to 35 days and usually starts in late April. Weather conditions can affect when nesting begins, as colder or wetter conditions may delay it. Trumpeter swan nests are often near water, which helps protect the eggs from predators and provides food for the parents.
Nests are very large, measuring 1.2 to 3.6 meters in diameter, and are made mostly of underwater plants and grasses. Males bring materials to the nest by facing away and tossing them over their shoulder toward the nest. Both parents help build the nest, but males do most of the work. During nesting, females eat more frequently to prepare for laying eggs, and males support them by ensuring their health.
A female typically lays four to six eggs, which are about 73 millimeters wide, 113.5 millimeters long, and weigh around 320 grams. These are the largest eggs of any flying bird. The female keeps the eggs warm for 32 to 37 days. She stands up every 20 minutes to roll the eggs with her beak to keep them at the right temperature. She briefly leaves the nest to feed, bathe, or preen, covering the eggs with plants when she is away. If she does not cover them, the male will do so.
The male stays near the nest to guard the eggs, becoming more aggressive if predators or other swans approach. When the female leaves briefly, the male may sit on the eggs to protect them.
After finding a mate, the male often starts calling to encourage the duet. During the egg-laying period, the male remains alert and guards the nest.
Conservation status
In the 19th and early 20th centuries, trumpeter swans were hunted heavily for food, feathers, and soft swanskins used in beauty products. These swans are also very sensitive to lead poisoning when they eat old lead shot from fishing weights as young birds. The Hudson's Bay Company captured thousands of swans each year, killing 17,671 swans between 1853 and 1877. In 1908, Edward Preble noted that the number of swans sold each year dropped from 1,312 in 1854 to 122 in 1877.
Sir John Richardson wrote in 1831 that trumpeter swans were the most common swan in the interior of fur-trading areas and that most swan skins sent to the Hudson's Bay Company came from this species. By the early 20th century, trumpeter swans were nearly gone in the United States, with fewer than 70 wild swans left near Yellowstone National Park. Surprisingly, in the 1950s, an aerial survey of Alaska’s Copper River found several thousand trumpeter swans. This group helped restore swan populations in other areas of their original range.
In 1918, Joseph Grinnell wrote that trumpeter swans once bred in North America from northwestern Indiana west to Oregon in the U.S. and from James Bay to the Yukon in Canada. They migrated as far south as Texas and southern California. In 1960, Winston E. Banko noted that their breeding range extended as far south as Nebraska, Missouri, and Illinois, but not in Michigan, where their range was further north.
In 1984, Harry G. Lumsden suggested that trumpeter swans may have disappeared from eastern Canada before European explorers arrived due to hunting by Indigenous people. Archaeological evidence shows trumpeter swans lived as far east as Newfoundland as early as 2,000 BCE. Historical records, such as Father Hennepin’s 1679 report of swans on the Detroit River and Antoine de la Mothe Cadillac’s 1701 account of swans summering in the same area, confirm their presence. John Lawson’s 1701 report also described trumpeter swans breeding in North Carolina.
Early efforts to reintroduce trumpeter swans had limited success because suitable habitats were reduced and released swans did not migrate. Recently, populations in all three major regions have grown steadily over the past 30 years. Data from the U.S. Fish and Wildlife Service shows a 400% increase in swan numbers during this time, with growth rates improving.
A challenge for swan populations near the Great Lakes is competition with non-native mute swans, which also use the same habitats. One important conservation area for trumpeter swans is Lois Hole Provincial Park, located near Edmonton, Alberta. Thousands of swans migrate through the Chain Lakes in Idaho’s Coeur d’Alene River basin each year. Between 2005 and 2021, an average of 52 swans died annually from lead exposure due to historic mining. Local groups, the Idaho Department of Fish and Game, and the U.S. Environmental Protection Agency are working to clean up the area and reduce lead exposure.
In 1986, Joe Johnson, a biologist at the W.K. Kellogg Bird Sanctuary, began reintroducing trumpeter swans from Alaska to Michigan. By 2015, the population had grown to 756 birds. The Michigan Department of Natural Resources helped protect native swans by reducing the number of non-native mute swans, which dropped from 15,000 in 2010 to 8,700 in 2015.
As of 2013, trumpeter swans are no longer listed as threatened in Minnesota. In winter, many swans gather in Monticello, Minnesota. The Ontario Trumpeter Swan Restoration Group started a conservation project in 1982 by collecting wild eggs and taking live birds. By 2021, 584 swans had been released in Ontario, and the population grew to between 2,500 and 3,000 birds. Despite lead poisoning from shotgun pellets, the population is stable and no longer needs rehabilitation.
Yellowstone National Park offers limited habitat for trumpeter swans, supporting only occasional residents and wintering migrants. Park biologists believe the swan population has declined due to loss of nests caused by spring flooding linked to climate change. In 2023, biologists counted 29 trumpeter swans in the park: 26 adults and 3 young swans.