Cygnus buccinator

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDING: Formerly throughout North America from central Alaska to western Hudson Bay (James Bay), southeast to Nova Scotia, with the southern limit extending to northwest Mississippi and eastern Arkansas in the east and possibly California in the west. Present breeding range includes Alaska (Interior, Southcentral, Gulf of Alaska, and Chilkat basin), Yukon, British Columbia, Alberta, Washington, Oregon, Nevada, Montana, Idaho, Wyoming, South Dakota, Minnesota, Wisconsin, Michigan, Saskatchewan, and Ontario (Mitchell 1994). Alaska contains over 85% of the world's breeding population, and breeding areas outside of Alaska are very localized (Mitchell 1994).

NONBREEDING: Formerly from the present range in southeast Alaska (a few small flocks along the Gulf of Alaska), along the British Columbia coast, Washington, Oregon, and occasionally California but historically extending to southern California, possibly Arizona and New Mexico, along Gulf Coast to central Florida, and along Alantic coast as far as ice free waters existed (Mitchell 1994). Present range includes the Gulf of Alaska coast, southeast Alaska, British Columbia, western Washington, western Oregon, occasionally California, eeastern Nevada, western Utah, southern Montana, eastern Idaho, northwestern Wyoming, southwestern South Dakota, and small resident populations in the midwestern states, Saskatchewan, and Ontario (Mitchell 1994). In the contiguous United States and adjacent Canada, the highest winter densities occur in western Wyoming, western British Columbia (coast and interior lakes), southeastern Oregon, and southwestern Montana, mainly on wildlife refuges (Root 1988).

Interior population (resulting from transplants and captive propagation) consists of flocks in Lacreek National Wildlife Refuge, South Dakota, and Hennepin County Park Reserve District, Minnesota; these gradually are exhibiting southward movement in fall but still are dependent on supplemental feeding.

Rocky Mountain population nests in the Rocky Mountains of Canada and the United States (Idaho, Montana, Wyoming) and winters primarily in the Greater Yellowstone Ecosystem (Spahr et al. 1991). Breeding areas in Canada include Peace River area of Alberta and British Columbia and Toobally Lakes area of Yukon, plus some areas farther north in Northwest Territories (Johnson and Herter 1989). U.S. flocks of the Rocky Mountain population currently summer in three locations (1) the Tri-state Area of eastern Idaho, southwestern Montana, and western Wyoming, (2) the Ruby Lake National Wildlife Refuge, and (3) Malheur NWR and Summer Lake area of Oregon. Trumpeter swans at Ruby Lake and Malheur NWRs were derived primarily from swans that were transplanted from Red Rock Lakes NWR, beginning in 1941 (Pacific Flyway Study Committee 2002).

Trumpeter swans are found throughout the Nearctic Region, mainly in Alaska, Canada, and the northern United States. A large percentage is found in Alaska, specifically in Prince William Sound and the Copper River Delta. Some trumpeter swans have even taken up residence in Yellowstone Park, Wyoming.

Biogeographic Regions: nearctic (Native )

Western North America.

Trumpeter swans were once abundant and widespread in North America.
Their breeding range extended from Alaska east to Ontario and south to
Oregon, the Rocky Mountains, Nebraska, and northern Missouri [20]. Now
only two major populations remain [4,17,20]. The Pacific population
breeds in Alaska and British Columbia, and winters along the Pacific
Coast from Alaska to northern Oregon [20,23]. The mid-continental
population nests in Alberta, British Columbia, Yukon, Northwest
Territories, Saskatchewan, and the Greater Yellowstone region [20,23].
Overhunting of trumpeter swans destroyed most of their traditional
migration patterns to southerly winter habitats. As a result, virtually
all mid-continental trumpeter swans, regardless of their summer range,
now winter in the Greater Yellowstone Ecosystem [23].

Trumpeter swans have been transplanted from Red Rock Lakes National
Wildlife Refuge, Montana, to several other National Wildlife Refuges
(NWR): Malheur NWR in Oregon, Ruby Lake NWR in Nevada, Lacreek NWR in
South Dakota, and Turnbull NWR in Washington. A small number of
breeding swans occur on all four refuges [4]. In Canada, attempts are
underway to reintroduce trumpeter swans in southern Ontario and in Elk
Island National Park [2].

More info on this topic.

This species can be found in the following regions of the western United States (according to the Bureau of Land Management classification of Physiographic Regions of the western United States):

1 Northern Pacific Border
2 Cascade Mountains
5 Columbia Plateau
8 Northern Rocky Mountains
9 Middle Rocky Mountains

AK ID MT NV OR SD WA WY AB BC NT YK MEXICO

Gulf of Mexico

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

As the largest North American swans, these birds can weigh up to 13.5 kg and measure approximately 1.6 m in length. Wingspan can often exceed 2 m. When they are young "cygnets", the bill features some degree of pink but is always black at the base. The feet and tarsi (portion of the foot that makes up the ankle region) may be a grey-yellow. The body is light to dark grey, and will gradually whiten with age. At age two, most but not all of their feathers have turned white, except for a few on the upper portion of the body.

At adulthood their feet, bill, and tarsals are black. They have pink to red mouths which can be seen as a small pink or red line (a 'grin') on the bill. Their feathers are completely white. There is also a small percentage of trumpeter swans that have a grey-white tint for feather color instead of pure white.

They appear very similar to tundra swans (Cygnus columbianus), with the most reliable differences found near the beak. Viewed face-forward or top-down, trumpeter swans have an angular, v-shaped forehead at the base of the beak. Tundra swans have a curved or straight forehead. Most tundra swans have a yellow-white 'teardrop' on their black beak, however this is not always a reliable field mark.

Range mass: 9.5 to 13.5 kg.

Range length: 1.4 to 1.6 m.

Range wingspan: 2.0 to 2.4 m.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: sexes alike

Length: 152 cm

Weight: 11900 grams

More info for the terms: cover, shrubs

Tall emergent vegetation provides shelter and cover for trumpeter swans
[10]. Adults may remove vegetation around the nest until the nest is
surrounded by open water. This provides good visibility and protection
from land predators [2]. During winter, trumpeter swans prefer open
sites with few trees or shrubs to obscure their vision while feeding
[23].

More info for the term: cover

Breeding habitat - Trumpeter swans nest on the margins of interconnected
shallow marshes and lakes, lakes within forest or sagebrush habitat,
and oxbows of rivers [18]. They prefer stable, quiet, shallow waters
where small islands, muskrat houses, or dense emergent vegetation
provide nesting and loafing sites. Nutrient-rich waters, with dense
aquatic plant and invertebrate growth, provide the best habitat [3,23].

Nests are built in water 1 to 3 feet deep [4]. Trumpeter swans build a
platform nest made of emergent vegetation. The nest is often located on
a muskrat house, beaver lodge, or small island [18]. In Alaska,
trumpeter swan nests are built 10 to 600 feet (3-183 m) from shore,
depending upon cover and water depth. Occasionally, a nest is located
on or near the shoreline of a small inlet in a large lake [10].

Winter habitat - Winter habitat must provide extensive beds of aquatic
plants and water that remains ice-free. In the Greater Yellowstone
region, cold temperatures and ice restrict trumpeter swans to sites
where geothermal waters, springs, or outflow from dams maintain ice-free
areas. In winter, trumpeter swans use shallow lakes, streams, and ponds
that do not entirely freeze over during the winter months [18,23].
Pacific Coast trumpeter swans use both esuaries and freshwater habitats,
and feed in pastures and croplands [23]. Good winter habitat also
contains a certain amount of level and open terrain, allowing these large
birds to loaf or fly without restriction of movement or visibility [3].

More info on this topic.

This species is known to occur in the following ecosystem types (as named by the U.S. Forest Service in their Forest and Range Ecosystem [FRES] Type classification):

FRES23 Fir-spruce
FRES24 Hemlock-Sitka spruce
FRES26 Lodgepole pine
FRES28 Western hardwoods
FRES29 Sagebrush
FRES36 Mountain grasslands
FRES37 Mountain meadows
FRES38 Plains grasslands
FRES39 Prairie

Trumpeter swans are generally found in wetland areas among aquatic and
emergent vegetation. In Montana, they commonly build their nests in
extensive beds of sedges (Carex spp.), bulrushes (Scirpus spp.),
cattails (Typha spp.), and reeds (Juncus spp.). In Alaska, they use
horsetails (Equisetum spp.) and sedges for nesting [4,10]. Plants found
in most trumpeter swan habitats include willow (Salix spp.), alder
(Alnus spp.), cottonwood (Populus spp.), water milfoil (Myriophyllum
exalbescens), arrowhead (Sagittaria latifolia), and pondweed
(Potamogeton spp.) [3,10].

More info on this topic.

This species is known to occur in association with the following cover types (as classified by the Society of American Foresters):

204 Black spruce
205 Mountain hemlock
217 Aspen
218 Lodgepole pine
222 Black cottonwood - willow
223 Sitka spruce
224 Western hemlock
225 Western hemlock - Sitka spruce
226 Coastal true fir - hemlock
227 Western redcedar - western hemlock
228 Western redcedar
235 Cottonwood - willow
253 Black spruce - white spruce
254 Black spruce - paper birch

More info on this topic.

This species is known to occur in association with the following plant community types (as classified by Küchler 1964):

K001 Spruce - cedar - hemlock forest
K004 Fir - hemlock forest
K008 Lodgepole pine - subalpine forest
K015 Western spruce - fir forest
K020 Spruce - fir - Douglas-fir forest
K021 Southwestern spruce - fir forest
K025 Alder - ash forest
K063 Foothills prairie
K064 Grama - needlegrass - wheatgrass

Systems

• Terrestrial
• Freshwater
• Marine

Trumpeter swans live on land but always in close proximity to water. They are found in wetlands with open water and areas with many rivers or streams. Waters can be salt water, fresh water, or brackish water. Their climate ranges from temperate to polar. Reasons for their choice of environment have to do with their diet and nesting habits. Cygnus buccinator feeds off many plants native to those areas. They are also known for laying their eggs near or on the water. They seek out the same habitat type for wintering grounds.

Habitat Regions: temperate ; polar ; terrestrial

Terrestrial Biomes: tundra

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh

Other Habitat Features: riparian ; estuarine

Depth range based on 97 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 0 - 0
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

Comments: Ponds, lakes, and marshes, breeding in areas of reeds, sedges or similar emergent vegetation, primarily on freshwater, occasionally in brackish situations, wintering on open ponds, lakes and sheltered bays and estuaries (AOU 1983). In the intermountain western U.S., winters in areas of geothermal activity, springs, and dam outflows (Spahr et al. 1991). Primarily breeds in freshwater, on edges of large inland waters; typically in emergent marsh vegetation, or on a muskrat house, beaver lodge, or island. The nest is a large mass of plant material. Uses same nesting sites in successive years.

See Pacific Flyway Study Committe (2004) for a summary of nesting, migration, and winter habitat requirements for the Rocky Mountain population.

Non-Migrant: Yes. At least some populations of this species do not make significant seasonal migrations. Juvenile dispersal is not considered a migration.

Locally Migrant: Yes. At least some populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Wyoming-Montana-Idaho breeders nonmigratory; interior breeders in British Columbia, Yukon, Alberta, and Northwest Territories migrate. Arrives in northern nesting areas in early May, departs northern latitudes by late September or early October. Uses traditional migration routes.

Yellowstone population consists of a resident year-round population and a migratory winter population. Migrants that visit Yellowstone in the winter are a combination of swans from the Yellowstone/Greater Yellowstone area and swans from Canada (primarily Grande Prairie, Alberta).

Trumpeter swans eat the roots, stems, leaves, and/or seeds of a variety
of aquatic vegetation, and they occasionally eat insects [2].
Initially, young cygnets eat large aquatic insects and snails. Cygnets
feed on the water's surface and often depend on the adults to stir up
the water around them. Within 2 to 3 weeks the cygnets start to eat
aquatic plants [2].

Trumpeter swans feed on the following: the tubers of duck potato and
sago pondweed (Potamogeton pectinatus); the stems and leaves of sago and
other pondweeds (Potamogeton spp.), water milfoil (Myriophyllum
verticullatum), muskgrass (Chara spp.), waterweed (Elodea canadensis),
and duckweed (Lemna triscula); the seeds of yellow pond lily (Nuphar
polysepala), water shield (Bransenia schreber), smartweed (Polygonum
spp.), sedges (Carex spp.), and spikerush (Eleocharis spp.); and the
stems and roots of grasses and sedges [2,3,4,17].

As cygnets, trumpeter swans' diets are mostly comprised of aquatic invertebrates. At five weeks of age, most cygnets have converted to a nearly herbivorous diet. This diet consists mostly of tubers, roots, stems, leaves and occasionally insects. In Alaska during mating season, the wetland plants commonly known as horsetail (genus Equisetum) and Lyngbye's sedge (Carex lyngbyei) are consumed in great quantities. However, because of the wide distribution of the species there are some variations of their diet such as duck potato (Sagittaria latifolia), water weeds (genus Elodea), pondweeds (genus Potamogeton) and sago pondweed (Potamogeton pectinatus) tubers.

Trumpeter swans attain their food by foraging underwater with tails bobbing in the air. They also yank plants out of the damp ground, with most of the plant intact.

Animal Foods: aquatic or marine worms

Plant Foods: leaves; roots and tubers

Primary Diet: herbivore (Folivore )

Comments: Adults feed mostly on aquatic vegetation; young first eat aquatic insects and crustaceans but in 5 weeks begin feeding on aquatic plants. Also may graze in fields (McKelvey and Verbeek 1988). Prefers shallow, slow-moving water for feeding.

More info for the term: natural

Predation is of little consequence in determining overall trumpeter swan
population levels, but may be an important cause of death to preflight
cygnets [3]. Except for man, trumpeter swans have few natural enemies
after flying age is reached. Coyotes (Canis lutrans), river otters
(Lutra canadensis), minks (Mustela vison), and golden eagles (Aquila
chrysaetos) have been blamed for cygnet deaths in Yellowstone National
Park and Red Rock Lakes National Wildlife Refuge [20]. The following
species also occur in trumpeter swan habitat and could potentially prey
on trumpeter swans: black bears (Ursus americanus), grizzly bears (U.
arctos), lynx (Lynx canadensis), bald eagles (Haliaetus leucocephalus),
greathorned owls (Bubo virgianus), mountain lions (Felis concolor),
bobcats (Lynx rufus), striped skunk (Mephitis mephitis), red fox (Vulpes
vulpes), raccoons (Procyon lotor), and gulls (Larus spp.) [20].

Trumpeter swans' main role in the ecosystem is linked to their diet. Trumpeter swans eat many insects when they are young. As they grow they switch to roots and aquatic plants, digging around to get them which in many cases allows water to fill the remaining holes supplying a very valuable nutrient to the plants. Cygnus buccinator can also be a host to a small number of parasites including tapeworms (Anoplocephala perfoliata), caecal paramphistomids (Zygocotyle lunata), trematode flukes (Echinostoma revolutum), another type of trematode (Orchipedum tracheicola), filarial worms (a nematode found in the heart) of the species Sarconema eurycerca, and other forms of tapeworms (Hymenolepis).

Ecosystem Impact: soil aeration

Commensal/Parasitic Species:

• Tapeworms (Anoplocephala perfoliata)
• Caecal paramphistomids (Zygocotyle lunata)
• Trematode flukes (Echinostoma revolutum)
• Trematodes (Orchipedum tracheicola)
• Filarial worms (Sarconema eurycerca)
• Tapeworms (Hymenolepis)

Although adults aggressively defend their nests, ground nests are easy targets for land predators. Many predators, such as bears, wolves and coyotes, wolverines, raccoons, and common ravens are known to snatch eggs. Post-hatchlings and adults are prey to fast predators such as coyotes, bobcats, red foxes, and golden eagles. The main predator of adult trumpeter swans is mankind. Humans have hunted more of these swans than anything else.

Trumpeter swans are aggressive towards predators, and at 12 kg with a 2 m wingspan, they can potentially inflict serious damage. Trumpeter swans do exhibit warning behaviors before they attack, including head bobbing and hissing.

Known Predators:

• Man (Homo sapien sapiens)
• Bears (Ursus)
• Wolves (Canis)
• Coyotes (Canis latrans)
• Wolverines (Gulo luscus)
• Red Fox (Vulpes vulpes)
• Raccoons (Procyon lotor)
• Bobcat (Lynx rufus)
• Ravens (Corvus corax)
• Golden Eagle (Aquila chrysaetos)

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 21 - 80

Comments: There are three regional populations (Pacific Coast, Rocky Mountain, and Interior) recognized by the USFWS (Mitchell 1994). An unknown number of breeding areas exist within the range of these populations (estimated at between 20 and 50 in all regions). Occurences have been searched for extensively, continent-wide survey was conducted in 1990 (Mitchell 1994).

10,000 - 100,000 individuals

Comments: In 2000, the total North American population was about 24,000 birds (USFWS 2003).

The 1995 Canadian subpopulation of the Rocky Mountain population recorded 2,076 swans, while the Tri-state subpopulation (Wyoming, Idaho, Montana) of the Rocky Mountain population counted 441 swans. In September 2001, the U.S. segment of the Rocky Mountain population collectively contained 416 adults, including 362 in the Tri-state Area, 23 in Oregon, and 31 in Nevada. Observers counted 417 swans (white birds and cygnets) in the U.S. Breeding Segment of the Rocky Mountain population of trumpeter swans during fall of 2004, a count identical to that from comparable areas in 2003 (USFWS 2004). Observers counted 4,584 swans (white birds and cygnets) in the Rocky Mountain population of trumpeter swans during February 2004, an increase of 15% from the 3,974 counted in February 2003 and a record-high count for the mid-winter survey (Pacific Flyway Study Committee 2004, USFWS 2004).

In the Yellowstone region, there are basically two trumpeter swan flocks: a resident year-round population and a migratory winter population. The winter population varies from 75-119 swans. In 2000, the resident population included 20 adults and 7 cygnets (National Park Service).

The 1995 Interior Population census counted 927 swans (Subcommittee on the Interior Population of Trumpeter Swans 1997).

More info for the term: marsh

No specific information was found in the literature regarding
fire-related effects on trumpeter swan habitat. Fire occuring in wetland
habitats, however, often removes excessive accumulations of fast-growing
hydrophytes, permitting better waterfowl access and growth of more
desirable trumpeter swan foods such as pondweed and duckweed [19,21].

There may be some negetive effects of burning waterfowl habitat.
Large-scale autumn burning may have a detrimental effect upon marshes by
reducing the retention of drifting snow. The ability of marsh vegetion
to catch and hold snow is vital to marsh survival [22].

More info for the terms: formation, severity

Pair formation - Trumpeter swans most often form pair bonds when they
are 2 or 3 years old, and first nest when they are 4 or 5 years old.
Most pairs remain together year-round and bond for life [2,18,23].

Nesting - In the Copper River area of Alaska, the Greater Yellowstone
area, and Red Rock Lakes National Wildlife Refuge, egg laying normally
begins in late April or early May and is completed about mid-May [4,17].
In interior Alaska, egg laying begins later than in the above areas
[17]. In Alberta, the eggs are layed in mid-May [2].

Clutch size and incubation - Each breeding pair uses only one nest and
the female lays five to six eggs [2,14,17]. If the eggs are destroyed
the pair will probably not renest [2]. The incubation period is 33 to
37 days [3,4,18].

Cygnet development and fledging - Trumpeter swan cygnets grow rapidly
[4]. They are fully feathered in 9 to 10 weeks, but are unable to fly
until 13 to 15 weeks in Alaska and 14 to 17 weeks in Montana [4,17].
Cygnets remain with their parents throughout their first winter. They
separate from their parents the following spring, but siblings may
remain together into their third year. Family bonds are strong;
subadult siblings may rejoin with parents after nesting ends or in
subsequent winters [23].

Molt - Nonbreeding subadults molt first. Most nonbreeders in Alaska
begin their molt in late June or early July. At Red Rock Lakes, the
molt may be completed as early as June [4]. It is rare for both members
of a breeding pair to be flightless at the same time. The male of the
pair usually molts first. Some paired birds may begin to molt as early
as nonbreeders. Many, however, delay a month or longer. Some trumpeter
swans are flightless until early September in Alaska and until October
in Montana. Trumpeter swans are normally flightless for about 30 days
[4].

Migration - The seasonal movements of trumpeter swans in the Greater
Yellowstone region are limited to local flights between breeding habitat
and contiguous wintering areas. No molt migration is known. Breeders
molt in the general vicinity of nesting territories [17].

In Alaska, trumpeter swan populations migrate south in shifts. This
occurs from September until very late in the year, with times and
distances varying depending on severity of the weather. Trumpeter swans
move from interior regions in September, as total freeze-up occurs by
the first week in October. By mid-October, they have usually left
Kenai, located on the coast. On the Copper River Delta, many swans
remain until about mid-November. They arrive at Lonesome Lake, British
Columbia, beginning October 20 through October 25 [17].

Life span - Trumpeter swans may live up to 35 years in captivity but
usually do not live more than 12 years in the wild [2].

In summer, nonbreeding flocks of 20-100 individuals may occur on large lakes and reservoirs. Defends breeding territory of about 5-10 acres.

Trumpeter swans produce a variety of sounds, but they are known for their low bugle call. In addition to the bugle call, they also use motions such as head bobbing to alert others of disturbances or in preparation for flight. Trumpeter swans are very social creatures except for in times of mating, when they become quite territorial. Pheromones are also used in mating rituals. The female emits pheromones when she is ready to mate. Breeding pairs perform visual, synchronous displays which likely reinforce the pair-bond. Trumpeter swans call to warn the flock of impending danger. Trumpeter swans perceive their environment through visual, auditory, tactile, and chemical stimuli.

Communication Channels: visual ; tactile ; acoustic ; chemical

Other Communication Modes: duets ; pheromones

Comments: Staging and breeding individuals may be active day and night (Henson and Cooper 1994).

Young trumpeter swans often have survival estimates from 40% to 100%, adult swan survival increases to 80% to 100%. The oldest captive trumpeter swan on record was 33 years old. In the wild, the oldest known individual was 24.

Range lifespan
Status: wild: 24 (high) years.

Range lifespan
Status: captivity: 33 (high) years.

Maximum longevity: 32.5 years (captivity) Observations: While sexual maturity may occur earlier, breeding normally does not occur before age 4. In the wild, these animals normally do not live over 12 years (http://www.fs.fed.us/database/feis/).

Trumpeter swans are monogamous and mate for life. During mating season, trumpeter swans reunite with their former mates or begin a process of courtship to secure a mate. Courtship displays consist of pairs simultaneously spreading or raising wings, wing quivering, head bobbing and trumpeting.

Mating System: monogamous

Adults begin mating at 4 to 7 years of age. Mating usually occurs from March to May. Nest-building can take 2 to 5 weeks to complete, and both parents are involved in construction. The nests range from 1.2 to 3.6 m in diameter and are usually surrounded by water. The materials used in nests building include various aquatic vegetation, grasses, and sedges.

After copulation and fertilization, the females lay 4 to 6 eggs. Incubation lasts for 32 to 37 days, done mainly by the female. The young, precocial cygnets spend their first 24 hours in the nest, then begin to swim. They fledge after 91 to 119 days and are independent after one year.

Breeding interval: Trumpeter swans breed once yearly.

Breeding season: Trumpeter swans breed from March to May.

Range eggs per season: 4 to 6.

Range time to hatching: 32 to 37 days.

Average birth mass: 200 g.

Range fledging age: 91 to 119 days.

Average time to independence: 1 years.

Range age at sexual or reproductive maturity (female): 4 to 7 years.

Range age at sexual or reproductive maturity (male): 4 to 7 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate)

Both parents contribute to nest building which lasts 2 to 5 weeks. The female will perform the majority of incubation. Unlike many birds, trumpeter swans do not have a specialized brood patch and instead will incubate the eggs using their feet. Upon hatching, the young are precocial but still require significant parental care. Both parents care for the cygnets throughout their first year.

Parental Investment: precocial ; male parental care ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Male, Female, Protecting: Male, Female); pre-weaning/fledging (Provisioning: Male, Female, Protecting: Male, Female); pre-independence (Provisioning: Male, Female, Protecting: Male, Female); post-independence association with parents; extended period of juvenile learning

Nesting begins in late April or early May in the intermountain western U.S. Clutch size is 2-9 (usually about 5). Incubation, mainly by female, lasts 33-37 days (Harrison 1978). Hatching occurs in latter half of June in southern Alaska, June in the intermountain Western U.S. Nestlings are precocial but remain with adults until subsequent spring. Fledging occurs at 100-120 days. Young remain with parents through winter; siblings may stay together for a few years, may rejoin parents after the nesting period. First nests at 4-5 years (may form pair bonds earlier). Life-long pair bond. Rarely more than one pair nests on a single body of water.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

There are 2 barcode sequences available from BOLD and GenBank.  Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.  See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

Download FASTA File

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 2
Specimens with Barcodes: 5
Species With Barcodes: 1

Canada

Rounded National Status Rank: N4B,N5N : N4B: Apparently Secure - Breeding, N5N: Secure - Nonbreeding

United States

Rounded National Status Rank: N4B,N4N : N4B: Apparently Secure - Breeding, N4N: Apparently Secure - Nonbreeding

Information on state- and province-level protection status of animals in the
United States and Canada is available at NatureServe, although recent changes
in status may not be included.

Candidate, Under Review [24]

Year Assessed

Assessor/s

Reviewer/s

Contributor/s

Justification

History

• 2008
  Least Concern
• 2004
  Least Concern

Historically, birds were heavily harvested for decorative feathers and skins. Many birds continue to be hunted illegally. If birds are illegally shot and do not die immediately, an embedded bullet may cause lead poisoning and eventual death. Today, habitat destruction is likely the greatest threat to trumpeter swans. Efforts are being made to protect trumpeter swans and their wetland habitat, with many states involved in reintroduction programs. As migratory birds, they are protected under the United States Migratory Bird Act.

Trumpeter swans are also affected by recent population increases of invasive mute swans. Mute swans are markedly more aggressive and will often chase trumpeters away from their shared wetland habitats. Some states are involved in mute swan control programs with the goal of reducing populations to allow for native swans to return.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: threatened

IUCN Red List of Threatened Species: least concern

Rounded Global Status Rank: G4 - Apparently Secure

Reasons: Although Pacific Coast population is increasing, the Rocky Mountain population has moderately increased, and the Interior population of midwestern, northern, and Canada subpopulations have expanded, serious threats to winter habitat availability and quality are present for all three major populations. The Pacific Coast population continues to lose wintering habitat in Washington and British Columbia. Some areas of Alaska breeding habitat are open to development; no overall swan management plan has been enacted for the state. Serious potential for disease outbreaks on reduced winter ranges exist. Species is sensitive to disturbance and pollution.

Intrinsic Vulnerability: Highly to moderately vulnerable.

Other Considerations: Water quality important for aquatic and emergent plant species utilized as forage and nesting materials.

Global Short Term Trend: Increase of 10 to >25%

Comments: Increasing mainly in Alaska; other continent-wide expansion due to regional and local reintroduction programs (Mitchell 1994).

Global Long Term Trend: Decline of 30-50%

Comments: Great loss of historical breeding and wintering habitat, hunting (primarily market hunting) reduced contiguous U.S. population to less than 100 individuals by 1935, but undocumented populations smaller than their present levels existed in Alaska and Canada (Mitchell 1994).

In North America the species increased from less than 4,000 birds in 1968 to nearly 24,000 birds in 2000, which represents an average annual population growth of 5.9 percent. The Rocky Mountain population increased from approximately 800 birds in 1968 to more than 3,600 birds in 2000; average population growth rate was 4.8 percent per year. See USFWS (2003).

Degree of Threat: Low

Comments: Pacific Coast population (Mitchell 1994) faces a serious threat of winter habitat loss to development. Rocky Mountain population faces a serious threat due to declining winter habitat, overcrowding on existing winter habitat, and potential for widespread disease introduction. Threats to Interior population may be the same winter habitat and disease threats that the Rocky Mountain population faces.

Trumpeters swans are sensitive to human disturbance (boating, float-plane use, photography, etc.) (Mitchell 1994)and pollution. They are unusually sensitive to lead poisoning due to habitat and foraging behavior. White Phosphorus from military operations has caused death at Eagle River Flats, Alaska (Mitchell 1994). Human activity near nest site may cause nest failure or cygnet loss by disturbing adults (responses by pairs varies) (Mitchell 1994). Vulnerable to illegal hunting or malicious shooting due to their conspicuousness and large size (Mitchell 1994).

Rocky Mountain population:
From 1935-1992, the trumpeters were fed grain during winter at Red Rock Lakes National Wildlife Refuge, 20 miles northwest of Harriman State Park, Idaho. Large sanctuaries in Yellowstone and Grand Teton National Parks and at Harriman State Park also protected the swans from human disturbance. Artificial feeding and sanctuaries saved the population from extinction but discouraged southward migration, which is essential to long-term recovery. Artificial feeding at Red Rock Lakes ceased in 1992.
In eastern Idaho, lack of dispersal southward has created a severe "bottleneck" as increasing numbers of trumpeters arrive from Canadian nesting areas to spend the winter within Harriman State Park on the Henry's Fork of the Snake River in eastern Idaho. At this site, which receives the greatest amount of swan use, the aquatic plants can no longer provide enough winter food to support the increasing flocks of swans, Canada geese, and ducks (U.S. Fish and Wildlife Service).
In the Yellowstone region, nest flooding is the primary cause of nest failure, and coyote predation is the major cause of swan mortality in the winter.

Prescribed burning is an effective method of manipulating waterfowl
habitat [19]. Fire can be used to convert forested uplands adjacent to
aquatic habitats to grasses and sedges, which are more suitable for
trumpter swan nesting [21]. Additionally, removal of dense vegetation
and prevention of woody species encroachment is vital to prairie marsh
maintenance [22]. Less dense vegetation allows more space for waterfowl
activities [19]. Ward [22] reported that spring burning in marshlands
is primarily done to remove vegetation and create more nesting edge for
waterfowl. Summer fires are used to create more permanent changes in
the plant community. Prescribed burning during the nesting season
should be avoided so as not to disturb nesting females and/or destroy
nests.

More info for the term: formation

The commercial swanskin trade, coupled with sport hunting and habitat
destruction, reduced the species to near extinction by 1920. The
trumpeter swans' traditional migration patterns and knowledge of
important winter and spring habitats were lost as the swans neared
extinction. Although recovery efforts have increased swan numbers,
historic migratory paths have not yet been restored. As a result,
virtually all the breeding trumpeter swans of Canada and the Greater
Yellowstone Ecosystem share the same high-elevation winter habitat in
the Greater Yellowstone Ecosystem. Increasing numbers of wintering
swans, concentrating on this limited, harsh winter habitat are
vulnerable to catastrophic losses. Reduced flows during drought, heavy
ice formation, unusually severe winter weather, disease, or
environmental pollution could destroy a large portion of the
mid-continental population during a single winter [23].

Trumpeter swans are sensitive to human activities on their breeding
grounds. Intrusions by humans at nesting wetlands have caused temporary
and permanent nest abandonment as well as movements from breeding and
staging areas [2,11]. Trumpeter swans will not nest on lakes
intensively developed for recreation. The swans are most sensitive to
disturbance from mid-April to mid-June [2].

Cygnet survival is associated with spring weather and favorable water
levels. It is extremely important to properly manage water levels so
that nest flooding is avoided and growth of aquatic vegetation is
encouraged through nutrient cycling [18].

Management efforts currently focus on ensuring adequate stream flows,
protecting and enhancing nesting and wintering habitat, and restoring
southward migration to lower elevation habitats [23].

Management Requirements: North American Trumpeter Swan Management Plan has been prepared (USFWS and Canadian Wildlife Service 1986). Henson and Grant (1991) recommended the following management guidelines for nesting areas that receive heavy use by humans: restrict sources of loud noises (e.g., airboats) during breeding season; discourage (e.g., through posting) human activity (such as cars stopping and passengers getting out to view swans nesting along roads); if wildlife viewing areas are desired, such sites should be more than 300 m from a nest and should be designed to minimize noise and visibility of observers.

Current/recent management includes ensuring adequate river flows, protecting and restoring nesting and winter habitat, restoring southward migration pathways to suitable wintering areas, and transplanting of swans to suitable winter habitat along the Snake River in southern Idaho (Spahr et al. 1991).

Rocky Mountain Population:

USFWS (http://www.r6.fws.gov/redrocks/rrl3.htm) reported the following information:
Since 1988, over 1,300 trumpeter swans have been captured at Harriman State Park and Red Rock Lakes National Wildlife Refuge and transplanted to new habitats in Oregon, southern Idaho, and Wyoming. Several were also moved to Utah.
Transplanted swans were neck collared and dyed, and closely monitored through a network of observers.
The disturbance from trapping and occasional planned disturbance has reduced the number of swans at high risk sites in the vicinity of Harriman State Park. Reduced swan use at Harriman has allowed some increase of aquatic plants which has improved habitat for both fish and waterfowl.
Transplanted swans have been sighted in all western states and are slowly increasing use of other wintering sites as far west as Oregon and California. Serious problems remain in eastern Idaho, however, as wintering swans continue to increase.
Up through 1995, biologists attempted to establish trumpeter swan migrations that would avoid tundra swan hunting areas. This was done to minimize the potential for a legal tundra swan hunter to accidentally harvest a trumpeter.
Beginning in 1994, tundra swan hunting regulations in Utah, Nevada, and Montana were changed to reduce the potential harvest of trumpeters, and to protect legal tundra swan hunters from legal action should they accidentally harvest a trumpeter. These changes enabled biologists to transplant trumpeters into areas where they have a greater potential to follow migrating tundra swans to southern wintering areas where food resources are plentiful.
Unless the present "bottleneck" can be opened, trumpeters from across western Canada will continue to end their southward migration in the tri-state area. They must either be persuaded to migrate through this region and continue south or they will exceed the carrying capacity of winter habitat and die there. The tri-state's local nesting swans, forced to share marginal sites with the growing Canadian flocks, will also be at risk.
Management options are limited. Substantial mortality is likely unavoidable; the problem has developed over decades and will not be easily solved. Additional transplants may help create use of other wintering areas but cannot possibly remove enough swans from eastern Idaho. Artificial feeding can no longer meet the needs of the increasing flocks. Feeding would concentrate swans as well as ducks and geese, creating a high risk of disease and discouraging any migration.
A well-organized program to systematically haze trumpeters offers another option to increase the number of birds that continue southward, but success is by no means a certainty. Fall hazing efforts will be increased; various techniques will be tried, and results will be closely monitored. Best results are likely if hazing occurs during the peak migration while the swans are still in good condition. To keep swans moving, hazing must be frequent and consistent over a broad area.
Regardless of hazing intensity and translocation efforts, some swans will likely remain in eastern Idaho and face harsh winters and limited food supplies. Our goal is to disperse as many swans as possible from the area.
Long-term population security will depend upon the survival of trumpeters in a wide variety of wintering sites. Currently, the Pacific Flyway Council is emphasizing monitoring over translocation in order to better understand the migration corridors used by the Rocky Mountain trumpeter swans.

Biological Research Needs: There are three research needs at present (Mitchell 1994):

1. Determine gene flow among subpopulations.

2. Obtain information on nutritional requirements of various age and sex classes, including the differences in foraging ecology and nutritional needs between migratory and sedentary poulations.

3. Investigate differences in foraging ecology and nutritional needs of swans foraging on agricultural crops versus aquatic vegetation on their wintering ares.

Global Protection: Many to very many (13 to >40) occurrences appropriately protected and managed

Comments: Localized migratory and nonmigratory populations in Canada and contiguous United States are very small (< 500 individuals) and are protected (to varing levels) in reserves. Alaska populations have varying levels of protection on their breeding grounds, but overwintering and migration habitats (occurrences with no protection) in British Columbia and Washington are declining.

Needs: Protection of winter areas (winter use EOs), resting and foraging habitat is needed (particularly in Washington, British Columbia, and Oregon as well) (Mitchell 1994). Non-point source pollution needs to be eliminated from breeding and wintering wetlands used by swans. Lost, reduced, or contaminated wetlands need to be restored. Further wetland loss needs to be prevented.

Trumpeter swans are very territorial animals, especially during mating season, and humans that enter their territory may be attacked.

Trumpeter swans used to be a commercial hunting target for feathers and skins, but over-hunting led to their marked decline. Today, only illegal hunting occurs.

Positive Impacts: body parts are source of valuable material