(DRAFT) - Taxonomy
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
TAXONOMY
NAME - swan, Trumpter
OTHER COMMON NAMES -
ELEMENT CODE -
CATEGORY - Birds
PHYLUM AND SUBPHYLUM - ,
CLASS AND SUBCLASS - ,
ORDER AND SUBORDER - ,
FAMILY AND SUBFAMILY - ,
GENUS AND SUBGENUS - Cygnus,
SPECIES AND SSP - buccinator,
SCIENTIFIC NAME - Cygnus buccinator
AUTHORITY -
TAXONOMY REFERENCES - 232
Taxonomy - 1 (DRAFT) - Status
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
STATUS
Coded Status
Migrant
See Comments
REFERENCES FOR STATUS - 232
COMMENTS ON STATUS -
The southern portion of the trumpeter swan population is more or less
nonmigratory, whereas the northern portion migrates to the coast of
southeastern Alaska and British Columbia, Washington, Oregon, Idaho,
Montana, and Wyoming *232*.
In Alaska, waterfowl are managed by the U.S. Fish and Wildlife Service and
the Alaska Department of Fish and Game. They are protected under
international treaties with Canada, 1916, Mexico, 1936, Japan, 1912, and the
Soviet Union, 1976 *232*.
Status - 1 (DRAFT) - Distribution
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
DISTRIBUTION
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - RIPARIAN
REFERENCES FOR HABITAT - 232
LAND USE -
Forest Land
Water
Lakes
Bays and Estuaries
Wetland
REFERENCES FOR LAND USE - 232
COMMENTS ON HABITAT ASSOCIATIONS -
Trumpeter swans prefer secluded regions, where they frequent shallow bodies
of water. Along the coast late summer and early fall, large numbers of
trumpeter swans congregate on ponds and marshes. Birds winter on ice-free
freshwater outlets, although sometimes they are temporarily driven to salt
water during extremely cold periods when freshwater locations freeze. The
wintering habitat of trumpeter swans in Alaska as unfrozen ponds, lakes,
sluggish-moving waters, marsh meadows, and inner brackish reaches of
coastal fjords and bays *232*.
Nesting trumpeter swans in Alaska are distributed along the North Pacific
coastal plain from Yakutat to Cook Inlet, through the forested valleys of
the Copper, Susitna, and Yukon rivers to the vicinity of the Arctic Circle
at elevations below 3,000 ft *232*.
ANIMAL/PLANT SPECIES ASSOCIATIONS -
Muskrat
Beaver
Coyote
Eagle
River otter
Golden Eagle
REFERENCES FOR SPECIES ASSOCIATIONS - 232
COMMENTS ON SPECIES ASSOCIATIONS -
Trumpeter swans utilize muskrat houses and beaver lodges for nesting.
Survival of young to the flight stage (90-100 days) is greatly affected by
severe weather, predator populations (coyotes and eagles), and diseases.
Mortality of adult trumpeter swans is caused primarily by weather (freezing
of feeding areas for extended periods causing starvation) and infrequently
by mammalian predation (coyotes and river otters), and avian predation
(golden eagles) *232*.
Habitat Associations - 1 (DRAFT) - Food Habits
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
HERBIVORE/GRAZER
REFERENCES FOR TROPHIC LEVEL - 232
LIFESTAGE FOOD FOOD PART
General Umbelliferae Not Specified
General Plants Not Specified
General Poaceae See Comments
General Insects Not Specified
General Snails Not Specified
General Invertebrate Cordates Not Specified
General Zosteraceae Not Specified
Juvenile Animals See Comments
General Sphenopsida Not Specified
General Cyperaceae Not Specified
Adult Umbelliferae Not Specified
Adult Poaceae Not Specified
Adult Insects Not Specified
Adult Snails Not Specified
Adult Invertebrate Cordates Not Specified
General Zosteraceae Tubers
General See Comments; Food See Comments
Adult See Comments; Food See Comments
Juvenile See Comments; Food See Comments
REFERENCES FOR GENERAL FOOD - 232
REFERENCES FOR ADULT FOOD - 232
REFERENCES FOR JUVENILE FOOD - 232
COMMENTS ON FOOD -
Adult trumpeter swans prefer wild celery (Angelica lucida) and other
freshwater plants, but they also eat grain, grasses, insects, snails, and
small invertebrates when available. Trumpeter swans normally consume
succulent green vegetation when available, with all parts of the aquatic
plants being utilized. Pondweed (Potamogeton spp.) tubers are used
extensively as food. Young cygnets in their first three weeks feed
primarily on animal matter, with plant life becoming increasingly more
important with age. In Southcentral Alaska, preferred foods include
marestail (Hippuris spp.), horsetails (Equisetum spp.), sedges (Carex spp.),
and buckbean (Menyanthes trifoliata). Communities dominated by these
species also contain most nest sites *232*.
Types of Feeding Areas Used: Most feeding occurs in shallow water areas,
although immature and adult swans may feed or graze to a limited extent upon
land; cygnets feed solely in water. Large lakes in Alaska that lack
emergent vegetation and are therefore unsuitable for breeding are often used
by nonbreeding swans when pondweed is common. Gernerally during their
Food Habits - 1 (DRAFT) - Food Habits
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
first two weeks, young cygnets feed in very shallow waters of six inches to
one foot in depth. When feeding occurs in deeper waters, they gather
foodstuffs brought to the surface by their parents *232*.
COMMENTS ON ADULT FOOD -
Adult trumpeter swans prefer wild celery (Angelica lucida) and other
freshwater plants, but they also eat grain, grasses, insects, snails, and
small invertebrates when available *232*.
Types of Feeding Areas Used: Most feeding occurs in shallow water areas,
although immature and adult swans may feed or graze to a limited extent upon
land *232*.
COMMENTS ON JUVENILE FOOD -
Young cygnets in their first three weeks feed primarily on animal matter,
with plant life becoming increasingly more important with age *232*.
Types of Feeding Areas Used: Most feeding occurs in shallow water areas,
although immature and adult swans may feed or graze to a limited extent upon
land; cygnets feed solely in water. Generally during their first two weeks,
young cygnets feed in very shallow waters of six inches to one foot in
depth. When feeding occurs in deeper waters, they gather foodstuffs brought
to the surface by their parents *232*.
Food Habits - 2 (DRAFT) - Environment Associations
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
ENVIRONMENTAL ASSOCIATIONS
G = General A = Adult
LIM = Limiting RA = Resting Adult
J = Juvenile FA = Feeding Adult
RJ = Resting Juvenile BA = Breeding Adult
FJ = Feeding Juvenile P = Pupae
L = Larvae E = Egg
RL = Resting Larvae
FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS
G Elevation: 3000-4000 ft.
G Elevation: Specified in Comments
BA Elevation: Specified in Comments
BA Elevation: 3000-4000 ft.
G Water Depth Preference: Specified in Comments
G Aquatic Features: Specified in Comments
G Inland Wetlands: Specified in Comments
G Coastal Wetlands: Specified in Comments
G Flow: Specified in Comments
G Water Velocity [Instream Flow Group Increments]: Specified in Comments
G Coastal Features: Specified in Comments
FA Water Depth Preference: Specified in Comments
FJ Water Depth Preference: Less than 1 ft.
FJ Water Depth Preference: Specified in Comments
BA Elevation: 300-500 ft.
BA Elevation: 500-1000 ft.
BA Elevation: Specified in Comments
BA Water Velocity [Instream Flow Group Increments]: Specified in Comments
BA Water Depth Preference: Specified in Comments
BA Aquatic Vegetation [specified type]: Specified in comments
BA Water Depth Preference: 1-5 ft.
G Meadows: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 232
REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 232
REFERENCES FOR BREEDING ADULT ENVIRONMENTAL ASSOC_ - 232
REFERENCES FOR FEEDING JUVENILE ENVIRONMENTAL ASSOC_ - 232
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
Trumpeter swans prefer secluded regions, where they frequent shallow bodies
of water. Along the coast late summer and early fall, large numbers of
trumpeter swans congregate on ponds and marshes. Birds winter on ice-free
freshwater outlets, although sometimes they are temporarily driven to salt
water during extremely cold periods when freshwater locations freeze. The
wintering habitat of trumpeter swans in Alaska as unfrozen ponds, lakes,
sluggish-moving waters, marsh meadows, and inner brackish reaches of
Environment Associations - 1 (DRAFT) - Environment Associations
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
coastal fjords and bays *232*.
Nesting trumpeter swans in Alaska are distributed along the North Pacific
coastal plain from Yakutat to Cook Inlet, through the forested valleys of
the Copper, Susitna, and Yukon rivers to the vicinity of the Arctic Circle
at elevations below 3,000 ft *232*.
COMMENTS ON FEEDING ADULT ENVIRONTAL ASSOC_ -
Types of Feeding Areas Used: Most feeding occurs in shallow water areas,
although immature and adult swans may feed or graze to a limited extent
upon land. Large lakes in Alaska that lack emergent vegetation and are
therefore unsuitable for breeding are often used by nonbreeding swans when
pondweed is common *232*.
COMMENTS ON BREEDING ADULT ENVIRONMENTAL ASSOC_ -
Nesting trumpeter swans in Alaska are distributed along the North Pacific
coastal plain from Yakutat to Cook Inlet, through the forested valleys of
the Copper, Susitna, and Yukon rivers to the vicinity of the Arctic Circle
at elevations below 3,000 ft *232*.
Reproductive Habitat: Alaska trumpeters require a minimum of 140 and up to
154 ice-free days to complete a reproductive cycle. This requirement
precludes use of otherwise suitable habitat above approximately 2,700 ft
elevation and dictates that most nesting occurs below 500 ft. Specific
physical features of the trumpeter swan breeding habitat include the
following requirements: stable waters that possess a relatively static
level, not exhibiting seasonal fluctuations; quiet lake, marsh, or slough
waters, not subject to obvious currents or constant wave action; shallow
waters of lakes or open marshes that do not preclude considerable digging
and foraging for lower aquatic plant parts (roots, tubers, etc.). Trumpeter
swans build their nests in extensive areas of marsh vegetation. The nests
are built directly on the marsh bottom in water 1 to 3 ft. deep. In Alaska,
sedges and horsetails predominate where nests are found. Trumpeter swans
also utilize muskrat houses and beaver lodges for nesting *232*.
COMMENTS ON FEEDING JUVENILE ENVIRONMENTAL ASSOC_ -
Types of Feeding Areas Used: Most feeding occurs in shallow water areas,
although immature and adult swans may feed or graze to a limited extent
upon land; cygnets feed solely in water. Gernerally during their first two
weeks, young cygnets feed in very shallow waters of six inches to one foot
in depth. When feeding occurs in deeper waters, they gather foodstuffs
brought to the surface by their parents *232*.
Environment Associations - 2 (DRAFT) - Life History
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
LIFE HISTORY
Reproductive Habitat: Alaska trumpeters require a minimum of 140 and up to
154 ice-free days to complete a reproductive cycle. This requirement
precludes use of otherwise suitable habitat above approximately 2,700 ft
elevation and dictates that most nesting occurs below 500 ft. Specific
physical features of the trumpeter swan breeding habitat include the
following requirements: stable waters that possess a relatively static
level, not exhibiting seasonal fluctuations; quiet lake, marsh, or slough
waters, not subject to obvious currents or constant wave action; shallow
waters of lakes or open marshes that do not preclude considerable digging
and foraging for lower aquatic plant parts (roots, tubers, etc.). Trumpeter
swans build their nests in extensive areas of marsh vegetation. The nests
are built directly on the marsh bottom in water 1 to 3 ft. deep. In Alaska,
sedges and horsetails predominate where nests are found. Trumpeter swans
also utilize muskrat houses and beaver lodges for nesting *232*.
Reproductive Seasonality: Most breeding pairs are at their nest sites by
early May, and the first egg appears some time between April 28 and May 11.
The first hatching dates range from June 16 to June 29. In Alaska, cygnets
are unable to fly until 13 to 15 weeks of age. After leaving the breeding
areas, larger numbers of trumpeter swans congregate on ponds and marshes
along the coast in late summer and early fall. Most swans depart by mid
October but some years may remain until freeze-up in November *232*.
Reproductive Behavior: Swans usually mate for life; however, if one of the
pair is lost, the other may subsequently mate again. Territorial behavior
is strikingly evident among trumpeter swans; a mated pair vigorously defends
the mating, nesting, and cygnet feeding grounds. A pair occupies its
territory as soon as there is open water in the spring, and some pairs
defend their territories until late summer, when the cygnets are half grown.
In Alaska, a study found only one pair of territorial trumpeters on each
small water area ranging from 6 to 128 waters. Only a few large lakes, 1 to
4 mi long, were occupied by two or three breeding pairs *232*.
Age at Sexual Maturity: Trumpeters may begin nesting as early as their
fourth year or as late as their sixth year. Perhaps the density of
territorial pairs accounts for some of the variation *232*.
Clutch Size: From 2 to 10 eggs are laid, usually 5 to 8. In Alaska, the
clutch size ranges from 4.9 to 5.2 eggs but may vary as a result of early
and late springs *232*.
Incubation Period: The period of incubation varies from 33 to 37 days
*232*.
Rearing of Young: The female usually broods her newly hatched young on the
nest for the first 24 hours, longer if the weather is inclement. Both
parents are solicitous of their young; the family forms a tightly knit
group, with the actively swimming or feeding young flanked by each parent.
The offspring are usually left by their parents upon approach of the
breeding season, at least until their first flightless molt in late June or
early July *232*.
Life History - 1 (DRAFT) - Life History
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
Natural Factors Influencing Populations: Survival of young to the flight
stage (90-100 days) is greatly affected by severe weather, predator
populations (coyotes and eagles), and diseases. Mortality of adult
trumpeter swans is caused primarily by weather (freezing of feeding areas
for extended periods causing starvation) and infrequently by mammalian
predation (coyotes and river otters), and avian predation (golden eagles)
*232*.
Human-related Factors Influencing Populations: Activities having the
greatest potential for causing future population declines are those that
alter or eliminate swan habitat, particularly nesting and molting areas, or
that disturb swan use areas, such as the following: aquatic substrate
alteration (e.g., from accelerated aufeis, mechanical removal); chronic
debilitation due to ingestion or contact with petroleum or petroleum
products; chronic debiltation due to ingestion or contact with chemicals;
harassment, active (e.g., intentional hazing, chasing); harassment, passive
(e.g., construction noise, vehicle noise, human scent); interruption of
ongoing behavior: alarm, flight; terrain alteration or destruction;
vegetation composition change to a less preferred or usable species;
vegetation damage/destruction due to contact with petroleum, petroleum
products, or chemicals (limited to plant species/associations important to
swans); vegetation damage/destruction due to hydraulic or thermal erosion
and/or deposition (limited to plant species/associations important to
swans); vegetation damage/destruction due to mechanical removal or material
overlay (limited to plant species/associations important to swans);
poisoning due to lead shot introduced in marsh habitat by hunters; loss of
security due to establishment of human recreational activity introduced to
swan nesting territories, including boating and floatplane activity,
camping, and cabin sites; illegal hunting; water level or water quality
fluctuation, including changes in drainage patterns, long-term increase or
decrease in water levels; and accidents (striking power, telephone, or fence
wires in flight) *232*.
Nest Disturbance: When trumpeter swan nests have been disturbed, the birds
frequently abandon their nest sites and sometimes walk overland to another
lake, which makes them much more subject to predation. On the Copper River
delta, pairs of trumpeter swans with nests or young were more sensitive
to human distrubance than adults without young. Also the timing of egg
removal is a critical factor in renesting. Even aircraft flying at 2,000 ft
can cause trumpeter swans to abandon their lake *232*.
Molting and Staging Areas: Most nonbreeding birds in Alaska begin their
molt in late June or early July. For breeding pairs, males usually molt
first. Birds are flightless for about 30 days *232*.
Migration Stops (resting and feeding areas): Trumpeter swans travel in
family groups, and having adequate resting and feeding areas is especially
critical to the young, which cannot travel as far *232*.
Wintering Habitat: Good swan wintering habitat usually contains a certain
amount of level and open terrain allowing trumpeter swans to loaf or fly
without restriciton of visibility or movement. On smaller streams, where
Life History - 2 (DRAFT) - Life History
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
air space over water is limited, this requiement becomes especially
important, because trumpeters need ample unrestricted air space for
take-off. Unobstructed snowfields or meadows adjacent to open streams or
ponds are regularly used for loafing sites, especially in late winter, when
the snow hardens with settling. On streams, water movement is important in
keeping such waters open during moderately cold weather, but some source of
warm water is a necessity during prolonged periods of cold weather in the
winter. When freshwater locations along the eastern North Gulf Coast
freeze, swans are sometimes driven to salt water during extremely cold
periods *232*.
LIFE HISTORY CODES -
Foraging Strategy: Grazing
Foraging Sites: Flowing water - aquatic weedbeds/vege
Nest/Den Site: Emergent aquatic vegetation
Nest Materials: Aquatic vegetation
Breeding Spawning Season: April
Breeding/Spawning Season: May
Breeding/Spawning Season: June
Duration of Pair Bond: Pair for life
Mating System (Single breeding season): Monogamy (mal
Territoriality: Defends entire breeding, feeding, and
Average Number of Offspring/Reproductive Effort: 2
Average Number of Offspring/Reproductive Effort: 3-4
Average Number of Offspring/Reproductive Effort: 5-7
Average Number of Offspring/Reproductive Effort: 8-10
Gestation/Incubation Period: 1-2 months
Parental Care of Young: Both parents
Dispersion: Clumped
REFERENCES FOR LIFE HISTORY- 232
Life History - 3 (DRAFT) - Management Practices
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Restricting/regulating human use of habitats
Beneficial Restricting/regulating human disturbance of populations
Beneficial Maintaining natural vegetation [native]
Adverse Water supply, flow withdrawl
Adverse Water supply, flow augmentation
Adverse Other management practices [specified in comments]
Beneficial Other management practices [specified in comments]
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 232
REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 232
COMMENTS ON MANAGEMENT PRACTICES -
Human-related Factors Influencing Populations: Activities having the
greatest potential for causing future population declines are those that
alter or eliminate swan habitat, particularly nesting and molting areas, or
that disturb swan use areas, such as the following: aquatic substrate
alteration (e.g., from accelerated aufeis, mechanical removal); chronic
debilitation due to ingestion or contact with petroleum or petroleum
products; chronic debiltation due to ingestion or contact with chemicals;
harassment, active (e.g., intentional hazing, chasing); harassment, passive
(e.g., construction noise, vehicle noise, human scent); interruption of
ongoing behavior: alarm, flight; terrain alteration or destruction;
vegetation composition change to a less preferred or usable species;
vegetation damage/destruction due to contact with petroleum, petroleum
products, or chemicals (limited to plant species/associations important to
swans); vegetation damage/destruction due to hydraulic or thermal erosion
and/or deposition (limited to plant species/associations important to
swans); vegetation damage/destruction due to mechanical removal or material
overlay (limited to plant species/associations important to swans);
poisoning due to lead shot introduced in marsh habitat by hunters; loss of
security due to establishment of human recreational activity introduced to
swan nesting territories, including boating and floatplane activity,
camping, and cabin sites; illegal hunting; water level or water quality
fluctuation, including changes in drainage patterns, long-term increase or
decrease in water levels; and accidents (striking power, telephone, or fence
wires in flight) *232*.
Management Practices - 1 (DRAFT) - References
Species swan, Trumpter
Species Id M040041
Date 26 AUG 96
References
232 * State of Alaska Department of Fish, and Game. 1986. Alaska
Habitat Management Guide: Life Histories and Habitat
Requirements of Fish and Wildlife. (ed.). Alaska Department of
Fish and Game Juneau, Alaska:763.
References - 1