(DRAFT) - Taxonomy
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
TAXONOMY
NAME - scoter, white-winged
OTHER COMMON NAMES - coot, whitewing and white-winged coot
ELEMENT CODE - 04/17/84
AOU CODE - 08/29/86
CATEGORY - Birds
PHYLUM AND SUBPHYLUM - Chordata, Vertebrata
CLASS AND SUBCLASS - Aves,
ORDER AND SUBORDER - Anseriformes,
FAMILY AND SUBFAMILY - Anatidae, Aythyinae
GENUS AND SUBGENUS - Melanitta,
SPECIES AND SSP - fusca, deglandi
SCIENTIFIC NAME - Melanitta fusca deglandi
AUTHORITY - Linnaeus
TAXONOMY REFERENCES - 609 and 424
COMMENTS ON TAXONOMY -
AKA coot, whitewing, white-winged coot *554*; young: gray
coots *554*; velvet scoter *540*
Taxonomy - 1 (DRAFT) - Status
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
STATUS
Coded Status
Federal Migratory
Game (Consumptive Recreational)
REFERENCES FOR STATUS - 1500, 828 and 758
Status - 1 (DRAFT) - Distribution
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
DISTRIBUTION
References on County Occurrence - 001, 059, 073, 093, 099, 103, 115, 119, 131, 133, 153, 179, 193, 199, 650, 700, 710, 740, 800, 810, CB1, CB2, CB3 and AO1
References on County Abundance - 001, 059, 073, 093, 099, 103, 115, 119, 131, 133, 153, 179, 193, 199, 650, 700, 710, 740, 800, 810, CB1, CB2, CB3, AO1 and 999
REFERENCES FOR HYDROLOGIC UNIT CODES - 001, 059, 073, 093, 099, 103, 115, 119, 131, 133, 153, 179, 193, 199, 650, 700, 710, 740, 800, 810, CB1, CB2, CB3, AO1 and 999
OTHER DISTRIBUTION
REFERENCES FOR OTHER DISTRIBUTION - H
Distribution - 1 HABITAT ASSOCIATIONS
HABITAT - Aquatic
REFERENCES FOR HABITAT - 609
LAND USE -
Streams and Canals
Reservoirs
Water
Lakes
Bays and Estuaries
Wetland
Forested Wetland
Nonforested Wetland
Forest Land
Evergreen Forest Land
REFERENCES FOR LAND USE - 4443, 540, 607, 424, 1500 and 538
NATIONAL WETLAND INVENTORY CODES
NWI NWICLS NWIMOD NWISPEC
Marine
Estuarine
Lacustrine
Palustrine
Riverine
REFERENCES FOR NWI - 4443 and 538
ANIMAL/PLANT SPECIES ASSOCIATIONS -
Diseases and Parasites: Bacterial: Botulism *2045*
Cholera *1992,1802*
Viral: Duck plague *1990*
Helminths: Digenea *1834*
Trematodes *1793,1675*
Ectoparasites *1913*
Miscellaneous *2008*
REFERENCES FOR SPECIES ASSOCIATIONS - 1897, 1942, 2045, 1992, 1802, 1990, 1834, 1793, 1675, 1913 and 2008
COMMENTS ON SPECIES ASSOCIATIONS -
Diseases and Parasites: General Reference
*1897,1942*;
POTENTIAL NATURAL VEGETATION -
065 Northern Cordgrass Prairie (Distichlis-Spartina)
101 Oak - Hickory - Pine Forest (Quercus-Carya-Pinus)
103 Southern Floodplain Forest (Quercus-Nyssa-Taxodium)
REFERENCES FOR PNV - 609 and 700
ECOREGION -
Southeastern Mixed Forest: Flat Plains
Southeastern Mixed Forest: Irregular Plains
Southeastern Mixed Forest: Plains with Hills
Habitat Associations - 1 REFERENCES FOR ECOREGION - 609 AND 700
Habitat Associations - 2 (DRAFT) - Food Habits
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
FOOD HABITS
TROPHIC LEVEL -
Omnivore
REFERENCES FOR TROPHIC LEVEL - 540
Food Habits - 1 (DRAFT) - Food Habits
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
LIFESTAGE FOOD FOOD PART
General Animals Larva stage
General Animals Adult stage
General Osteichthyes Adult stage
General Cypriniformes Adult stage
General Clupeiformes Adult stage
General Molluscs Adult stage
General Bivalve Molluscs Adult stage
General Cirripeds Adult stage
General Malacostraca Adult stage
General Trichoptera Larva stage
General Chlorophyta Leaves/Needles
General Plants Leaves/Needles
General Branchiopods Adult stage
General Crustaceans Adult stage
General Insects Larva stage
General Tracheophyta Leaves/Needles
General Angiospermae Leaves/Needles
General Hydrocharitaceae Leaves/Needles
General Monocotyledoneae Leaves/Needles
General Poaceae Leaves/Needles
General Cane Reed Leaves/Needles
Important Animals Adult stage
Important Molluscs Adult stage
Important Bivalve Molluscs Adult stage
Juvenile Animals Adult stage
Juvenile Crustaceans Adult stage
Juvenile Insects Not Specified
Juvenile Molluscs Not Specified
Juvenile Poaceae Not Specified
Juvenile Haloragidacea Not Specified
Juvenile Trichoptera Larva stage
Juvenile Coleoptera Not Specified
Juvenile Orthoptera Not Specified
Juvenile Hemiptera Not Specified
Adult Crustaceans Not Specified
Adult Osteichthyes Not Specified
Adult Osteichthyes Egg/Fetus stage
Adult Snails Not Specified
Adult Malacostraca Not Specified
Adult Insects Not Specified
Adult Insects Larva stage
Adult Hydrocharitaceae Not Specified
Adult Plants Not Specified
Adult Salientia Not Specified
Adult Salientia Larva stage
REFERENCES FOR GENERAL FOOD - 607, 424, 1500, 538 and 554
REFERENCES FOR IMPORTANT FOOD - 554
REFERENCES FOR ADULT FOOD - 4940, 5771, 538, 4946 and 5554
Food Habits - 2 (DRAFT) - Food Habits
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
REFERENCES FOR JUVENILE FOOD - 5554, 5454 and 538
Food Habits - 3 (DRAFT) - Environment Associations
Species scoter, white-winged
Species Id M040073
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 Bottom Type [Aquatic]: Sand
G Bottom Type [Aquatic]: Boulders
G Aquatic Habitat Zonation: Shallows with emergent vegetation [littoral zone]
G Water Level: Permanently flooded areas
G Water Depth Preference: 1-5 ft.
G Water Depth Preference: 5-10 ft.
G Water Depth Preference: Specified in Comments
G Terrestrial Features: Rock outcrops
G Terrestrial Features: Depressions
G Coastal Features: Sand beaches
G Coastal Features: Rocky offshore islands
G Coastal Features: Sandy offshore islands
G Coastal Features: Vegetated offshore islands
G Coastal Features: Rocky beaches
G Inland Wetlands: Inland open fresh water
G Coastal Wetlands: Coastal shallow fresh marsh
G Coastal Wetlands: Coastal open fresh water
G Coastal Wetlands: Sounds and bays
G Aquatic/Terrestrial Ecotones: Woodland/water
G Shrubs: Other species [list in comments]
G Aquatic/Terrestrial Ecotones: Woodland/grassland
G Percent Shrub Ground Cover: Specified in Comments
G Average Height of Overstory Trees: Specified in Comments
G Percent Forb Ground Cover: Specified in Comments
G Human Association: Wildlife refuges/sanctuaries
FJ Water Depth Preference: Specified in Comments
FA Water Depth Preference: Specified in Comments
REFERENCES FOR ENVIRONMENTAL ASSOC_ - 609, 540, 607, 424, 1500 and 538
REFERENCES FOR FEEDING ADULT ENVIRONMENTAL ASSOC_ - 538, 4946 and 5454
REFERENCES FOR RESTING ADULT ENVIRONMENTAL ASSOC_ - 538, 4946 and 5454
REFERENCES FOR FEEDING JUVENILE ENVIRONMENTAL ASSOC_ - 5454
COMMENTS ON ENVIRONMENTAL ASSOCIATIONS -
00290S=feeds at 15 feet or less; rarely up to 40 feet
*424,1500*; 00610Z=rose, gooseberry, raspberry, buckbush *424*;
Environment Associations - 1 (DRAFT) - Environment Associations
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
00620R=nettles *424*; 00650S=northern coniferous forest zone *540*;
00790S=53.9% *607,538*; 00750S=height and diversity not important
*607,538*; 00840S=17.1% *607,538*
Environment Associations - 2 (DRAFT) - Life History
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
LIFE HISTORY
PHYSICAL DESCRIPTION: adult male, winter plumage=head and
neck black with small crescent shaped white spot behind and below eye;
bill=edges of both mandibles black; sides of upper mandible red or
purple shading to orange near base; ridge white; prominent black knob at
base above; lower mandible reddish orange on top, white in center, base
black; nostril=round and large; eye=white or pale blue gray; body and
tail=entire plumage black with brownish tinge on sides and breast;
feet=orange on inner sides, purplish pink on outer sides; webs=dusky to
black; toes=irregularly marked with black; wings=black with tips white;
secondaries and greater coverts are white; wing-lining=dusky brown and
silvery brown; axillars=dusky brown *554*; adult male, feathers of face
come close to nostrils *607*; adult female, head and
neck=brownish-black, sometimes 2 indistinct whitish spots in region of
ear and before eye; bill=dull black, whitish on upper mandible,
sometimes a patch of deep pink on sides, knob less prominent than in
males; eye=dark brown; body=entire body blackish brown, some feathers
edged in white; feet=light brownish red; webs=blackish; tail=blackish
brown; wings-=blackish brown with white speculum *554*; juvenile, first
autumn=sexes alike, dark sooty brown; blackish on crown and back; paler
on breast; patches of white on sides of head, in ear region, and in
front of eye; eye=light gray brown, female=dark brown; first
winter=sexes differentiate; male becomes blacker, female becomes
browner; white face patches obilterated; bill of the young male shows
color but is not swollen; second autumn=male's eye becomes white; bill
not completely developed; third autumn=both sexes fully developed *554*;
partial molt=March/April; complete molt=August/September; voice=silent
in water; in flight utters a bell-like low whistle; also utters a short
croak *554*; downy young=strongly patterned black and white *536*;
length, adult male=269-293 mm, adult female=251-266 mm *540*; wing
spread, adult male=282 mm, adult female=267, immature male=274 mm,
immature female=259 mm; weight, male=1361-1769 g (average=1588 g),
female=953-1406 g (average=1179 g) *424*; largest of scoters; carries
bill pointed downward *1500*; REPRODUCTION: breeding season=June to
August *1500*; incubation period=25-31 days; fledgling period=63-77 days
*1500*; rate of laying=1.3-1.5 days/egg *424*; first broods hatch out in
mid-July *424*; finish laying June 20-July 1 *607*; eggs=6-14
(frequently 5-17), 9 are typical; pale salmon or pinkish; 65 X 46 mm
*540,1500,554*; bonding behavior begins on wintering grounds *538*;
nesting behavior, female swims ashore, creeps into thickest weeds or
brush she can find, scratches a hollow, lays one egg, scrapes dirt over
it, next day, digs it out, lays another and buries both, near
completion, plucks down from breast and uses it to line the nest, sits
close, runs to water when forced off nest *607*; pair bonds renewed each
year *540*; female sexual behavior-chin lifting with a thin whistle
directed at favored male; uses true inciting and ritualized drinking
*536*; make short attacks towards male *540*; male sexual
behavior-threat display with underwater attacks; neck-erect-forward
during rapid swimming; ritualized drinking; water twitching and
ritualized preening; utter whistling note; upward stretch and wing
flapping; holds bill down with very 'swollen head and neck' *536*;
copulatory behavior-female assumes prone position shortly before the male
Life History - 1 (DRAFT) - Life History
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
mounts; mutual drinking by both sexes; male displays include water
twitching and preening behind the wing to expose the white speculum;
preens on side and shoulder; male flicks wings while mounted; when
dismounted, male retains hold on nape of female's neck then releases and
swims away; female swims away and flaps wings *536*; male abandons mate
at beginning of incubation period *540*; sexual maturity=second winter
*540*; ducklings are large *607*; BEHAVIOR: home range-not fixed, pairs
remain on waiting area for only 3-4 days *424*; nest
density-grasslands=0.02 nests/acre; parklands=1 nest/acre, boreal
forest=1.05 nests/acre; can be found very close together *424*; nesting
site-hundreds of yards back into woods; nest up to half a mile from
water; nest extensively on islands in exceptionally dense cover; nest in
rose bushes, raspberry, gooseberry, willows, whitetop meadows, nettles,
buckbush *424*; vegetation features are an important aspect of breeding
habitat selection *538*; prefer parklands near shallow lakes *538*; nest
near prairie ponds, wooded lakes, and on tundra *1500*; breed in
northern coniferous forest zone in coastal areas having boulder strewn
islets that are dominated by herbaceous vegetation but with shrubs and
trees; nests among gull or tern colonies *540*; shoreline avoided for
nesting, chooses wooded areas far from shore *540*; height and diversity
of surrounding trees not important; shrub cover-29.4% juniper, 24.2%
bushes, 17.1% forb cover, rest is mixed shrub/forb; nest site-under
boulder; under stone projecting from earth, in a cavity, among stones
covered by stems and branches of juniper; concealed under overhanging
bushes, small spruces, willows; 2-3 miles from sea *607,538*;
nest-scraped out hollow poorly lined with sticks, leaves, rubbish, down
added between fourth and eighth eggs *424,554*; 71-91% nesting success;
little tendency towards nest desertion; most egg loss due to raven and
crow predation during laying *538*; continue to lay if eggs lost but do
not renest *424*; territoriality-share area without conflict; no fixed
territory but maintains a defended zone around mate; female incites male
to attack intruders *424*; each pair occupies a fixed water area of
varying size away from the nest site *538*; female sometimes deposits
eggs in nests of American wigeon, gadwall, lesser scaup; also dump
nesting in nest of same species when nests are in close proximity *538*;
female takes brood to brood-rearing habitat where brood rearing is
frequent; one hundred or more young aggregate and are tended by a number
of females *540*; brood records-1 week old=23,33,or 50 in group; 1.5-2.5
weeks old=30 young with 3 females attending; less than 2 weeks old=85;
on very large lakes, 20-100 young gather with one female attending; in
mid-August late brooding hens desert broods and large groups break up
into small mixed age groups; drakes abandon mates and congregate to
molt; females molt later on nesting ground *424*; migrations-fall
migration on Chesapeake Bay 3/15-5/1 with peak during 3/25-4/25; high
count on Chincoteague National Wildlife Refuge=10000 (3/24/51); Newport
News, Virginia Christmas count averages (1973-1977)=8 *582*; 60% breed
on Atlantic coast, the further north and east they breed the more likely
they are to migrate to the Atlantic coast; after arriving at the coast
they follow the coastline to favored breeding grounds; migrate 2-3 miles
offshore in groups of 100-300; migrate at high altitude because of long
overland passage prior to reaching the coast,during storms they barely
skim the wave crests; fly at night overland but are diurnal by the time
they reach the coast *424*; males and females arrive to breed together
Life History - 2 (DRAFT) - Life History
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
and already paired; male stays until first week of incubation; yearlings
and 2 year olds do not breed, spend 1st summer in flocks at sea near
winter grounds *424*; population numbers during migration-Chesapeake Bay
(late September/mid-October) 65 birds (1967-1969) *424*; summer flocks-
immature birds in flocks of 5-30 males in groups of 20 or less *538*;
flocks together with surf scoter in rafted up flocks of 50-2000 birds in
the spring *538*; has to take off into the wind or patter along the
surface using its feet to gain momentum; flocks in irregular formation;
fly high under good conditions; in strong weather they fly close to the
water or take advantage of eddies between waves; fly along coast; may
fly over capes or necks of land; sleep and rest in huge rafts off shore;
do not feed on migration *554*; one month between arrival on breeding
grounds and start of egg laying *540*; August-flocks of males found;
October-females and young flock; gather over submerged beds of mussels
or other bivalves *607*; non-breeding habitat=found in Chesapeake Bay
proper; in litoral zone of the ocean; common in coastal bays and
estuarine bays *538*; more likely than other scoters to be found on
large inland lakes during winter *540*; stay within a mile from shore;
usually in saltwater rather than brackish habitats *540*; winter
behavior=may take off from the water and fly over land at 200-300 feet
in a line or 'V'; short flights; resettle on water; strong swimmer, good
diver *554*; food and foraging-feed on mussel beds of submerged ledges
and sunken rocks *554*; forage during day *538*; feeds off sandy beaches
and rocky head lands; dive up to 40 feet but most feeding done at less
than 15 feet *424,1500*; opens wings when diving, keeps them open under
water; uses wings to steer when submerged *536*; feeds on fish,
including minnows, sculpins, and gizzard shad *1500*; also eats
molluscs, mussels, Atlantic razor clam, Arctic wedge clam, quohogs,
periwinkles, hermit crabs, caddisfly larvae, algae, vegetable matter,
amphipods, oysters, scallops, crustaceans, insects, eelgrass, burr reed
*607,424,538,554*; animal matter=94% of diet, plant matter=6%, molluscs
make up 75% with 75% of that being clams *424*; gravel accounts for 7%
of stomach volume; eat great numbers of scallops and oysters off
commercial shellfish beds; swallow molluscs whole-has a very powerful
gizzard *554*; juveniles eat large amounts of crustaceans *538*;
behavior-keeps wings tightly folded until within 100 feet or less of the
water *582*; POPULATION PARAMETERS: age ratios=1.01 immatures/adult;
immatures more vulnerable to hunting mortality; sex ratios=2.62
males/female (72.4% males) *424*; causes of mortality=2-3% due to
ingestion of lead shot (highly susceptible due to diving foraging); oil
spills, flooding on breeding grounds, freezes on wintering grounds;
illegal hunting, pesticides *582*; low tolerance to severe weather
*538*; crows and ravens eat eggs; herring and great black-backed gulls
eat ducklings *538*; droughts decrease breeding range; civilization
infringes on breeding grounds *554*; estimates of population
size-breeding population=675000 *540*; wintering in North America,
555000 *424*; Audubon Christmas counts (1954-1962)=21386 average total
counts *538*; population counts on all 3 species=breeding population in
North America 1979 USFWS count=1345000 *582*; USFWS January inventory
for Chesapeake Bay and Maryland/Virginia coast 1979=21096, 1980=17506
*582*; management on commercial shellfish beds-since they feed during
day, can be driven away with boats equipped with sirens and guns *554*;
OTHER: do not visit crop fields; cannot rise vertically from water;
Life History - 3 (DRAFT) - Life History
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
awkward on land *582*; hard to count since many small flocks are missed
on aerial surveys and some are too far off the coast to be noticed
*424*
REFERENCES FOR LIFE HISTORY- 536, 582, 540, 607, 424, 1500, 538, 609 and 554
Life History - 4 (DRAFT) - Management Practices
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
MANAGEMENT PRACTICES
RESULT MANAGEMENT PRACTICE
Beneficial Maintaining unique or special habitat features [wetlands, caves,
Beneficial Developing/maintaining freshwater marsh
Beneficial Controlling pollution [thermal, chemical, physical]
Beneficial Controlling water levels
Beneficial Regulating harvest - restricting weapons/gear use
Beneficial Other management practices [specified in comments]
Beneficial Restricting/regulating human use of habitats
Adverse Applying pesticides
REFERENCES FOR BENEFICIAL MANAGEMENT PRACTICES - 582 and 554
REFERENCES FOR ADVERSE MANAGEMENT PRACTICES - 582
COMMENTS ON MANAGEMENT PRACTICES -
999(B)=010-control use of lead shot *582*; control illegal
hunting *582*
Management Practices - 1 (DRAFT) - References
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
References
424* Bellrose, R.C. 1978. Ducks, Geese and Swans of North
America. 2nd ed.. Stackpole Books Harrisburg, Penn:540.
536* Johnsgard, P.A. 1965. Handbook of Waterfowl. Cornell Univ.
Press Ithaca, N.Y:38.
538* Johnsgard, P.A. 1975. Waterfowl of North America. Indiana
Univ. Press Bloomington:575.
540* Johnsgard, P.A. 1979. A Guide to North American Waterfowl.
Indiana Univ. Press Bloomington.
554* Kortright, F.H. 1967. The Ducks, Geese, and Swans of North
America. Stackpole Books Harrisburg, Penn:476.
582* Meanley, B. 1982. Waterfowl of the Chesapeake Bay Country.
Tidewater Publ. Centreville, Md:210.
607* Pearson, G.T. (ed.)1936. Birds of America. Garden City
Publ. Co. Garden City, N.Y:260.
609* Peterson, R.T. 1980. Birds of eastern and central North
America. 4th Ed.. Houghton Mifflin Co. Boston, Mass:384.
700* Ornithology, Virginia Society of. 1979. Virginia's
Birdlife: An Annotated Check-list. Virginia Avifauna No. 2.
Virginia Society of Ornithology Lynchburg, Va:118.
758* (ed.)1982. Fish and wildlife. 50 CFR 10 (Code of Federal
Regulations). General Serv. Admin. Washington, D.C:7.
828* Service, U.S. Fish and Wildlife. 1983. Republication of the
lists of endangered and threatened species. Federal Register
17.11-17.12:1-24.
1500* Terres, J.K. 1982. AUDUBON SOCIETY ENCYCLOPEDIA OF NORTH
AMERICAN BIRDS. Alfred A. Knopf N.Y.
1675* Bourgeois, C.E., Threlfall, W. 1982. Metazoan parasites of
three species of Scoter (Anatidae). Can. J. Zool.
60(10):2253-2257.
1793* VandeVusse, F.J. 1980. A review of the genus
Dendritobilharzia Skrjabin and Zakharow 1920 (Trematoda:
Schistosomatidae). J. Parasitol. 66(5):814-822.
1802* Montgomery, R.D., Stein, G., Jr., Stotts, V.D., Settle,
F.H. 1979. The 1978 epornitic of avian cholera on the Chesapeake
Bay. Avian Dis. 23(4):966-978.
1834* Scott, M.E., Manfred, E.R., McLaughlin, J.D. 1980.
References - 1 (DRAFT) - References
Species scoter, white-winged
Species Id M040073
Date 26 AUG 96
Prevalence and intensity of Typhlocoelum cucumerium (Digenea) in
wild anatids of Quebec, Canada. J. Wildl. Dis. 16(1):71-75.
1897* Humphreys, P. 1978. Ducks, geese, swans (Anseriformes).
Zoo and Wild Animal Medicine Fowler, M.E. W.B. Saunders Co.
Philidelphia:183-209.
1913* Peters, H.S. 1936. A list of external parasites from birds
of the eastern part of the United States. Bird-Banding 7:9-27.
1942* Wobeser, G.A. 1981. DISEASES OF WILD WATERFOWL.:300.
1990* Bennett, G.F. 1972. Blood parasites of come birds from
Labrador. Can. J. Zool. 50:353-356.
1992* Locke, L.N., Stotts, V., Wolfhard, G. 1970. An outbreak of
fowl cholera in waterfowl on the Chesapeake Bay. J. Wildl. Dis.
6:404-407.
2008* MacNeill, A.C., Barnard, T. 1978. Necropsy results in
free-flying and captive Anadidae in British Columbia. Can. Vet.
J. 19:17-21.
2045* Rosen, M.N. 1971. Botulism. Infectious and Parasitic
Diseases of Wild Birds Davis, J.W., Anderson, R.C., Karstad, L.,
Trainer, D.O. The Iowa State University Ames, Iowa:100-117.
4443* Humburg, P.. Pers. Comm. Unpubl., Missouri Dept. Conserv.
1110 College Ave, Columbia, Mo.
4940* Bellrose, F.C. 1980. Ducks, Geese, and Swans of North
America. Stackpole Books Harrisburg, PA:540.
4946* Bent, A.C. 1925. Life Histories of N. American Wild Fowl:
Part 2. US Nat. Mus. Bull. 180:376.
5454* Brown, P.W. 1981. Reproductive ecology & productivity of
white-winged scoters. Unpb..
5554* Cottam, C. 1939. Food habits of North American diving
ducks. USDA Tech. Bull. 643:139.
5771* Kortright, F.H. 1953. The Ducks, Geese, and Swans of North
America. Stackpole Co. & Wildlife Manage. Institute:476.
References - 2