Fr: Petit Fuligule - Fuligule à tête noire
Ang: Lesser Scaup
All: Kanadabergente
Esp: Porrón Bola
Ita: Moretta grigia minore
Nd: Kleine Topper
Sd: mindre bergand
Photographers:
Roger Ahlman
Pbase Galleries Peru and Ecuador
John Anderson
John Anderson Photo Galleries
Jean Michel Fenerole
Photos d’Oiseaux du monde
Tom Grey
Tom Grey's Bird Pictures & Tom Grey's Bird Pictures 2
Ken Havard
My Bird Gallery & Flickr gallery 1 & Flickr gallery 2
Alan & Ann Tate
AA Bird Photography
Text by Nicole Bouglouan
Sources :
HANDBOOK OF THE BIRDS OF THE WORLD vol 1 by Josep del Hoyo-Andrew Elliot-Jordi Sargatal - Lynx Edicions - ISBN: 8487334105
GUIDE DES CANARDS, DES OIES ET DES CYGNES – de Steve Madge - Delachaux et Niestlé - ISBN: 2603013769
Animal Diversity Web (University of Michigan Museum of Zoology)
What Bird-The ultimate Bird Guide (Mitchell Waite)
Bird Web (Seattle Audubon Society
About.com – Birding / Wild Birds
Wikipedia, the free encyclopaedia
Lesser Scaup
Aythya affinis
Anseriformes Order - Anatidae Family
INTRODUCTION:
The Lesser Scaup is a North American diving duck that breeds mainly in Alaska and Canada, and in some parts of the United States. It migrates southwards to spend the winter as far as Central America and even to Colombia. It frequents wetland habitats during the breeding season, but it is usually present all year round on seasonal wetlands with emergent vegetation and submerged plants. It forages by diving and swimming in shallow water, and feeds on insects, crustaceans and molluscs, and some seeds of aquatic plants, especially in fall. It nests on the ground in grassy areas and the female alone incubates, feeds and rears the chicks.
The Lesser Scaup is one of the most abundant duck species in North America, but degradation and destruction of wetlands and pollution may affect this species.
However, the Lesser Scaup is not considered globally threatened.
This species was described first in 1838 by Thomas Campbell Eyton, an English naturalist.
DESCRIPTION OF THE BIRD:
Biometrics:
Length: M: 40-46 cm – F: 38-45 cm
Wingspan: 68-78 cm
Weight: M: 575-1200 g – F: 550-1100 g
The Lesser Scaup is a medium-sized diving duck.
The adult male in breeding plumage has black breast, neck, upper mantle, tail and vent. Body sides and belly are white. The back is finely barred black-and-white. On the upperwing, the secondary flight-feathers have white subterminal patches and small black tips, forming a white mirror bordered with black.
The head shows iridescent purple to green sheen. There is a small peak at the back of the crown. Back of head and neck are flat, not rounded like on Greater Scaup.
The bill is pale blue with narrow black nail. The eyes are bright yellow. Legs and webbed feet are dark grey.
The female is chocolate brown overall with paler body sides. We can see a white wingbar like on male’s wings. The wing-coverts are flecked with grey.
The head is darker brown with a white patch around the bill base, mainly on upper mandible. However, not all females show this white patch.
The bill is darker blue-grey with black nail. The eyes are darker yellow but vary with age. Legs and feet are dark grey.
The male in non-breeding plumage is a cross between a female and a breeding male, with the body plumage mottled brown and grey and a blackish head.
The juvenile resembles adult female but it shows more white on both upperparts and body sides. The eyes are dark brown.
The juvenile male is often darker than the young female.
RANGE:
The Lesser Scaup breeds in Alaska and Canada, and also in the USA in N and S Dakota, Montana, Wyoming, NE Washington and the Klamath region of S Oregon and in NE California.
It spends the winter in suitable habitats in Pacific coastal regions, and in South in Colorado and Florida, and along the Atlantic coast to Massachusetts. It can be found in S Great lakes region, and Ohio and Mississippi river drainages.
The species also occurs in winter in Mexico, Central America, the Antilles and Hawaiian Islands. Smaller numbers can be found in N South America, including Venezuela and offshore islands, Trinidad, Colombia, Suriname and Ecuador.
Some individuals are seen in winter in Greenland, British Isles, the Netherlands and the Canary Islands.
HABITAT:
The Lesser Scaup breeds generally in wetland habitats with shallow water. It nests in wetland, meadow or grassland areas near ponds, and large marshes in prairies or forested regions.
During winter, it frequents lake reservoirs, rivers and sheltered areas of coastal bays. It is often found on freshwater lakes and ponds well inland.
CALLS AND SONGS: SOUNDS BY XENO-CANTO
The Lesser Scaup uses visual displays, sometimes accompanied by calls during the courtship period. It makes a soft, gurgling sound and a faint “wee-a” call while flicking both wings and tail.
The female is much more vocal and gives a soft “arrr” during courtship, also a harsh grunt and a grating bark.
She produces a “purrrr” call directed at predators and when she needs the help of her mate to keep away other males.
BEHAVIOUR IN THE WILD:
The Lesser Scaup feeds on insects, crustaceans and molluscs (clams and snails), and takes seeds of several aquatic plant species, especially Nuphar lutea or Yellow Pond Lily. It also feeds on stems and leaves of several plants. On the Great Lakes, it consumes introduced Zebra Mussels.
It forages by diving and swimming in shallow, open water, swimming underwater and sometimes by dabbling or up-ending. The small prey are eaten underwater, but the larger ones are brought to the surface. The diet varies seasonally and according to the range.
The Lesser Scaup is gregarious outside of breeding season. They form large flocks in winter for moulting and during the migration. They are diurnal but they may sometimes feed at night.
The Lesser Scaup is monogamous but mate-switching is common. The pair forms during the late spring migration.
The male’s displays include head-shaking followed by throwing the head far back and bringing it forwards very quickly. It also performs bowing movements and ritualized preening. Some displays are sometimes performed underwater.
The species nests on the ground close to water and surrounded by thick vegetal cover.
The Lesser Scaup is migratory. It is among the latest migrants that move N in spring and it moves towards the breeding grounds in mid-May.
In autumn, the migration is equally late. The last birds leave the breeding grounds when the water freezes.
The flight is direct with rapid wingbeats.
REPRODUCTION OF THIS SPECIES:
The breeding season starts in May, and the peak of egg-laying takes place in June.
The Lesser Scaup nests on the ground, usually on dry land close to water, often on islands in lakes. The nest-site is surrounded by thick vegetal cover such as cattails, bulrushes and others. The nest is a cup in a slight depression, made with dry grass and lined with down. It is placed on the ground.
The female lays 9-11 to 8-14 olive-buff eggs. She incubates alone during 21-27 days. The downy chicks leave the nest very soon after hatching and go to the water. They are with their mother but they are able to feed themselves. They can fly between 47 and 60 days after hatching.
The male abandons the female through the incubation between mid-June and late June.
PROTECTION / THREATS / STATUS:
The Lesser Scaup is affected by predation of both eggs and chicks by mammals and birds, especially Corvidae, Laridae, Birds of Prey, Strigidae, the American Coot, and the Arctic Loon.
The species is still abundant but it is threatened by destruction of wetlands and pollution. Disturbances such as hunting and fishing at nesting and roosting sites force them to go and feed later, often after dark.
The Lesser Scaup is the most abundant diving duck in North America. The species is not globally threatened, but the population is slowly declining. It is currently evaluated as Least Concern.
