FWS Focus

Overview

Characteristics
Overview

The lesser scaup is a medium-bodied diving duck, meaning they feed by diving under the surface of deep water to find their food. Males have a dark emerald to black head and a mostly gray to white body. Females are mostly brown on their body and have a dark brown head with a white patch at the base of the bill. Scaup have evolved a bill structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.

Learn more about structure
perfect for catching invertebrates swimming in the water column. Interestingly, lesser scaup have a significantly delayed spring migration compared to most other species, and they typically do not begin nesting until mid-summer. Lesser scaups are found in all four flyways, but the majority of birds migrate through the Central and Mississippi. 

Scientific Name

Aythya affinis
Common Name
Lesser Scaup
FWS Category
Birds
Kingdom

Location in Taxonomic Tree

Genus
Species

Identification Numbers

TSN:

Characteristics

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

Lesser Scaup is a medium-sized duck. They are often seen migrating together with the greater scaup, but the smaller size of the lesser scaup can be obvious enough to separate the species. 

Measurements

Length: 15 to 18 in (38 to 45 cm)

Wingspan: approximately 29 in (73.66 cm)

Weight

Males and females are similar in size with the average male weight around 1.8 pounds (0.82 kg) and the females 1.6 pounds (0.73 kg).

Color & Pattern

Males have a dark purple to black head and a mostly gray to white body. Females are mostly brown on their body and have a dark brown head with a white face patch at the base of the bill. 

Sound

While lesser scaup make purrs and sharp whistling calls, they are not often heard. In fact, females are silent. 

Characteristic category

Behavior

Characteristics
Behavior

Lesser scaup are diving ducks, which submerge completely underwater to catch food. They can be very active while feeding, diving and surfacing repeatedly and quickly. When trying to impress a mate, males show off by flicking their head and moving it up and down. Lesser scaup have a significantly delayed spring migration compared to most other species, often being the last to migrate. They typically do not begin nesting until mid-summer.

Characteristic category

Life Cycle

Characteristics
Reproduction

Most nests of lesser scaup occur in upland areas among tall vegetation, but some build floating nests in the water. Like other ducks, the nest is lined with down feathers on top of dry grass and other vegetation. The females will lay nine to 12 eggs. 

Characteristic category

Habitat

Characteristics
Habitat

In the summer, they nest in grasslands, parklands, and the tundra near water. Most nests occur in upland areas, but some individual build nests over water similar to canvasback. In winter, lesser scaup gather in coastal bays and estuaries, lakes and reservoirs, and managed wetlands. It is not unusual to see this species in groups or rafts that are composed of thousands of individuals during the winter. In some areas, lesser scaup are very common on aquaculture ponds. National wildlife refuges are limited in their capacity to manage for diving ducks, but it is assumed that management of seasonal emergent wetlands, promotion of submersed aquatic vegetation and promulgation of sanctuary conditions benefits this species.

Grassland

Ecosystem with large, flat areas of grasses.

Tundra

Cold, treeless region in Arctic and Antarctic climates.

Coastal
Lake
Wetland
Characteristic category

Food

Characteristics
Food

Lesser scaup are omnivores, consuming both plant and animal matter, but historically they probably consumed primarily animal matter, and still do if available. Preferred animal matter include amphipods, mussels, clams, snails and other aquatic invertebrates.

Geography

Characteristics
Range

Lesser scaup is one of the most widespread duck species in North America. This species breeds throughout Alaska and across parts of northern and central Canada down through the Prairie Pothole Region. It will spend its winters mostly along the Pacific, Atlantic and Gulf coasts, with some inland areas in Texas, Louisiana, Mississippi and Mexico receiving substantial use.

Launch Interactive Map