Greater scaup

Scientific name: Aythya marila

How weight is recorded: Whole weight

Field notes

Appearance

Males display a glossy dark head (appearing black or dark green in good light), white flanks, and a grey back; females are brown with a white facial patch at the bill base. Both sexes show a distinctive pale wing stripe in flight and a relatively small, rounded head.

Size and weight

Males 450–550 g, females 380–450 g; body length 42–51 cm.

Habitat

Greater scaup inhabit deep freshwater lakes, large reservoirs, and coastal bays with open water and minimal emergent vegetation. They prefer areas with clear sightlines and access to diving depths of 2–8 meters.

Distribution

Breed across northern Eurasia and North America; winter across temperate and subtropical regions of the Northern Hemisphere, with significant populations on the Great Lakes, coastal bays, and large inland reservoirs.

Diet

Greater scaup dive for benthic invertebrates (amphipods, chironomid larvae, molluscs) and aquatic plants; diet shifts more plant-based in winter and on coastal waters.

Behaviour

Highly gregarious, forming rafts of hundreds or thousands on open water; primarily diurnal feeders with peak activity at dawn and dusk. Flight is swift and direct; they are strong, agile divers.

Hunting tips

Scout open water edges and shallow bays for rafting birds at first and last light. Read the water surface for feeding sign (bubbles, ripples from diving activity) and listen for flock calls. Approach from downwind using natural cover along shorelines; decoy spreads work best in sheltered bays where birds rest between feeding bouts.

Whole weight

This species is logged by whole weight — the animal weighed entire, as taken.

Where it is hunted

Listed as huntable in 5 countries in Huntify.

Names in other languages

These field notes are general species knowledge, not legal advice. Always check the current seasons, quotas and firearm rules where you hunt.