Named for its most distinctive feature. The bill. It is a remarkable piece of engineering. Broad. Spatulate. Fringed with fine lamellae that act as a sieve. The kuruwhengi feeds by swimming slowly through shallow water. Its bill is submerged. It pumps water in and out through these filters. Tiny insects, crustaceans, and seeds are trapped. It is a highly efficient feeding method. The shoveler exploits food sources that other dabbling ducks cannot reach. The adaptation is specific. The niche is secure. The male is a striking bird. In breeding plumage, he has a deep blue-grey head. A bold white crescent sits between the eye and the bill. The belly is bright chestnut. A pale blue patch marks the upper wing. The female is more modest. She is mottled brown overall. She shares the same distinctive bill shape. Both sexes have bright yellow eyes. These give them a slightly startled expression. As if they are perpetually surprised by their own success. The look is accidental. The effect is charming. This is a dabbling duck. It tips forward in shallow water to feed. But its preferred method is the head-down, filter-feeding swim. It often feeds in small flocks. The birds swim side by side in a loose line. Bills are submerged. They create a gentle, rhythmic splashing sound as they work their way across a pond. When disturbed, they burst into the air. Flight is fast and direct. Their wings whistle. The noise signals departure. The group moves together. Breeding pairs form in winter. The male performs a series of head-bobbing displays. Soft calls attract a mate. The nest is a well-hidden bowl of grass and down. It is built among dense vegetation near water. The female incubates the clutch of seven to ten eggs alone. The male stands guard nearby. The ducklings are precocial. They leave the nest within hours of hatching. They feed themselves from the start. The independence is immediate. The survival rate varies. Significant challenges have come from wetland drainage. More than ninety percent of New Zealand's natural wetlands have been drained since human arrival. The shoveler has lost much of its historical habitat. However, it has adapted to some modified environments. It uses farm ponds, sewage treatment ponds, and constructed wetlands. It remains common in the North Island. Large wetland complexes like the Waikato peat lakes still provide good habitat. It is scarce in the South Island. Wetlands are fewer and more degraded there. The distribution is uneven. The pressure is real. The kuruwhengi is a bird of the shallow edge. A filter-feeder in a world of muddy margins. Its continued presence depends on our willingness to leave a few of those margins intact. The requirement is simple. The execution is difficult. The bird persists. It adapts. It carries on.