Game Birds of the World

The counterpart to the Australian shelduck in New Zealand, the New Zealand shelduck is commonly known in that country as the Paradise shelduck. The two species are very similar, and certainly are very closely related; however, the New Zealand shelduck generally has darker body plumage, especially on the breast. The female has an entirely white head, making it the most attractive of all the "typical" shelducks. The female exhibits a greater seasonal plumage change than does the male, shifting from a dark and rather male-like body plumage in the non-breeding season to a more rusty brown during breeding. Juveniles typically resemble adult males during their first autumn, but may have some white on the face and around the eyes in a pattern resembling that of the female Australian shelduck. The adult plumage is attained during the first winter.

Once pair bonds are formed, the birds are monogamous and apparently have lifetime breeding associations. Breeding occurs only if the males are able to establish and hold territories. Established pairs re-form their bonds after the molting period and reclaim their territories.

Like other shelducks, females of this species seek out tree holes, hollow logs, rabbit burrows, rock crevices, or other cavities for their nests. A clutch of 8–10 eggs is laid and incubated by the female for about 32–33 days, while the male guards the nearby territory. The male returns to the nest at the time of hatching, when the entire family moves to a nursery area within the breeding territory. Both sexes defend their brood until they fledge at about eight weeks of age.