T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Duck (Australasian shoveler) Anas rhynchotis

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Subfamily: Anatinae
Genus: Anas
Species: A. rhynchotis
Binomial name: Anas rhynchotis
Synonyms: A. r. rhynchotis, A. r. variegata
Common name: Australasian shoveler, Spoonbill, Shoveler, Spoony, Spoonie, Shoveller, kuru whengi

Anas rhynchotis is a species of dabbling duck in the genus Anas. It ranges from 46–53 cm long. It lives in heavily vegetated swamps. They occur in Australia, Tasmania and New Zealand. Their preferred wetland habitat is the fertile raupo edged shallows.

Anas rhynchotis is rarely seen away from the water because it can't eat grass. They swim with their bill submerged, sieving seeds of aquatic plants, small plants, insects etc from the water surface, and even through mud. They also eat worms and insects in flooded pasture. The ducks sifting apparatus is very well developed with fine growths called lamellae on the edges of it's large wedge shaped bill, and it has bristles on its' tongue that sieve soft food. This ducks peculiar broad bill is predominant as soon as the chick is hatched. 
The male shoveler (650 grams) is a duck with variegated plumage, blue-grey head with a white vertical stripe between the eye and bill, a striking reddish-brown breast, and blue wings. The female is not as colourful and weights about 600 grams.

Courtship in New Zealand starts around August which involves vocalisations from the drake (male) accompanied with head-bobbing whilst swimming toward the duck (female). The most heard vocalisations are from the drakes in the form of a "Sock, sock-sock, sock, sock-sock". Often several drakes will peruse an already paired duck: Generally the mated males are aggressive and will not tolerate this behaviour from the bachelors, and fighting may ensue. Courtship flights are common in the morning and evenings mostly, where the duck is followed in a short rapid flight by one or more (usually two) drakes. This tests the speed and agility of the drakes. The duck may be biased in picking the 'winner' in these tests however, especially if she has paired with one of the competitors. She will even sometimes excrete mid-flight on a perusing male if he is especially not to her fancy. There is a clear and unexplained sex ratio difference with a lot more males to females. This difference is not present in broods of ducklings however. Males with a lot of white breast feathers are not usually paired. These white feathers are often a sign of an older shoveler as first year males almost never have them. Mating will occur as early as August, though nesting rarely happens until at least October. The nests are constructed of grass lined with down, and are covered by vegetation. Six to ten cream-coloured eggs with a blue tint are laid between August and December. The female is the sole incubator for 26 days.

The Anas rhynchotis is one of the few native birds that are not protected, with about 30,000 shot during duck hunting season.

  

Thanks to Wikipedia for text and information     https://creativecommons.org/licenses/by-sa/3.0/