Pacific Black Duck

Once again it Wednesday and time for an Australian bird. Last week it was the very colourful and popular bird, the Rainbow Lorikeet, however to redress the balance, here is a duck without much colour but a beautiful head pattern.  It is the Pacific Black duck - Anas superciliosa. 

 

It is a dabbling duck found in much of Indonesia, New Guinea, Australia, New Zealand, and many islands in the southwestern Pacific, reaching to the Caroline Islands in the north and French Polynesia in the east.   It is usually called the Grey Duck in New Zealand, where it is also known by its Maori name, Pārera.

 

Both adults are fully water proof using the oil excreted from the preening gland at the base of their tail. They have same plumage except that all the colours are paler on the female and she is slightly smaller.

The size range is 54–61 cm;

Their most distinct feature is their dusty-brown head with cream face and brown stripe that runs from top of bill through the brown-red eye with a second smaller brown stripe that runs from side of mouth  along cheek.  Back, tail dusty-brown with feathers edged in cream, throat cream, breast, belly and under tail all brown with cream buff edges, flight feathers brown, secondary feathers broad green spectrum edged in black, under wing white and used to signal to other ducks in courtship displays, bill olive-grey with black nostrils, webbed feet olive-grey with 3 toes forward and one very small toe backward.

 

 

It is not resident on the Marianas islands, but sometimes occurs there during migration. The now extinct Mariana Mallard was probably originally derived from hybrids between this species and the mallard, which came to the islands during migration and settled down there. 

There are three subspecies of Anas superciliosa:

rogersi − Mathews, 1912 Australasian Duck, breeds in Indonesia, southern New Guinea and Australia

pelewensis − Hartlaub & Finsch, 1872 – Island Black Duck, breeds on the southwest Pacific islands and northern New Guinea

superciliosa Gmelin, 1789 − New Zealand Grey Duck, breeds in New Zealand

 

The New Zealand subspecies has declined sharply in numbers, at least in its pure form, due to competition from and hybridisation with the introduced mallard. Rhymer et al. (1994) say their data "points to the eventual loss of identity of the Grey Duck as a separate species in New Zealand, and the subsequent dominance of a hybrid swarm akin to the Mariana Mallard."

It was assumed that far more mallard drakes mate with Grey Duck females than vice versa based on the fact that most hybrids show a mallard-type plumage, but this is not correct; it appears that the mallard phenotype is dominant, and that the degree to which species contributed to a hybrid's ancestry cannot be determined from the plumage. The main reasons for displacement of the Pārera seem to be physical dominance of the larger mallards, combined with a marked population decline of the Pārera due to over hunting in the mid-20th century.

 

Most Australian coastal streams, lagoons, mountain lakes and inland swamps have their quota of Pacific Black Ducks as they are one of our most widely spread and abundant ducks.  They can be found in any wet/water habitat and often mix and feed with native Grey Ducks and Chestnut Teal Ducks.  Found throughout Australia, except inland deserts, mainly where fresh water is present but sometimes salt water, they are randomly nomadic following floods but will be rather more sedentary on permanent waters especially on eastern and northern coastal areas and part of this can be attributed to human feeding.

In south eastern Australia seasonal shifts in populations, north over winter and south in spring and summer. Across northern Australia the birds stay on coastal waters during winter-spring dry season and then disperse inland with the summer monsoons.

 

 

 

Breeding season is timed to occur when water areas are at their fullest and aquatic plants mature. In southern Australia this takes place in spring following winter rains, in the north birds breed in autumn after summer rains.  If the rainfall is erratic they will breed when the rivers are at their peak, if living in an area of abundant rain through the year then they will breed all year round.

They form seasonal pairs before breeding time starts with a series of postures including flapping of wings and pretending to mate. Nests range from scrapes in the ground to well-woven cups in grass or reeds also holes in trees stumps,(see above), in deserted nests of other water birds or flat surfaces in stag horns and large low ferns.

The female plucks soft small feathers from her breast to line the nest area and also to cover the 7-13 eggs when she leaves to go off and feed accompanied by the male. Eggs are oval with a smooth glossy white shell and the female incubates them for 26-30 days. Ducklings are semi- precocial – hatched with eyes open, covered with down, capable of walking/swimming soon after hatching but stay with the parents near the nest.

Courtship is accompanied by ritualised displays including preening, bobbing and wing-flapping. This behaviour is often initiated by the female, and, other than copulation, the male helps little in the breeding process. Often, two broods will be raised in a year. The number of offspring produced may seem quite high, but only 20% of these will survive past two years of age.

 

 

Ducklings - top of head, neck and back dusky down, yellow face with black lines thru eyes and cheek, under parts yellow, yellow spots on sides of back and rear edge of wing, bill and web feet dark olive-green.

Ducklings are not born water proofed and can die easily if left wet or cold from pneumonia. They also do not like to be brought up alone and in care are always buddied up with another duckling or a baby chicken, so consider this if you are thinking of getting one (get two!). 

 

They feed in the water by diving, dabbling and grazing using their wide bill, their tongues work like pistons so water is sucked in at the trips of their bills and then pushed out again past filter-plates at the sides and the rear.

 

 

Their natural food consists of both plant and animal food from the water as well as aquatic plant seeds, insects, yabbies, shrimps and crustaceans. Ducklings feed mainly on aquatic insects.

 

 

 

The female has a loud raucous quack, single or repeated slowly or quickly when distressed. Male has a softer quack and a whistle during courtship displays.

 

The introduced Mallard presents a particular danger to the Pacific Black Duck as they have similar food and habitat needs and so complete for survival. When these two species interbreed the feral Mallard strain is dominant and in successive generations the characteristics of our native Pacific Black can be lost.

 

 In addition the Mallard imparts unfavourable traits to these hybrids such as that they are sedentary birds and not able to survive the erratic (and ever more so) climate of Australia and so do not adapt as pure native duck species, which are nomadic especially in times of drought.

 

 

 

Important Information

Thousands of our beautiful water birds die each year of Botulism, which is a bacterial infection affecting the nervous system, from still, dirty or oxygen-deficient water. They get sick and die a slow death from ingesting foul water, decaying vegetable or animal matter containing the neurotoxin produced by the bacteria. 

If the water in rivers, dams, lakes or ponds is not clean and fresh, if there is garbage, plastic or sewer in the water or if there is an abundance of weed or algae then you  should tell authorities as soon as possible  You could be saving their life.

Being so abundant in Australia. this lovely duck is the most popular shot game bird and in coastal districts makes up over 70% of other killed.  It may be able to survive some of the controlled hunting but coupled with its ever dwindling habitat, feral and domestic animals, drought, fire, roads and disease it cannot maintain its numbers.

 

 

Once again we find a native bird being constantly feed by humans which upsets their balance of breeding, growth and health.

Bread, biscuits, cake or any processed foods are of no nutritional value to these birds or any other native bird or animal. If you have ducks in your garden, park, school or any other area enjoy them naturally.

Inform and educate people to the damage feeding is to these beautiful creatures, they are feeding them because they care.  If you must supplement their diet then lettuce, spinach, alfalfa sprouts, budgie/canary seeds, milk thistle, worms, insects are all good foods.

The short video of Pacific Black ducks accompanied by a White Ibis can be accessed at

 http://youtu.be/u31TSAoirHw

If there is a black space below, click it and the video will appear.

     

I hope you enjoyed seeing and hearing about the Pacific Black duck.

Many thanks for visiting and leaving comments on any of my post.

Tomorrow, I am finishing my post on Broad Water mainly by showing a video.

I am linkingthispost with Wild Bird Wednesday