Wednesday, March 26, 2014

BIRD - AUSTRALIAN PELICAN

Australian Pelican

Pelecanus conspicillatus
Pelecanidae

The Australian Pelican is often seen around the coasts, where it can be seen roosting on sandbanks, rock platforms and reefs, or swimming in lagoons, bays and estuarine waters, dipping their oversized bills into the water to catch fish. However, on the rare occasions that monsoonal rains flood the salt lakes in the arid inland of Australia, many pelicans take advantage of the conditions and flock there in their thousands to breed. When it dries out, they leave and head for other less-ephemeral terrestrial wetlands or the coast.







Description

There are seven species of pelicans in the world, all of which are similar in shape and, with one exception, are primarily white in colour. Males are larger than females. The most characteristic feature of pelicans is the elongated bill with its massive throat pouch. The Australian Pelican's bill is 40 cm - 50 cm long and is larger in males than females. Pelicans have large wings and a wingspan of 2.3 m - 2.5 m.


Feeding

The bill and pouch of pelicans play an important role in feeding. The bill is sensitive and this helps locate fish in murky water. It also has a hook at the end of the upper mandible, probably for gripping slippery food items. When food is caught, the pelican manipulates it in its bill until the prey typically has its head pointing down the pelican's throat. Then with a jerk of the head the pelican swallows the prey. The bill is delicately built. The lower jaw consists of two thin and weakly articulated bones from which the pouch hangs. When fully extended, the bill can hold up to 13 litres. The pouch does not function as a place to hold food for any length of time. Instead it serves as a short-term collecting organ. Pelicans plunge their bills into the water, using their pouches as nets. Once something is caught, a pelican draws its pouch to its breast. This empties the water and allows the bird to manoeuvre the prey into a swallowing position. The pouch can also serve as a net to catch food thrown by humans, and there are sightings of pelicans drinking by opening their bill to collect rainwater.


The Australian Pelican may feed alone, but more often feeds as a cooperative group. Sometimes these groups are quite large. One group numbered over 1,900 birds. A flock of pelicans works together, driving fish into a concentrated mass using their bills and sometimes by beating their wings. The fish are herded into shallow water or surrounded in ever decreasing circles.

Breeding

Breeding depends on environmental conditions, particularly rainfall. Pelicans are colonial breeders with up to 40 000 individuals grouping on islands or secluded shores. Breeding begins with courtship. The female leads potential mates (two to eight or more) around the colony. As the males follow her in these walks, they threaten each other while swinging their open bills from side to side trying to attract the female's attention. The males may also pick up small objects, like sticks or dry fish, which they toss in the air and catch again, repeating the sequence several times.


Both sexes perform "pouch-rippling" in which they clap their bills shut several times a second and the pouch ripples like a flag in a strong breeze. As the courtship parade progresses, the males drop out one by one. Finally, after pursuits on land, water or in the air, only a single male is left. The female leads him to a potential nest site.


During the courtship period, the bill and pouch of the birds change colour dramatically. The forward half of the pouch becomes bright salmon pink, while the skin of the pouch in the throat region turns chrome yellow. Parts of the top and base of the bill change to cobalt blue, and a black diagonal strip appears from the base to the tip. This colour change is of short duration, the intensity usually subsiding by the time incubation starts.


The nest consists of a scrape in the ground prepared by the female. She digs the scrape with her bill and feet, and lines it with any scraps of vegetation or feathers within reach of the nest. Within three days egg-laying begins and eggs are laid two to three days apart. Both parents share incubation and the eggs are incubated on their feet.


The first-hatched chick is substantially larger than its siblings. It receives most of the food and may even attack and kill its nest mates. A newly hatched pelican has a large bill, bulging eyes, and skin that looks like small-grained bubble plastic. The skin around the face is mottled with varying degrees of black and the colour of the eyes varies from white to dark brown. This individual variation helps the parents to recognise their chick from hundreds of others.


The chicks leave their nests to form creches of up to 100 birds. They remain in creches for about two months, by the end of which they have learnt to fly and are fairly independent. Wild birds may live between ten and possibly 25 years or more.

BIRD - ROYAL SPOONBILL

Royal Spoonbill

Platalea regia
Threskiornithidae



During the breeding season the Royal Spoonbill develops a lush crest of white feathers, up to 200 millimetres long, which sprouts from the back of its head. During mating displays this crest may be raised and spread, revealing a patch of salmon-pink coloured skin beneath. Both sexes develop these crests, but the females’ crests are often smaller. Royal Spoonbills usually nest in simple pairs among the noisy breeding colonies of other waterbirds, such as ibis and Yellow-billed Spoonbills, and various species of egrets and herons.

















Description

The Royal Spoonbill is a large white waterbird with black, spatulate (spoon-shaped) bill, facial skin, legs and feet. During the breeding season, it has a distinctive nuchal (back of head or nape of neck) crest, which can be up to 20 cm long in male birds (usually shorter in females). The crest can be erected during mating displays to reveal bright pink skin underneath. Breeding adults also have a creamy-yellow wash across the lower neck and upper breast and a strip of bright pink skin along the edge of the underwings which is obvious when the bird opens its wings. The facial skin is black with a yellow patch above the eye and a red patch in the middle of the forehead, in front of the crest feathers. Females are slightly smaller with shorter legs and bill. Out of breeding season, the nuchal crests are reduced, the underwing is not bright pink and the plumage is less brilliant, often appearing 'dirty'. Young birds are similar to non-breeding adults without a crest or coloured face patches, and are slightly smaller with a shorter, smoother bill. The Royal Spoonbill is most often seen wading in shallow waters, sweeping its submerged bill back and forth in a wide arc to find food.

Similar Species

Their large spoon-shaped bills easily distinguish spoonbills from all other water birds. Its black face, bill and legs all distinguish the Royal Spoonbill from the slightly larger Yellow-billed Spoonbill, which has a yellow bill and legs. The Royal Spoonbill also has a distinctive nuchal crest during breeding season, which is visible even in silhouette.


Feeding

The Royal Spoonbill feeds mainly on fish in freshwater, and on shrimps in tidal flats; it will also eat other crustaceans and aquatic insects. The structure of its bill limits it to feeding in water that is less than 40 cm deep over sand, mud or clay, where it can sweep the water with its bill. It uses several methods to catch food: slow sweeping from side to side with an open bill, rapid sweeping while walking fast or even running through the water, as well as dragging, probing or grabbing. The spatulated bill has many vibration detectors, called papillae, on the inside of the spoon, which means the bird can feel for prey items even in murky water and can feed by day or night. Once food is caught, it lifts its bill up and lets the items slide down its throat. It will bash shrimps against hard objects to remove their shells.

Breeding

The Royal Spoonbill forms monogamous pairs for the duration of the breeding season and nest in colonies alongside many other waterbirds, including Yellow-billed Spoonbills, ibises, herons and cormorants. A solid bowl-shaped nest is built of sticks and twigs lined with leaves and water plants, and is usually placed in the crown of a tree over water or among high reeds and rushes. Nest sites may be reused year after year. Both sexes incubate the eggs and feed the young. When threatened at the nest, the adult birds will raise all their feathers to appear much larger and crouch down low over the nest. The young are often fed by both parents for several weeks after fledging and young birds will forage alongside their parents for some time before the family group disperses.

BIRD - AUSTRALIAN WHITE IBIS

Australian White Ibis

Threskiornis molucca
Threskiornithidae

In regional areas, Australian White Ibis (and Straw-necked Ibis) are sometimes called ‘the farmers’ friend’, due to their habit of flocking into areas afflicted by plagues of locusts and gorging on the ravaging hoards of insects. In urban areas, however, where many Ibis scrounge for a living by scavenging at rubbish tips and in city parks, and their plumage becomes soiled by refuse, they are sometimes disparagingly referred to as ‘tip turkeys’.










Description

The Australian White Ibis is identified by its almost entirely white body plumage and black head and neck. The head is featherless and its black bill is long and down-curved. During the breeding season the small patch of skin on the under-surface of the wing changes from dull pink to dark scarlet. Adult birds have a tuft of cream plumes on the base of the neck. Females differ from males by being slightly smaller, with shorter bills. Young birds are similar to adults, but have the neck covered with black feathers. In flight, flocks of Australian White Ibis form distinctive V-shaped flight patterns. Another common name for this bird is Sacred Ibis, but this more appropriately refers to a closely related African species.

Feeding

The Australian White Ibis' range of food includes both terrestrial and aquatic invertebrates and human scraps. The most favoured foods are crayfish and mussels, which the bird obtains by digging with its long bill. Mussels are opened by hammering them on a hard surface to reveal the soft body inside.

Breeding

The male Australian White Ibis secures a pairing territory on a branch of a tall tree in order to attract a female. The courtship ceremony involves the male putting on a noisy display, as well as showing aggression towards other males. When a female arrives, the male attracts her by bowing from his branch. He then offers the female a twig, forging a bond when she grasps it and they begin to preen one another. Once the pair bond is cemented, the birds fly off to build a nest at another location. Australian White Ibis nest in large colonies, often with the Straw-necked Ibis, T. spinicollis. Young are born naked and helpless. One or two broods may be reared in a year.

Tuesday, March 25, 2014

BIRD - WHITE FACED HERON

info from http://birdlife.org.au/bird-profile/white-faced-heron


White-faced Heron

Egretta novaehollandiae
Ardeidae






The White-faced Heron is particularly versatile. It can be seen in many different wetland habitats: they occur on reefs, in rock pools and mudflats by the coast, in estuaries and saltmarsh, swamps, rivers, drains and at farm dams; they even occur in pasture and hypersaline wetlands. There they can be seen foraging for a wide range of prey, mostly small aquatic creatures, using various methods, including standing and waiting for their prey, slowly stalking it, frantically dashing after it, or disturbing it by stirring the water with their feet.

Distribution

White-faced Herons are the most commonly seen herons in Australia. They are found throughout the mainland and Tasmania, and most coastal islands. They also occur in Indonesia, New Guinea, New Caledonia and New Zealand.

Feeding

The White-faced Heron feeds on a wide variety of prey, including fish, insects and amphibians. Food is obtained in a variety of ways, such as walking and disturbing prey, searching among damp crevices or simply standing in the water and watching for movement.

Breeding

White-faced Herons may breed outside the breeding season in response to rainfall. Both sexes share the building of the nest, incubation of the eggs and care of the young. The nest is an untidy structure of sticks, placed in a tree. Normally only one brood of young is raised in a year.