Yellow-billed Spoonbill
Encyclopedia
The Yellow-billed Spoonbill (Platalea flavipes) is common in southeast Australia; it is not unusual on the remainder of the continent, and is a vagrant to New Zealand, Lord Howe Island
and Norfolk Island
. It is around 90 cm (35 in) long, and has white plumage with a yellow bill, legs and feet. It nests in trees, marshes or reed-beds, and often roosts in trees. It occurs in shallows of wetlands and occasionally on dry pasture. It feeds largely on aquatic life, which it finds by sweeping its bill from side to side. Like all members of the ibis and spoonbill family
, it always flies with its head extended.
first described the Yellow-billed Spoonbill, naming it Platalea flavipes although noting its distinctness from other members of the genus. Bonaparte erected the genus Platibis in 1856, and Gould followed this classification in his later work. He noted the species appeared in great numbers across New South Wales in 1839, particularly in the north between the Hunter and lower Namoi River
s. The year had been wet, in contrast to droughts in previous years.
A 2010 study of mitochondrial DNA of the spoonbills by Chesser and colleagues found that the Yellow-billed and Roseate Spoonbill
s were each others' closest relative, and the two were descended from an early offshoot from the ancestors of the other four spoonbill species. They felt the genetic evidence meant it was equally valid to consider all six to be classified within the genus Platalea or alternatively the two placed in the monotypic genera Platibis and Ajaja respectively. However, as the six species were so similar morphologically, keeping them within the one genus made more sense.
than the larger-ended and more spoon-like bill of the Royal Spoonbill
, which acts like a pair of tongs
.
and Norfolk Island
. It is not found in Tasmania.
The Yellow-billed Spoonbill has a row of small blunt knobs known as papillae which line the margins of the upper and lower mandible of the "spoon". These are sensory structures which help the bird sense vibration and hence seize its prey.
One field study at Lake Cowal in New South Wales found the water depth selected for feeding to be less than 40 cm (10 in). As well as lakes and swamps, the birds feed in paddocks inundated after heavy rain. Foraging occurs both during the day and at night.
Yellow-billed Spoonbills also probe submerged plants directly for prey, and seize prey such as spiders above ground. They have been observed dragging their bills alongside themselves through shallow water while walking.
Prey items recorded at Lake Cowal include freshwater crustaceans such as the common yabby
(Cherax destructor); shrimp of the genus Macrobrachium
and family Atyidae
; insects, particularly aquatic bugs of the families Notonectidae
and Corixidae; fish such as mosquitofish (Gambusia affinis) and flat-headed gudgeon (Philypnodon grandiceps); and occasionally freshwater snails and plant material such as medic burr (Medicago polymorpha
).
Lord Howe Island
Lord Howe Island is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, directly east of mainland Port Macquarie, and about from Norfolk Island. The island is about 11 km long and between 2.8 km and 0.6 km wide with an area of...
and Norfolk Island
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
. It is around 90 cm (35 in) long, and has white plumage with a yellow bill, legs and feet. It nests in trees, marshes or reed-beds, and often roosts in trees. It occurs in shallows of wetlands and occasionally on dry pasture. It feeds largely on aquatic life, which it finds by sweeping its bill from side to side. Like all members of the ibis and spoonbill family
Threskiornithidae
The family Threskiornithidae includes 34 species of large terrestrial and wading birds, falling into two subfamilies, the ibises and the spoonbills. It was formerly known as Plataleidae. The spoonbills and ibises were once thought to be related to other groups of long-legged wading birds in the...
, it always flies with its head extended.
Taxonomy
The renowned ornithologist John GouldJohn Gould
John Gould was an English ornithologist and bird artist. The Gould League in Australia was named after him. His identification of the birds now nicknamed "Darwin's finches" played a role in the inception of Darwin's theory of evolution by natural selection...
first described the Yellow-billed Spoonbill, naming it Platalea flavipes although noting its distinctness from other members of the genus. Bonaparte erected the genus Platibis in 1856, and Gould followed this classification in his later work. He noted the species appeared in great numbers across New South Wales in 1839, particularly in the north between the Hunter and lower Namoi River
Namoi River
The Namoi River is a major tributary of the Darling River in inland New South Wales, Australia.- Course :The headwaters of the Namoi, including the Macdonald River, the Peel River, the Cockburn River and the Manilla River, rise on the western slopes of the Great Dividing Range on the Northern...
s. The year had been wet, in contrast to droughts in previous years.
A 2010 study of mitochondrial DNA of the spoonbills by Chesser and colleagues found that the Yellow-billed and Roseate Spoonbill
Roseate Spoonbill
The Roseate Spoonbill, Platalea ajaja, is a gregarious wading bird of the ibis and spoonbill family, Threskiornithidae...
s were each others' closest relative, and the two were descended from an early offshoot from the ancestors of the other four spoonbill species. They felt the genetic evidence meant it was equally valid to consider all six to be classified within the genus Platalea or alternatively the two placed in the monotypic genera Platibis and Ajaja respectively. However, as the six species were so similar morphologically, keeping them within the one genus made more sense.
Description
Measuring around 90 cm (35 in), the Yellow-billed Spoonbill has all white plumage. The long spoon-shaped bill, bare-skinned face, legs and feet are all yellow, while the iris is pale yellow. The sexes are similar in plumage and coloration. In the breeding season, the face is lined with black, long hackles develop on the chest, and the wings have black tips. The bill of the Yellow-billed Spoonbill is narrower and works more like a forcepsForceps
Forceps or forcipes are a handheld, hinged instrument used for grasping and holding objects. Forceps are used when fingers are too large to grasp small objects or when many objects need to be held at one time while the hands are used to perform a task. The term 'forceps' is used almost exclusively...
than the larger-ended and more spoon-like bill of the Royal Spoonbill
Royal Spoonbill
The Royal Spoonbill, Platalea regia, also known as the Black-billed Spoonbill, occurs in intertidal flats and shallows of fresh and saltwater wetlands in Australia, New Zealand, Indonesia, Papua New Guinea, and the Solomon Islands. It has also been recorded as a vagrant in New Caledonia...
, which acts like a pair of tongs
Tongs
Tongs are used for gripping and lifting tools, of which there are many forms adapted to their specific use. Some are merely large pincers or nippers, but the greatest number fall into three classes:...
.
Distribution and habitat
The Yellow-billed Spoonbill is found across eastern, northern and southwestern Australia, particularly around water, and has been recorded as a vagrant to New Zealand, Lord Howe IslandLord Howe Island
Lord Howe Island is an irregularly crescent-shaped volcanic remnant in the Tasman Sea between Australia and New Zealand, directly east of mainland Port Macquarie, and about from Norfolk Island. The island is about 11 km long and between 2.8 km and 0.6 km wide with an area of...
and Norfolk Island
Norfolk Island
Norfolk Island is a small island in the Pacific Ocean located between Australia, New Zealand and New Caledonia. The island is part of the Commonwealth of Australia, but it enjoys a large degree of self-governance...
. It is not found in Tasmania.
Feeding
The Yellow-billed Spoonbill is carnivorous, catching small animals by sweeping its bill through shallow water and swallowing prey once it is detected. When slow sweeping, the spoonbill walks with the bill at an angle at about 60 degrees to horizontal and with the bill tip open about 2 to 4 cm (0.8–1.6 in), sweeping an arc of around 120 degrees in front of the bird. The bird walks slowly, kicking up debris and small animals from the bottom of the water, which it then senses and catches with its bill. When an item is detected, the spoonbill switches to intensive sweeping of a small area.The Yellow-billed Spoonbill has a row of small blunt knobs known as papillae which line the margins of the upper and lower mandible of the "spoon". These are sensory structures which help the bird sense vibration and hence seize its prey.
One field study at Lake Cowal in New South Wales found the water depth selected for feeding to be less than 40 cm (10 in). As well as lakes and swamps, the birds feed in paddocks inundated after heavy rain. Foraging occurs both during the day and at night.
Yellow-billed Spoonbills also probe submerged plants directly for prey, and seize prey such as spiders above ground. They have been observed dragging their bills alongside themselves through shallow water while walking.
Prey items recorded at Lake Cowal include freshwater crustaceans such as the common yabby
Common yabby
The common yabby, Cherax destructor, is an Australian freshwater crustacean in the Parastacidae family. It is listed as a vulnerable species of crayfish by the World Conservation Union , though the validity of this listing is questionable; wild yabby populations remain strong, and have expanded...
(Cherax destructor); shrimp of the genus Macrobrachium
Macrobrachium
Macrobrachium is a genus of freshwater shrimp characterised by the extreme enlargement of the second pair of pereiopods, at least in the male...
and family Atyidae
Atyidae
Atyidae is a family of shrimp, present in all tropical and most temperate waters of the world. Adults of this family are almost always confined to fresh water...
; insects, particularly aquatic bugs of the families Notonectidae
Notonectidae
Notonectidae is a cosmopolitan family of aquatic insects in the order Hemiptera, commonly called backswimmers because they swim upside down. They are all predators, up to nearly 2 cm in size. They are similar in appearance to Corixidae , but can be separated by differences in their...
and Corixidae; fish such as mosquitofish (Gambusia affinis) and flat-headed gudgeon (Philypnodon grandiceps); and occasionally freshwater snails and plant material such as medic burr (Medicago polymorpha
Medicago polymorpha
Medicago polymorpha is a plant species of the genus Medicago. It is native to the Mediterranean basin but is found throughout the world. It forms a symbiotic relationship with the bacterium Sinorhizobium medicae, which is capable of nitrogen fixation...
).