Our Beautiful World

Large wading birds, Threskiornithidae
Ibis and Spoonbills

An adult Roseate Spoonbill and two chicks on a nest in a zoo

The family Threskiornithidae includes 34 species of large wading birds. The family has been traditionally classified into two
subfamilies, the ibises and the spoonbills, however recent genetic studies are casting doubt on the arrangement, and revealing the spoonbills to be nested within the old world ibises, and the new world ibises as an early offshoot. (So here we go again....)

Members of the family have long, broad wings with 11 primary feathers and about 20 secondaries. They are strong fliers and,
rather surprisingly, given their size and weight, very capable soarers. The body tends to be elongated, the neck more so, with
rather long legs. The bill is also long, decurved in the case of the ibises, straight and distinctively flattened in the spoonbills.
They are large birds, but mid-sized by the standards of their order, ranging from the Dwarf Olive Ibis, Bostrychia bocagei,
at 45 cm and 450 gr , to the Giant Ibis, Thaumatibis gigantea, at 100 cm and 4.2 kg.

They are distributed almost worldwide, being found near almost any area of standing or slow-flowing fresh or brackish water.
Ibises are also found in drier areas, including landfills.
The Llanos are notable in that these wetland plains support seven species of ibis in the one region.

The Llanos in Colombia.

Llanos, ( Spanish: “Plains”) wide grasslands stretching across northern South America and occupying western Venezuela and northeastern Colombia. The Llanos have an area of approximately 570,000 square km,
delimited by the Andes Mountains to the north and west, the Guaviare River and the Amazon River basin to the south,
and the lower Orinoco River and the Guiana Highlands to the east.

The elevations of the Llanos rarely exceed 300 metres. The Llanos Altos form extensive platforms between rivers and rise 30 to 60 metres above the valley floors. The Llanos are drained by the Orinoco and its western tributariesAnnual precipitation is concentrated between April and November and ranges from 1,100 mm to 4,570 mm. Mean daily temperatures in the Llanos exceed 24 °C throughout the year.

Most of the Llanos is treeless savanna that is covered with swamp grasses and sedges in the low-lying areas and
with long-stemmed and carpet grasses in the drier areas. Much of the Llanos Bajos is subject to seasonal flooding.
Trees are concentrated along rivers and in the Andean piedmont; trees scattered on the open savanna include scrub
oak and dwarf palm. Most mammals nest in the gallery forests and feed on the grassland; among these are included
several species of deer and rabbit, as well as the anteater, armadillo, tapir, jaguar, and capybara, which is the world’s
largest living rodent.

All ibises are diurnal; spending the day feeding on a wide range of invertebrates and small vertebrates: ibises by probing in soft
earth or mud, spoonbills by swinging the bill from side to side in shallow water. At night, they roost in trees near water.
They are gregarious, feeding, roosting, and flying together, often in formation.

Nesting is colonial in ibises, more often in small groups or singly in spoonbills, nearly always in trees overhanging water,
but sometimes on islands or small islands in swamps. Generally, the female builds a large structure out of reeds and sticks
brought by the male. Typical clutch size is 2 to 5; hatching is asynchronic. Both sexes incubate in shifts, and after hatching feed
the young by partial regurgitation. Two or three weeks after hatching, the young no longer need to be brooded continuously
and may leave the nest, often forming creches but returning to be fed by the parents.

Scarlet ibis, SeaWorld, California
Photo: Tokyo Junkie


Subfamily: Threskiornithinae - Ibises
Genus Threskiornis
African Sacred Ibis, Threskiornis aethiopicus
Malagasy Sacred Ibis, Threskiornis bernieri
Black-headed Ibis, Threskiornis melanocephalus
Australian White Ibis, Threskiornis molucca
   Solomons White Ibis, Threskiornis molucca pygmaeus
Straw-necked Ibis, Threskiornis spinicollis
Genus Pseudibis
Red-naped Ibis, Pseudibis papillosa
White-shouldered Ibis, Pseudibis davisoni
Giant Ibis, Pseudibis gigantea
Genus Geronticus
Northern Bald Ibis, Geronticus eremita
Southern Bald Ibis, Geronticus calvus
Genus Nipponia
Crested Ibis, Nipponia nippon
Genus Bostrychia
Olive Ibis, Bostrychia olivacea
Sao Tome Ibis, Bostrychia bocagei
Spot-breasted Ibis, Bostrychia rara
Hadada Ibis, Bostrychia hagedash
Wattled Ibis, Bostrychia carunculata
Genus Theristicus
Plumbeous Ibis, Theristicus caerulescens
Buff-necked Ibis, Theristicus caudatus
Black-faced Ibis, Theristicus melanopis
Genus Cercibis
Sharp-tailed Ibis, Cercibis oxycerca
Genus Mesembrinibis
Green Ibis, Mesembrinibis cayennensis
Genus Phimosus
Bare-faced Ibis, Phimosus infuscatus
Genus Eudocimus
American White Ibis, Eudocimus albus
Scarlet Ibis, Eudocimus ruber
Genus Plegadis
Glossy Ibis, Plegadis falcinellus
White-faced Ibis, Plegadis chihi
Puna Ibis, Plegadis ridgwayi
Genus Lophotibis
Madagascar Ibis, Lophotibis cristata

Subfamily: Plataleinae - Spoonbills
Genus Platalea
Eurasian Spoonbill, Platalea leucorodia'
Black-faced Spoonbill, Platalea minor
African Spoonbill, Platalea alba
Royal Spoonbill, Platalea regia
Yellow-billed Spoonbill, Platalea flavipes
Roseate Spoonbill, Platalea ajaja


over 250


over 500


over 225
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