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
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
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.
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 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
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 worlds
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
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
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
the young by partial regurgitation. Two or three weeks
after hatching, the young no longer need to be brooded
and may leave the nest, often forming creches but returning
to be fed by the parents.
ibis, SeaWorld, California
Photo: Tokyo Junkie
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
Red-naped Ibis, Pseudibis papillosa
White-shouldered Ibis, Pseudibis davisoni
Giant Ibis, Pseudibis gigantea
Northern Bald Ibis, Geronticus eremita
Southern Bald Ibis, Geronticus calvus
Crested Ibis, Nipponia nippon
Olive Ibis, Bostrychia olivacea
Sao Tome Ibis, Bostrychia bocagei
Spot-breasted Ibis, Bostrychia rara
Hadada Ibis, Bostrychia hagedash
Wattled Ibis, Bostrychia carunculata
Plumbeous Ibis, Theristicus caerulescens
Buff-necked Ibis, Theristicus caudatus
Ibis, Theristicus melanopis
Sharp-tailed Ibis, Cercibis oxycerca
Green Ibis, Mesembrinibis cayennensis
Bare-faced Ibis, Phimosus infuscatus
American White Ibis, Eudocimus albus
Scarlet Ibis, Eudocimus ruber
White-faced Ibis, Plegadis chihi
Puna Ibis, Plegadis ridgwayi
Madagascar Ibis, Lophotibis cristata
Eurasian Spoonbill, Platalea leucorodia'
Black-faced Spoonbill, Platalea minor
African Spoonbill, Platalea alba
Royal Spoonbill, Platalea regia
Yellow-billed Spoonbill, Platalea flavipes
Spoonbill, Platalea ajaja