The white-faced ibis (''Plegadis chihi'') is a wading
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
in the
ibis
The ibises () (collective plural ibis; classical plurals ibides and ibes) are a group of long-legged wading birds in the family Threskiornithidae, that inhabit wetlands, forests and plains. "Ibis" derives from the Latin and Ancient Greek word f ...
family,
Threskiornithidae
The family Threskiornithidae includes 36 species of large wading birds. The family has been traditionally classified into two subfamilies, the ibises and the spoonbills; however recent genetic studies have cast doubt on this arrangement, and ha ...
.
This
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
breeds colonially in
marsh
A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...
es, usually nesting in bushes or low trees. Its breeding range extends from the western United States south through Mexico, as well as from southeastern Brazil and southeastern Bolivia south to central Argentina, and along the coast of central Chile. Its winter range extends from southern
California
California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
and
Louisiana
Louisiana , group=pronunciation (French: ''La Louisiane'') is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is borde ...
south to include the rest of its breeding range.
Description
The white-faced ibis is very similar to the
glossy ibis
The glossy ibis (''Plegadis falcinellus'') is a water bird in the order Pelecaniformes and the ibis and spoonbill family Threskiornithidae. The scientific name derives from Ancient Greek ''plegados'' and Latin, ''falcis'', both meaning "sickle" a ...
in its non-breeding
plumage
Plumage ( "feather") is a layer of feathers that covers a bird and the pattern, colour, and arrangement of those feathers. The pattern and colours of plumage differ between species and subspecies and may vary with age classes. Within species, ...
s, but it tends to be slightly smaller and the plumage color is somewhat warmer. Breeding adults have a pink bare face bordered with white feathers (rather than a bluish bare face with no bordering feathers), a grey bill, and brighter colored, redder legs. Adults have red eyes year-round, whereas glossy ibises have dark eyes. Juveniles of the two species are nearly identical.
Measurements:
* Length: 18.1-22.1 in (46-56 cm)
* Weight: 15.9-18.5 oz (450-525 g)
* Wingspan: 35.4-36.6 in (90-93 cm)
White-faced Ibis by Dan Pancamo.jpg, Winter Quintana, Texas
White-faced Ibis.jpg, Non-breeding plumage
White-faced ibis (Plegadis chihi) immature in flight composite.jpg, Juvenile
The Pantanal
The Pantanal () is a natural region encompassing the world's largest tropical wetland area, and the world's largest flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but it extends into Mato Grosso and p ...
, Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
Distribution
The white-faced ibis occurs in Canada, the United States, Central America and the southern half of South America.
In 2012, the total population size was estimated to be 1.2 million individuals, and increasing. The
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...
rates it as being of
Least Concern
A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...
.
Migration between North and South America does not occur. Within North America, birds breeding in northern areas of the range move south to wintering areas.
For example, breeders in northern California and southern Oregon move to wintering areas in southern California and Mexico.
Origin
The white-faced ibis bears a strong resemblance to the related
glossy ibis
The glossy ibis (''Plegadis falcinellus'') is a water bird in the order Pelecaniformes and the ibis and spoonbill family Threskiornithidae. The scientific name derives from Ancient Greek ''plegados'' and Latin, ''falcis'', both meaning "sickle" a ...
, and in the past was sometimes considered to be a subspecies of the glossy ibis.
[Ryder, Ronald. (1967) “Distribution, Migration and Mortality of the White-Faced Ibis (''Plegadis chihi'') in North America”. Bird-Banding 38: 257-277.] Another theory was that a small population of glossy ibis dispersed to the Americas, which became isolated and evolved into a separate species.
Audubon White-faced Ibis
', Retrieved 11 April 2014 However, recent molecular phylogenetic studies show that the white-faced ibis may actually be
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
.
[Ramirez, J. L., C. Y. Miyaki, and S. N. Del Lama. "Molecular phylogeny of Threskiornithidae (Aves: Pelecaniformes) based on nuclear and mitochondrial DNA." Genetics and Molecular Research 12.3 (2013): 2740-2750.] In fact, members of the white-faced ibis populations in the United States appear to be more closely related to glossy ibises than to members of white-faced ibis populations in Southern Brazil.
Feeding
The white-faced ibis eats a variety of organisms, including many invertebrates such as insects, leeches, snails, crayfish and earthworms. It may also eat vertebrates such as fish, newts, and frogs.
Great Basin Bird Observatory White-faced Ibis
', Retrieved 22 April 2014
Texas Parks and Wildlife White-faced Ibis
', Retrieved 11 April 2014 Its feeding style is to use its bill to probe for prey.
Breeding and nesting
![Juvenile white-faced ibis (Plegadis chihi)-4089](https://upload.wikimedia.org/wikipedia/commons/2/28/Juvenile_white-faced_ibis_%28Plegadis_chihi%29-4089.jpg)
This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south through Mexico, as well as from southeastern Brazil and southeastern Bolivia south to central Argentina, and along the coast of central Chile. Its winter range extends from southern California and Louisiana south to include the rest of its breeding range.
The white-faced ibis chooses to nest in the parts of a marsh with dense vegetation
such as bulrush, cattails, shrubs and short trees.
[Ryder, Ronald A. and David E. Manry.(2005]
White-faced Ibis (''Plegadis chihi'')
, The Birds of North America Online” (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology. Retrieved from the Birds of North America Online:, It will then build a nest from reeds. The white-faced ibis usually lays three or four blue-green eggs at a time.
Lifespan
White-faced ibises in captivity live up to fourteen years on average. In the wild, white-faced ibises usually live for nine years; however the oldest recorded wild white-faced ibis lived for fourteen years and six months.
Threats
In the past, the white-faced ibis faced many threats from humans. Studies completed in Utah in the 1960s (before this species was added to the
Migratory Bird Treaty Act
The Migratory Bird Treaty Act of 1918 (MBTA), codified at (although §709 is omitted), is a United States federal law, first enacted in 1918 to implement the convention for the protection of migratory birds between the United States and Canada . ...
) showed that 82.9% of recorded deaths in banded birds were a result of being shot.
However, the main causes of decline of this species previously were pesticides and habitat destruction.
The pesticide
DDT
Dichlorodiphenyltrichloroethane, commonly known as DDT, is a colorless, tasteless, and almost odorless crystalline chemical compound, an organochloride. Originally developed as an insecticide, it became infamous for its environmental impacts. ...
caused eggshells to be so thin and fragile that parent white-faced ibises crushed the eggs when they were incubating them.
Also, since this species is so dependent on wetlands and marshes for both feeding and nesting, changes to water systems such as pollution and man-made draining of water habitats had devastating impacts on members of this species in the past.
In order to correct these damages, DDT was banned in 1970 and various programs were created to better maintain and protect wetland nesting habitats.
[D. Dark-Smiley and D. Keinath. (2003) “Species Assessment for White-faced Ibis”. United States Department of the Interior Bureau of Land Management.] Yet, there is still some debate as to whether or not populations of white-faced ibises in all geographic areas are recovered and growing.
References
External links
White-faced Ibis- Cornell Lab of Ornithology
- USGS Patuxent Bird Identification InfoCenter
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{{Taxonbar, from=Q746696
white-faced ibis
The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae.
This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...
Wading birds
Birds of the Americas
Native birds of the Western United States
Birds of the Rio Grande valleys
Birds of Mexico
Birds of Argentina
Birds of Bolivia
Birds of Brazil
Birds of Chile
Birds of Paraguay
Birds of Uruguay
white-faced ibis
The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae.
This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...
white-faced ibis
The white-faced ibis (''Plegadis chihi'') is a wading bird in the ibis family, Threskiornithidae.
This species breeds colonially in marshes, usually nesting in bushes or low trees. Its breeding range extends from the western United States south ...