Chestnut-headed Oropendola
Encyclopedia
The Chestnut-headed Oropendola (Psarocolius wagleri) is a New World
tropical icterid bird
. The scientific name of the species
commemorates Johann Georg Wagler
, who established Psarocolius, the oropendola
genus
.
s. The iris is blue and the long bill
is whitish. Females are similar
, but smaller and duller than males. Young birds are duller than adults and have brown eyes. The populations south of an area around the border of Honduras
and Nicaragua
are sometimes separated as a subspecies
P. w. ridgwayi, but the separation of this form has been questioned.
The distinctive songs of the male include a gurgle followed by a crash guu-guu-PHRRRRTTT. Both sexes have loud chek and chuk calls.
coastal lowlands from southern Mexico
to central Costa Rica
, both slopes of southern Costa Rica and Panama
, and the Pacific lowlands of Colombia
and northeastern Ecuador
. Though it usually stays below 1,000 meters ASL
, it has also been recorded as much as 1,300 m ASL – for example in the Serranía de las Quinchas
of Colombia –; it may in fact be more common at such high altitudes at particular times or in particular places, but its altitudinal movements are insufficiently understood. The species is common across its large range and not considered threatened by the IUCN.
The Chestnut-headed Oropendola inhabits forest
canopy, edges and old plantations. It is a quite common bird in parts of its range
, seen in small flocks foraging
in trees for large insect
s, fruit
and berries.
It is a colonial
breeder which builds a hanging woven nest of fibres and vines, 60–100 cm long, high in a tree. There may be 40-50 females and only 4-5 males in a colony. The female lays two dark-marked pale blue eggs
which hatch in 17 days and fledge
in 30. Botflies (Oestridae) are the main cause of nestling mortality
, but brood parasitism
by Giant Cowbird
s (Molothrus oryzivorus) also occurs, and the young cowbirds will feed on the fly larvae.
New World
The New World is one of the names used for the Western Hemisphere, specifically America and sometimes Oceania . The term originated in the late 15th century, when America had been recently discovered by European explorers, expanding the geographical horizon of the people of the European middle...
tropical icterid bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
. The scientific name of the species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
commemorates Johann Georg Wagler
Johann Georg Wagler
Johann Georg Wagler was a German herpetologist.Wagler was assistant to Johann Baptist von Spix, and became Director of the Zoological Museum at the University of Munich after Spix's death in 1826...
, who established Psarocolius, the oropendola
Oropendola
The oropendolas comprise two or three genera of South and Central American passerine birds in the New World blackbird family.All the oropendolas are large birds with pointed bills, and long tails which are always at least partially bright yellow...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
.
Description
The male is 35 cm long and weighs 225 g; the smaller female is 28 cm long and weighs 125 g. The wings are very long. Adult males are mainly black with a chestnut head and rump and a tail which is bright yellow apart from two dark central featherFeather
Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds and some non-avian theropod dinosaurs. They are considered the most complex integumentary structures found in vertebrates, and indeed a premier example of a complex evolutionary novelty. They...
s. The iris is blue and the long bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
is whitish. Females are similar
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
, but smaller and duller than males. Young birds are duller than adults and have brown eyes. The populations south of an area around the border of Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
and Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
are sometimes separated as a subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
P. w. ridgwayi, but the separation of this form has been questioned.
The distinctive songs of the male include a gurgle followed by a crash guu-guu-PHRRRRTTT. Both sexes have loud chek and chuk calls.
Range and ecology
It is a resident breeder in the CaribbeanCaribbean
The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...
coastal lowlands from southern Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
to central Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, both slopes of southern Costa Rica and Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
, and the Pacific lowlands of Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
and northeastern Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
. Though it usually stays below 1,000 meters ASL
Above mean sea level
The term above mean sea level refers to the elevation or altitude of any object, relative to the average sea level datum. AMSL is used extensively in radio by engineers to determine the coverage area a station will be able to reach...
, it has also been recorded as much as 1,300 m ASL – for example in the Serranía de las Quinchas
Serranía de las Quinchas
The Serranía de las Quinchas is an 860 km2 area of tropical rainforest and cloud forest in Colombia. It lies in the mid Magdalena River Valley in the foothills of the Cordillera Oriental of the Colombian Andes. It ranges in altitude from 200 m to 1700 m asl...
of Colombia –; it may in fact be more common at such high altitudes at particular times or in particular places, but its altitudinal movements are insufficiently understood. The species is common across its large range and not considered threatened by the IUCN.
The Chestnut-headed Oropendola inhabits forest
Forest
A forest, also referred to as a wood or the woods, is an area with a high density of trees. As with cities, depending where you are in the world, what is considered a forest may vary significantly in size and have various classification according to how and what of the forest is composed...
canopy, edges and old plantations. It is a quite common bird in parts of its range
Range (biology)
In biology, the range or distribution of a species is the geographical area within which that species can be found. Within that range, dispersion is variation in local density.The term is often qualified:...
, seen in small flocks foraging
Foraging
- Definitions and significance of foraging behavior :Foraging is the act of searching for and exploiting food resources. It affects an animal's fitness because it plays an important role in an animal's ability to survive and reproduce...
in trees for large insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
and berries.
It is a colonial
Bird colony
A bird colony is a large congregation of individuals of one or more species of bird that nest or roost in close proximity at a particular location. Many kinds of birds are known to congregate in groups of varying size; a congregation of nesting birds is called a breeding colony...
breeder which builds a hanging woven nest of fibres and vines, 60–100 cm long, high in a tree. There may be 40-50 females and only 4-5 males in a colony. The female lays two dark-marked pale blue eggs
Bird egg
Bird eggs are laid by females and incubated for a time that varies according to the species; a single young hatches from each egg. Average clutch sizes range from one to about 17...
which hatch in 17 days and fledge
Fledge
Fledge is the stage in a young bird's life when the feathers and wing muscles are sufficiently developed for flight. It also describes the act of a chick's parents raising it to a fully grown state...
in 30. Botflies (Oestridae) are the main cause of nestling mortality
Death
Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....
, but brood parasitism
Brood parasite
Brood parasites are organisms that use the strategy of brood parasitism, a kind of kleptoparasitism found among birds, fish or insects, involving the manipulation and use of host individuals either of the same or different species to raise the young of the brood-parasite...
by Giant Cowbird
Giant Cowbird
The Giant Cowbird, Molothrus oryzivorus, is a large passerine bird in the New World family Icteridae. It breeds from southern Mexico south to northern Argentina, and on Trinidad and Tobago. It may have relatively recently colonised the latter island....
s (Molothrus oryzivorus) also occurs, and the young cowbirds will feed on the fly larvae.