Chestnut-backed Antbird
Encyclopedia
The Chestnut-backed Antbird, Myrmeciza exsul, is a passerine
bird
in the antbird
family. It is found in humid forests in Central
and South America
(Chocó-Magdalena
), ranging from eastern Nicaragua
to western Ecuador
. It mainly occurs in lowlands up to an altitude of 900 metres (2,952.8 ft) m, but locally it occurs higher.
This is a common bird in the understory thickets of wet forest, especially at edges, along streams and in old treefall clearings, and in adjacent tall second growth. The female lays two purple or red-brown spotted white eggs, which are incubated by both sexes, in an untidy cup nest which is constructed from vines, plant fibre and dead leaves and placed low in vegetation. The male and female parents both feed the chicks.
The Chestnut-backed Antbird is heavy-bodied and short-tailed, typically 14 centimetres (5.5 in) long, and weighing 28 gram (0.987670938943135 oz). Both sexes have a pale blue bare patch of skin around each eye. The adult male has a blackish head, neck and breast, and the rest of the upperparts, wings and tail are chestnut
. The flanks and the lower belly are a somewhat darker brown. The female has a brownish-black head and neck, but this does not extend to the breast. Her underparts are a darker chestnut in the nominate subspecies of the Caribbean
lowlands from Nicaragua to Panama
, but more rufous
in M. e. occidentalis of the Pacific
lowlands in Costa Rica
and Panama. M. e. niglarus from eastern Panama and far north-western Colombia
(northern Chocó Department
) is similar. Young birds are duller and slatier than the adults.
The subspecies
found in far south-east Panama (Darién Province
), Colombia (except northern Chocó Department) and Ecuador, M. e. maculifer and M. e. cassini, have two wing bars consisting of white spots. They were once considered a separate species, the Wing-spotted Antbird (M. maculifer), but are vocally similar to the subspecies without spots on the wings, and the two groups hybridize where their distributions come into contact.
This species has a grating naar call, and the male’s song is a whistled peeet peeew answered by the female’s higher pitched version.
The Chestnut-backed Antbird is normally found as pairs throughout the year, but occasionally joins mixed-species feeding flocks or army ant
s. It feeds on insect
s, other arthropod
s, and sometimes small frog
s or lizard
s taken from leaf litter and vine tangles in low vegetation or on the ground. It is easier to hear than see in its dense habitat, but can be attracted by imitating its whistled song. It may then give a territorail display with puffed-up body, drooped wings, and pumping tail.
Passerine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
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...
in the antbird
Antbird
The antbirds are a large family, Thamnophilidae, of passerine birds found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 200 species, known variously as antshrikes, antwrens, antvireos, fire-eyes, bare-eyes and bushbirds...
family. It is found in humid forests in Central
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
(Chocó-Magdalena
Tumbes-Chocó-Magdalena
Tumbes-Chocó-Magdalena is a biodiversity hotspot, which includes the tropical moist forests and tropical dry forests of the Pacific coast of South America and the Galapagos Islands. The region extends from easternmost Panama to the lower Magdalena Valley of Colombia, and along the Pacific coast of...
), ranging from eastern 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...
to western 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...
. It mainly occurs in lowlands up to an altitude of 900 metres (2,952.8 ft) m, but locally it occurs higher.
This is a common bird in the understory thickets of wet forest, especially at edges, along streams and in old treefall clearings, and in adjacent tall second growth. The female lays two purple or red-brown spotted white eggs, which are incubated by both sexes, in an untidy cup nest which is constructed from vines, plant fibre and dead leaves and placed low in vegetation. The male and female parents both feed the chicks.
The Chestnut-backed Antbird is heavy-bodied and short-tailed, typically 14 centimetres (5.5 in) long, and weighing 28 gram (0.987670938943135 oz). Both sexes have a pale blue bare patch of skin around each eye. The adult male has a blackish head, neck and breast, and the rest of the upperparts, wings and tail are chestnut
Chestnut (color)
Chestnut, also known as Indian red, is a color, a medium brownish shade of red, and is named after the nut of the chestnut tree.As Indian red, it is named after the red laterite soil found in India. It is thus an earth tone as well as a red. It is composed of naturally occurring iron oxides. Other...
. The flanks and the lower belly are a somewhat darker brown. The female has a brownish-black head and neck, but this does not extend to the breast. Her underparts are a darker chestnut in the nominate subspecies of the Caribbean
Caribbean
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...
lowlands from Nicaragua to 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...
, but more rufous
Rufous
Rufous is a colour that may be described as reddish-brown or brownish-red, as of rust or oxidised iron.The first recorded use of rufous as a colour name in English was in the year 1782....
in M. e. occidentalis of the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
lowlands in 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....
and Panama. M. e. niglarus from eastern Panama and far north-western 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...
(northern Chocó Department
Chocó Department
Chocó is a department of Colombia known for its large Afro-Colombian population. It is in the west of the country, and is the only Colombian department to have coastlines on both the Pacific Ocean and the Atlantic Ocean. It also has all of Colombia's border with Panama. Its capital is...
) is similar. Young birds are duller and slatier than the adults.
The 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...
found in far south-east Panama (Darién Province
Darién Province
Darién is a province in eastern Panama. It is also the largest province in Panama. It is hot, humid, heavily forested, and sparsely populated, having 48,378 habitants...
), Colombia (except northern Chocó Department) and Ecuador, M. e. maculifer and M. e. cassini, have two wing bars consisting of white spots. They were once considered a separate species, the Wing-spotted Antbird (M. maculifer), but are vocally similar to the subspecies without spots on the wings, and the two groups hybridize where their distributions come into contact.
This species has a grating naar call, and the male’s song is a whistled peeet peeew answered by the female’s higher pitched version.
The Chestnut-backed Antbird is normally found as pairs throughout the year, but occasionally joins mixed-species feeding flocks or army ant
Army ant
The name army ant is applied to over 200 ant species, in different lineages, due to their aggressive predatory foraging groups, known as "raids", in which huge numbers of ants forage simultaneously over a certain area, attacking prey en masse.Another shared feature is that, unlike most ant...
s. It feeds on 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, other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, and sometimes small frog
Frog
Frogs are amphibians in the order Anura , formerly referred to as Salientia . Most frogs are characterized by a short body, webbed digits , protruding eyes and the absence of a tail...
s or lizard
Lizard
Lizards are a widespread group of squamate reptiles, with nearly 3800 species, ranging across all continents except Antarctica as well as most oceanic island chains...
s taken from leaf litter and vine tangles in low vegetation or on the ground. It is easier to hear than see in its dense habitat, but can be attracted by imitating its whistled song. It may then give a territorail display with puffed-up body, drooped wings, and pumping tail.