The ancient antwren (''Herpsilochmus gentryi'') is a species of tropical bird in the family

Thamnophilidae The antbirds are a large passerine bird family, Thamnophilidae, found across subtropical and tropical Central and South America, from Mexico to Argentina. There are more than 230 species, known variously as antshrikes, antwrens, antvireos, fire ...

. It is primarily found in ''terra firme'' forests of northern Peru and southeastern Ecuador. This species was described in 1998 and named after the American botanist

Alwyn Gentry Alwyn Howard Gentry (January 6, 1945 – August 3, 1993) was an American botanist and plant collector, who made major contributions to the understanding of the vegetation of tropical forests. Education Gentry was born on January 6, 1945, in Cl ...

. Habitat loss poses the greatest threat to this species.

Taxonomy and systematics

The ancient antwren was described in 1998 by Bret M. Whitney and Jose Alvarez Alonso. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

was collected along the Rio Tigre in the Department of Loreto, Peru. The specific epithet, ''gentryi'', refers to the American botanist

. It is closely related to the

Todd's Antwren Todd's antwren (''Herpsilochmus stictocephalus'') is a species of bird in the family Thamnophilidae. It is found in the Guiana Shield (eastern Venezuela to Amapá). Its natural habitat is subtropical or tropical moist lowland forest A for ...

, to which it may be a sister species. This species is monotypic, with no known subspecies.

Description

The ancient antwren is small passerine, with a total length of 10-11 centimeters (4 in) and weight of 10.2-11 grams.

Sexual dimorphism Sexual dimorphism is the condition where the sexes of the same animal and/or plant species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most ani ...

is present in this species, but not as apparent when compared to other members of this genus. Adult males have solid black crowns with a bold yellowish supercilium, dark gray upperparts and rump, and yellowish throat and underparts. Females and subadults display whitish or yellow spots on the crown and generally have darker olive breasts and sides than adult males. The scapulars and coverts of this species are black tipped with white in all plumages, and the wings are overall short. The tail is short and graduated, with black rectrices outlined in white. The song of this species is described as a long decelerating series of notes that rises slightly in frequency, then decreases. This song is distinct from other members of this genus save for

Todd's antwren Todd's antwren (''Herpsilochmus stictocephalus'') is a species of bird in the family Thamnophilidae. It is found in the Guiana Shield (eastern Venezuela to Amapá). Its natural habitat is subtropical or tropical moist lowland forest A for ...

. The calls of ancient antwren have been described as short “chups”, longer “tink” calls, and rattle-like calls, and can be distinguished from other ''

Herpsilochmus ''Herpsilochmus'' is a genus of insectivorous passerine birds in the antbird family (Thamnophilidae). They are found in forest, woodland and shrub in South America, although a single species the rufous-winged antwren (''H. rufimarginatus'') also ...

'' species by tonality and note structure. Its closest relative, the

, does not overlap in range. It is

sympatric In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...

with another member of ''

'', the

Dugand's antwren Dugand's antwren (''Herpsilochmus dugandi'') is a species of bird in the family Thamnophilidae. It is found in Colombia, Ecuador, and Peru. Its natural habitat is subtropical or tropical moist lowland forests. The bird is named in commemoration ...

, but there is limited habitat overlap with this species. Ancient antwren can be distinguished from this species by its brighter yellow or olive underparts and lack of any rufous on the head or breast.

Distribution and habitat

This species is restricted to humid ''terra firme'' forest in north-central Peru and southeastern Ecuador within the Amazon basin. In Peru, appears to be restricted to two types of ''terra firme'' forest; ''varrilal'', a stunted forest type characterized by white sands, and ''irapayal'', an open-canopy forest with an understory dominated by palms. In Ecuador, it is found in ''terra firme'' forest on the highest and driest ridgetops. The ancient antwren appears to prefer patchy habitats with high-contrast edges. It is found at elevations up to 200 meters. Like others in its genus, this species occupies the canopy and sub-canopy. This species is considered a sedentary resident, with no documentation of migration or movement.

Behavior and ecology

Breeding

Little is known about the breeding habits of this species. The breeding season is believed to be early in the year, from January to March, based on skull ossification of juvenile birds and sightings of family groups in April.

Feeding and foraging

The ancient antwren forages high in canopy or sub-canopy, where it gleans prey from leaves and branches. Diet is poorly known, but feeds on insects, likely spiders and

lepidoptera Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...

n larvae. Foraging behavior has been described as active, with interspersed wing flutters and short hops. This species has been documented to forage in mixed flocks with other canopy-dwelling birds, as well as in small family groups or mated pairs.

Status and threats

The ancient antwren is currently ranked as

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 ...

by the IUCN in 2017. Due to its relatively recent discovery, the population trends of this species are poorly understood. It is relatively common in its preferred habitat in Peru and rare and local in Ecuador.

Mining Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef, or placer deposit. The exploitation of these deposits for raw material is based on the economic via ...

and

oil exploration Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particularly petroleum and natural gas, in the Earth using petroleum geology. Exploration methods Vis ...

pose the greatest threats to this species through habitat loss or degradation, especially as its preferred habitat is naturally uncommon within

Amazonia The Amazon rainforest, Amazon jungle or ; es, Selva amazónica, , or usually ; french: Forêt amazonienne; nl, Amazoneregenwoud. In English, the names are sometimes capitalized further, as Amazon Rainforest, Amazon Forest, or Amazon Jungle. ...

References

{{Taxonbar, from=Q1269483

ancient antwren The ancient antwren (''Herpsilochmus gentryi'') is a species of tropical bird in the family Thamnophilidae. It is primarily found in ''terra firme'' forests of northern Peru and southeastern Ecuador. This species was described in 1998 and named a ...

Birds of the Peruvian Amazon

Taxonomy articles created by Polbot