Undulated antshrike

Not to be confused with undulated antpitta.

Undulated antshrike
Conservation status
Least Concern  (IUCN 3.1) [1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Thamnophilidae
Genus:	Frederickena
Species:	F. unduliger
Binomial name
Frederickena unduliger (Pelzeln, 1868)
Range of combined undulated and fulvous antshrikes (see taxonomy section)

The undulated antshrike (Frederickena unduliger) is a species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is found in Bolivia, Brazil, and Peru. ^[2]

Taxonomy and systematics

The undulated antshrike was described by the Austrian ornithologist August von Pelzeln in 1868 and given the binomial name Thamnophilus unduliger. ^[3]

The undulated antshrike's taxonomy is unresolved. The South American Classification Committee of the American Ornithological Society, the International Ornithological Committee, and the Clements taxonomy assign it three subspecies, the nominate F. u. unduliger (Pelzeln, 1868), F. u. diversa (Zimmer, JT, 1944), and F. u. pallida (Zimmer, JT, 1944). BirdLife International's Handbook of the Birds of the World (HBW) includes a fourth subspecies, F. u. fulva (Zimmer, JT, 1944) that the other taxonomies recognize as a full species, the fulvous antshrike. ^{[4] [2] [5] [6] [7]}

Description

The undulated antshrike is a large dark antbird, 22 to 25 cm (8.7 to 9.8 in) long and weighing 75 to 85 g (2.6 to 3.0 oz). The species exhibits significant sexual dimorphism, though both sexes of all subspecies have a crest, a brown to pale yellow iris, a heavy black bill with a hook at the end like true shrikes, and black legs and feet. Adult males of all three subspecies are mostly black with irregular thin white bars everywhere but the throat. Adult females of the nominate subspecies are mostly cinnamon with wavy black bars; their forehead and crest are rufous and black and their tail is black with thin gray bars. Females of subspecies F. u. pallida are paler overall than the nominate and have no bars on their mantle and their underparts. Females of F. u. diversa are intermediate between the other two. ^{[8] [9] [10]}

Distribution and habitat

The undulated antshrike is a bird of the western Amazon Basin. The nominate subspecies is found in northwestern Brazil along the upper Rio Negro and possibly as far south as the Rio Solimões (upper Amazon). Subspecies F. u. diversa is found from eastern Peru south of the rios Amazon and Marañón east into Brazil as far as the Rio Juruá and south into northwestern Bolivia as far as southern La Paz and Beni departments. F. u. pallida is found in Brazil south of the Amazon between the rios Purus and Madeira, and probably south into the eastern part of north-central Bolivia's Pando Department. ^{[8] [9] [10]}

The undulated antshrike inhabits lowland evergreen forest such as terra firme . It greatly favors dense, viny, vegetation in the understorey, especially at openings such as those formed by fallen trees and along watercourses. In elevation it ranges up to about 1,100 m (3,600 ft). ^{[8] [9] [10]}

Behavior

Movement

The undulated antshrike is presumed to be a year-round resident throughout its range. ^[8]

Feeding

The undulated antshrike's diet has not been detailed but is assumed to include large insects and other arthropods. It forages singly or in pairs in dense foliage and vine tangles, mostly on the ground and up to about 3 m (10 ft) above it. It hops from branch to branch and along the ground to find prey. It typically jerks its tail sideways while foraging. It occasionally joins mixed-species feeding flocks that pass through its territory. ^{[8] [10]}

Breeding

Only one study has been made of the undulated antshrike's breeding biology; three nests were observed. Its nesting season in Peru included October and November. The nests were a large woven cup. The three nests each had two eggs that were white with purplish markings. Both parents incubated the eggs during the day and the female alone at night. Both parents provisioned the nestlings. The incubation period, time to fledging, and other details of parental care are not known. ^{[8] [11]}

Songs and calls Listen to undulated antshrike on xeno-canto

Vocalization

The song of the undulated antshrike's subspecies F. u. diversa is a "short series of 8-13 directly connected 'wuiw' notes, increasing in strength and pitch". ^[9] The songs of the other two subspecies are not known well though they apparently differ from that of diversa. ^[8] What is thought to be a typical call is "a long (e.g. 1 second), nasal, downward-inflected churr" ^[8] written as "TCHEErrrrl" ^[10] . Other calls that may be from different populations are "a squeal followed by a sharp note" and a "short scratchy call repeated in short series". ^[8]

Status

The IUCN follows HBW taxonomy and so includes the fulvous antshrike in its assessement of the undulated antshrike, and together they are assessed as being of Least Concern. It has a large range; its population size is not known and is believed to be decreasing. No immediate threats have been identified. ^[1] The undulated antshrike is considered uncommon to rare in most of its range. It occurs in several large protected areas and its range "includes vast areas of intact suitable habitat". "This antshrike is probably an indicator of high-quality forest, as it is generally absent from disturbed areas." ^[8]

References

1. BirdLife International (2018). "Undulated Antshrike Frederickena unduliger". IUCN Red List of Threatened Species . 2018: e.T22701244A130210797. doi: 10.2305/IUCN.UK.2018-2.RLTS.T22701244A130210797.en . Retrieved 17 April 2024.
2. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2024). "Antbirds". IOC World Bird List. v 14.1. Retrieved 4 January 2024.
3. von Pelzeln, August (1868). Zur Ornithologie Brasiliens : Resultate von Johann Natterers Reisen in den Jahren 1817 bis 1835 (in German and Latin). Vol. 2. Wien: A. Pichler's Witwe & Sohn. p. 139.
4. Remsen, J. V., Jr., J. I. Areta, E. Bonaccorso, S. Claramunt, G. Del-Rio, A. Jaramillo, D. F. Lane, M. B. Robbins, F. G. Stiles, and K. J. Zimmer. Version 4 March 2024. A classification of the bird species of South America. American Ornithological Society. https://www.museum.lsu.edu/~Remsen/SACCBaseline.htm retrieved March 5, 2024
5. Clements, J. F., P.C. Rasmussen, T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, A. Spencer, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2023. The eBird/Clements checklist of birds of the world: v2023. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved October 28, 2023
6. Isler, Isler, Whitney, Zimmer & Whittaker (2009). Species limits in antbirds (Aves: Passeriformes: Thamnophilidae): an evaluation of Frederickena unduligera (Undulated Antshrike) based on vocalizations. Zootaxa 2305: 61-68
7. Zimmer, K. J. (2010). Split Frederickena unduligera into two species. SACC. Accessed April 17, 2024
8. Zimmer, K., M.L. Isler, E. de Juana, and H. F. Greeney (2020). Undulated Antshrike (Frederickena unduliger), version 1.0. In Birds of the World (S. M. Billerman, B. K. Keeney, P. G. Rodewald, and T. S. Schulenberg, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.undant2.01 retrieved April 17, 2024
9. van Perlo, Ber (2009). A Field Guide to the Birds of Brazil. New York: Oxford University Press. pp. 230–231. ISBN   978-0-19-530155-7.
10. Schulenberg, T.S., D.F. Stotz, D.F. Lane, J.P. O’Neill, and T.A. Parker III. 2010. Birds of Peru. Revised and updated edition. Princeton University Press, Princeton, New Jersey Plate 158
11. Sánchez-Martínez, M.A., and G. A. Londoño (2016). Nesting behavior of male and female Undulated Antshrike (Frederickena unduliger). Journal of Field Ornithology 87(1):21–28.

External links

• Image at ADW