Fasciated antshrike

The fasciated antshrike (Cymbilaimus lineatus) is a species of bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds".^[2] It is found in Central America from Honduras south and in every mainland South American country except Argentina, Chile, Paraguay, and Uruguay.^[3][4]

Fasciated antshrike
Male in Panama
Female in Panama
Conservation status
Least Concern  (IUCN 3.1)^[1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Thamnophilidae
Genus:	Cymbilaimus
Species:	C. lineatus
Binomial name
Cymbilaimus lineatus (Leach, 1814)

Taxonomy and systematics

The fasciated antshrike has three subspecies, the nominate C. l. lineatus (Leach, 1814), C. l. fasciatus (Ridgway, 1884), and C. l. intermedius (Hartert & Goodson, 1917).^[2] What is now the bamboo antshrike (C. sanctaemariae) was considered another subspecies of it until the 1980s.^[5] The two are the only species in genus Cymbilaimus.^[2]

Description

The fasciated antshrike is 17 to 18 cm (6.7 to 7.1 in) long and weighs 35 to 40 g (1.2 to 1.4 oz). This species exhibits significant sexual dimorphism. Both sexes of all subspecies have a red iris and a heavy bill with a hook at the end like true shrikes. Adult males of the nominate subspecies have a black forehead and crown with a few very thin white bars. The rest of their plumage is thin black and white bars. Females have a rufous crown. Most of the rest of their plumage is thin dark brown and pale yellowish brown bars; their tail is barred with dark brown and pale buff. Subadult males resemble adults but with wider white bars. Males of subspecies C. l. fasciatus have strong black and white bars on the forehead that contrast with the all-black crown. Females have brown and cinnamon bars on their tail. C. l. intermedius is similar to fasciatus but with wider pale bars on its tail. The plumages of these last two vary individually and with age which produces overlap between them.^{[6][7][8][9][10][11][12][13][14]}

Distribution and habitat

The fasciated antshrike has a disjunct distribution. Subspecies C. l. fasciatus is the northernmost, and its range is separate from the larger area shared by the other two. It is found from El Paraíso Department in southeastern Honduras, south through Nicaragua and Costa Rica on the Caribbean slope, and through Panama on both the Caribbean and Pacific slopes though locally in the latter. Its range continues into Colombia's Magdalena River Valley, east into northwestern Venezuela, and south along the Pacific slope into northwestern Ecuador as far as northern Los Ríos Province. Subspecies C. l. intermedius is found from southern Colombia and Venezuela south through eastern Ecuador and eastern Peru into Bolivia and from that western limit east into northwestern and southern Amazonian Brazil as far as Tocantins and Goiás. The nominate subspecies C. l. lineatus is found from eastern Bolívar state in Venezuela east through Guyana and Suriname into French Guiana and south into Amazonian Brazil north of the Amazon between the Branco and Negro rivers.^{[3][6][7][8][9][10][11][12][13][14]}

The fasciated antshrike inhabits evergreen forest both primary and secondary in the lowlands and Andean foothills. In Central America it tends to be in second growth and thickets rather than the forest interior. Elsewhere it does occur in the forest interior but also frequents the forest edge. In all areas it favors vine tangles and dense mid-storey vegetation. In elevation it occurs below 400 m (1,300 ft) in Honduras; in most of the rest of its range it occurs below 800 m (2,600 ft). It reaches 1,200 m (3,900 ft) in Brazil and Costa Rica, 1,400 m (4,600 ft) in Colombia, 1,000 m (3,300 ft) in Ecuador and Peru (though locally to 1,500 m (4,900 ft) in the latter), and 1,300 m (4,300 ft) in Venezuela. The ranges of the fasciated and bamboo antshrikes overlap but the bamboo generally occurs at higher elevations than the fasciated.^{[3][6][7][8][9][10][11][12][13][14]}

Behavior

Movement

The fasciated antshrike is presumed to be a year-round resident throughout its range.^[6]

Feeding

The fasciated antshrike feeds primarily on large insects of several families; its diet also includes other arthropods like spiders, small lizards, frogs, and small amounts of fruit. It forages singly or in pairs and sometimes joins mixed-species feeding flocks as they pass through its territory. It typically feeds in vine clusters and near tree trunks between 5 and 20 m (15 and 65 ft) above the ground, but will also sometimes descend lower. It hops sluggishly through vegetation taking prey by reaching, lunging, and making short sallies from a perch. It will also follow army ants to take prey flushed by them, but they are not obligate ant-followers.^{[6][9][10][11][12][13]}

Breeding

The fasciated antshrike's breeding season varies geographically but has not been fully defined. It spans April to June in Costa Rica and July to November in Amazonian Brazil; recently fledged young were noted in the Guianas in September and October. Its nest is a cup made from plant and fungal fibers attached by its rim in a branch fork. It is typically placed 2 to 10 m (7 to 30 ft) above the ground and hidden by foliage. The usual clutch is two eggs; the eggs are creamy white with blotches that range from lilac to olivaceous brown. Both parents incubate the clutch during the day and the female alone at night. The incubation period, time to fledging, and other details of parental care are not known.^[6][13]

Songs and calls Listen to fasciated antshrike on xeno-canto

Vocalization

The fasciated antshrike's song is "an evenly paced series of 3–10 plaintive, lazily delivered whistles, notes longer than spaces, middle notes sometimes longer and at slightly higher pitch".^[6] The notes have been described as sounding like "weh".^[14] One author renders the song as "cü-ü,cü-ü, cü-ü..."^[11] and another as "weeo wEEo wEEo weeo"^[12]. The species' calls include a "rattle-like chatter" and a "plaintive downsliding whistle" that are sometimes mixed in a series.^[6] Because it mostly stays high in dense vegetation it is more often heard than seen.^[12]

Status

The IUCN has assessed the fasciated antshrike as being of Least Concern. It has an extremely large range; its estimated population of at least 500,000 mature individuals is believed to be decreasing. No immediate threats have been identified.^[1] It is considered uncommon to common in most of its range though rare to uncommon in Honduras and parts of Costa Rica.^[6][8][9] Its range includes many protected areas and "vast areas of unprotected but still intact suitable habitat, particularly in Amazon Basin and Guianan regions".^[6]

References

1. BirdLife International (2021). "Fasciated Antshrike Cymbilaimus lineatus". IUCN Red List of Threatened Species. 2021: e.T22701223A167215460. doi:10.2305/IUCN.UK.2021-3.RLTS.T22701223A167215460.en. Retrieved 13 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. Check-list of North American Birds (7th ed.). Washington, D.C.: American Ornithologists' Union. 1998. p. 361.
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. Species Lists of Birds for South American Countries and Territories. https://www.museum.lsu.edu/~Remsen/SACCCountryLists.htm retrieved March 5, 2024
5. Pierpont, N.; Fitzpatrick, F.W. (1983). "Specific status and behavior of Cymbilaimus sanctaemariae, the Bamboo Antshrike, from southwestern Amazonia". Auk. 100 (3): 645–652. Retrieved April 13, 2024.
6. Zimmer, K. and M.L. Isler (2020). Fasciated Antshrike (Cymbilaimus lineatus), version 1.0. In Birds of the World (J. del Hoyo, A. Elliott, J. Sargatal, D. A. Christie, and E. de Juana, Editors). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.fasant1.01 retrieved April 13, 2024
7. vanPerlo, Ber (2006). Birds of Mexico and Central America. Princeton Illustrated Checklists. New Jersey: Princeton University Press. pp. plate 60, map 60.3. ISBN 0691120706.
8. Fagan, Jesse; Komar, Oliver (2016). Field Guide to Birds of Northern Central America. Peterson Field Guides. Boston: Houghton Mifflin Harcourt. pp. 226–227. ISBN 978-0-544-37326-6.
9. Garrigues, Richard; Dean, Robert (2007). The Birds of Costa Rica. Ithaca: Zona Tropical/Comstock/Cornell University Press. p. 174–175. ISBN 978-0-8014-7373-9.
10. McMullan, Miles; Donegan, Thomas M.; Quevedo, Alonso (2010). Field Guide to the Birds of Colombia. Bogotá: Fundación ProAves. p. 128. ISBN 978-0-9827615-0-2.
11. Ridgely, Robert S.; Greenfield, Paul J. (2001). The Birds of Ecuador: Field Guide. Vol. II. Ithaca: Cornell University Press. pp. 390–391. ISBN 978-0-8014-8721-7.
12. 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 157
13. Hilty, Steven L. (2003). Birds of Venezuela (second ed.). Princeton NJ: Princeton University Press. pp. plate 140.
14. 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.