Riparian antbird

Riparian antbird
male at Rio Branco, Acre, Brazil
female at same locality
Conservation status
Least Concern  (IUCN 3.1) [1]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Thamnophilidae
Genus:	Cercomacroides
Species:	C. fuscicauda
Binomial name
Cercomacroides fuscicauda (Zimmer, JT, 1931)
Synonyms
Cercomacra nigrescens fuscicauda Cercomacra fuscicauda

The riparian antbird (Cercomacroides fuscicauda) is a species of passerine bird in subfamily Thamnophilinae of family Thamnophilidae, the "typical antbirds". It is found in Bolivia, Brazil, Colombia, Ecuador, and Peru. ^[2]

Taxonomy and systematics

The riparian antbird was described as a subspecies of the blackish antbird (at the time Cercomacra nigrescens, now Cercomacroides nigriscens). ^[3] Significant vocal differences between it and the other five subspecies showed it to be a full species. ^{[4] [5] [6]} A molecular phylogenetic study published in 2014 found that Cercomacra, as then defined, was polyphyletic. The genus was split to create two monophyletic genera, and six species including the riparian antbird were moved to the newly erected genus Cercomacroides . ^{[7] [2]}

The riparian antbird is monotypic. ^[2]

Description

The riparian antbird is 14 to 15 cm (5.5 to 5.9 in) long. Males are almost entirely dark gray, though a slightly lighter gray on their underparts. They have a mostly concealed white patch between their scapulars, a small white patch on the scapulars, and narrow white tips on their wing coverts. Females have a rufous-tinged tawny crown; their upperparts and wings are brownish olive with a small white interscapular patch. Their forehead and face are orange-tawny. Their tail is gray with an olivaceous tinge on the feather edges. Their throat and underparts are orange-rufous with a gray tinge to their flanks. ^{[8] [9] [10]}

Distribution and habitat

The riparian antbird is found from southern Amazonas Department in extreme southeastern Colombia south through far eastern Ecuador, eastern Peru, and southwestern Amazonian Brazil into northeastern Bolivia as far as Cochabamba Department. It almost exclusively inhabits riverside várzea forest and thickets on river islands; in southeastern Peru it also occurs in stands of bamboo. In elevation it mostly ranges between 100 and 600 m (300 and 2,000 ft), though in Ecuador it occurs below 500 m (1,600 ft) and elsewhere locally reaches 850 m (2,800 ft). ^{[8] [9] [10]}

Behavior

Movement

The riparian antbird is believed to be a year-round resident throughout its range. ^[8]

Feeding

The riparian antbird's diet and foraging behavior have not been studied. They are probably similar to those of its former "parent" blackish antbird, which see here. ^[8]

Breeding

Nothing is known about the riparian antbird's breeding biology. ^[8]

Songs and calls Listen to the riparian antbird on xeno-canto

Vocalization

The male riparian antbird's song is "a low-pitched introductory note followed by a rattle of descending notes, sounding like 'what cheer' ". The female's song is similar to that of female blackish antbirds (which see here) but has a higher pitch. The species' calls include a "single, slightly nasal [contact] note", a "longer series of low-pitched notes with weaker overtones than the contact calls", and in alarm "three or four notes in rapid succession". ^[8]

Status

The IUCN has assessed the riparian antbird as being of Least Concern. Its population size is not known and is believed to be decreasing. No immediate threats have been identified. ^[1] It is considered generally fairly common though sparse in Ecuador and uncommon and local in Peru. ^{[8] [9] [10]} Its range includes many large protected areas. Its "[p]reference for second-growth and edge habitats renders it less vulnerable to disturbance than are most antbirds". ^[8]

References

1. BirdLife International (2017). "Riparian Antbird Cercomacroides fuscicada". IUCN Red List of Threatened Species . 2017: e.T103658612A112356381. doi: 10.2305/IUCN.UK.2017-1.RLTS.T103658612A112356381.en . Retrieved 30 June 2024.
2. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (January 2024). "Antbirds". IOC World Bird List. v 14.1. Retrieved 4 January 2024.
3. Zimmer, J.T. (1931). Studies of Peruvian birds. 1. New and other birds from Peru, Ecuador and Brazil. Amer. Mus. Novit.. 500: 1–23.
4. Mayer, S., P. Coopmans, N. Krabbe, and M. L. Isler. 2014. Vocal evidence for species rank to Cercomacra nigrescens fuscicauda J. T. Zimmer. Bulletin British Ornithologists’ Club 134: 145-154.
5. "Proposal (636) Split Cercomacra fuscicauda from Cercomacra nigrescens". South American Classification Committee of the American Ornithological Society. 2014. Retrieved 30 June 2024.
6. 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
7. Tello, J.G.; Raposo, M.; Bates, J.M.; Bravo, G.A.; Cadena, C.D.; Maldonado-Coelho, M (2014). "Reassessment of the systematics of the widespread Neotropical genus Cercomacra (Aves: Thamnophilidae)". Zoological Journal of the Linnean Society. 170 (3): 546–565. doi:10.1111/zoj.12116. S2CID   44187523.
8. del Hoyo, J., N. Collar, and G. M. Kirwan (2020). Riparian Antbird (Cercomacroides fuscicauda), 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.blaant5.01 retrieved June 30, 2024
9. Ridgely, Robert S.; Greenfield, Paul J. (2001). The Birds of Ecuador: Field Guide. Vol. II. Ithaca: Cornell University Press. pp. 415–416. ISBN   978-0-8014-8721-7.
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 169