UPPERCASE: current genusUppercase first letter: generic synonym● and ● See: generic homonymslowercase: species and subspecies●: early names, variants, misspellings‡: extinct†: type speciesGr.: ancient GreekL.: Latin<: derived fromsyn: synonym of/: separates historical and modern geographic namesex: based onTL: type localityOD: original diagnosis (genus) or original description (species)
White-throated Barbtail is a small furnariid that is endemic to northern Venezuela; it occurs in two disjunct populations (each recognized as a separate subspecies), one in the coastal mountains of northeastern Venezuela, and one on the Paria Peninsula. White-throated Barbtail is brown above with a narrow pale supercilium; the throat is white or whitish, and the breast and belly also are whitish, but densely scalloped with dusky. In appearance it is similar superficially to the more widespread Spotted Barbtail (Premnoplex brunnescens), but the pale markings of the Spotted Barbtail are buffy, not whitish. White-throated Barbtails forage for insects in the understory of mossy humid montane forest with numerous epiphytes. These barbtails usually are solitary or in pairs, but occasionally associate with small mixed species flocks. White-throated Barbtail is uncommon to locally fairly common, but it has a small geographic range, within which habitat loss is an ongoing threat. Consequently the conservation status of White-throated Barbtail is assessed as Vulnerable.
Field Identification
14–15 cm. Sexes alike. Whitish supercilium, dark brownish ear coverts and sides of neck streaked whitish; forehead and crown dark gray-brown, feathers outlined in blackish (giving scalloped appearance); upperparts dark gray-brown, tinged rufous; wings mostly dark fuscous; tail graduated, central rectrices slightly stiffened, all with distal 3–6 mm of shafts lacking barbs, producing very “spiny” appearance, dark fuscous; throat to upper breast whitish, rest of underparts dark brownish with whitish streak-like spotting.
Similar Species
Differs from similar Spotted Barbtail (P. brunnescens), with which there is no geographical overlap, primarily in having supercilium, throat, and neck and ventral spotting whitish, breast spots also denser and larger, and bill thicker.
Plumages
The immature plumage of White-throated Barbtail has been described only as "similar to that of adults" (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
), and a recently fledged young picuted in Hernandez C. et al. (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
) supports this somewhat vague description.
Bare Parts
Iris
dark brown
Bill
maxilla black, mandible pale grayish-pink, often with black tip
Tarsi and Toes
dark gray-brown to black
Measurements
ssp. tatei
Bill
culmen 17.7, 18 mm (n = 2♂♂, including holotype; 3
Chapman, F. M. (1925). Remarks on the life zones of northeastern Venezuela with descriptions of new species of birds. American Museum Novitates 191:1–15.
)
culmen from base: range 19-20 mm (mean 19.4 mm) (n = 5♂♂); range 19-20 mm (mean 19.2 mm) (n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Wing
59, 61 mm (n = 2♂♂, including holotype; 3
Chapman, F. M. (1925). Remarks on the life zones of northeastern Venezuela with descriptions of new species of birds. American Museum Novitates 191:1–15.
)
range 59-61 mm (mean 60 mm) (n = 5♂♂); range 59-61 mm (mean 59.8 mm) (n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Tail
58, 58 mm (n = 2♂♂, including holotype; 3
Chapman, F. M. (1925). Remarks on the life zones of northeastern Venezuela with descriptions of new species of birds. American Museum Novitates 191:1–15.
)
range 57-64 mm (mean 60.8 mm) (n = 5♂♂); range 57-60 mm (mean 59 mm) (n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Tarsus
20.5, 20.5 mm (n = 2♂♂, including holotype; 3
Chapman, F. M. (1925). Remarks on the life zones of northeastern Venezuela with descriptions of new species of birds. American Museum Novitates 191:1–15.
)
ssp. pariae
Bill
exposed culmen,16 mm; culmen from base, 20 mm (n = 1♂, holotype); culmen from base, range 20-21 mm (mean 20.2 mm) (n = 5♂♂, including holotype); culmen from base, range 19-21 mm (mean 20 mm) (n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Wing
60 mm (n = 1♂, holotype); range 60-62 mm (range 61.4 mm) (n = 5♂♂, including holotype); range 58-61 mm (mean 59.8 mm) (n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Tail
56 mm (n = 1♂, holotype); range 56-59 mm ( mean 57.4) (n = 5♂♂, including holotype); range 51-58 mm (mean 54.6 mm)(n = 5♀♀) (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Tarsus
20 mm (n = 1♂, holotype; 1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
)
Systematics History
Although described as a full species (3
Chapman, F. M. (1925). Remarks on the life zones of northeastern Venezuela with descriptions of new species of birds. American Museum Novitates 191:1–15.
), P. tatei was subseguently considered conspecific with P. brunnescens by many authors (4
Cory, C. B., and C. E. Hellmayr (1925). Catalogue of birds of the Americas and related islands. Part IV. Field Museum of Natural History Zoological Series 13(4).
, 5
Phelps, W. H., and W. H. Phelps, Jr. (1950). Lista de las aves de Venezuela con su distribución. Parte 2. Passeriformes. Boletín de la Sociedad Venezolana de Ciencias Naturales 12:1–427.
, 6
Peters, J. L. (1951). Check-list of Birds of the World. Volume 7. Museum of Comparative Zoology, Cambridge, MA, USA.
, 7
Vaurie, C. (1980). Taxonomy and geographical distribution of the Furnariidae (Aves, Passeriformes). Bulletin of the American Museum of Natural History 166:1–357.
). More recently, differences in voice, habitat, and behavior (8
Areta, J.I. (2007). Behavior and phylogenetic position of Premnoplex barbtails (Furnariidae). Condor 109(2): 399–407.
), supported by genetic distance (9
Pérez-Emán, J.L., Hernández, L.L. and Brumfield, R.T. (2010). Phylogenetic relationships of the White-throated Barbtail, Premnoplex tatei (Furnariidae), an endemic of the northeastern mountain range of Venezuela. Condor 112(3): 561–570.
) led to its elevation to species status. In addition, based on differences in plumage and voice (10
Boesman, P. (2016). Notes on the vocalizations of White-throated Barbtail (Premnoplex tatei). HBW Alive Ornithological Note 91. In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
, 11
del Hoyo, J., N. J. Collar and G. M. Kirwan (2017). Paria Barbtail (Premnoplex pariae). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/1343653.
), and preliminary genetic sampling (9
Pérez-Emán, J.L., Hernández, L.L. and Brumfield, R.T. (2010). Phylogenetic relationships of the White-throated Barbtail, Premnoplex tatei (Furnariidae), an endemic of the northeastern mountain range of Venezuela. Condor 112(3): 561–570.
), some authors have justified recognizing each subspecies as a full species (11
del Hoyo, J., N. J. Collar and G. M. Kirwan (2017). Paria Barbtail (Premnoplex pariae). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/1343653.
, 12
Remsen, J. V., Jr., C. J. Sharpe and G. M. Kirwan (2017). White-throated Barbtail (Premnoplex tatei). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/56527.
).
Described as: Premnoplext tatei Chapman, 1925, Mt. Turumiquire, 7900ft [c. 2400 m], N. E. Venezuela. American Museum Novitates no. 191, p. 7.
Holotype: AMNH 188018, adult male collected 8 April 1925 by G. H. Tate.
Distribution
Serranía de Turimiquire and Cordillera de Caripe (Cerros Peonía, Turimiquire, Macanillal and Negro) in NE Anzoátegui, S Sucre and N Monagas, NE Venezuela.
Identification Summary
Chapman's (1925) original description of the male holotype was as follows: "Crown Prout's brown, the feathers with lighter margins; forehead with minute whitish streaks; a narrow but well-defined whitish superciliary from the bill to the nape, auriculars and lores grayish; nape conspicuously streaked with whitish, the outer borders of the white streaks tinged with chestnut and margined with blackish; back, rump and upper tail-coverts chestnut-auburn deeper and richer in tone than in P. brunnescens brunnescens; tail darker than back, agreeing in color with that of [Premnoplex brunnescens] coloratus; remiges fuscous-black with their coverts margined with the color of the back; underparts, sides of the throat and breast largely ivory-white (pale olive-buff of Ridgway), the throat practically unmarked; the malar region chestnut narrowly margined with black, these margins becoming broader and more pronounced on the breast and sides of the breast and reducing the white area to a guttate mark on the abdomen and linear streak on the sides; ground color of the flanks, ventral region and crissum cinnamon-brown; feet and maxilla black, mandible horn-color, its cutting edge and tip blackish." See also species' Identification section.
Premnoplex tatei tatei
Chapman, 1925
PROTONYM:Premnoplex tatei
Chapman, 1925. American Museum Novitates no.191, p.7.
TYPE LOCALITY:
Mt. Turumiquire, 7900 feet, northeastern Venezuela.
UPPERCASE: current genusUppercase first letter: generic synonym● and ● See: generic homonymslowercase: species and subspecies●: early names, variants, misspellings‡: extinct†: type speciesGr.: ancient GreekL.: Latin<: derived fromsyn: synonym of/: separates historical and modern geographic namesex: based onTL: type localityOD: original diagnosis (genus) or original description (species)
Described as: Premnoplex tatei pariae Phelps, Sr and Phelps, Jr, 1949, Cerro Humo, Irapa, Paria Peninsula, Venezuela.
Distribution
Cerros Humo, Olvido and Azul, in Paria Peninsula (N Sucre), NE Venezuela.
Identification Summary
Compared with nominatetatei, pariae has a darker, duskier crown, and a nearly pure buff throat
(instead of white with squammations), the underparts are more dusky and darker brown, the light markings below are more extensive, the breast is less distinctly marked, and the belly bears wider whitish streaks (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
). It is slighly longer billed, but samples sizes are low.
Phelps and Phelps (1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
) describe the holotype adult male as follows: "Top of head brownish olive the feathers edged with dusky, giving a faintly scalloped appearance, the feathers of forehead with indistinct pale shaft stripes; a wide dusky nuchal collar, the feathers with prominent pale buffy shaft streaks; back Auburn, feathers with faint dusky shaft streaks; uropygium Auburn; lores dusky; post-ocular superciliary streak, gular region and sides of neck streaked with pale buffy and dusky, continuous with nuchal collar; earcoverts dusky mixed with buffy white. Chin and throat buffy white, feathers very faintly edged with dusky, merging into the pale Cream-Buff breast, the feathers with more accentuated dusky edges giving a faint scalloped appearance; abdomen has a streaked appearance, the feathers uniform with those of breast but with heavy dusky brownish edgings; sides and flanks dusky brown, the feathers with prominent whitish buff shaft streaks; shanks and under tail-coverts Prout's Brown. Remiges Fuscous; primaries narrowly edged with grayish brown, secondaries and tertials broadly with Auburn ; upper wing-coverts Auburn, uniform with back, the feathers with dusky shaft streaks; bend of wing, under wing-coverts and axillaries buffy white mixed with dusky. Central rectrices dusky brown, remaining ones Fuscous with dusky brown outer vanes; lower aspect of tail pale brownish."
Premnoplex tatei pariae
Phelps & Phelps, 1949
PROTONYM:Premnoplex tatei pariae
Phelps & Phelps, 1949. Proceedings of the Biological Society of Washington 62, p.35.
TYPE LOCALITY:
Cerro Humo, Irapa, Peninsula de Paria, Sucre, Venezuela.
UPPERCASE: current genusUppercase first letter: generic synonym● and ● See: generic homonymslowercase: species and subspecies●: early names, variants, misspellings‡: extinct†: type speciesGr.: ancient GreekL.: Latin<: derived fromsyn: synonym of/: separates historical and modern geographic namesex: based onTL: type localityOD: original diagnosis (genus) or original description (species)
Forms a superspecies with sister species, Spotted Barbtail Premnoplex brunnescens (13
American Ornithologists’ Union (1983). Check-list of North American Birds, Sixth edition. American Ornithologists’ Union, Washington, DC, USA.
, 14
American Ornithologists’ Union (1998). Check-list of North American birds. 7th edition. American Ornithologists’ Union, Washington, DC, USA.
, 15
Valderrama, E., Pérez-Emán, J.L., Brumfield, R.T., Cuervo, A.M. and Cadena, C.D. (2014). The influence of the complex topography and dynamic history of the montane Neotropics on the evolutionary differentiation of a cloud forest bird (Premnoplex brunnescens, Furnariidae). J. Biogeogr. 41(8): 1533–1546.
).
Distribution
White-throated Barbtail is endemic to montane forests in northeastern Venezuela, distributed in two disjunct populations. The nominate form on the Turimiquire Massif and P. t. pariaeon the Paria Peninsula (5
Phelps, W. H., and W. H. Phelps, Jr. (1950). Lista de las aves de Venezuela con su distribución. Parte 2. Passeriformes. Boletín de la Sociedad Venezolana de Ciencias Naturales 12:1–427.
, 16
De Schauensee, R. M. (1966). The species of birds of South America and their distribution. Livingston Publishing Corporation, Wynnewood, Pennsylvania.
, 17
Remsen, J. V., Jr. (2003). White-throated Barbtail (Premnoplex tatei). In Handbook of the birds of the World, Volume 8: Broadbills to tapaculos (del Hoyo, J., A. Elliott and J. Sargatal), Lynx Editions, Barcelona, Spain. pp. 321.
, 9
Pérez-Emán, J.L., Hernández, L.L. and Brumfield, R.T. (2010). Phylogenetic relationships of the White-throated Barbtail, Premnoplex tatei (Furnariidae), an endemic of the northeastern mountain range of Venezuela. Condor 112(3): 561–570.
). See subspecies' Distribution.
Habitat
Understory of montane evergreen forest, preferring wet, mossy forest, especially where dominated by small palms and Araceae in the understory (16
De Schauensee, R. M. (1966). The species of birds of South America and their distribution. Livingston Publishing Corporation, Wynnewood, Pennsylvania.
, 18
Meyer de Schauensee, R. (1970). A Guide to the Birds of South America. Livingston Publishing Company, Wynnewood, PA, USA.
, 19
Hilty, S. L. (2003). Birds of Venezuela. Princeton University Press, Princeton, New Jersey, USA.
, 20
Ridgely, R. S., and G. Tudor (2009). Field Guide to the Songbirds of South America: The Passerines. University of Texas Press, Austin, TX, USA.
). Known from elevations of 1100–2400 m (tatei) or 800–1200 m (pariae) (21
Renjifo, L. M., G. P. Servat, J. M. Goerck, B. A. Loiselle, and J. G. Blake (1997). Patterns of species composition and endemism in the northern Neotropics: A case for conservation of montane avifauna. Ornithological Monographs 48:577–594
, 22
Restall, R. L., C. Rodner, and M. Lentino (2006). Birds of Northern South America: An Identification Guide. Volumes 1–2. Christopher Helm, London, UK.
, 23
Sharpe, C. J. & Lentino, M. 2015. Fafao gargantiblanco, Premnoplex tatei. In: J.P. Rodríguez, A. García-Rawlins y F. Rojas-Suárez eds. Libro Rojo de la Fauna Venezolana. Cuarta edición. Provita y Fundación Empresas Polar, Caracas, Venezuela.
, 11
del Hoyo, J., N. J. Collar and G. M. Kirwan (2017). Paria Barbtail (Premnoplex pariae). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/1343653.
, 12
Remsen, J. V., Jr., C. J. Sharpe and G. M. Kirwan (2017). White-throated Barbtail (Premnoplex tatei). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/56527.
).
Diet and Foraging
Few data, but generally considered to consume mostly arthropods (17
Remsen, J. V., Jr. (2003). White-throated Barbtail (Premnoplex tatei). In Handbook of the birds of the World, Volume 8: Broadbills to tapaculos (del Hoyo, J., A. Elliott and J. Sargatal), Lynx Editions, Barcelona, Spain. pp. 321.
). Forages in the undergrowth, solitarily or in pairs (19
Hilty, S. L. (2003). Birds of Venezuela. Princeton University Press, Princeton, New Jersey, USA.
), possibly regularly in mixed-species flocks including those with Slaty Antwren Myrmotherula schisticolor and another globally threatened bird, Grey-headed Warbler Basileuterus griseiceps (24
Hilty, S. L. (1999). Three bird species new to Venezuela and notes on the behaviour and distribution of other poorly known species. Bulletin of the British Ornithologists’ Club 119 (4):220–235.
,25
Areta, J.I. (2007). Behavior and phylogenetic position of Premnoplex barbtails (Furnariidae). Condor. 109(2): 399–407.
). Gleans items from logs and boulders, but does not hitch or climb on trunks, and is said to possibly less acrobatic than P. brunnescens (24
Hilty, S. L. (1999). Three bird species new to Venezuela and notes on the behaviour and distribution of other poorly known species. Bulletin of the British Ornithologists’ Club 119 (4):220–235.
,17
Remsen, J. V., Jr. (2003). White-throated Barbtail (Premnoplex tatei). In Handbook of the birds of the World, Volume 8: Broadbills to tapaculos (del Hoyo, J., A. Elliott and J. Sargatal), Lynx Editions, Barcelona, Spain. pp. 321.
). Most foraging
is done 0.2–3 m above ground, sometimes even hopping on the ground, sticking its head into holes in fallen trunks and rotten logs, and frequently tossing leaves aside (24
Hilty, S. L. (1999). Three bird species new to Venezuela and notes on the behaviour and distribution of other poorly known species. Bulletin of the British Ornithologists’ Club 119 (4):220–235.
).
Sounds and Vocal Behavior
The song of nominate tatei is described as low-pitched, doubled or tripled, whistled notesor a bubbly series of low, soft, reedy whistles, “we-whúr, we-whúr, we-héét” (R12
Remsen, J. V., Jr., C. J. Sharpe and G. M. Kirwan (2017). White-throated Barbtail (Premnoplex tatei). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/56527.
). The song of pariae is delivered at somewhat lower frequencies, at a faster rate, and contains shorter notes that that of nominate (10
Boesman, P. (2016). Notes on the vocalizations of White-throated Barbtail (Premnoplex tatei). HBW Alive Ornithological Note 91. In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
). It is described by del Hoyo et al. (11
del Hoyo, J., N. J. Collar and G. M. Kirwan (2017). Paria Barbtail (Premnoplex pariae). In Handbook of the Birds of the World Alive (del Hoyo, J., A. Elliott, J. Sargatal, D. A. Christie and E. de Juana), Lynx Edicions, Barcelona, Spain. Available at https://www.hbw.com/node/1343653.
) as a continuously repeated short, rapid, almost rattled but variable series of 2–6 subdued mellow notes
, “pu-dut...pu-du-du-dut...pu-du-dut....”
Spacing
See Conservation Status.
Breeding
Few data. The nest has only recently been found but the eggs remain undescribed (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
). The scant available data suggest that, as expected, the nesting of P. tatei is similar to that of its sister species, P. brunnescens (26
Greeney, H. F. (2011). Spotted Barbtail (Premnoplex brunnescens). In Neotropical Birds Online (Schulenberg, T. S.), Cornell Lab of Ornithology, Ithaca, New York, U.S.A. pp. Available at https://doi.org/10.2173/nb.spobar1.01.
). What is perhaps the most remarkable difference, however, suggests an important ecological difference between these species. Unlike the exclusive choice of riparian nesting sites seen in P. brunnescens (27
Greeney, H. F. (2008). Breeding ecology of the Spotted Barbtail (Premnoplex brunnescens): a journey into the unknown world of a tropical understory furnariid. PhD thesis, University of Wroclaw, Wroclaw, Poland.
, 28
Greeney, H. F. (2009). Nest orientation in the Spotted Barbtail, Premnoplex brunnescens, is strongly correlated with stream flow. Journal of Ethology 27:203–208.
, 26
Greeney, H. F. (2011). Spotted Barbtail (Premnoplex brunnescens). In Neotropical Birds Online (Schulenberg, T. S.), Cornell Lab of Ornithology, Ithaca, New York, U.S.A. pp. Available at https://doi.org/10.2173/nb.spobar1.01.
), the first described nest of P. tatei was not constructed over flowing water (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
).
Phenology
Adult pariae observed with two fledglings in second week of July (25
Areta, J.I. (2007). Behavior and phylogenetic position of Premnoplex barbtails (Furnariidae). Condor. 109(2): 399–407.
) and breeding condition adults collected in May (pariae) and August (tatei)(1
Phelps, W. H., and W. H. Phelps, Jr. (1949). Eight new birds from the subtropical zone of the Paria Peninsula, Venezuela. Proceedings of the Biological Society of Washington 62:33–44.
). A nest of the nominate race held two nestlings on 22 May 2007 (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
). No further information.
Nest Site
The single described nest was found along an infrequently traveled dirt road, under an overhanging dirt bank (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
).
Nest
The singled described nest was built within a shallow earthen cavity under a projecting earthen embankment beside a small and non-transited dirt road, 2.5 m above the ground. Unlike most described nests of closely-related Spotted Barbtail P. brunnescens (26
Greeney, H. F. (2011). Spotted Barbtail (Premnoplex brunnescens). In Neotropical Birds Online (Schulenberg, T. S.), Cornell Lab of Ornithology, Ithaca, New York, U.S.A. pp. Available at https://doi.org/10.2173/nb.spobar1.01.
), the portions of this nest that were built by the birds consisted of a ring or short tube of moss, forming a small, downward-facing entrance into the cavity, and a thin pad of moss within the cavity that served as the egg cup (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
). Although this type of sparse modification of a natural cavity is not the most commonly described form for P. brunnescens, is has been known to build very similar nests (29
Skutch, A. F. (1969). Life histories of Central American birds III. Pacific Coast Avifauna 35:1–580.
, 30
Greeney, H. F. (2008). Nest construction behavior and variability in nest architecture and nest placement of the Spotted Barbatail (Premnoplex brunnescens). Boletín de la Soceidad Antioqueña de Ornitología 18:26–37.
).
Eggs
Undescribed.
Young Birds
Nestlings estimated to be 5–7 days old weighed 10 g and were pink-skinned, with feathers just beginning development under the skin on all major feather tracts, wing pin feathers just beginning to emerge from the skin, and had a sparse covering of long pale gray natal down (31
Greeney, H. F. (2008). Nestling growth and plumage development of the Spotted Barbtail (Premnoplex brunnescens). Kempffiana 4:21–29.
, 2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
). Thirteen days later these nestlings were fully feathered and weighed 19 and 20 g. They fledged the following day, and these observations were used to estimate a 19–21 day nestling period (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
).
Parental Care
The following observations are derived from observations of Hernández C. et al. (2
Hernández C., L. L., J. C. Azpúrua, J. E. Miranda, H. F. Greeney and J. L. Pérez-Emán (2020). First description of the nest of the White-throated Barbtail Premnoplex tatei (Furnariidae). Cotinga 41:
). Both sexes deliver food to nestlings and remove faecal sacs. At 5-7 days old, nestlings were fed at a rate of 2.1 feeds/nestling/hr, with more food delivered during the morning and a decrease in visits near midday. Adults usually vocalized soon after leaving the nest, either immediately or sometimes from up to 40 m. On several occasions, while one adult was inside the nest, its mate vocalized from the vicinity of the nest (genders undetermined). No further information.
Population Spatial Metrics
See Conservation Status.
Population Status
See Conservation Status.
Conservation Status
White-throated Barbtail is a range-restricted species, present in Caripe-Paria Region EBA, and under considerable threat from habitat loss caused by deforestation related to agriculture and coffee cultivation (32
Stattersfield, A. J., M. J. Crosby, A. J. Long, and D. C. Wege (1998). Endemic bird areas of the world: priorities for biodiversity conservation. BirdLife Conservation Series 7.
, 33
Oliveira-Miranda, M. A., Huber, O., Rodríguez, J. P., Rojas-Suárez, F., Oliveiera-Miranda, R., Zambrano-Martínez, S. & Hernández, D. G. 2010. Riesgo de eliminación de los ecosistemas terrestres de Venezuela. In Rodríguez, J. P. & Rojas-Suárez, F. (Eds.). Libro Rojo de los Ecosistemas Terrestres de Venezuela. Provita, Shell Venezuela, Lenovo (Venezuela). Caracas, Venezuela, pp.108–235.
, 23
Sharpe, C. J. & Lentino, M. 2015. Fafao gargantiblanco, Premnoplex tatei. In: J.P. Rodríguez, A. García-Rawlins y F. Rojas-Suárez eds. Libro Rojo de la Fauna Venezolana. Cuarta edición. Provita y Fundación Empresas Polar, Caracas, Venezuela.
). In the past, this species was considered Vulnerable when evaluated as a polytypic species (34
Stattersfield, A. J., and D. R. Capper, Editors (2000). Threatened Birds of the World. Lynx Edicions, Barcelona, Spain.
, Remsen 2003, 35
Sharpe, C.J. and Lentino, M. (2008). Fafao gargantiblanco Premnoplex tatei Chapman 1925. P. 149 in: .
), but each subspecies was recently considered individually BirdLife International, who considered nominate tatei to be ENDANGERED, and felt that pariae merited a threat level of ENDANGERED. White-throated Barbtail is considered uncommon to rare, and possibly very local, being absent from some apparently suitable areas (23
Sharpe, C. J. & Lentino, M. 2015. Fafao gargantiblanco, Premnoplex tatei. In: J.P. Rodríguez, A. García-Rawlins y F. Rojas-Suárez eds. Libro Rojo de la Fauna Venezolana. Cuarta edición. Provita y Fundación Empresas Polar, Caracas, Venezuela.
). The nominate race is known from Cerros Peonía, Turimiquire and Quiriquire (“Piedra ‘e Mole”) in Serranía de Turimiquire; Macanillal (36
Colvee, J. (1999). Observaciones Preliminares sobre el Estado Actual del Hábitat de Cuatro Especies de Aves en la Serranía de Turimiquire, Edos, Monagas, Anzoátegui y Sucre de Venezuela. Sociedad Conservacionista Audubon de Venezuela.
) and Cerro Negro (37
Boesman, P. and Curson, J. (1995). Grey-headed Warbler Basileuterus griseiceps in danger of extinction? Cotinga. 3: 35–39.
) in Cordillera de Caripe. It is estimated to have an overall range of 2300 km² and a total population c.1700–7000 individuals by BirdLife International. Two estimates of population density on Cerro El Olvido (pariae) were 1.9 individuals/ha and 2.4 pairs/ha of suitable habitat, which have been extrapolated to give 1800 mature individuals in area from Cerro Patao to E (38
Bond, R., P. Convey, C. Sharpe, and A. Varey (1989). Cambridge Columbus zoological expedition to Venezuela 1988. Unpublished report for the Cambridge Expeditions Committee, University of Cambridge, Cambridge, UK.
, 35
Sharpe, C.J. and Lentino, M. (2008). Fafao gargantiblanco Premnoplex tatei Chapman 1925. P. 149 in: .
); on Cerro Humo (pariae), densities were lower, at 0.8 birds/ha (39
Evans, K., King, R., Calvert, N., Brunton, D. and Jolles, A. (1994). Paria Peninsula '94: Final Report. An Oxford University Ornithological Expedition to Venezuela. Oxford University, Oxford.
). Densities of one pair per 200 m of trail in 1995 (25
Areta, J.I. (2007). Behavior and phylogenetic position of Premnoplex barbtails (Furnariidae). Condor. 109(2): 399–407.
) lies between these two figures. The total population of pariae is estimated at 2400 individuals by BirdLife International. Population density estimates, if correct, suggest that the species may occur in high densitis in remaining habitat, but known localities lie almost entirely within Paria Peninsula National Park, a park that has historically lacked significant management or legal enforcement (40
Sharpe, C.J. (2001). Situación Ambiental del Parque Nacional Península de Paria. Fundación Tierra Viva, Caracas.
, 41
Castillo, R. and Salas, V. (2005). Estado de conservación del Parque Nacional Península de Paria. BioParques, Caracas, Venezuela.
). Similarly, most surviving forest in Turimiquire Massif (tatei) is badly degraded, despite official protection in Cueva del Guácharo National Park, where the largest remaining forest block (“Piedra ‘e Mole”, in Serranía de Turimiquire) measures only c. 80 km² (42
Azpúrua, J.C., Hernández, L.L., Miranda, J.E. and Pérez-Emán, J.L. (2013). Status of the Grey-headed Warbler (Basileuterus griseiceps, Parulidae), an endemic and threatened species from north-eastern Venezuela. Orn. Neotropical. 24(4): 445–457.
).
Priorities for Future Research
Despite the "formal protection" of forests within much of the range of White-throated Barbtail, habitat there is being destroyed at alarming rates, for both cultivation and the construction of roads. Current and thorough surveys are urgently needed in order to more accurately estimate current population status and future trends. More details on its reproductive biology and foraging behavior will no doubt be very useful for informing sound conservation measures.
Greeney, H. F. and J. V. Remsen, Jr. (2020). White-throated Barbtail (Premnoplex tatei), 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.whtbar1.01
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