SPECIES

Slate-throated Redstart Myioborus miniatus Scientific name definitions

William D. Harrod and Ronald L. Mumme
Version: 2.0 — Published July 29, 2022

Systematics

Systematics History

Originally described by Swainson in 1827 as Setophaga miniata Swainson, 1827, The Philosophical Magazine 1:368. The type locality was given as "woods of Valadolid" [Morelia, Michoacan] (9).

As it was originally described in Setophaga, it was originally thought to be close to the similar American Redstart (Setophaga ruticilla). Subsequent work, beginning with Baird (10) and Parkes (11), has shown that Slate-throated Redstart is part of a well defined clade of 12 species of Myioborus redstarts of the American tropics and subtropics, and the similarity to American Redstart is due to convergence (12, 13; see Related Species).

Geographic Variation

Slate-throated Redstart shows extensive geographic and subspecific variation (see Subspecies), particularly in ventral coloration and the extent of white in the tail. The color of the breast and belly is vivid vermilion red for birds in northern and central Mexico, but red-orange, orange, and yellow-orange in Central America, and yellow in South America. Geographic variation in the pattern of white in the tail also is substantial; birds in southern Mexico and northern Central America have the least amount of white in the tail, and the extent of white increases to both the north and south, reaching its peak in the subspecies verticalis in central Bolivia (Figure 2).

Subspecies

Twelve subspecies historically have been recognized, primarily on the basis of ventral coloration, the extent of white in the tail, crown color, and the extent of black on the face; miniatus , molochinus, intermedius , hellmayri , connectens , comptus , aurantiacus , ballux , sanctaemartae , pallidiventris , subsimilis , and verticalis . The legitimacy of recognizing all 12 subspecies, however is open to debate. Pérez-Emán et al. (3) examined genetic variation across most of the geographic range of Slate-throated Redstart, examining variation in two mitochondrial genes from 36 specimens of 10 of the 12 recognized subspecies. Although Mexican and Central American subspecies were well represented in the genetic sampling, representatives of sanctaemartae, pallidiventris, and verticalis from the tepuis were not included in the analysis. The study identified four well-supported monophyletic groups: (1) a well-differentiated and genetically distinct basal lineage comprising the nominate subspecies miniatus (northern and central Mexico); (2) a clade comprising the subspecies molochinus and intermedius (Sierra de Los Tuxtlas of eastern Mexico, and the interior highlands of southern Mexico and Guatemala); (3) a Central American lineage representing populations belonging to four poorly differentiated subspecies, hellmayri, connectens, comptus, and aurantiacus; and (4) a clade of South American subspecies (ballux, subsimilis, and verticalis) that requires more extensive sampling to resolve adequately. The lack of genetic structure in the third clade (Central American lineage), which was sister to the molochinus/intermedius lineage, is surprising given that hellmayri and connectens are geographically isolated from comptus and aurantiacus by several hundred kilometers of Nicaraguan lowlands, and that these two subspecies groups differ considerably in both ventral coloration and the amount of white in the tail (Figure 2).

Because the Central American subspecies are not genetically well differentiated, at least in terms of variation in mtDNA, some might argue that they should not be recognized as distinct subspecies (3). However, they nonetheless appear to be locally adapted evolutionary units; field experiments in Costa Rica have shown that the substantial geographic variation in tail pattern (Figure 2) is adaptive and likely driven by diversifying selection for enhanced flush-pursuit foraging performance (2, 3). On the other hand, some subspecific distinctions in Central America are indeed questionable; for example, comptus (northern and central Costa Rica) and aurantiacus (southern Costa Rica and western Panama) are very difficult to distinguish by ventral coloration, tail pattern (Figure 2), and mtDNA, and retaining both as distinct subspecies is difficult to defend (3). Similarly, because much of the variation in ventral coloration and tail pattern in South America is continuous and clinal, consolidation of some South American subspecies may be inevitable unless future genetic work reveals unexpected evidence of strong genetic structure.


SUBSPECIES

Myioborus miniatus miniatus Scientific name definitions

Systematics History

Setophaga miniata Swainson, 1827, The Philosophical Magazine 1:368. Type locality woods of Valladolid [= Morelia], Michoacán, Mexico (9).

Distribution

Occurs in Mexico from southern Sonora, southwestern Chihuahua, and San Luis Potosí south to southern Oaxaca and western Chiapas.

Identification Summary

Breast and belly dark vermilion red, face black. The outer three rectrices are broadly tipped with white, and the white is more extensive than it is in the other four subspecies from southern Mexico and northern Central America (molochinus, intermedius, hellmayri, and connectens; Figure 2).


SUBSPECIES

Myioborus miniatus molochinus Scientific name definitions

Systematics History

Myioborus miniatus molochinus Wetmore, 1942, Proceedings of the Biological Society of Washington 55:105. Type locality between 3,000 and 4,000 feet elevation on Volcán San Martín, Sierra de Tuxtla, Veracruz, Mexico (14).

Type specimen is an adult male collected by M. A. Carriker, Jr. on 17 April 1940, and housed at the Smithsonian National Museum of Natural History (14).

Distribution

Sierra de los Tuxtlas, in southeastern Veracruz, eastern Mexico.

Identification Summary

Endemic to the Sierra de los Tuxtlas of southeastern Veracruz in eastern Mexico. Similar to miniatus, but with much less white in the outer rectrices (Figure 2), brighter red underparts, and a relatively shorter tail (see Measurements: Table 1).


SUBSPECIES

Myioborus miniatus intermedius Scientific name definitions

Systematics History

Setophaga intermedia Hartlaub, 1852, Revue et Magasin de Zoologie Pure et Appliquée 4(2):5. Type locality given as "Guatemala" (15). The type locality was later restricted to Panajachel, western Guatemala, by Griscom (16).

Distribution

Southern Mexico (eastern Oaxaca and northern and eastern Chiapas) and eastern Guatemala northeast of the Pacific cordillera.

Identification Summary

Compared to miniatus, breast and belly more reddish orange and with much less white in the tail (similar in extent to hellmayri and connectens; Figure 2).


SUBSPECIES

Myioborus miniatus hellmayri Scientific name definitions

Systematics History

Myioborus miniatus hellmayri van Rossem, 1936, Condor 38:117. Type locality Volcán de Santa Ana, Sonsonate, El Salvador, altitude 6,000 feet (17).

The type specimen, an adult male, was collected by A. J. van Rossem on 8 May 1927 (17).

Distribution

Distribution historically described as the Pacific cordillera from southern Guatemala through southwestern El Salvador (17, 5), but museum specimens from the Pacific cordillera of southern Chiapas, Mexico (e.g., from the mountains northeast of Mapastepec) are generally assigned to hellmayri as well.

Identification Summary

Underparts are salmon orange and the outer tail feathers, like intermedius and connectens, have very little white (Figure 2).


SUBSPECIES

Myioborus miniatus connectens Scientific name definitions

Systematics History

Myioborus miniatus connectens Dickey and van Rossem, 1928, Proceedings of the Biological Society of Washington 41:189. Type locality Los Esesmiles, Chalatenango, El Salvador, altitude 8,000 feet (18).

The type specimen, an adult male, was collected by A. J. van Rossem on 5 March 1927 (18).

Distribution

Mountains of the interior cordillera of El Salvador and Honduras south to north-central Nicaragua.

Identification Summary

Underparts orange compared to the reddish orange of intermedius and the salmon orange of hellmayri. White in the outer rectrices is very limited, similar to intermedius and hellmayri (Figure 2).


SUBSPECIES

Myioborus miniatus comptus Scientific name definitions

Systematics History

Myioborus miniatus comptus Wetmore, 1944, Proceedings of the United States National Museum 95:74. Type locality 900 meters elevation on Cerro Santa María, a spur of Volcán Rincón de la Vieja, above Hacienda Santa María, Costa Rica (19).

The type specimen, a male, was collected by Alexander Wetmore on 14 November 1940 (19). The type specimen is housed at the Smithsonian National Museum of Natural History.

Distribution

Restricted to the mountains of western and central Costa Rica.

Identification Summary

Breast and belly yellowish orange, and the outer tail feathers have significantly more white than molochinus, intermedius, hellmayri, and connectens, and slightly more white than miniatus; the outer three rectrices (rectrices 4-6) are broadly tipped in white, and some birds have a smaller white spot on rectrix 3 (Figure 2). As originally described by Wetmore (19), very similar to aurantiacus, but darker above and somewhat more orange below.


SUBSPECIES

Myioborus miniatus aurantiacus Scientific name definitions

Systematics History

Setophaga aurantiaca S. F. Baird, 1865, Smithsonian Miscellaneous Collections 181:261. Type locality Dota Mountains, San José, and Barranca, Costa Rica (10); restricted to Santa María de Dota by Deignan (20: 549).

Distribution

Eastern Costa Rica and western Panama.

Identification Summary

Very similar to comptus, but slightly paler above and less orange below. The pattern of white in the outer rectrices is essentially identical to comptus (Figure 2).


SUBSPECIES

Myioborus miniatus ballux Scientific name definitions

Systematics History

Myioborus miniatus ballux Wetmore and Phelps, 1944, Proceedings of the Biological Society of Washington 57:11 (21). Type locality from 1,600 meters near Queniquea, Táchira, Venezuela.

Type specimen, an adult male, was collected by W. H. Phelps on 7 November 1940 (21). The type specimen is housed at the Smithsonian National Museum of Natural History.

Distribution

Southeastern Panama (Darién), northern Colombia (excluding the Sierra Nevada de Santa Marta) and western Venezuela (east to Trujillo) south through the Colombian Andes to northern Ecuador.

Identification Summary

As originally described, similar to verticalis but with less extensive white on the outer rectrices; similar to pallidiventris but yellow underparts tinged with orange, especially on the breast; and similar to aurantiacus but paler yellow below with more extensive white in the rectrices.


SUBSPECIES

Myioborus miniatus sanctaemartae Scientific name definitions

Systematics History

Myioborus miniatus sanctaemartae J. T. Zimmer, 1949 American Museum Novitates 1428:11. Type locality Las Nubes, Santa Marta, Colombia (22).

The type specimen was collected by Grace H. Hull on 10 December 1898 (22), and is housed at the American Museum of Natural History.

Distribution

Restricted to the Sierra Nevada de Santa Marta, northern Colombia.

Identification Summary

Similar to pallidiventris, with its pale yellow underparts, but with significantly less white in the outer rectrices (Figure 2).


SUBSPECIES

Myioborus miniatus pallidiventris Scientific name definitions

Systematics History

Setophaga verticalis pallidiventris Chapman, 1899, Bulletin of the American Museum of Natural History 12(9):153. Type locality Quebrada Seca [inland from Cumaná], Venezuela (23).

The type specimen was collected by F. W. Urich on 2 December 1898, and is housed at the American Museum of Natural History (23).

Distribution

Northern Venezuela, from Falcón east to Sucre and Monagas.

Identification Summary

Similar to sanctaemartae and verticalis, but with considerably more white in the tail than sanctaemartae (Figure 2), and paler below than verticalis.


SUBSPECIES

Myioborus miniatus subsimilis Scientific name definitions

Systematics History

Myioborus miniatus subsimilis Zimmer, 1949, American Museum Novitates 1428:13 (22). Type locality Alamor, Peru, altitude 4,450 feet.

The type specimen, an adult male, was collected on 22 August 1921 by George K. Cherrie and Geoffrey Gill. The specimen is currently housed at the American Museum of Natural History (22).

Distribution

Occurs in the western Andes in southwestern Ecuador and northwestern Peru.

Identification Summary

Zimmer (22) recognized this subspecies as distinct from verticalis of the neighboring eastern Andes on the basis of its paler ventral coloration (similar to pallidiventris) and relative reduction of black on the forehead and sides of the crown. Zimmer also suggested that subsimilis could be distinguished from verticalis by "the lesser extent of white on the tail" (22, p. 13), but systematic measurement of museum specimens indicates no such difference (Figure 2).


SUBSPECIES

Myioborus miniatus verticalis Scientific name definitions

Systematics History

Setophaga verticalis d’Orbigny and Lafresnaye, 1837, Magasin de Zoologie 7(2):50. Type locality Ayupaya, Bolivia (24).

Distribution

Occurs in the eastern Andes from southern Ecuador (Loja) south to central Bolivia, and in the tepuis of southern Venezuela, western Guyana, and northern Brazil.

Identification Summary

Similar in ventral coloration to ballux but with significantly more white in the outer rectrices (Figure 2); specimens of verticalis, particularly those from the southern part of the range (central Bolivia), have more extensive tail white than any other subspecies of Slate-throated Redstart (Figure 2), and the extent of white decreases gradually over the range of verticalis from south to north (22).

Related Species

Slate-throated Redstart is one of 12 species of Myioborus redstarts that comprise a well-defined monophyletic lineage within Parulidae (12 , 13). Painted Redstart (Myioborus pictus) appears to be sister to all other members of the genus, with Slate-throated Redstart in turn sister to the remaining 10 Myioborus species. In many regions of southern Central America and South America, Slate-throated Redstart is ecologically replaced at higher elevations by a member of this sister clade (25). In Costa Rica and western Panama, it is replaced at higher elevations by Collared Redstart (Myioborus torquatus). In South America, it is replaced at higher elevations by Yellow-crowned Redstart (Myioborus flavivertex) in the Sierra Nevada de Santa Marta of northern Colombia; by White-fronted Redstart (Myioborus albifrons) in the Andes of western Venezuela; by Golden-fronted Redstart (Myioborus ornatus) in the Andes of central and eastern Colombia; and by Spectacled Redstart (Myioborus melanocephalus) in the Andes of southern Colombia, Ecuador, Peru, and northern and central Bolivia.

No cases of hybridization between Slate-throated Redstart and any of its high-elevation congeneric replacements have been recorded. However, an apparent case of hybridization between a female Slate-throated Redstart and a male Painted Redstart in Arizona in 2016 is well documented (26).

Nomenclature

The genus name Myioborus is derived from the Greek muia ("fly") and borus ("devouring, or "to eat up"), which is accurate and descriptive for the species given the importance of flies and other winged insects in the diet (see Diet and Foraging). The specific epithet miniatus means "painted vermilion" and accurately describes the color of the underparts of the original type specimen in the nominate subspecies Myioborus miniatus miniatus of northern and central Mexico.

Fossil History

None reported.

Recommended Citation

Harrod, W. D. and R. L. Mumme (2022). Slate-throated Redstart (Myioborus miniatus), version 2.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.sltred.02