taxonID	type	description	language	source
03E5FD39FFF0FFD6C6EEFA24FC76FF37.taxon	description	Breeding. — Cadena et al. (2007) reported nests from 1 March to 5 June 2001, in the Cosanga area, near San Isidro Lodge, Napo Province. At San Isidro Lodge, MSN observed a juvenile accompanying its parents on 12 January 2019, a family group with two young on 17 June, and an adult collecting food (beetles and moths) on 17 August. On 16 February 2020, a juvenile was observed catching moths. Distribution. — Montane evergreen forest and forest borders in the eastern slope of the Andes (Amazon basin), from the Colombian massif region in Putumayo (Avendaño et al. 2013; Chavez-Paz et al. 2017; Felix & Coral-Jaramillo 2017), through the Ecuadorian east Andean slope — from north to south — entering the Cajamarca Department in far northeast Peru. Its altitudinal distribution in Ecuador is 1500 – 2700 m (Freile & Restall 2018). A complementary taxonomic history review is given in Supplementary Material A 9.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
03E5FD39FFF1FFD6C6EEFE8DFDCFFBB3.taxon	description	Breeding. — A juvenile was observed and photographed giving begging calls and following its parents in the Montezuma region (Tatamá National Park), Risaralda Department, Colombia, on 26 June 2019. Begging calls were recorded by MSN (XC 607806). Distribution. — West slope of Western Cordillera of Colombia, from the headwaters of San Juan River on Cerro Tatamá, Risaralda Department south to Cerro Munchique, Cauca Department at 900 ‒ 2400 m (Hilty & Brown 1986; Hilty 2020 b). The southern limit of this Colombian endemic may be in the Patía River drainage at a place named “ Hoz del Minamá ” (F. Ayerbe-Quiñones pers. comm.). This Colombian endemic subspecies does not overlap geographically with C. s. semifuscus.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
03E5FD39FFF1FFD5C6EEFB09FE57FF37.taxon	description	Breeding. — In Ecuador: MSN observed a begging fledgling in Quinde Luna (feeders area), northwest Pichincha Province, on 2 February 2019; a juvenile being fed by an adult was photographed by MSN at Birdwatchers House on Santa Rosa area, Pichincha Province, on 4 November 2018. In Colombia: A juvenile reported from west Nariño in July (Fjeldså & Krabbe 1990). At Ñambí River, La Planada, Nariño Department: on 9 August 1995 and 13 May 1996, a pair carrying nesting material; a nest under construction on 23 April 1997; adults feeding fledglings and juveniles between October and December 1995, and in July 1996; young birds being fed in June and September 1997 (Bohórquez & Stiles 2002); adults carrying food and feeding young in April, and on 29 June and 11 July 1998 (Strewe 2001). Distribution. — From the Pacific slope in Nariño Department, Colombia (southern bank of the Patía River valley), southwards along the Ecuadorian western Andean slope towards El Porvenir, in Bolívar Province, at 1200 ‒ 2300 m (locally higher) (Freile et al. 2020; Hilty 2020 b). The southern limit is inferred by the existence of a single skin of a male dated 1899 (NHMUK 1931.11.23.8), from El Porvenir, Bolívar Province, with no confirmed reports of this taxon in this Province since then. Possibly, the current southern limit of the distribution of C. s. semifuscus is the Angamarca River. However, this river is considered a lesser barrier (Krabbe et al. 1998), allowing occasional dispersal to Bolívar Province, as far south as El Porvenir. A revision of mislabeled specimens is available in Supplementary Material A 9.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
03E5FD39FFF2FFD5C6EEF891FD19F813.taxon	discussion	We suggest the treatment of this population as a new subspecies of the Chocó-Andean Chlorospingus semifuscus group, endemic of southwest Ecuador, as follows.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
03E5FD39FFF2FFD5C6EEFE8DFB8DF8CB.taxon	description	Breeding. — A juvenile female was collected in Cayandeled or Chimbo junction by J. Stolzmann and J. Siemiradski, but the specific date of that skin is difficult to discern. They collected in January, February, March, and September 1883 (Berlepsch & Taczanowski 1884). Distribution. — Along the Chimbo River headwaters and tributaries, in Bolívar and Chimborazo provinces, southwards the junction and drainage of the Chimbo and Chanchán rivers (Fig. 1). This population could be restricted to the remaining suitable habitat in this region, which is surrounded by agricultural land, farms, and cattle pasture. According to the skin label (NHMUK 1885.6.12.856), the site where the first individual of this population was collected is Chillanes, in Bolívar Province. This locality is at a higher elevation, but not distant from the Chimbo-Chanchán river junction and Pallatanga town in Chimborazo Province, where L. Fraser spent a fair time during his expedition in Ecuador. It is difficult to elucidate the exact original locality of this specimen, since no other details are specified by Sclater & Salvin (1877). However, it may be located in the same general region and habitat where other similar individuals of C. “ Chimborazo ” have been found later in the same province. After two field expeditions visiting suitable habitat in the Cañar River drainage and Molleturo-Naranjal road area, we did not find representatives of this population or any of the Chlorospingus populations reviewed here (Fig. 1). This population might be restricted on its southern limit by the Cañar River drainage. We cannot estimate the altitudinal range of this population precisely. Still, the altitudes where specimens of this group were collected are Cayandeled (1372 m), Surupata (1128 m) (Berlepsch & Taczanowski 1884), and Santa Rosa de Chilicay (this study ~ 1217 – 1227 m; Fig. 1). We consider this population uncommon and very localized. Taxonomic status. — Given the uncertainties about the origin and nature of C. “ Chimborazo ” and the results of phylogenetic analyses, this population could be treated as a variant of C. s. semifuscus with yellow-olive breast band, and different iris colorations from pale yellow to variations of red. On the other hand, based on its distribution between C. s. semifuscus and C. “ El Oro, ” it might comprise a stable hybrid population between these two. However, until further studies are conducted, we are inclined to support the treatment as a morph of C. s. semifuscus. A complementary taxonomic history review is available in Supplementary Material A 9.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
03E5FD39FFF3FFCBC6EEFF50FA57FBB3.taxon	diagnosis	Diagnosis. — Similar to C. f. phaeocephalus (Fig. 1) but inhabits the cloud forest of the southwestern Andes of Ecuador. The type series is presented in Figure 7. The color of the pectoral band of C. f. phaeocephalus is somewhat more yellowish than in C. s. xanthothorax, as supported by Zimmer´s (1947) review. The pectoral band in C. s. xanthothorax is a rather bright combination between spectrum yellow (C. 55) and olive-yellow (C. 52), with more olive yellow on flanks, whereas the pectoral band in C. f. phaeocephalus is a brighter lemon chrome (b. 21) on the center with more olive-yellow (C. 52), mainly on the flanks. Both C. s. xanthothorax and C. f. phaeocephalus present pale silvery yellow iris. In examined specimens, the relevant plumage difference between adult individuals in these two populations might be the throat pattern coloration. In C. f. phaeocephalus, the throat is more buff-white or whitish with some grayish or glaucous speckles (see holotype description below), but this feature is age variable and difficult to distinguish in the field given the poor light conditions of cloud forests. In both taxa, postocular spots on adults are related to ontogeny and probably sex (females). Both sexes of C. s. xanthothorax are smaller than the other members of C. f. phaeocephalus and the C. semifuscus group (Fig. 5). Description of Holotype MECN 9592 (in life). — Adult. Weight 22 g. Culmen, lores, fore crown, supercilium and lower auricular region blackish neutral gray (C. 82) with weak hints of yellowish olive-green (C. 50) randomly distributed on some barbules. Crown and back of the head are dark neutral gray (C. 83). Nape, back, rump, wing-coverts, and upper tail coverts are yellowish olive-green (C. 50). On upper-wings, primaries, secondaries, tertials inner webs, and under wings are brownish olive (C. 29), better diagnosed when wings are folded, mainly at the end of the primary projection. Bill: upper mandible, matte black, with some hints of pale russet vinaceous (C. 221 D) near the gape. Lower mandible is a mixture of matte black with some light russet vinaceous (C. 221 D). The malar transitions from a very pale cream color (C. 54) near the base of the bill reaching the throat to a light neutral gray (C. 85) with some hints of yellowish olive-green (C. 50) barbules. It presents a thin blackish neutral gray (C. 82) moustachial stripe. Chin is buffy-white. Throat center presents the same transition between pale cream color and dark neutral gray. In the field, the throat plumage can be perceived as a mixture of speckled dark gray and buff. The pectoral band is a fairly bright combination between spectrum yellow (C. 55) and olive-yellow (C. 52), with more olive-yellow (C. 52) on flanks. Center of belly is a pale pearl gray (C. 81) and / or silvery-white that narrows in the vent. Flanks are bright spectrum yellow (C. 55) with some pale neutral gray (C. 86) on middle flanks. Tail from above is yellowish olive-green (C. 50). Outer webs spectrum yellow and inner webs are dull yellowish olive-green (C. 50), with black rachises. Tail from below dull yellowish olive-green (C. 50). Under-tail coverts are spectrum yellow (C. 55). Iris: silvery yellow. The iris can vary, and is perceived as pale-yellow in the field. Tarsometatarsus, flesh color (C. 5). Tarsi and toes light neutral gray with hints of flesh color. Specimen measurements MECN 9592 (Fig. 7); wing chord mean 86.7 mm, tarsus mean 22.3 mm, tail 56.0 mm, bill length from the distal edge of the nostril to the tip of the bill 8.5 mm, bill depth at the center of nostrils 5.4 mm and bill width at center of nostrils 4.5 mm. Empty stomach. Showing molt at both P 10 (primaries). Type locality: Sambotambo road (boundaries of Buenaventura Reserve; 03 ° 39 ’ 07.32 ” S, 79 ° 44 ’ 36.32 ” W; 969 m elevation; Fig. 1), El Oro Province, Ecuador; collected on 8 September 2017, by MSN and JSN; prepared by Hernando Román; field catalog number EOC 002; GenBank accession number provided in Appendix I. Paratypes. — Two female specimens complete the type series (Fig. 7), as follows. Study skin MECN 9214; wing chord mean 64.00 mm, tarsus mean 28.72 mm, tail 60.00 mm, bill length from the distal edge of the nostril to the tip of the bill 8.10 mm, bill depth at the center of nostrils 5.32 mm and bill width at center of nostrils 4.83 mm. Locality: Buenaventura Reserve at 1090 m; collected on 2 January 2017, by MSN and JSN. MECN 9593; wing chord mean 65.00 mm, tarsus mean 27.70 mm, tail 52.00 mm, bill length from the distal edge of the nostril to the tip of the bill 8.18 mm, bill depth at the center of nostrils 5.14 mm and bill width at center of nostrils 4.79 mm; collection site is the same as holotype. Both skins prepared by Hernando Román; field catalog numbers EOC 001 and EOC 003, GenBank Accession numbers provided in Appendix I. Dawn song. — Two complete dawn songs of this taxon by MECN 9592 (XC 607786, XC 607789) are deposited at xeno-canto. org. For description per element see Table 3; for spectrograms, see Figure 6, and Supplementary Material A 2. A single, sharp, high-pitched element (note “ a ”) repeated several times before pre-trill notes and dry staccato trill similar than C. s. semifuscus; but pre-trill notes “ b ” and “ c ” delivered in different order and post-trill notes different than nominal. Etymology. — We choose an epithet that matches the obvious field diagnostic feature of this new member of the C. semifuscus group, which is its olive-yellow breast band. Xanthothorax combines two Greek words, xanthos meaning yellow and thorax meaning breast (Jobling 2010). Distribution and habitat. — Mainly found in the borders of humid subtropical lower montane cloud forests in El Oro Province and in similar ecosystems in adjacent Loja Province (Ridgely & Greenfield 2001). To our knowledge, this subspecies is restricted in its northern limit by the arid Jubones River valley. The southernmost record is from Vicentino south of Puyango River, in Loja Province (Best et al. 1993). Its southern distribution might be limited by the transition from the Chocoan humid to Tumbesian dry ecosystems, between Puyango and Catamayo rivers. Its elevation range is ~ 800 ‒ 1700 m. Uncommon and localized, in general, but frequently found in Buenaventura Reserve (Robbins & Ridgely 1990) and in suitable habitat and elevation in El Oro province (Garzón-Santomaro et al. 2019) and adjacent Loja province. Breeding. — Juveniles were reported begging for food on 26 February (vocalization recorded by MSN, XC 607791) and 9 September 2017. Both breeding records were within the area where we collected the holotype.	en	Sánchez-Nivicela, Manuel, Avendaño, Jorge Enrique, Sánchez-Nivicela, Juan C., Torres, Ana, Fuchs, Jérôme, Bird, Bentley, Bonaccorso, Elisa (2021): A taxonomic assessment of Chlorospingus flavopectus phaeocephalus and Chlorospingus semifuscus (Passeriformes: Passerellidae), including the description of a new subspecies. Zootaxa 5057 (2): 151-180, DOI: https://doi.org/10.11646/zootaxa.5057.2.1
