Systematics

The Indonesian Serin and the formerly conspecific Mindanao Serin (Chrysocorythus mindanensis) were previously placed in Serinus by most authors (e.g., 5 Paynter, R. A., Editor (1968). Check-list of Birds of the World. A Continuation of the Work of James L. Peters. Volume 14. Museum of Comparative Zoology, Cambridge, Massachusetts, USA. Close , 6 King, B., E. C. Dickinson, and M. W. Woodcock (1975). A Field Guide to the Birds of South-East Asia. Collins, London, UK. Close , 1 Clement, P., A. Harris, and J. Davis (1993). Finches and Sparrows: An Identification Guide. Christopher Helm, London, UK. Close , 7 Inskipp, T., N. Lindsey, and W. Duckworth (1996). An Annotated Checklist of the Birds of the Oriental Region. Oriental Bird Club, Sandy, UK. Close , 8 Dickinson, E. C., Editor (2003). The Howard and Moore Complete Checklist of the Birds of the World. Third edition. Christopher Helm, London, UK. Close ), nevertheless the morphological distinctiveness of Mountain Serin (as the single species was usually known) was long noted, with White and Bruce (9 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ) stating that it may belong elsewhere, and Wolters (10 Wolters, H. E. (1967). Über einege asiatische Carduelinae. Bonner Zoologische Beiträge 18(1–2):169–172. Close ) considering it sufficiently distinct to merit its own genus. The latter’s hypothesis has since been confirmed by molecular data (11 Zuccon, D., R. Prŷs-Jones, P. C. Rasmussen, and P. G. P. Ericson (2012). The phylogenetic relationships and generic limits of finches (Fringillidae). Molecular Phylogenetics and Evolution 62(2):581–596. Close ) and it is here treated in a separate genus Chrysocorythus Wolters, 1967 (type species Serinus mindananensis Ripley and Rabor, 1961). When placed in Serinus, the name orientalis for birds in West Java becomes preoccupied by a synonym of European Serin (Serinus serinus), and the replacement name chaseni must be used (12 Kinzelbach, R., E. C. Dickinson, and S. Somadikarta (2009). A substitute name for Serinus estherae orientalis Chasen. Bulletin of the British Ornithologists’ Club 129(1):63–64. Close ).

Taxon mindananesis was described as a species (13 Ripley, S. D., and D. S. Rabor (1961). The avifauna of Mount Katanglad. Postilla 50:1–20. Close ) but was subsequently lumped in an expanded Chrysocorythus estherae (14 Dickinson, E. C., R. S. Kennedy, and K. C. Parkes (1991). The Birds of the Philippines: An Annotated Checklist. B.O.U. Check-list 12. British Ornithologists’ Union, Tring, UK. Close , 15 Kennedy, R. S., P. C. Gonzales, E. C. Dickinson, H. C. Miranda, and T. H. Fisher (2000). A Guide to the Birds of the Philippines. Oxford University Press, Oxford, UK. Close ). Assessing them independently, both Eaton et al. (16 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ) and del Hoyo and Collar (17 del Hoyo, J., and N. J. Collar (2016). Handbook of the Birds of the World and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2. Lynx Edicions, Barcelona, Spain. Close ) opted to treat the Philippines and Indonesian taxa as species again, both citing substantial differences in morphology as justification. Adopting the Tobias et al. (18 Tobias, J. A., N. Seddon, C. N. Spottiswoode, J. D. Pilgrim, L. D. C. Fishpool, and N. J. Collar (2010). Quantitative criteria for species delimitation. Ibis 152(4):724–746. Close ) scoring system of species delimitation (where seven is considered a threshold for species status), del Hoyo and Collar (17 del Hoyo, J., and N. J. Collar (2016). Handbook of the Birds of the World and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2. Lynx Edicions, Barcelona, Spain. Close ) distinguished Chrysocorythus mindanensis by its dark, not whitish, eye-ring (prominent in all other subspecies of Chrysocorythus estherae except renatae) (score 2); more extensive yellow on head, throat, and breast (score 3); no black on throat and lack of heavy streaking on breast (score 3); richer yellow rump (not scored); and its much stouter and more arched bill (scored 2)—total score ten. The genetic relationships between taxa remain unknown, and other authorities (e.g., 19 Dickinson, E. C., and L. Christidis, Editors (2014). The Howard and Moore Complete Checklist of the Birds of the World. 4th edition. Volume 2: Passerines. Aves Press, Eastbourne, UK. Close , 20 Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood (2019). The eBird/Clements Checklist of Birds of the World: v2019. Cornell Lab of Ornithology, Ithaca, NY, USA. Close , 21 Gill, F., D. Donsker, and P. Rasmussen, Editors (2020). IOC World Bird List v10.1. Close ) continued to favor a more conservative, single-species treatment, but this is now reversed here.

Most named variation lies in the extent of yellow on the head and underparts, with an undescribed taxon from Central Sulawesi province having all yellow replaced by orange. Bill size broadly increases from west to east; see figure in Schuchmann and Wolters (3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close ).

Four described subspecies recognized herein (20 Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood (2019). The eBird/Clements Checklist of Birds of the World: v2019. Cornell Lab of Ornithology, Ithaca, NY, USA. Close ), with an additional, undescribed subspecies from the Lore Lindu area of north-central Sulawesi, discussed below.

‘Lore Lindu Serin’

Distribution

First observed in 1980 (9 White, C. M. N., and M. D. Bruce (1986). The Birds of Wallacea (Sulawesi, the Moluccas & Lesser Sunda Islands, Indonesia). An Annotated Check-list. British Ornithologists’ Union Check-list 7. British Ornithologists’ Union, London, UK. Close ), and now known from several localities within Lore Lindu National Park, Central Sulawesi province, including Guning Rorekatimbu, Gunung Rano Rano, and Pakuli (22 Watling, D. (1983). Ornithological notes from Sulawesi. Emu 83(4):247–261. Close , 23 van den Berg, A. B., and C. A. W. Bosman (1986). Supplementary notes on some birds of Lore Lindu Reserve, central Sulawesi. Forktail 1:7–13. Close , 24 Bishop, K. D., and B. King (1986). The Sunda Serin Serinus estherae in Sulawesi. Kukila 2(4):90–92. Close , 2 Ottaviani, M. (2018). Is the subspecies of Mountain Serin Chrysocorythus estherae from Lore Lindu National Park, northern Central Sulawesi province, Indonesia, an undescribed taxon? BirdingASIA 30:54–59. Close ).

Identification Summary

Reviewed in detail by Ottaviani (2 Ottaviani, M. (2018). Is the subspecies of Mountain Serin Chrysocorythus estherae from Lore Lindu National Park, northern Central Sulawesi province, Indonesia, an undescribed taxon? BirdingASIA 30:54–59. Close ) where this population was informally referred to as “linduensis”. Adult male is unique in that the forehead, malar region, crown, rump, and wingbars are orange, not yellow. Whilst Eaton et al. (16 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ) suggested that this was only present on some individuals, Ottaviani (2 Ottaviani, M. (2018). Is the subspecies of Mountain Serin Chrysocorythus estherae from Lore Lindu National Park, northern Central Sulawesi province, Indonesia, an undescribed taxon? BirdingASIA 30:54–59. Close ) argued instead that yellow-crowned birds at Lore Lindu in fact involve young males yet to acquire adult plumage. The adult female similarly differs from renatae in exhibiting an orange-yellow rump, uppertail-coverts, and wingbars. The bill of Lore Lindu birds is black (brown in renatae) and may be heavier than the latter.

---

SUBSPECIES

Chrysocorythus estherae vanderbilti Scientific name definitions

Systematics History

Serinus estherae vanderbilti Meyer de Schauensee, 1939, Notulae Naturae of the Academy of Natural Sciences of Philadelphia 18:2.—Blangbeke, 7,000 ft., Acheen [= Atjeh], northern Sumatra.

The holotype, an adult male collected on 11 April 1939 by Sidney Dillon Ripley (1913–2001), is held at the Academy of Natural Sciences at Drexel University, Philadelphia (ANSP 137344).

Synonym:
Serinus estherae ripleyi Chasen, 1939, Treubia 17:137.—Mt. Leuser, 3,300 m, Atjeh northern Sumatra (25 Chasen, F. N. (1939). Preliminary diagnoses of new birds from North Sumatra. I. Treubia 17(2):137–138. Close ). The holotype, an adult male collected on 1 February 1937 by Andries Hoogerwerf (1906–1977), is held in the Naturalis Biodiversity Center, Leiden (RMNH.AVES.14057) (26 Dekker, R. W. R. J., and C. Quaisser (2006). Type specimens of birds in the National Museum of Natural History, Leiden. Part 3. Passerines: Pachycephalidae-Corvidae (Peters’s sequence). NNM Technical Bulletin 9, Nationaal Natuurhistorisch Museum, Leiden, the Netherlands. Close ); three paratypes (another male and two females) are held in the Museum Zoologicum Bogoriense, Cibinong (MZB 10108, 10187, and 10188) (25 Chasen, F. N. (1939). Preliminary diagnoses of new birds from North Sumatra. I. Treubia 17(2):137–138. Close , 26 Dekker, R. W. R. J., and C. Quaisser (2006). Type specimens of birds in the National Museum of Natural History, Leiden. Part 3. Passerines: Pachycephalidae-Corvidae (Peters’s sequence). NNM Technical Bulletin 9, Nationaal Natuurhistorisch Museum, Leiden, the Netherlands. Close ). Chasen’s name was published in July, whereas Meyer de Schauensee’s appeared in June (see 5 Paynter, R. A., Editor (1968). Check-list of Birds of the World. A Continuation of the Work of James L. Peters. Volume 14. Museum of Comparative Zoology, Cambridge, Massachusetts, USA. Close ).

Distribution

Confined to north-west Sumatra, in the Mt. Leuser area (27 van Marle, J. G., and K. H. Voous (1988). The Birds of Sumatra. An Annotated Check-list. B.O.U. Check-list 10. British Ornithologists’ Union, Tring, UK. Close ).

Field Identification

Has the smallest bill of any Chrysocorythus taxon. Plumage rather poorly known, but male has darker lores and throat than nominate, with thicker breast spots and a narrower eye-ring (16 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ). Measurements of a single male (3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close ): wing length 67 mm, tail length 42 mm, bill length 8 mm, bill width 5 mm, and tarsus length 11 mm.

---

SUBSPECIES

Chrysocorythus estherae estherae Scientific name definitions

Systematics History

Crithagra Estherae Finsch, 1902, Notes from the Leyden Museum 23:151.—Mt. Pangrango, 6,000 ft., western Java.

Known from two syntypes, both held in the Naturalis Biodiversity Center, Leiden, and collected by Max Eduard Gottlieb Bartels (1871‒1934): an adult female collected on 11 March 1901 (RMNH.AVES.44657) and an adult male taken on 29 April 1902 (RMNH.AVES.44659) (26 Dekker, R. W. R. J., and C. Quaisser (2006). Type specimens of birds in the National Museum of Natural History, Leiden. Part 3. Passerines: Pachycephalidae-Corvidae (Peters’s sequence). NNM Technical Bulletin 9, Nationaal Natuurhistorisch Museum, Leiden, the Netherlands. Close ).

Distribution

Known only from Gunung Gede in West Java (28 MacKinnon, J. R., and K. Phillipps (1993). A Field Guide to the Birds of Borneo, Sumatra, Java, and Bali. Oxford University Press, Oxford, UK; New York, NY, USA; Tokyo, Japan. Close ).

Field Identification

Described under Plumages.

---

SUBSPECIES

Chrysocorythus estherae orientalis Scientific name definitions

Systematics History

Serinus estherae orientalis Chasen, 1940, Treubia 17:263.—Mt. Ajekajek, ca. 2,300 m, Tengger Mountains, eastern Java. (29 Chasen, F. N. (1940). Notes on some Javan birds. Treubia 17(4):263–266. Close )

The holotype, an adult male collected on 3 July 1939 by Adriaan Cornelis Valentin van Bemmel (1908–1990), is held in the Naturalis Biodiversity Center, Leiden (RMNH.AVES.14058) (26 Dekker, R. W. R. J., and C. Quaisser (2006). Type specimens of birds in the National Museum of Natural History, Leiden. Part 3. Passerines: Pachycephalidae-Corvidae (Peters’s sequence). NNM Technical Bulletin 9, Nationaal Natuurhistorisch Museum, Leiden, the Netherlands. Close ). Seven paratypes (five additional males and two females) are all held in the Museum Zoologicum Bogoriense, Cibinong (MZB 12413‒12419) (29 Chasen, F. N. (1940). Notes on some Javan birds. Treubia 17(4):263–266. Close , 26 Dekker, R. W. R. J., and C. Quaisser (2006). Type specimens of birds in the National Museum of Natural History, Leiden. Part 3. Passerines: Pachycephalidae-Corvidae (Peters’s sequence). NNM Technical Bulletin 9, Nationaal Natuurhistorisch Museum, Leiden, the Netherlands. Close ).

Serinus estherae chaseni Kinzelbach, Dickinson, and Somadikarta, 2009, Bulletin of the British Ornithologists’ Club 129:63. (12 Kinzelbach, R., E. C. Dickinson, and S. Somadikarta (2009). A substitute name for Serinus estherae orientalis Chasen. Bulletin of the British Ornithologists’ Club 129(1):63–64. Close ). This was offered as a replacement for Chasen’s name (29 Chasen, F. N. (1940). Notes on some Javan birds. Treubia 17(4):263–266. Close ), and consequently has the same type locality and type material, because Chasen’s name orientalis is a primary homonym, being preoccupied by Serinus orientalis C. L. Brehm, 1831, from Austria [currently treated as a synonym of European Serin (Serinus serinus)] (12 Kinzelbach, R., E. C. Dickinson, and S. Somadikarta (2009). A substitute name for Serinus estherae orientalis Chasen. Bulletin of the British Ornithologists’ Club 129(1):63–64. Close ). When, as here, this species is removed from Serinus, Chasen’s original name orientalis reverts (under Art. 59.4 of the Code 30 International Commission on Zoological Nomenclature (1999). International Code of Zoological Nomenclature. Fourth edition. The International Trust for Zoological Nomenclature, London, UK. Close ).

Distribution

East Java (Tengger Mts and western Yang).

Field Identification

Very poorly known. Apparently very like the nominate, but exhibits only a small area of yellow on moustachial area (not extending across chin) and a narrower white eye-ring (16 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ); bill also considerably smaller (“shorter and less robust”) in both sexes according to Chasen (29 Chasen, F. N. (1940). Notes on some Javan birds. Treubia 17(4):263–266. Close ). Measurements of a single male (the type specimen, as measured by Schuchmann and Wolters; 3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close ): wing length 69 mm, tail length 45 mm, bill length 8 mm, bill width 5 mm, and tarsus length 11 mm.

---

SUBSPECIES

Chrysocorythus estherae renatae Scientific name definitions

Systematics History

Chrysocorythus estherae renatae Schuchmann and Wolters, 1982, Bulletin of the British Ornithologists’ Club 102:12.—Mt Rantekombola, South Sulawesi, 2,300 m. (3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close )

The holotype, an adult, probably male, collected by Christian Krause on 6 August 1980, is held in the Leibniz Institute for the Analysis of Biodiversity Change, Museum Koenig, Bonn (ZFMK 81.563) (3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close , 31 Rheinwald, G., and R. van den Elzen (1984). Die Wirbeltiersammlungen des Museums Alexander Koenig und ihre Typusexemplare. II. Vögel. Bonner Zoologische Monographien 19:49–150. Close , 32 van den Elzen, R. (2010). Type specimens in the bird collections of the Zoologisches Forschungsmuseum Alexander Koenig, Bonn. Bonn Zoological Bulletin 59:29–77. Close ).

Distribution

Known only from Gunung Rantekombola, in South Sulawesi province.

Field Identification

Fills both the geographical and morphological gap between western Sundaic taxa, and the formerly conspecific Mindanao Serin (Chrysocorythus mindanensis). Differs from all other subspecies of Mountain Serin by its longer (11 mm versus 7–9 mm) and wider (8 mm versus 5–7 mm) bill, which is the largest of any taxon, and measurements also suggest it possesses a much longer tail (3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close ); otherwise similar to vanderbilti but the yellow on the forecrown is more restricted (16 Eaton, J. A., B. van Balen, N. W. Brickle, and F. E. Rheindt (2016). Birds of the Indonesian Archipelago: Greater Sundas and Wallacea. Lynx Edicions, Barcelona, Spain. Close ). Measurements of holotype (a male, from Schuchmann & Wolters 3 Schuchmann, K.-L., and H. E. Wolters (1982). A new subspecies of Serinus estherae (Carduelidae) from Sulawesi. Bulletin of the British Ornithologists’ Club 102(1):12–14. Close ): wing length 71 mm, tail length 58 mm, bill length 11 mm, bill width 8 mm, and tarsus length 13 mm.

Contra its previous treatment in Serinus, and Delacour (33 Delacour, J. (1946). Notes on the taxonomy of the birds of Malaysia. Zoologica 31:1–8. Close ) who had suggested a close taxonomic affinity to the Vietnamese Greenfinch (Chloris monguilloti) (geographically the closest finch), molecular data (11 Zuccon, D., R. Prŷs-Jones, P. C. Rasmussen, and P. G. P. Ericson (2012). The phylogenetic relationships and generic limits of finches (Fringillidae). Molecular Phylogenetics and Evolution 62(2):581–596. Close ) recovered the Indonesian Serin as most closely related to the European Goldfinch (Carduelis carduelis) and Citril Finch (Carduelis citrinella) (albeit with low support), the three species forming a clade sister to Serinus and Spinus. Nonetheless, Chrysocorythus represents a distinct clade (matched in its disjunct range and distinct morphology) and is here placed in its own genus.

Not reported, and intrinsically unlikely.

Nothing known.