The Wilson Journal of Ornithology 123 ( 3 ): 459 - 463 , 2011 
PHENOTYPIC DISCRIMINATION OF THE ANDEAN IBIS 
( THER1ST1CUS BRAN/CK1I) 
NIGEL J. COLLAR 1 - 2 - 3 AND JEREMY P. BIRD 1 
ABSTRACT.—Many authors do not recognize the highland Andean Ibis (Theristicus branickii) as a species distinct from 
lowland Black-faced Ibis (T. melanopis). We considered this problem using a new system of quantitative criteria for species 
recognition. Andean Ibis differs from Black-faced Ibis markedly in proportions (shorter bill: mean 118 vs. 140 mm: longer 
tail: mean 215 vs. 185 mm), structure (no wattle), and color pattern (rufous-chestnut crown, face and nape rather than 
rufous-chestnut crown only: larger white vs. smuller rusty-buff belly-patch). We propose elevation of Andean Ibis to full 
species. It is rare in Ecuador and Bolivia, vagrant in Chile and only likely to be moderately abundant in Peru. Received 28 
September 2010. Accepted 19 January' 2011. 
Opinion is unevenly divided over whether the 
Black-faced Ibis ( Theristicus melanopis ) of south¬ 
ern South America, itself only relatively recently 
split from Buff-necked Ibis (T. caudatus) (e.g., 
Steinbacher 1979), is one or two species. The 
majority view is that it is one with its high Andean 
representative, branickii, considered a subspecies 
(Hellmayr and Conover 1948, Meyer de .Schauen- 
see 1966, Blake 1977, Steinbacher 1979, Parker et 
al. 1982, Fjeldsa and Krabbe 1990, Hancock et al. 
1992, Matheu and del Hoyo 1992, Stotz et al. 
1996, Ridgely and Greenfield 2001, Dickinson 
2003, Jaramillo 2003, Restall et al. 2006, 
Schulenberg et al. 2007). These two laxa are 
treated as two species by Sibley and Monroe 
(1990), Clements (1991, 2000, 2007). Wells 
(1998), Clements and Shany (2001). Walker and 
Fjeldsa (2002), and Martinez Pina and Gonzalez 
Cifuentes (2004). 
Diagnoses were provided only by Clements and 
Shany (2001), who indicated melanopis “has a 
larger black wattle on throat". Walker and Fjeldsd 
(2002), who described and illustrated something 
closer to melanopis than to branickii, and 
Martinez Pina and Gonzalez Cifuentes (2004: 
82), who wrote (our translation): “like \melano- 
pis\, but legs much shorter, neck thicker, gular 
wattle divided, and head and hindcollar brown". 
Those maintaining one species since publica¬ 
tion of Sibley and Monroe (1990) seem not to 
have looked afresh at the evidence. Hancock et al. 
(1992: 185) mentioned that branickii is “some¬ 
what smaller than the other subspecies [here 
including caudatus]... but has the longest wings" 
1 Birdl.ife International. Wellbrook Court. Girlon Road, 
Cambridge CB3 0NA. United Kingdom, 
2 Bird Group. Department of Zoology. Natural History 
Museum, Tring, Herts HP23 6AP, United Kingdom. 
’Corresponding author; e-mail: nigel.colIar@birdlife.org 
with rufous-tinged neck-base, palest breast and 
undersides, rather dark gray wing-coverts and 
more consistently gray dorsal coloration (nothing 
outside quotation marks is accurate). Matheu and 
del Hoyo (1992: 499) called it "paler, [with] less 
ochraceous forencck and breast, and usually 
smaller area of bare skin on throat", and noted 
that it is sometimes given species status “on [the] 
basis mainly of ecological differences". Ridgely 
and Greenfield (2001) also noted branickii is at 
times given species status but. as only branickii 
occurs in Ecuador, they offered no diagnosis from 
nominotypical melanopis. Restall et al. (2006) 
offered no diagnosis either, and illustrated a 
nominotypical melanopis captioned as branickii. 
Schulenberg el al. (2007: 80) reported that 
melanopis differs from branickii “by often 
showing a black throat wattle...: paler (sometimes 
almost white) wing coverts, more extensive black 
on belly, and generally darker buff lower breast 
and belly”. Two reviews pre-dating Sibley and 
Monroe (1990), namely Blake (1977) and Fjeldsa 
and Krabbe (1990), offered similarly partial and 
even mistaken comparisons. Only Jaramillo 
(2003: 68), although not splitting the taxa, 
produced a reasonably close diagnosis: “Differs 
from melanopis in shorter bill, smaller wattle, 
more vivid and extensive cinnamon on cap and 
back of neck, paler breast and foreneck, and more 
restricted black belly”. 
The fullest and (as evidence assembled below 
reveals) best description of branickii to date, 
however, is the French original, von Berlepsch 
and Stolzntann (1894) reported that it differs from 
melanopis by the lack of a wattle (the mesial line 
being feathered), dirty white (not buffy-rufous) 
lower breast and beJiy. gray (not white) upper¬ 
wing-coverts, and longer wings and tail, although 
two features they used to distinguish branickii 
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