Cocoa Woodcreeper (Xiphorhynchus susurrans) [XC274076]
by Peter Boesman from La Selva biological station, Heredia, Costa Rica (call)
Cocoa Woodcreeper (Xiphorhynchus susurrans) [XC361040]
by Kent Livezey from Pipeline Road, Soberania National Park, Panama (song)
Subspecies
Xiphorhynchus guttatus (Sibley and Monroe 1990, 1993) was split into Cocoa Woodcreeper (Xiphorhynchus susurrans) and Buff-throated Woodcreeper (Xiphorhynchus guttatus) following AOU (1998); Dusky-billed Woodcreeper (Xiphorhynchus eytoni) (Sibley and Monroe 1990, 1993) is now lumped with Xiphorhynchus guttatus following SACC (2005), who also recognise Cocoa Woodcreeper (Xiphorhynchus susurrans).
Sister to Buff-throated Woodcreeper (Xiphorhynchus guttatus) and treated by most authors as conspecific, but recently elevated to full species on grounds of differences in calls and body size. However, geographical patterns in songs more complex than previously realized, and size differences do not correspond to species limits as presently recognized. No published data support recognition by most recent authors of "nanus group" with Cocoa Woodcreeper (Xiphorhynchus susurrans) instead of Buff-throated Woodcreeper (Xiphorhynchus guttatus). Two subspecies groups, differing markedly in plumage patterns: "susurrans group" (with jardinei and margaritae) in east of range (Trinidad, Tobago, Margarita I and adjacent Venezuelan mainland), and "nanus group" (including all remaining subspecies) in Central America, northern Colombia and northern and western Venezuela. Preliminary molecular analyses suggest close affinity of "nanus group" to nominate Buff-throated Woodcreeper (Xiphorhynchus guttatus) and allied subspecies polystictus, but populations in "susurrans group" were not included in the analyses. Birds from north-eastern Colombia and adjacent north-western Venezuela, described as subspecies demonstratus, considered inseparable from nanus.
The following 8 subspecies are recognised:
confinis (Bangs, 1903) - Caribbean slope of eastern Guatemala and northern Honduras.
costaricensis (Ridgway, 1888) - Central America, on both slopes, from south-eastern Honduras to western Panama (western Chiriquí, western Bocas del Toro).
marginatus Griscom, 1927 - Pacific slope of central Panama (eastern Chiriquí, Veraguas and western Azuero Peninsula).
nana (Lawrence, 1863) - Both Caribbean and Pacific slopes of eastern Panama (west to Canal Zone and eastern slope of Azuero Peninsula), northern Colombia (east to western Guajira, Atrato Valley, lower Cauca Valley, upper Magdalena Valley south to Tolima, and east of Andes in north-western Arauca) and western and northern Venezuela (Zulia, Táchira and western Apure east to eastern Miranda).
rosenbergi Bangs, 1910 - Upper Cauca Valley in Valle (western Colombia).
BirdLife International Species Factsheet