448

BAIRD’S [OLIVE-CROWNED] YELLOWTHROAT  Geothlypis [semiflava] bairdi and CHIRIQUI

(MASKED) YELLOWTHROAT Geothlypis [aequinoctialis] chiriquensis (p. 368). Differences in voice,

morphology, and genetics suggest that both of these taxa are best treated as species. Molecular evidence

also indicates that Chiriqui is not closely related to the Masked Yellowthroat group of South America, but

instead is sister to Baird’s Yellowthroat (Escalante et al. 2009).

STRIPE-CROWNED [GOLDEN-CROWNED] WARBLER  Basileuterus [culicivorus] culicivorus (p. 370).

Differences in morphology and voice indicate that the culicivorus group (e. Mexico to Panama) is best

treated as a species separate from other taxa in the Golden-crowned Warbler complex in S America and

perhaps also from birds in w. Mexico.

PANAMA [ROSY] THRUSH-TANAGER  Rhodinocichla [rosea] eximia (p. 374). Differences in morph­

ology and voice suggest that the eximia group (Costa Rica to Panama) is best treated as a species separate

from other populations of the Rosy Thrush-Tanager complex, including Mexican [Rosy] Thrush-Tanager

R. [r.] schistacea and 2–3 potential species-level taxa in Colombia and Venezuela.

YELLOW-THROATED BRUSHFINCH  Atlapetes [albinucha] gutturalis (p. 376). Differences in mor-

phology and voice comparable to some other accepted brushfinch species suggest that the albinucha group

(e. Mexico; White-naped Brushfinch) and gutturalis group (s. Mexico to S America) are perhaps better

treated as separate species, as done for many years before being lumped with no convincing rationale.

ORANGE-BILLED SPARROW  Arremon aurantiirostris (p. 378). Distinct differences in both call and

song, coupled with minor plumage differences, suggest that the rufidorsalis group (Mexico to nw. Panama;

Northern Orange-billed Sparrow), aurantiirostris group (Costa Rica to nw. Peru; Western Orange-billed

Sparrow), and spectabilis group (s. Colombia to n. Peru, e. of Andes; Eastern Orange-billed Sparrow) may

represent separate species.

OLIVE SPARROW  Arremonops rufivirgatus (p. 380). Differences in morphology and song suggest that

the superciliosus group (Honduras to Costa Rica; Southern Olive Sparrow) may be specifically distinct

from n. populations of the Olive Sparrow complex, which comprises 4 additional groups. Based on

plumage, song, and ecology, the enigmatic taxon twomeyi of Honduras is also part of the Southern Olive

Sparrow group, despite inexplicably having been described (and still maintained) as a race of Green-

backed Sparrow A. chloronotus.

WHITE-EARED GROUND SPARROW  Melozone leucotis (p. 380). Differences in morphology and song

suggest that the occipitalis group (s. Mexico to El Salvador; Spectacled Ground Sparrow) and leucotis

group (Honduras to Costa Rica; Black-chested Ground Sparrow) may represent separate species. Also see

Sandoval et al. (2017).

STRIPE-HEADED SPARROW  Peucaea ruficauda (p. 382). Differences in morphology, plumage, and

voice suggest that the acuminata group (w. Mexico; Northern Stripe-headed Sparrow) and ruficauda

group (s. Mexico to Costa Rica; Southern Stripe-headed Sparrow) may represent separate species.

NORTHERN [WEDGE-TAILED] GRASSFINCH  Emberizoides [herbicola] sphenurus (p. 382). Differ-

ences in song and morphology suggest that the sphenurus group (Costa Rica to n. S America) is specifically

distinct from other populations in s. S America.

MIDDLE AMERICAN BUSH-TANAGER  Chlorospingus [flavopectus] ophthalmicus (p. 384). Dawn songs

of the ophthalmicus group (Middle America) are distinctly high-pitched vs. the low-pitched songs of the

flavopectus group (S America), supporting species status for these 2 groups; within each region there are

likely further cryptic species, but biological data (notably dawn songs) are sparse or lacking for many

regions and taxa.

ASHY-THROATED BUSH-TANAGER  Chlorospingus canigularis (p. 384). A large range disjunction

and plumage differences suggest the olivaceiceps group (Costa Rica to w. Panama; Olive-crowned Bush-

Tanager) may be specifically distinct from the canigularis group (S America) but we have found no

song recordings for olivaceiceps (calls of the two groups are similar, which may not be saying much with

Chlorospingus).

HICK’S [VARIABLE] SEEDEATER  Sporophila [corvina] ophthalmica (p. 392). Differences in plumage

and voice indicate that the ophthalmica group (Costa Rica to nw. Peru) and corvina group (Mexico to

Panama; Black Seedeater) are best treated as separate species, with a narrow and apparently stable hybrid

zone in cen. Panama (Olson 1981).