449

BLACK [VARIABLE] SEEDEATER  Sporophila [corvina] corvina (p. 394). See above under Hick’s

Seedeater.

BLUE SEEDEATER  Amaurospiza concolor (p. 396). Based purely on genetic lineages, IOC split the

concolor group (s. Mexico to Panama) and aequatorialis group (sw. Colombia to n. Peru) as species.

Morphology and voice of all Amaurospiza are similar, and Ecuadorian birds respond aggressively to songs

from Mexican birds (Howell, pers. obs.). Moreover, samples used in studies to date are very small, and it

seems equally plausible to subsume most or all taxa as subspecies of a widespread Blue Seedeater (Howell

& Dyer 2022).

SOUTHERN BLACK-FACED GROSBEAK  Caryothraustes [poliogaster] scapularis (p. 400). Differences

in plumage and voice indicate that the scapularis group (e. Honduras to Panama) and poliogaster group

(Mexico to w. Honduras, Northern Black-faced Grosbeak) are best treated as separate species. Mexican

birds ignore Costa Rica recordings but respond strongly to their own vocalizations (R. C. Hoyer, pers.

comm.), and vocal differences are appreciably greater than, e.g., those between Rose-breasted and Black-

headed Grosbeaks in N America, which are treated as species.

RED-THROATED ANT-TANAGER  Habia fuscicauda (p. 404). Seemingly minor differences in voice

and morphology suggest that the salvini group (Mexico to n. Nicaragua; Salvin’s Ant-Tanager) and fusci­

cauda group (s. Nicaragua to n. Colombia; Cabanis’s Ant-Tanager) may represent separate species.

MIDDLE AMERICAN [RED-CROWNED] ANT-TANAGER  Habia [rubica] rubicoides (p. 404). Differ-

ences in voice and morphology indicate that the rubicoides group (e. Mexico to Panama) is best treated as

a species separate from populations of the Red-crowned Ant-Tanager complex in S America.

COMMON BANANAQUIT  Coereba [flaveola] luteola (p. 410). Differences in voice and morphology

suggest that the luteola group (mainland Americas) may represent a species separate from the flaveola

group (Caribbean region), which likely comprises multiple species.

BLUE-GRAY TANAGER  Tangara episcopus (p. 410). Striking plumage differences between the cana

group (Mexico to nw. Peru; Northern Blue-gray Tanager) and episcopus group (S America, e. of Andes;

Amazonian Blue-gray Tanager) suggest separate species may be involved.

WHITE-SHOULDERED TANAGER  Loriotus luctuosus (p. 418). Differences in morphology and provi-

sionally in voice between the axillaris group (Honduras to Panama, Caribbean slope; Costa Rican Tana-

ger), nitidissimus group (Costa Rica to Panama, Pacific slope; Chiriqui Tanager), and widespread luctuosus

group (cen. Panama to S America; White-shouldered Tanager) suggest they may represent separate species.

WHITE-THROATED SHRIKE-TANAGER  Lanio leucothorax (p. 420). Differences in plumage and

provisionally in voice suggest that the leucothorax group (Honduras to Panama, Caribbean slope) and

melanopygius group (Costa Rica to Panama, Pacific slope; Black-rumped Shrike-Tanager) may best be

treated as species, with a narrow hybrid zone in w. Panama (Kennard & Peters 1927, Wetmore et al.

1984).

GRAY-HEADED TANAGER  Eucometis penicillata (p. 420). Differences in morphology and voice be-

tween the spodocephalus group (Mexico to nw. S America; Northern Gray-headed Tanager) and penicillata

group (widespread in S America) suggest they may represent separate species.

SCARLET-RUMPED CACIQUE  Cacicus microrhynchus (p. 424). Differences in voice and morphology

indicate that the microrhynchus group (Honduras to Panama) and pacificus group (nw. S America; Pacific

Cacique) are best treated as separate species.

YELLOW-BILLED CACIQUE  Amblycercus holosericeus (p. 428). Differences in voice and morphology

suggest that the holosericeus group (Mexico to w. Peru; Western Yellow-billed Cacique) and australis group

(Colombia to Bolivia, e. of Andes; Eastern Yellow-billed Cacique) may represent separate species.