Peruvian Sheartail

Common name: Peruvian Sheartail
Scientific name: Thaumastura cora
Clades: Mellisugini - Bees

The Peruvian Sheartail is a captivating sight, darting from flower to flower or floating elegantly over their territory. His elongated tail-streamers, with eye-catching white patches, flutter and whip behind him, lending a sprightly, airy quality to his flight. During courtship, the male showcases his inner tail feathers by holding them stiffly out to the sides, splitting his tail in a dramatic display. This energetic courtship involves rapid back-and-forth flights in front of the female, with his glittering gorget flared, producing strident squeaks and a thin whining sound with his outer tail feathers.

The adult male Peruvian Sheartail is adorned in dull metallic green, with his head bearing traces of buff and the green shade darkening towards the tail. His inner rectrices (R1) are short, barely extending beyond the green uppertail coverts, dark green on the outside vane and white on the inner vane. The second rectrices (R2) are highly distinctive, elongated with black tips and outer vanes, and white inner vanes. The outer rectrices (R3, R4, and R5) are progressively shorter, black with white-tipped outlines. His wings are dusky, and his face features dark green loral and orbital regions with a small white postocular spot. The gorget on his throat and neck is brilliant iridescent magenta in direct light, turning to cyan and then black as the viewing angle changes. His breast is off-white to light gray, forming a white collar around the gorget that does not extend to the dorsal surface. The flanks transition gradually from green dorsally to grayish-white on the belly, sometimes tinged with traces of beige. His femoral tufts and undertail coverts are white.

The female is similar to the male but has a faint beige tinge throughout her plumage, including the green of her dorsal surface, throat, and flanks. She lacks a gorget; her throat is cream-colored with a trace of beige and few if any, darker feathers. Her upper breast is less white than the male’s, with traces of beige. Her tail is not as elongated, with inner rectrices (R1) off-white basally and distally bronzy green on the outer web, grading from light proximally to nearly black distally. The second rectrices (R2) are the longest, with a white spot on the proximal inner vane and tip, and dark black elsewhere. The third rectrices (R3) have white on both the proximal inner and outer vane tips, with black elsewhere, while the fourth and fifth rectrices (R4 and R5) are black with white tips.