Green Torntail (female)

Quick Facts

• Scientific Name: Discosura conversii
• Spanish Name: Colacerda verde
• Family: Trochilidae
• Known Nicknames: Convers's Thorntail
• Average Length: 7.5–10 cm / 3.0–3.9 in
• Average Weight: 3.0–3.5 g / 0.11–0.12 oz
• Wingspan: 10–12 cm / 4.0–4.7 in
• Key Feature: Prominent white rump band and heavily spotted green-and-white underparts
• Primary Diet: Nectarivore and Insectivore
• Range: Central America to South America (Costa Rica to Western Ecuador)
• Habitat: Canopy and edges of humid montane and lowland forests
• Social Structure: Solitary
• Nesting/Breeding: Small cup nests high in tree canopies
• Conservation Status: Least Concern (LC)
• Population Trend: Stable

The female Green Torntail (*Discosura conversii*) is a diminutive and elusive hummingbird of the humid forest canopy, distinguished from its flamboyant male counterpart by its subtle yet intricate plumage. Shimmering with metallic green upperparts, she features a characteristic white band across a coppery-bronze rump, a hallmark of the *Discosura* genus. Her most striking facial feature is a bold white malar stripe that cuts across her dark cheeks, contrasting sharply with her dusky, white-spotted underparts. While she lacks the male’s namesake elongated tail feathers, her shorter, notched tail and petite frame allow her to zip through the treetops with remarkable agility as she forages for nectar and small insects.

Fun Facts

The female Green Thorntail is a master of mimicry, often mistaken for a large bee or a hawkmoth due to her tiny size and rapid, darting flight patterns. While she lacks the long, wire-like tail feathers of the male, she sports a distinctive white "mustache" streak and a prominent white rump band that flashes like a signal during flight. A clever strategist, she frequently engages in "trap-lining," memorizing a specific circuit of flowers and visiting them in a precise order throughout the day. She is also known to be a "nectar thief," using her sharp bill to pierce the base of long tubular flowers to steal nectar that she otherwise couldn't reach, bypassing the plant's pollination process entirely.

Habitats & Distribution

This species is primarily distributed across Central and South America, with a range extending from central Costa Rica through Panama and into the Pacific lowlands and foothills of western Colombia and western Ecuador. It is most commonly found on the Caribbean slope in the northern portions of its range and transitions to the Pacific slope in its southern reaches. Its preferred habitats include the canopy and borders of humid evergreen forests, as well as adjacent tall second-growth forests and semi-open areas. It typically occupies elevations ranging from 300 to 1,400 meters above sea level, where it is frequently observed foraging among flowering trees and epiphytes within the mid-to-upper levels of the forest strata.

Behaviours & Reproduction

Exhibiting a solitary and somewhat elusive nature, these birds primarily inhabit the high forest canopy where they engage in "trap-lining," visiting a sequence of flowering trees rather than aggressively defending a single territory. Their social structure is minimal, with interactions between individuals largely limited to brief territorial disputes or mating encounters. During the breeding season, the female takes on the entirety of the reproductive labor, from site selection to chick rearing, without any assistance from the male. She constructs a minute, cup-shaped nest positioned high on a thin branch, utilizing plant down and spider webs for structure and lichens for camouflage. Following a brief courtship display by the male, the female typically lays two eggs. She incubates them and subsequently feeds the hatchlings a diet of regurgitated nectar and tiny arthropods. This independent reproductive strategy allows the female to minimize activity around the nest, protecting her young from potential predators through stealth and isolation.

Diet

The female Green Thorntail primarily sustains itself on a diet of nectar sourced from a variety of flowering plants, particularly those located high within the forest canopy such as Inga and Calliandra trees. Utilizing its specialized tongue, it extracts sugar-rich nectar to fuel its incredibly high metabolism, often visiting epiphytes and vines in a strategic trap-lining pattern where it follows a consistent route between scattered food sources. To balance its nutritional needs with essential proteins, this hummingbird also consumes small arthropods, including midges and spiders, which it captures through aerial hawking or by gleaning them directly from foliage. Interestingly, because of its diminutive size and rapid energy expenditure, the female Green Thorntail must feed almost continuously throughout the day, often consuming more than its own body weight in nectar to maintain the energy levels required for its rapid wing beats.

Colors

The female Green Thorntail displays dark green upperparts and blackish underparts heavily speckled with metallic green. It is distinguished by a prominent white malar stripe on the face and a conspicuous white band across the rump. Its short, dark, slightly forked tail and overall dusky green tones provide effective camouflage within the dense, shadowed foliage of the tropical forest canopy.

Load More