Slender Sheartail Hummingbird Species

The Slender Sheartail (Doricha enicura) is a small hummingbird found in tropical Central and South America. With an average body length of only 7-8 centimeters, it is aptly named for its slender body and elongated outer tail feathers. This diminutive bird has green upperparts and a dull white underbelly, with the male distinguished by its iridescent violet throat patch. The Slender Sheartail inhabits a range of forest and woodland habitats from sea level up to 2500 meters in elevation. Here we will explore the classification, physical characteristics, habitat, diet, behavior, reproduction, conservation status, and cultural significance of this delicate yet captivating hummingbird species.

Classification and Taxonomy

The Slender Sheartail belongs to the family Trochilidae and the order Apodiformes. Trochilidae encompasses all hummingbird species, while Apodiformes also includes swifts and treeswifts. Its scientific name is Doricha enicura, with the genus Doricha containing 6 other closely related sheartail hummingbird species. It has no recognized subspecies. This genus was previously classified under the catch-all “hermit hummingbird” genus Phaethornis by early ornithologists, but Doricha is now defined as a distinct group. The Slender Sheartail’s two closest relatives within Doricha are the Long-tailed Sheartail and the Black-hooded Sunbeam.

Physical Description

The most prominent features of the Slender Sheartail are its small size, slender build, medium-long bill, and elongated outer tail feathers. As mentioned, it measures only 7-8 cm in total body length, making it one of the smallest hummingbird species in the world. Its weight averages between 2-3 grams.

The plumage of both sexes is predominantly bright emerald green on the upperparts and crown. The underparts are dull white from the throat to vent. The male Slender Sheartail can be uniquely identified by its brilliant violet, gorget-shaped throat patch, a trait absent in females. The tail is forked, with the outer two feather pairs sharply elongated, measuring 2.5-3 cm in the male and slightly shorter in the female. The slender black bill measures around 13-15 mm long and slightly decurved. Leg color ranges from brownish to pale pink.

Habitat and Distribution

The Slender Sheartail occupies a wide range of forest and woodland habitats across Central and South America. Its range extends from southern Mexico through Panama, and south to Bolivia, Paraguay, and northern Argentina. This species occurs at elevations from sea level up to 2500 m, most commonly between 500-2000 m.

Preferred habitats include humid montane forest, cloud forest, and foothill forest. It also readily inhabits secondary forest, selectively logged areas, forest edge, semi-open woodland, and shade coffee plantations with sufficient understory vegetation. Larger trees and ample flowering plants help sustain their nectar requirements. The Slender Sheartail’s small size allows it to occupy partially open areas and exploit scattered patches of flowers and small trees. However, it avoids open savannahs and human settlements.

Diet and Feeding

Like all hummingbirds, the Slender Sheartail subsists primarily on sugar-rich floral nectar, as well as small arthropods for protein. Its specialized bill and tongue allow it to lick up nectar at an extremely high lick rate of around 10-15 licks per second. This constant nectaring provides the high energy needs required to power its rapid metabolism and flight muscles.

Small insects like gnats, aphids, spiders, caterpillars supplement its diet with protein and nutrients. The Slender Sheartail typically hawks insects from flowers and other perches by sallying out to catch them mid-air. It favors certain plants with abundant nectar and insects, including fuchsias, lobelias, and epiphytic bromeliads. However, it visits a wide variety of flower species across different habitats.

Behavior and Flight

The Slender Sheartail displays very active, energetic flight and movement while foraging. It has extremely quick wingbeats up to 70 beats per second, allowing acrobatic maneuverability. Males are highly territorial, using aerial displays to chase intruders from flower patches and other defended feeding sites. Chasing and aggression peaks during the breeding season.

Outside of the breeding territory, this species exhibits trap-lining foraging behavior. It continually visits a regular circuit of productive flowers in succession rather than defending a feeding territory. Trap-lining allows more efficient nectar harvesting from a variety of flower types. The Slender Sheartail is solitary or seen in pairs outside the breeding season. It interacts aggressively with other hummingbirds.

Reproduction and Breeding

The breeding season of the Slender Sheartail varies across its range, typically tracking periods of increased flower availability. In Central America and Mexico, breeding occurs primarily from November to April during the dry season. Further south, timing shifts to align with seasonal flowering following equatorial rainy and dry periods.

Males perform elaborate courtship displays to attract females, including aerial dancing and shuttle displays where they fly rapidly back and forth through the territory. If a female perches in the defended area, the male may commence mating by grasping onto her back to transfer sperm.

The female alone builds the small cup nest, which is delicately crafted from soft plant fibers and spider silk. It is well camouflaged, placed along a branch, tree fork, or other sheltered site up to 15 meters high. The female lays only two tiny white eggs. She alone incubates the eggs for 15-19 days until hatching. The chicks are fed regurgitated food by the female and fledge at approximately 20-26 days old. The female may raise two broods per season.

Conservation Status

The Slender Sheartail is currently classified as Least Concern by the IUCN Red List. Its large range and population are presumed stable, with no major threats. Total population size has not been quantified but is thought to number in the millions. However, some localized declines have occurred in Costa Rica and other parts of Central America due to habitat loss. Expanding agriculture and urbanization are the primary threats throughout its range. The species readily inhabits fragmented forest and modified habitats, provided adequate flowers and nest sites still exist. Targeted conservation efforts are not deemed necessary given its overall population health, but continued habitat preservation across its range will be important for its long-term persistence.

Cultural Significance

With its diminutive size, energetic flight, and iridescent colors, the Slender Sheartail contributes to the wonder of nature appreciated by cultures across its range. It is a highlight for birdwatchers and ecotourists visiting Neotropical forests, sought after for its beauty and charm. This species has been featured on postage stamps in several Latin American countries. While not an economic resource, it helps pollinate various plants, including rare endemic orchids. The Slender Sheartail serves as an indicator of ecosystem health, with its presence signaling intact forest habitat. Continued appreciation of this and other hummingbirds supports habitat conservation across Latin America, ensuring we may continue to enjoy their diversity. In sum, the Slender Sheartail exemplifies the delicate splendor of hummingbirds and remains a captivating contribution to tropical ecosystems.