The Napo Sabrewing (Campylopterus villaviscensio) is a large, stunning hummingbird found in humid lowland and foothill forests of northeastern Ecuador and eastern Peru. This striking bird has vibrant emerald green upperparts, a glittering violet-blue throat, gray underparts, and a deeply forked black tail. The Napo Sabrewing is a member of the hummingbird family Trochilidae and is placed in its own monotypic genus Campylopterus. This species was first described by the German ornithologist Jean Cabanis in 1872 based on a trade skin specimen from Napo Province in Ecuador.
The male Napo Sabrewing reaches around 16-18 cm in length and weighs 9-12 grams, making it one of the larger hummingbird species in South America. Females are slightly smaller at 14-15 cm. Both sexes have a long, strongly decurved black bill that measures around 35 mm. The male’s plumage is primarily a bright metallic emerald green above, including on the crown, back, rump, and wing coverts. The underparts are pale grayish from the throat to undertail coverts. The most striking feature is the male’s iridescent violet-blue throat that dazzles in direct sunlight. Females are similar but less vibrant, with a pale gray throat and breast, duller green upperparts, and distinct white spotting on the tail.
In flight, the male’s deeply forked tail and broad wings make the Napo Sabrewing instantly recognizable. The outer tail feathers measure around 55 mm and are boldly marked with white. Females have a slightly shorter and less forked tail. Juveniles resemble adult females but have buffy edges to their plumage feathers. The Napo Sabrewing’s flight is described as slow and floppy, with quick wingbeats interspersed by glides. In courtship displays, the male flies in exaggerated u-shaped patterns to show off his iridescent colors.
Distribution and Habitat
The Napo Sabrewing is endemic to the upper Amazon basin of northeastern Peru and eastern Ecuador. Its range extends along the eastern slope of the Andes from southern Colombia south to the Cordillera del Cóndor. Within Ecuador, it occurs from the Río Napo south to the Río Pastaza, with isolated records further south along the Río Marañón. There are also records from the north bank of the Amazon River in Loreto, Peru.
This species inhabits humid lowland and foothill rainforests at elevations between 100-1500 m. It prefers primary forest, forest edges, and second growth with an abundance of flowering plants. The Napo Sabrewing is often found along forested rivers and streams where territories are established. It appears to be resident across its range and does not undertake migrations.
Behavior and Ecology
The Napo Sabrewing lives solitarily or in pairs. Males appear to be territorial, using their wing displays during breeding season to advertise ownership and ward off intruders. Courtship consists of aerial displays where males fly in wide arcs and circles to show off their plumage. Mating likely occurs on exposed perches.
Females alone build the nest, selecting an open cup-like structure made of plant fibers bound with spider webs situated out on a vertical tree limb or vine. Typical clutch size is two white eggs which are incubated by the female for 15-19 days. The chicks remain in the nest for another 22-26 days before fledging. Little is known about this species’ breeding biology across the range.
Feeding occurs from low growth up to the subcanopy on a variety of rainforest flowers, including from heliconias, bananas, and bromeliads. The Napo Sabrewing favors flowers with sturdy structures and upward or horizontal orientation, and those with pink or purple coloration. It uses its specialized decurved bill to access nectar. This species is important for pollination of understory plants in Andean foothill forests.
The Napo Sabrewing has a relatively broad distribution across northern Amazonia but occurs at naturally low densities. Its total population size is unknown but estimated to number fewer than 50,000 individuals. Habitat loss from deforestation poses the greatest threat, especially at elevations below 500 m. The species is also potentially threatened by climate change as temperatures increase in its Andean foothill range.
The Napo Sabrewing is evaluated as Near Threatened on the IUCN Red List of Threatened Species. It has been recorded in several protected areas throughout its range which offer refuge from forest destruction. Further survey work is needed to assess population trends and identify key sites for continued protection efforts. Maintaining connectivity of humid lowland forests will be important for the long-term preservation of this rare hummingbird.
– The Napo Sabrewing was named for its strongly hooked bill, resembling a “saber”, that is adapted for nectar-robbing from long floral tubes. The Latin name Campylopterus translates to “bent wing”.
– Compared to other hummingbirds, the Napo Sabrewing has relatively short wings in relation to its body size and weight. This gives it highly maneuverable but slow flight.
– The iridescent colors on the Napo Sabrewing’s throat are not from pigments, but result from the physical structure of the feathers that refracts light. Small air bubbles and melanin granules in the keratin cause wavelength-specific scattering.
– Like all hummingbirds, the Napo Sabrewing has unique adaptations like a camera-shutter tongue that extends to capture nectar and a double ball-and-socket shoulder joint that allows it to hover and fly backwards.
– The Napo Sabrewing was featured on a postage stamp issued by Ecuador in 2004, highlighting the country’s avifauna. It has also appeared on gold and silver commemorative coins.
In summary, the Napo Sabrewing is a little-known but spectacular hummingbird inhabiting the lowland forests of the western Amazon. Its specialized morphological traits allow it to thrive in its humid forest home. Ongoing protection of primary rainforest habitats will be crucial for ensuring the persistence of this unique and striking bird into the future.