The Red-billed Streamertail (Trochilus polytmus) is a medium-sized hummingbird found exclusively on the Caribbean island of Jamaica. With its long, deeply forked tail and bright red bill, the red-billed streamertail is considered one of the most distinctive and beautiful hummingbird species in the world. This article will provide a comprehensive overview of the red-billed streamertail, including its taxonomy, physical description, habitat, diet, behavior, reproduction, conservation status, and cultural significance.
Taxonomy
The red-billed streamertail belongs to the avian family Trochilidae and the genus Trochilus. It was first described by the French naturalist Louis Jean Pierre Vieillot in 1817. The species name polytmus comes from the Greek words poly meaning “many” and tomus meaning “cutting”, referring to its deeply forked tail. The red-billed streamertail has three recognized subspecies:
– Trochilus polytmus polytmus – The nominate subspecies found throughout most of Jamaica.
– Trochilus polytmus scitulus – The “Blue Mountain streamertail”, found only in the Blue Mountains and John Crow Mountains of eastern Jamaica. Slightly smaller with more iridescent plumage.
– Trochilus polytmus sclateri – The “black-billed streamertail” found only in western Jamaica. Has a black upper mandible unlike the red bill of other subspecies.
Some taxonomists consider the black-billed streamertail to be a separate species, Trochilus sclateri. More research is needed to determine the exact taxonomic classification. Overall, the red-billed streamertail belongs to the larger Caribaean assemblage of streamertail hummingbirds found throughout the Caribbean islands.
Physical Description
The most distinctive feature of the red-billed streamertail is its long, deeply forked tail, which can measure up to 8 cm in adult males. The tail feathers are elongated and taper to fine points, giving the bird a unique streamer-like appearance in flight.
Adult males measure on average 10-12 cm long and weigh 4-5 grams. Females are slightly smaller at 9-11 cm long with a mass of 3-4 grams. As the common name suggests, the bill of the red-billed streamertail is bright red with a black tip. The upperparts are mostly iridescent green, while the underparts are white. The throat and breast show some light grey spotting. The legs are short and black.
Females have slightly duller plumage overall with more grey spotting on the underside. Immature birds resemble adult females but with even less pronounced forked tails. The red bill appears in the first year. Overall, the plumage pattern does not vary significantly across the subspecies, with the black-billed streamertail being the main exception.
Habitat
The red-billed streamertail occupies a variety of forest and woodland habitats across Jamaica from sea level up to over 1500 m elevation. This includes tropical rainforests, mountain forests, elfin forests, wooded gullies, forest edges, and cultivated areas like gardens and plantations.
The species seems to prefer landscapes with a mosaic of small forest patches, edges, and openings like light gaps. It is commonly found in humid broadleaf forests as well as drier, scrubby woodlands. Abundant flowering plants are critical for providing nectar. Overall, the red-billed streamertail is flexible and adaptable in its habitat as long as there are sufficient flowers and some trees or tall shrubs for perching.
Diet
Like all hummingbirds, the red-billed streamertail feeds almost exclusively on plant nectar and tiny insects and spiders. Its long, slender bill is perfectly adapted for accessing nectar from flowers. The red-billed streamertail will visit the flowers of over 100 different plant species, though it prefers flowers with long, tubular corollas where it can reach the nectar with its specialized tongue. Some favorite nectar sources include heliconia, fuchsia, and hibiscus flowers.
The red-billed streamertail supplements its diet with small arthropods like flies, mosquitoes, aphids, and spiders. It gleans these from foliage and the air while hovering. This provides protein and fat to support the high metabolic demands of hovering flight. The ratio of nectar to insects in the diet varies across seasons and availability. Like other hummingbirds, the red-billed streamertail has high energy requirements and must consume over half its body weight in nectar each day. It feeds every 10-15 minutes while active during the day.
Behavior
The red-billed streamertail displays some interesting behaviors and adaptations related to its unique lifestyle and feeding habits. It is a tireless, acrobatic flyer capable of precision hovering in place as it accesses flowers. The wings beat an estimated 70 times per second! This rapid wingbeat produces the characteristic humming sound. The streamer-like tail provides stability and maneuverability during flight.
The species is territorial and males will aggressively defend flower patches or feeding territories against intruders, engaging in aerial dive displays and chases. Red-billed streamertails are typically solitary. They perch relatively low in trees, vines, and shrubs between foraging bouts, allowing an easy escape.
Like most hummingbirds, the red-billed streamertail enters a nightly state of torpor to conserve energy. This is an adapted hypothermic state where the body temperature and metabolic rate are substantially reduced. This allows the small bird to survive on minimal energy reserves overnight.
Reproduction
The breeding season for the red-billed streamertail runs from January to June, coinciding with the dry season in Jamaica. Courtship displays include aerial pursuits and dive displays by the male as he repeatedly rises and plunges to impress the female. Once paired, the female will construct a small cup nest out of plant down, spider webs, and lichens camouflaged on a thin tree branch.
The female lays two tiny white eggs and incubates them alone for 15-20 days. After hatching, both parents participate in feeding the chicks with regurgitated food. The young fledge at about 20-25 days old but remain dependent on the parents for several more weeks. Red-billed streamertails likely raise 2-3 broods per season. Nest predators include snakes, lizards, and other birds. Parents may aggressively mob potential nest predators.
Conservation Status
The red-billed streamertail is classified as Least Concern on the IUCN Red List. Its population appears to be stable and the species remains relatively common across Jamaica. However, habitat loss from deforestation, urbanization, and agriculture poses threats, especially at lower elevations. Predation by introduced species like mongooses and rats may also impact nesting success.
Parts of the streamertail’s range are protected in reserves like the Blue and John Crow Mountains National Park. But increased habitat protection and limits on development will be important conservation measures going forward. Eco-tourism relies on charismatic species like the streamertail and can potentially provide incentives to preserve habitats. Continued monitoring of populations is recommended to detect any declines.
Cultural Significance
The red-billed streamertail holds a special place in Jamaican culture. Its unique forked tail feathers were prized by indigenous peoples and early settlers for decorative purposes. The hummingbird represented agility and precision. It remains the national bird of Jamaica and is featured on the country’s $2 coin. The species has come to symbolize freedom, beauty, and independence for Jamaica.
Many Jamaican businesses, sports teams, and institutions use the streamertail in their logos and branding. The vibrant red-billed streamertail continues to be an iconic living symbol of Jamaica that appears in artwork, stories, and jewelry across the island. Protecting this special bird into the future will ensure it remains a part of Jamaica’s national identity and natural heritage.
In summary, the red-billed streamertail is a fascinating and beautiful tropical hummingbird species found only in Jamaica. Its specialized adaptations for nectar-feeding including wing morphology and feeding behaviors represent an evolutionary marvel. While currently stable, increased habitat protection and monitoring will be needed going forward to ensure the streamertail remains a vibrant part of Jamaica’s ecosystems and culture. This unique long-tailed hummingbird serves as a symbol of freedom and beauty for the Jamaican people.