Trochilus polytmus

Geographic Range

Red-billed streamertails ( Trochilus polytmus ) are indigenous to Jamaica. This species of hummingbird inhabits the majority of the island; however, their population has declined in the eastern areas. They have ceased to inhabit the extreme northeastern coastal areas, which are now mostly inhabited by another type of hummingbird, black-billed streamertails . Hybrids of these species may be found in regions where their populations overlap.

• Biogeographic Regions
• neotropical neotropical
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

Red-billed streamertails occupy a wide range of habitats. They are commonly found within, or along the edges of montane forests. This species also occupies man-made habitats including plantations, parks and gardens. They are most common at altitudes of approximately 1000 m (3000 ft) above sea level, but range from coastal areas to even higher elevations.

• Habitat Regions
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest
• rainforest rainforest
• mountains mountains

• Other Habitat Features
• agricultural agricultural

Physical Description

Like other hummingbirds, red-billed streamertails are a small species. Females average 10.5 cm in length, males are usually larger, ranging from 20 to 30 cm long. These lengths include a bill and tail; among males their lengths average 2.3 cm and 13 to 17 cm, respectively. On average, females weigh 4.4 g and males weigh 5.2 g.

Sexual dimorphism is very pronounced in this species. The upper section of a female's body is green, while the lower parts are white. The sides of their breasts and belly are lightly spotted. A female's tail is centrally green, while the remaining portions are dark blue. Their tails do not have streamers, but instead have outer feathers with white tips. Males have a straight coral red bill with a black tip. Females have a similar bill, although it is duller red and the distal part is black. Males have a black head and lateral crown feathers that extend beyond the nape, forming ear coverts. Their bodies are iridescent emerald green, which darkens towards the back. They have a black, forked tail. The feathers of their tail are uniformly graduated from the uropygial gland outwards, except for the second outermost tail feather (streamers). This particular tail feather is very long and is internally scalloped and fluted. These long tail feathers and the bird’s red colored bill accounts for the common name 'red-billed streamertail'. The streamers are often in a crossed position similar to that of an old-fashioned doctors coat tail, as a result, Jamaicans have nicknamed them 'doctor birds'.

• Other Physical Features
• endothermic endothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful
• ornamentation ornamentation

Reproduction

There are three distinct phases involved in the mating rituals of red-billed streamertails. In the first phase, the female flies into the male’s territory, lands close to the male and the two begin threatening each other. In the second phase, the female holds her head at a 45 degree angle and shakes her head up and down. The male follows suit, when the head shaking becomes synchronized, the male begins the final phase. In the third phase, the male uses his bright feathers to attract females for mating by displaying a U-shaped flying pattern accompanied by rhythmic chirping. This flying display involves hovering and tail waving, which results in the display of their streamers. Four to six rounds of mating rituals usually occur before copulation takes place.

• Mating System
• polygynous polygynous

Red-billed streamertails breed year-round. However, the peak of breeding occurs from January to mid-May. The clutch of these birds, as with most hummingbirds, contains two eggs laid in a cup-shaped nest made up of plant fibers, cobwebs and lichens. The eggs are usually bean-sized, white, non-glossy and elliptical to oval shaped. Their incubation period generally lasts from 17 to 19 days. The eggs may hatch synchronously; however, there can be up to a 48 hour difference in the hatching times. Hatching is followed by a fledging period that lasts 19 to 24 days. Young remain under the care of the female for 3 or 4 weeks. Red-billed streamertails can produce up to 3 clutches, resulting in a maximum of 6 offspring per year.

• Key Reproductive Features
• iteroparous iteroparous
• year-round breeding year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• induced ovulation induced ovulation
• fertilization fertilization
• oviparous oviparous

Male involvement in reproduction is limited to copulation. Female red-billed streamertails are solely responsible for the pre-hatching to pre-independence care and of their offspring, which also includes making and repairing the nest. Their offspring are born blind, with their eyes still closed and almost no feathers, except for the two dorsal rows of neossoptile down, which measures approximately 5 mm. At this stage of development, offspring are inactive and fed solely by their mother through regurgitation. This feeding mode continues until they are independent.

• Parental Investment
• altricial altricial
• female parental care female parental care
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

The population dynamics of red-billed streamertails have seldom been studied and remain unknown. As such, little to no information is known regarding their survivorship and lifespan.

Behavior

The feeding behavior of red-billed streamertails includes hovering in the air, appearing motionless. This consistent hovering has caused them to not use their feet for walking or climbing, but rather for perching, grasping and clinging. The consumption of primarily high-calorie, extremely sweet nectar contributes to intense individual competition. As a result, both males and females are solitary and extremely territorial. They aggressively defend their territory against invasions by competitors including conspecifics and large insects, such as hawk moths . While defending their territory, red-billed streamertails perform aerial flights and other intimidating displays. They usually perch on high exposed branches as lookout points for possible intruders. Male's tufts become erect when an intruder is spotted and they send out a high ‘zeet’ call. If the intruder persists, the male will fly with its bill open and head feathers erect. Continued resistance causes the hummingbird to engage in a usually non-harmful claw attack. Females respond to intruders by sitting with their bill open and turning their head. If the intruder decides not to leave, she sends out alarm calls. If that does not work, the female will fake an attack on the intruder with its bill.

Red-billed streamertails are known to bathe quite regularly, taking both sunbaths and water baths. Sunbathing is a behavior seen in males, especially among those that inhabit cool montane forests. It is achieved by first spreading their wings widely with the primaries nearly touching the outer rectrices. Males hold their wings motionless for several minutes, in a position perpendicular to the sunlight. Red-billed streamertails take water baths by splashing in shallow water including water found in bird baths and fountains. They also cling to rocks beside waterfalls, allowing their bodies to gather moisture and splash from the flowing water as they vibrate their wings and fluff their bodies.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• daily torpor
• solitary solitary
• territorial territorial

Home Range

The home range size of red-billed streamertails is currently not known.

Communication and Perception

Both male and female red-billed streamertails use vocalizations to communicate. Their voices are commonly heard in their habitats, these birds are often heard before they are seen. Their calls usually include a sharp, loud, high-pitched ‘teeet-teeet’ or ‘tee-tee-tee’, a loud and metallic-sounding ‘ting, ting’ or ‘chink-chink’ and a prolonged ‘twink-twink-twink’ that has a dropping pitch at the end. These calls are mainly used to communicate during mating and when defending their territory. Calls are also used by the offspring during the latter part of their dependent development. Apart from vocalizations, males produce a non-vocal sound using their streamers. Because they are scalloped and fluted on the inside, they produce a whirring, humming sound when fluttered during flight.

Red-billed streamertails usually consume extremely sweet nectar; they are attracted by the bright colors (usually red) and the scent of the flowers. They also use visual perception when they are mating, as seen when males try to impress females, or when they are defending territories, in the form of erect feathers and attacks.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic

• Other Communication Modes
• vibrations vibrations

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Like most other hummingbirds, red-billed streamertails have a daily sugar consumption of up to half their body mass in order to fulfill the energy needs associated with hovering flight. Their main source of food is extremely sweet, high-calorie, high energy nectar taken from brightly colored, fragrant flowers of a wide variety of trees, herbs, shrubs and epiphytes. They feed on native and introduced plant species found on the island including the genera Hohenbergia , Bauhinia , Meriania , Tecoma , Besleria , Psychotria , Erythrina , Eucalyptus , Spathodea and Calliandra . They usually feed on tubular-shaped flowers. They feed on nectar by inserting their long beaks into the tubes of these flowers, before using their long, extendable, straw-like tongue to collect the nectar, licking it up to 13 times per second. Red-billed streamertails feed in a hovering position, some feed while hanging on to the flowers.

Red-billed streamertails also feed on small insects, 3 cm to 20 m above ground. They feed on insects from the air, or eat them off of leaves, flowers and branches, as well as small spiders from webs. It is more common for females to consume insects than males. Insects may provide necessary protein during breeding periods to ensure the proper development of offspring. In addition, they sometimes feed on alternate sources such as the fruits of cat's claw plants that have been previously opened by other birds. They may also feed from holes in Eucalyptus trees made by yellow-bellied sapsuckers and drinking sugar water from local hummingbird feeders. They drink water from bird baths and water fountains by hovering and sipping the water that runs over the edge, or by perching on the edge while drinking.

• Primary Diet
• herbivore herbivore
  • nectarivore nectarivore

• Animal Foods
• insects

• Plant Foods
• nectar
• sap or other plant fluids

• Foraging Behavior
• stores or caches food stores or caches food

Predation

Apart from humans who occasionally destroy nests and damage eggs, red-billed streamertails have no known predators. There are currently no known studies on their anti-predatory mechanisms, or lack thereof.

Ecosystem Roles

Red-billed streamertails, as with many hummingbirds, occupy a unique niche in their environment. This is achieved via their flight agility, and more importantly, their ability to hover. Red-billed streamertails have established a symbiotic relationship (mutualism) with long tubular-shape flowers containing extremely sweet, high-calorie nectar and feed nearly exclusively on this nectar. The tubular-shape of these flowers makes them inaccessible to other organisms such as butterflies and bumblebees. As a result, red-billed streamertails are their primary pollinators.

Red-billed streamertails act as predators to flying insects, spiders and ants. However, they are not known to be preyed upon by any other species. As is the case with most Jamaican birds, red-billed streamertails are not commonly affected by parasites. The only known parasite to this species is Haemoproteus witti , a blood parasite that has a low prevalence of infection.

• Ecosystem Impact
• pollinates

Economic Importance for Humans: Positive

Until the 1960's, red-billed streamertails were widely trapped and used for the wild bird trade, but such activities are currently rare. These birds are pollinators for many plants that cannot be pollinated by other animals and they help in the pollination of plants found in man-made habitats such as parks and gardens. They also play a role in controlling the population of insects, some of which are pests. Red-billed streamertails also provide an opportunity for research and education in topics such as hybridization and flight energetics.

• Positive Impacts
• research and education
• pollinates crops
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of red-billed streamertails on humans.

Conservation Status

Red-billed streamertails have a restricted geographic range, but their population is sufficiently large to exceed the threshold of vulnerable status.

Additional Links

Encyclopedia of Life

Contributors

Aldane Hoilett (author), Indiana University-Purdue University Fort Wayne, Mark Jordan (editor), Indiana University-Purdue University Fort Wayne, Leila Siciliano Martina (editor), Texas State University.

References

Arlott, N. 2010. Birds of the West Indies . Princeton, NJ: Princeton University Press.

Brokaw, J. 2012. " Trochilus polytmus " (On-line). Cornell Lab of Ornithology. Accessed March 07, 2013 at http://neotropical.birds.cornell.edu/portal/species/research?p_p_spp=251771 .

Gill, F., F. Stokes, C. Stokes. 1973. Contact Zones and Hybridization in the Jamaican Hummingbird, Trochilus polytmus (L.). The Condor , Vol. 75 No.2: 170-176. Accessed March 07, 2013 at http://www.jstor.org/stable/10.2307/1365864 .

Gosse, P., R. Hill. 1847. The Birds of Jamaica . London: John Van Voorst, Patternoster Row. Accessed March 07, 2013 at https://play.google.com/books/reader?id=FyxOAAAAcAAJ&printsec=frontcover&output=reader&authuser=0&hl=en&pg=GBS.PR1 .

2003. Trochilus polytmus . Pp. 463-464 in Grzimek's Animal Life Encyclopedia , Vol. 9, Second Edition. Farmington Hills, MI: Gale.

2009. Hummingbirds. Pp. 352-361 in The Princeton Encyclopedia of Birds , Vol. 1, First Edition. Princeton, NJ: Princeton University Press.

2012. "Red-billed Streamertailed Hummingbirds" (On-line). AvianWeb.com. Accessed March 07, 2013 at http://www.avianweb.com/redbilledstreamertailhummingbirds.html .