The red-billed streamertail (''Trochilus polytmus''), also known as the doctor bird, scissor-tail or scissors tail hummingbird, is a species of
hummingbird
Hummingbirds are birds native to the Americas and comprise the Family (biology), biological family Trochilidae. With approximately 366 species and 113 genus, genera, they occur from Alaska to Tierra del Fuego, but most species are found in Cen ...
in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is
endemic
Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to
Jamaica
Jamaica is an island country in the Caribbean Sea and the West Indies. At , it is the third-largest island—after Cuba and Hispaniola—of the Greater Antilles and the Caribbean. Jamaica lies about south of Cuba, west of Hispaniola (the is ...
and is the national bird of the country.
[HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 6. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v6_Dec21.zip retrieved August 7, 2022]
Taxonomy and systematics
The red-billed streamertail was
formally described by the Swedish naturalist
Carl Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
in 1758 in the
tenth edition of his ''
Systema Naturae
' (originally in Latin written ' with the Orthographic ligature, ligature æ) is one of the major works of the Sweden, Swedish botanist, zoologist and physician Carl Linnaeus (1707–1778) and introduced the Linnaean taxonomy. Although the syste ...
'' under the
binomial name
In taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, altho ...
''Trochilus polytmus''. Linnaeus quoted the description in Latin by the Irish physician
Patrick Browne in his ''The Civil and Natural History of Jamaica'' which had been published two years earlier in 1756. The specific epithet ''polytmus'' is from the
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...
''polutimos'' meaning "costly" or "valuable".
The
International Ornithological Committee
The International Ornithologists' Union (IOU) is an international organization for the promotion of ornithology. It links basic and applied research and nurtures education and outreach activities. Specifically, the IOU organizes and funds global co ...
(IOC),
BirdLife International
BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding i ...
's ''
Handbook of the Birds of the World
The ''Handbook of the Birds of the World'' (HBW) is a multi-volume series produced by the Spanish publishing house Lynx Edicions in partnership with BirdLife International. It is the first handbook to cover every known living species of bird. ...
'', and the
Clements taxonomy treat the red-billed streamertail and
black-billed streamertail
The black-billed streamertail (''Trochilus scitulus'') is a species of hummingbird in the "emeralds", tribe Trochilini of subfamily Trochilinae. It is endemic to eastern Jamaica.HBW and BirdLife International (2021) Handbook of the Birds of the ...
(''T. scitulus'') as separate species. However, the North American Classification Committee of the
American Ornithological Society calls ''T. polytmus'' "streamertail" and assign the red-billed and black-billed forms to it as subspecies.
[Clements, J. F., T. S. Schulenberg, M. J. Iliff, T. A. Fredericks, J. A. Gerbracht, D. Lepage, S. M. Billerman, B. L. Sullivan, and C. L. Wood. 2022. The eBird/Clements checklist of birds of the world: v2022. Downloaded from https://www.birds.cornell.edu/clementschecklist/download/ retrieved November 10, 2022] The two species (or subspecies) interbreed in their narrow contact zone.[Brokaw, J. (2020). Streamertail (''Trochilus polytmus''), version 1.0. In Birds of the World (T. S. Schulenberg, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.stream1.01 retrieved September 5, 2022]
The species as defined by the IOC is monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...
: no subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...
are recognised.[
]
Description
The male red-billed streamertail is long including the tail streamers and weighs . The female is about long and weighs . The adult male has a coral red bill with a black tip. It has a dull black to blue-black crown; it and the nape form a deep velvety black crest. The rest of its upperparts are bright metallic green. Its tail is black with a green to bronzy green gloss. The next to outermost pair of tail feathers is very long, giving the species its English name. The male's face and most of its underparts are metallic yellowish green; the undertail coverts are blue-black or black with a bluish gloss. The adult female's bill is a duller red than the male's. Its upperparts are metallic bronze green to greenish bronze that is duller on the crown. Its tail lacks the male's streamers. Its central pair of feathers are bright bronze green and the rest black with some bronze green gloss, and the outermost two pairs have wide white tips. Its underparts are white with metallic bronze green spots on the breast and flanks. Immature males are similar to the adult but lack the tail streamers; its tail feathers have bronze green tips.[
]
Distribution and habitat
The red-billed streamertail is found throughout Jamaica except in the extreme eastern end, where the black-billed is found. It inhabits evergreen montane forest
Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...
, lowland tropical forest, and secondary forest
A secondary forest (or second-growth forest) is a forest or woodland area which has regenerated through largely natural processes after human-caused Disturbance (ecology), disturbances, such as Logging, timber harvest or agriculture clearing, or ...
. It shuns mangroves and arid highlands. In elevation it ranges from sea level to ; it is considered fairly common in the lowlands and abundant at middle and higher elevations.[
]
Behavior
Movement
The red-billed streamertail is an elevational migrant.[
]
Feeding
The red-billed streamertail forages for nectar at a wide variety of native and introduced flowering species; it especially prefers '' Besleria lutea''. It forages at all heights from the ground to the canopy. It has also been observed "robbing" nectar from holes in flowers created by bananaquits (''Coereba flaveola'') and visiting wells drilled by yellow-bellied sapsuckers (''Sphyrapicus varius''). In addition to nectar it feeds on small insects taken while hovering or gleaned from foliage or spiderweb.[
]
Breeding
Both sexes of the red-billed streamertail aggressively defend territories. Males court females that enter their territory. Both sexes perch and repeatedly nod their heads, after which the male flies up and down in front of the female while spreading its tail streamers. The species breeds at any time of year, mostly between January and May, and may raise three broods in a year. The nest is a cup of fine plant fibers bound with spiderweb with lichen on the outside. It is typically built on a fine twig between above the ground. The female incubates the clutch of two eggs for 17 to 19 days and fledging occurs 19 to 24 days after hatch.[
]
Vocal and non-vocal sounds
The red-billed streamertail's vocalizations include "a loud metallic ''ting'' or ''teet'' and a prolonged ''twink-twink-twink'' dropping in pitch at the end." Adult males in flight produce a distinctive whirring sound. The whirring is synchronized with the wingbeats and video footage shows primary feather eight (P8) bending with each downstroke, creating a gap that produces the fluttering sound.
Status
The IUCN
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
has assessed the red-billed streamertail as being of Least Concern. It has a very large range but its population size and trend are not known. No immediate threats have been identified.[ "The ready occupation of man-made habitats suggests that habitat loss is unlikely to be a problem."][
]
Gallery
Red-billed streamertail (Trochilus polytmus) juvenile male.jpg, Juvenile male
Red-billed streamertail (Trochilus polytmus) juvenile male feeding 2.jpg, Juvenile male feeding
Red-billed streamertail (Trochilus polytmus) feeding.jpg, Adult male feeding
Red-billed streamertail (Trochilus polytmus) female in flight 2.JPG, Female in flight
References
External links
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{{Taxonbar, from=Q952376
red-billed streamertail
Hummingbird species of Central America
Endemic birds of Jamaica
National symbols of Jamaica
red-billed streamertail
red-billed streamertail