Overview
Brief Summary
Although the male Rufous Hummingbird's courtship display has been described as tracing a steep U or vertical oval, climbing high and then diving steeply, with whining and popping sounds at the bottom of the dive, Hurly et al. (2001) report that this is not accurate for many populations and likely is true for none. In their observations, males made J-shaped dive displays that were concave upward during both the climb and the dive. Males produce a high-pitched whine during dives. Toward the bottom of the arc, they produce a distinctive pulsing sound (chu-chu-chu-chu), and then end with a buzzing or “rattle” sound during the waggle. The male also performs a shuttle-flight display a few centimeters above an intruder, usually a female perched in low vegetation, hovering in a horizontal orientation and throwing himself from side to side with his head facing the female and his tail describing an arc on the order of 130°, and approximately 40 to 50 cm in length, in the horizontal plane. A characteristic throbbing buzz can be heard as the male moves from side to side. A single male may mate with several females.(Hurly et al. 2001)
The nest of a Rufous Hummingbird is typically well concealed in the lower part of a coniferous tree, deciduous shrub, or vine. It is generally less than 5 m above the ground, although it may be as high as 10 m. Built by the female alone, it is a compact cup of soft materials held together with pieces of spider web and lined with plant down, The outside is camouflaged with pieces of lichen. Old nests may be repaired and re-used. The clutch of two (sometimes one, possibly rarely three or even four) white eggs is incubated by the female alone for 15 to 17 days. The female is also solely responsible for feeding the young after hatching. Age at first flight is around 21 days.
This species is widespread and abundant, although there is some evidence of recent declines.
(Kaufman 1996; AOU 1998)
- American Ornithologists' Union. 1998. Check-list of North American Birds, 7th edition. American Ornithologists' Union, Washington, D.C.
- Hurly, T.A., R.D. Scott, and S.D. Healy. 2001. The function of displays of male Rufous Hummingbirds. The Condor 103: 647-651.
- Kaufman, K. 1996. Lives of North American Birds. Houghton Mifflin, Boston.
Trusted
This bird can be found in the winter from Southern California, through Mexico, and along the northern Gulf Coast. In the summer, it breeds from southern Alaska southward to northern California, south central Idaho, and western Montana. These birds frequently visit the eastern states and have the northernmost range of any hummingbird. Selasphorus rufus is declining over most of its range.
- Rufous Hummingbird: Selasphorus rufus (Audubon WatchList, National Audubon Society)
- Rufous Hummingbird: Selasphorus rufus (All About Birds, Cornell Lab of Ornithology)
Trusted
Distribution
Geographic Range
Rufous Hummingbird, Selasphorus rufus, is found in western and coastal North America from March through August, and migrates to Mexico in the winter months of October through February (Johnsgard 1983).
Biogeographic Regions: nearctic (Native )
Trusted
National Distribution
Canada
Origin: Native
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Breeding
United States
Origin: Native
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Type of Residency: Breeding
Trusted
Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Breeding range extends from southern Alaska, southern Yukon, British Columbia, and southwestern Alberta southward through Washington, Oregon, and western Montana to northwestern California and Idaho (Calder 1993, AOU 1998).
Winter range extends from coastal southern California (rarely), Sinaloa, Chihuahua, southern Texas, and Gulf Coast (east to western Florida) south to southern Baja California and southern mainland Mexico (e.g., Oaxaca, Veracruz (Calder 1993, AOU 1998). Individuals often occur ouside usual species range.
Coded range extent refers to breeding range.
Trusted
Physical Description
Morphology
Physical Description
The adult male rufous has a white breast with greenish back and crown. The back is sometimes glossed with metallic bronze-green. The pileum (the top of the head from the bill to the nape) is bronze-green, and the gorget (collar) is bright orange-red. The chin and throat is a shiny metallic scarlet color. The bill is long, straight, thin, black or dark brown in color. The feet are a dusky color. The adult female rufous has a metallic bronze-green back, and the pileum is a little duller than the male rufous. From the chin and the throat, down to the breast of the female, is a dull white color. Rufous Hummingbird has a body length of about 7.3 to 9.1 cm (2.87 to 3.58 in), and weighs around 2.8 g to 4.0 g (0.097 to 0.141 Oz). Unlike other birds that have large sound-producing muscles extending from the windpipe to the chest bone,the rufous has two sets of small vocal muscles in the trachea (Johnsgard 1983; Toops 1992; Sayre 1999).
Range mass: 2.8 to 4 g.
Average mass: 3.37 g.
Average basal metabolic rate: 0.06853 W.
Trusted
Size
Ecology
Habitat
Habitat
During breeding season, Rufous Hummingbirds are found in forests, on seed-tree harvest units, riparian shrub, and spruce-fir habitats. During the winter, it lives wherever flowers are present. It migrates to lowland stream bottoms, foothill brush land, seacoast and high mountain meadows (Johnsgard 1983; Paige et al. 1999).
Terrestrial Biomes: desert or dune ; savanna or grassland ; chaparral ; forest ; mountains
Trusted
Comments: Breeding habitat includes coniferous forest, second growth, thickets, and brushy hillsides, with foraging extending into adjacent scrubby areas and meadows with abundant nectar flowers (AOU 1998); habitat is chiefly secondary succession communities and forest openings (Calder 1993). On national forest lands in northern Idaho and western Montana, this species was most commonly detected on clearcut and seed-tree harvest units and in post-fire habitats; also riparian shrub, cedar-hemlock, and spruce-fir habitats (Hutto 1995). It had a higher probability of detection in cut rather than uncut forests (Hutto and Young, unpublished).
This hummingbird also is associated with old-growth coniferous forest stands. In western Oregon, it nested in 16-120 year-old second-growth and older than 120 year-old mature forest (Meslow and Wight 1975). In northern Idaho cedar-hemlock, it was significantly more abundant in selectively harvested and old-growth stands than in old-growth stands recently fragmented by clearcuts (Hejl and Paige 1993). In Oregon Cascades Douglas-fir forests, it was positively associated with stand age where old-growth stands included numerous small openings, and it was found in stands with large to very large western hemlocks (Gilbert and Allwine 1991). In two Washington Cascades studies, its occurrence in old-growth (200-700 years old) was double or nearly double that in young (40-80 years) or mature (80-190 years) forest stands (Carey et al. 1991; Manuwal 1991). Old-growth stands showed greater spatial diversity and midstory cover, and lower canopy cover (Carey et al. 1991). Abundance was higher in mesic and dry old-growth Douglas-fir stands than in wet stands (Manuwal 1991).
Nests are placed in trees, shrubs, or vines, about 1-15 meters (usually less than 5 meters) above ground (e.g., in blackberry bush, huckleberry bush, overhanging vine, alder, drooping branch of conifer, among roots of fallen tree, crown of deciduous tree; Johnsgard 1983). Baltosser (1989) observed that areas with both greater quantities and more predictable nectar supplies supported more hummingbird nests; this pattern may also apply to rufous hummingbird.
Habitat in migration and winter includes open situations where flowers are present (AOU 1998). During southward migration, this species uses mountain meadows and disturbed habitats with Castilleja spp, Aquilegia formosa, Epilobium angustifolium, Delphinium spp. Penstemon barbatus, Monarda menthaefolia, Linaria vulgaris, and Cleome serrulata (Calder 1993). In Mexico, it occurs in pine woods with abundant flowers and flowering shrubs; in open country with scattered trees and shrubs; suburban gardens, parks, vacant lots (Edwards 1972). Nonbreeding habitat also includes oak forests interspersed with pine and juniper between 2,300-3,000 meters; higher oak-fir forests; shrubby secondary succession habitats; arid thorn forest; brush at farm and roadside edges with Salvia spp.; scrublands and disturbed oak woodland (Calder 1993).
Trusted
Migration
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.
Route from Mexico to Alaska is longest migration of any North American hummingbird (True 1993). Stopover habitats are critical for accumulating resources required for migration.
Migration patterns coincide with weather patterns and flowering times (Calder 1993). Rufous hummingbirds migrate northward along the Pacific Coast and through lowlands west of the Rockies in winter and early spring (Calder 1993), arriving in California in late February-early March, Oregon by March 1, Alaska by mid-April. Southward migration is chiefly through mountains of Cascades/Sierras and Rocky Mountains. Southward migrants were observed in Colorado over a 6-week period in July and early August (Calder 1993). Arrival in southern Arizona/New Mexico occurs by late July/August and in central Mexico by August/September (Baltosser 1989; Calder 1993). Males migrate before females and juveniles (Phillips et al. 1964).
Trusted
Trophic Strategy
Food Habits
The Rufous Hummingbird consumes flies, ants, small beetles, tiny wasps and other small insects for a source of protein. Nectar is its most important food source for energy. It also drinks sap from the holes made by the Red-naped Sapsuckers for an extra food source. It feeds on nectar from several different flowering plants, such as honeysuckle, scarlet sage, horsemint, and black locust. This hummingbird is attracted to red and tubular flowers, preferring flowers that are spread farther apart giving it needed space for the beat of its wings. It eats about 1/2 to about 3 times its body weight. The Rufous Hummingbird feeds on nectar a minimum of sixty times a day. It consumes numerous small meals instead of a few big meals. It consumes nectar from flowering plants with its fork-like tongue at 13 licks per second ( Johnsgard 1983; Toops 1992; Chloe 1999; Sayre 1999; Gates and Gates 2000).
Trusted
Comments: Diet includes nectar, insects, and tree sap from sapsucker wells. This species obtains nectar from a wide variety of flowering plant species, (e.g., columbine, scarlet gilia, penstemon, paintbrushes, sage, lilies, larkspurs, heaths, currants, salmonberry, honeysuckles, fireweed, horsemint, toad-flax, snapdragon, bee-flower, and others (Calder 1993). Arrival on southward migration in southern Arizona and New Mexico coincides with blooming and high abundance of Agave spp. (Baltosser 1989).
Experimental manipulation with feeders in successional forest habitat showed that rufous hummingbirds preferred the greatest available sucrose concentrations, ranging from 20 percent to 60 percent, and preferred nectar sources at greater heights (2-3 meters; Blem et al. 1997).
Insects are important sources of fat, protein, and salts; these are obtained by hawking, gleaning, and in tree sap (Calder 1993).
Trusted
Population Biology
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 81 to >300
Comments: This species is represented by a large number of occurrences (subpopulations).
Trusted
Global Abundance
>1,000,000 individuals
Comments: Total population size is unknown but presumably exceeds 1,000,000. Rich et al. (2004) estimated population size at 6,500,000.
Trusted
General Ecology
This hummingbird actively defends feeding and nesting territory both inter- and intraspecifically (Cody 1968; Baltosser 1989; Calder 1993). Banding returns show the species has strong fidelity to breeding sites, wintering sites, and migration routes (Calder and Jones 1989; Calder 1993); it has been shown to have strong spatial memory for nectar sites (Hurly 1996). Rufous hummingbirds establish and defend territories around nectar sources on breeding sites, migration stopovers, and wintering sites. Migrating birds can gain an average mass of 0.23 g per day, and conserve energy by going into torpor at night (Hixon and Carpenter 1988). Feeding territory size depends on flower density and fluctuates with the rate of weight gain possible from nectar availability and the cost of territorial defense (Kodric-Brown and Brown 1978; Gass 1979; Carpenter et al. 1983). Feeding territory sizes range from 32 to 3,300 square meters (Gass 1979; Kodric-Brown and Brown 1978). Calder (1993) notes that banded birds have been recaptured at feeders 2 kilometers apart in summer.
Breeding densities reported range from 0.17 to 2.6 nests per hectare (Horvath 1964 cited in Calder 1993). In Oregon Coast Range Douglas-fir forests, densities reported at 0.16 birds per hectare in young stands, 0.13 birds per hectare mature stands, and 0.33 birds per hectare in old-growth stands (Carey et al. 1991). Average relative abundances reported on BBS routes range from 0.83 to 4.94 birds per 25-mile survey route (Sauer et al. 1997). In winter, 95 individuals captured in 12 nets over two days in a pine-oak post-fire succession habitat in Sierra de Manantlan Biosphere Reserve, Jalisco, Mexico (Calder 1993).
Baltosser (1983, cited in Miller and Gass 1985) reported high egg and nestling predation (25 percent to 58 percent) in four species of hummingbirds; however, nest predation is apparently unstudied in rufous hummingbirds. Predation on adult hummingbirds is not likely to play a large role in adult mortality (Miller and Gass 1985; Calder 1993).
Some observers suggest that artificial feeders may increase populations above natural levels by providing food beyond flowering seasons (see Calder 1993) or encouraging birds to delay migration past availability of natural foods. Feeders may also subject birds to predation, disease, or collision with windows. However none of these factors are fully studied or quantified (Calder 1993).
Trusted
Life History and Behavior
Cyclicity
Comments: This hummingbird is capable of altering energy balance by employing nocturnal torpor.
Trusted
Life Cycle
- Rufous Hummingbird: Selasphorus rufus (Audubon WatchList, National Audubon Society)
- Rufous Hummingbird: Selasphorus rufus (All About Birds, Cornell Lab of Ornithology)
Trusted
Life Expectancy
Lifespan/Longevity
Average lifespan
Status: wild: 107 months.
Trusted
Lifespan, longevity, and ageing
Trusted
Reproduction
Reproduction
The breeding season for the Rufous Hummingbird begins in April and ends in July. The peak of the season usually occurs in May. The male will mate with several females during the breeding season. The male arrives at the desired breeding territory 2 to 3 weeks before the females. He attracts the female by climbing high into the air (20 to 45 m (75 to 150 ft)) then diving toward the female, pulling out of the dive and arcing back up into the sky after bottoming out within 2 or 3 inches of the female. During this mating display his wings are flapping at a rate of 200 wing beats per second, which creates the unique metallical "buzzing" sound heard during these displays. The female signals acceptance of the male as a mate by displaying the white tips of her tail. Copulation lasts only 3 to 5 seconds (Johnsgard 1983; Toops 1992; Chloe 1999).
The female builds her nest in blackberry vines, huckleberry bushes and other well protected overgrowths. Nests are built of mosses, leaves, and lichens woven together with spider webs. Rufous Hummingbirds usually lay two eggs about 1.3 cm (1/2 in) in size. The eggs take anywhere from 12 to 14 days to hatch, and the young leave the nest about 1 week after hatching. The female fiercely defends her nest from predators, while the male plays no role in defending or raising the young. (Johnsgard 1983; Toops 1992; Chloe 1999).
Range time to hatching: 12 to 14 days.
Average fledging age: 7 days.
Average eggs per season: 2.
- Johnsgard, P. 1983. The hummingbirds of North America. Washington, D.C.: Smithsonian Institution Press.
- Toops, C. 1992. Hummingbirds: Jewels in Flight. Stillwater, MN: Voyageur Press, Inc.
- Chloe, 1999. "Hummingbirds" (On-line). Accessed August 12, 2000 at http://www.mschloe.com/hummer/huminfo.htm.
Trusted
Clutch size is two. Young are capable of first flight about 20 days after hatching (Terres 1980). Bent (1940) reported of instance of as many as 20 nests only a few yards apart in second-growth. Individuals may re-use a nest in subsequent years (Bent 1940, Calder 1993).
Trusted
Molecular Biology and Genetics
Molecular Biology
Barcode data: Selasphorus rufus
There are 5 barcode sequences available from BOLD and GenBank. Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species. See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
-- end --
Download FASTA File
Trusted
Statistics of barcoding coverage: Selasphorus rufus
Public Records: 5
Species: 5
Species With Barcodes: 1
Trusted
Conservation
Conservation Status
IUCN Red List Assessment
Red List Category
Red List Criteria
Version
Year Assessed
Assessor/s
Reviewer/s
Contributor/s
Justification
History
- 2008Least Concern
- 2004Least Concern
Trusted
Conservation Status
This widespread, abundant species is in no immediate danger of extinction. It is, like all hummingbirds, protected by the U.S. Migratory Bird Act and in CITES Appendix II.
US Migratory Bird Act: protected
US Federal List: no special status
CITES: appendix ii
State of Michigan List: no special status
IUCN Red List of Threatened Species: least concern
Trusted
National NatureServe Conservation Status
Canada
Rounded National Status Rank: N5B - Secure
United States
Rounded National Status Rank: N5B - Secure
Trusted
NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Large range in western North America; large population size; many subpopulations; tolerates and even benefits from common types of habitat alteration; some evidence suggests a slow overall decline, but better information is needed on trends.
Trusted
Trends
Global Short Term Trend: Relatively stable (=10% change)
Comments: Breeding Bird Survey (BBS) data indicate a slow decline over the past several decades, with most of the decline before the mid-1990s. No other evidence indicates that the species is declining, and the degree to which BBS data accurately reflect overall population changes for this species is unknown.
Global Long Term Trend: Unknown
Comments: Breeding Bird Survey (BBS) data for 1968-2007 indicate a significant survey-wide decline averaging 2.4% per year; this amounts to a 61% decline over this time period. However, number of individuals per route tends to be quite low for this species. BBS abundance (average number of individuals per route) declined from 1.4-2.1 in the 1960s and 1970s to 0.8-0.9 in 2000-2007, so the decline was only about 1 individual or less per route.
Trusted
Threats
Comments: No major threats have been identified. Habitat alterations by humans often improve conditions for this species.
Trusted
Management
Restoration Potential: Still a relatively common species, so potential exists for increasing populations, but full potential unknown until causes for declines better understood. Protecting food plants in migration, breeding, and winter habitats from degradation would be an important component of a restoration program. Given the loss of old-growth forests in the Pacific Northwest and the centuries-long prospect of restoring old-growth stands, further research is needed to understand this species' relationship with old-growth and breeding success in younger-aged forest stands.
Preserve Selection and Design Considerations: Little information available on landscape relationships, such as patch size and area sensitivity. Ranked at moderately high risk of local extinction from forest fragmentation (Lehmkuhl et al. 1991). In northern Idaho, negatively associated with fragmented old-growth cedar-hemlock forest, and more abundant in continuous old-growth (Hejl and Paige 1993). Will nest in coniferous forest and forage in nearby meadows and openings, using ecotones and seral habitats that supply food resources. Positively associated with old-growth coniferous forests and forages in early successional habitats and forest openings, but the full spectrum or configuration of habitats important to the species' survival are not fully known. An ample supply of nectar-producing flowers is likely a limiting factor. In the fall, populations migrate south along mountain corridors using high flowering meadows which would be critical to protect from degradation (USDA Forest Service 1994). Regional to international perspective is important given the species' high mobility throughout the seasons following phenology of flowering plants.
Management Requirements: Activities that reduce nectar or insect food sources may be detrimental, such as pesticides and herbicides, some grazing practices, or eradication of flowering shrubs such as RIBES or MANZANITA spp. (USDA Forest Service 1994). Flora of mountain meadows should be protected and grazing in these habitats avoided where it reduces nectar-producing plants.
TIMBER HARVEST: Effects of timber harvest need further study. Density and occurrence positively associated with old-growth coniferous stands in Cascades, Oregon Coast Range, and northern Idaho (Carey et al. 1991, Gilbert and Allwine 1991, Manuwal 1991, Hejl and Paige 1993). In one study, showed a negative response to recent fragmentation of old-growth by clearcuts (Hejl and Paige 1993). In the Rocky Mountains, was more abundant in clearcuts with tall shrubs and in partially cut harvest units than in untreated coniferous forest habitats; equally abundant in low shrub clearcuts as untreated forests (Hejl et al. 1995).
Calder (1993), however, suggests that clearcuts increase seral flower abundance beyond what would normally be found under the forest canopy or in natural openings. Hutto and Young (in prep) suggest that harvest units and other human-altered environments with vegetation structures that do not occur in natural seral habitats may serve as "ecological traps" that attract birds with elevated food resources, but become detrimental to reproduction and survival due to increased predation or brood parasitism. Whether reproductive success in harvest units differs from natural forest stands has not been studied.
GRAZING: Grazing effects mostly unstudied. A negative response to grazing in aspen riparian habitat in California and Nevada reported by Page et al. (1978, cited in Saab et al. 1995). Would be detrimental where grazing reduces nectar-producing shrubs and forbs.
Management Research Needs: Much research has been done on physiology and the coevolution of hummingbirds and flowers, but many areas of natural history and ecology unknown. Further study needed on lifespan and survivorship; disease, nest predation and other sources of mortality; philopatry, territory and home range size; details of habitat relationships; limiting factors. Very little known about the causes of long-term declines in the Pacific Northwest. Need research on effects of land management activities such as timber harvest and grazing, particularly impacts on food resources, nest predation, reproductive success, and survival. Need further research on habitat relationships throughout seasons, such as the importance of old-growth forest stands, successional habitats, or other habitats to breeding, foraging, and survival. Need an understanding of landscape relationships, such as patch sizes, area sensitivity, juxtaposition of nesting and foraging habitats. Information on threats on stopover and wintering sites; further description of migration routes; and details of habitat use during migration and winter all needed. Need information on direct and indirect effects of pesticides, herbicides, and other toxins.
Trusted
Global Protection: Very many (>40) occurrences appropriately protected and managed
Comments: Many occurrences are in protected areas.
Trusted
Relevance to Humans and Ecosystems
Benefits
Economic Importance for Humans: Positive
Rufous Hummingbirds play an important role in pollinating at least 129 plant species (Paige et al. 1999).
Trusted
Pollinator
- A Hummingbird-Pollinated Species of Boraginaceae in the Arizona Flora (V. Grant and K. A. Grant In: Proceedings of the National Academy of Science, Vol. 66, No. 3, pp. 917-919, July 1970)
- Rufous hummingbird: Selasphorus rufus (Audubon Watchlist, National Audubon Society)
- Migratory Pollinators Program: Rufous hummingbirds (Arizona-Sonora Desert Museum, Center for Sonoran Desert Studies)
- Rufous Hummingbird (M. Patterson In: Birds of Oregon: A General Reference. D. B. Marshall, M. G. Hunter, and A. L. Conteras, Eds., 2003, pp. 346-348, OSU Press, Corvallis, OR)
- Hummingbirds as Desert Pollinators: Beautiful and beneficial, hummingbirds important to desert plants (R. Dailey, Suite101.com)
Trusted
Pollinator
- A Hummingbird-Pollinated Species of Boraginaceae in the Arizona Flora (V. Grant and K. A. Grant In: Proceedings of the National Academy of Science, Vol. 66, No. 3, pp. 917-919, July 1970)
- Rufous hummingbird: Selasphorus rufus (Audubon Watchlist, National Audubon Society)
- Migratory Pollinators Program: Rufous hummingbirds (Arizona-Sonora Desert Museum, Center for Sonoran Desert Studies)
- Rufous Hummingbird (M. Patterson In: Birds of Oregon: A General Reference. D. B. Marshall, M. G. Hunter, and A. L. Conteras, Eds., 2003, pp. 346-348, OSU Press, Corvallis, OR)
- Hummingbirds as Desert Pollinators: Beautiful and beneficial, hummingbirds important to desert plants (R. Dailey, Suite101.com)
Trusted
Risks
Stewardship Overview: Classified as a moderate conservation priority on the Partners in Flight WatchList due to population trend and localized winter distribution (Muehter 1998). A long-term population decline is evident from BBS data in the Pacific Coast populations in British Columbia, Washington, Oregon and northern California for 1966-1996, but the reasons for this decline are a puzzle. Some suggest that the species has benefited from feeders and non-native flower plantings in suburban gardens, and possibly from timber harvest practices that have increased the availability of early seral habitats, but how these changes have actually affected demographics is unquantified. Given the species' association with old-growth coniferous forests in the Pacific Northwest (see Carey et al. 1991, Gilbert and Allwine 1991, Manuwal 1991, Hejl and Paige 1993) further work needs to be done to illuminate habitat relationships and causes of declines. Most aspects of management effects and needs unknown.
Species Impact: No adverse impacts to humans or other species known. An important plant pollinator, however, and co-evolved with many hummingbird flowers. Grant and Grant (1968) list 129 plant species in western U.S. that are pollinated by hummingbirds.
Trusted
Wikipedia
Rufous Hummingbird
The Rufous Hummingbird (Selasphorus rufus) is a small hummingbird, about 8 cm long (3 inches) with a long, straight and very slender bill. The female is slightly larger than the male.
Contents |
Description
The adult male, (shown in the photo), has a white breast, rufous face, upperparts, flanks and tail and an iridescent orange-red throat patch (gorget). Some males have some green on back and/or crown. The female has green upperparts with some white, some iridescent orange feathers in the center of the throat, and a dark tail with white tips and rufous base. Females and the rare green-backed males are extremely difficult to differentiate from Allen's Hummingbird. This is a typical-sized hummingbird, being a very small bird. It weighs 2–5 g (0.071–0.18 oz), measures 7–9 cm (2.8–3.5 in) long and spans 11 cm (4.3 in) across the wings.[2]
They feed on nectar from flowers using a long extendible tongue or catch insects on the wing. These birds require frequent feeding while active during the day and become torpid at night to conserve energy.
Because of their small size, they are vulnerable to insect-eating birds and animals.
Breeding
Their breeding habitat is open areas and forest edges in western North America from southern Alaska to California. This bird nests further north than any other hummingbird. The female builds a nest in a protected location in a shrub or conifer. The male aggressively defends feeding locations within his territory. The same male may mate with several females.
Migration
They are migratory, many of them migrating through the Rocky Mountains and nearby lowlands in July and August to take advantage of the wildflower season there. They may stay in one spot for considerable time, in which case the migrants, like breeding birds, often aggressively take over and defend feeding locations. Most winter in wooded areas in the Mexico state of Guerrero, traveling over 2,000 miles by an overland route from its nearest summer home—a prodigious journey for a bird weighing only three or four grams.
This is the western hummingbird most likely to stray into eastern North America. There has been an increasing trend for them to migrate east to winter in the eastern United States-(Florida), rather than in Mexico. (They do arrive at the Turks and Caicos Islands.) This trend is the result of increased survival with the provision of artificial feeders in gardens. In the past, individuals that migrated east in error would usually die, but now they often survive. Provided sufficient food and shelter is available, they are surprisingly hardy, able to tolerate temperatures down to at least -20°C. Most hummingbirds that migrate east are juvenile birds and may occasionally be adult females but are very seldomly adult males. Since juvenile or female are essentially indistinguishable from Allen's Hummingbirds unless they are examined in hand, many of the eastern vagrants are classified as "Rufous/Allen's Hummingbird". However, a majority are believed to be from the Rufous species.[3]
Research on hummingbird hovering
In 2005, a research team led by Dr. Douglas Warrick of Oregon State University used trained rufous hummingbirds in a study to determine the mechanics of hummingbird hovering. The study employed digital particle imaging velocimitry to capture the bird’s wing movements on film, which enabled the discovery that the hummingbird’s hovering is achieved due primarily to its wing’s downstroke (which accounts for 75% of its lift) rather than its upstroke (which makes up the additional 25% of the lift).[4][5]
References
- ^ BirdLife International (2009). "Selasphorus rufus". IUCN Red List of Threatened Species. Version 2010.4. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/143129. Retrieved 05 April 2011.
- ^ [1]
- ^ [2]
- ^ "Master fliers of the bird kingdom". BBC. 2005-06-27. http://news.bbc.co.uk/2/hi/science/nature/4124666.stm. Retrieved 2009-10-30.
- ^ McCall, William (2005-06-24). "Study says hummingbirds fly more like birds than insects". Seattle Times/Associated Press. http://seattletimes.nwsource.com/html/localnews/2002346777_hummingbird24m.html. Retrieved 2009-10-30.
Further reading
- BirdLife International (2004). Selasphorus rufus. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 9 May 2006. Database entry includes justification for why this species is of least concern
Unreviewed
Names and Taxonomy
Taxonomy
Comments: Constitutes a superspecies with S. sasin (AOU 1983).
Trusted




