Adult males are distinctive within the context of the normally-occurring hummingbird species in B.C., but are quite similar to male Broad-tailed Hummingbird that has occurred as a vagrant in southern B.C. This identification concern is more applicable to birds observed in southern portions of the province, where either species could occur as a vagrant. Male Broad-tailed Hummingbird is distinguished from male Ruby-throated by its magenta-rose (rather than bright red) gorget that lacks the black chin, and the lack of a blackish “mask” through the eyes as is present in Ruby-throated. In Broad-tailed Hummingbird, the eyes are set in a pale dusky area above the gorget that extends under the chin. The tail is much more shallowly forked in Broad-tailed, appearing rather square-tipped when spread, with rufous edges on the inner feather and sometimes pale or whitish spots on the outer feathers. In addition, modified outer primaries of Broad-tailed produce a unique, buzzy wing-trill in flight that is not produced by Ruby-throated Hummingbird. Adult male Ruby-throated Hummingbird may also be confused with male Anna’s Hummingbird if seen briefly or if the iridescent crown of Anna’s Hummingbird is not apparent or appears dark (as occurs in certain lights). The gorget (and crown) of male Anna’s Hummingbird is iridescent rose-pink, rather than red as in Ruby-throated, and the underparts are heavily marked with dusky-grey and metallic green mottling (much less extensive in Ruby-throated). Anna’s Hummingbird is also a somewhat larger, bulkier bird with a relatively heavier bill. If the colour of the gorget is not apparent, male Ruby-throated could be confused with male Black-chinned Hummingbird. The Black-chinned, however, is a dingier and greyer bird on average (especially when worn), with a slightly longer and droopier bill and a tendency to wag and spread its tail habitually while feeding or hovering (rarely performed by Ruby-throated). The shape of the primaries, as visible on a perched bird, provides the most reliable mark for differentiating these two species. In Ruby-throated Hummingbird, the primaries are all relatively narrow, tapered, and pointed at the tips, whereas in Black-chinned Hummingbird they are relatively blunt and rounded.
The identification of female and immature Ruby-throated Hummingbird can be particularly difficult, especially with out-of-range birds, and should be approached cautiously. Female and immature Black-chinned Hummingbirds are extremely similar to Ruby-throated, and many individuals require exceptional views to determine their true identity. Black-chinned Hummingbird is a duller, greyer bird (especially on the crown) but this requires experience or direct comparison in order to be useful. The shape of the primaries, shape of the bill, and hovering behaviour, as mentioned above for the male, are similarly useful for identifying females and immatures and are the most important distinguishing features. Female Costa’s Hummingbird, which could occur as a vagrant in B.C., is very similar to female Ruby-throated but has a shorter tail (wingtips barely exceed tail on perched Costa’s, but shorter than tail on perched Ruby-throated) and, like female Black-chinned, tends to be a slightly duller, greyer bird with less contrasting and bright green colouration on the crown and upperparts. Also similar to female Ruby-throated, the female Anna’s Hummingbird is a somewhat larger, bulkier, bigger-headed bird with darker and more extensive dusky-grey mottling over the underparts and more pronounced green mottling on the sides and flanks. As well, female Anna’s Hummingbirds typically show several iridescent rose-red spots on the throat (these are infrequent in female Ruby-throated, but are shown by immature males). Other potential confusion species in B.C., such as Rufous Hummingbird and Calliope Hummingbird have a brighter and more extensive buffy or rufous-buff wash on the sides and flanks. Additionally, female Calliope has a very short tail (not exceeding the primaries when perched) and is a noticeably smaller bird.
| Male produces a monotonous series of chip notes at dawn that functions as a song, as well as a scratchy, jumbled series of notes from a high perch following copulation. Other calls include a soft, somewhat nasal or twangy tchew or tchup, as well as a quiet tic-tic by the female during feeding. During territorial encounters, gives a series of harsh, rapid, squeaky twitters, chirps, and squeals. Both sexes give a repetitive chee-dit during fall migration. This is the only North American hummingbird whose nestlings are known to produce begging calls. Source: Robinson et al. (1996); Williamson (2001); Howell (2002) |
Courtship
Like most temperate hummingbirds, this species has an elaborate courtship display that begins immediately after arriving on the breeding grounds. Two types of courtship displays are given, known as the “Dive Display” and the “Shuttle Display.” During the “Dive Display,” which begins once a female has entered the male’s territory, the male undertakes a series of U-shaped looping dives that can begin as high as 15 m above the female and bottom-out at 3-10 m above the female. This display is also used to deter invaders into the territory, so it is not strictly a courtship display. Once the female has perched, the male then begins the “Shuttle Display” which involves a series of very rapid side-to-side horizontal arcs with the gorget flared. This display is done within 0.5 m of the perched female, and is usually accompanied by a loud and exaggerated wing buzz. Following mating, the male largely abandons the female.
Nest
Nest-building begins shortly after arrival on the breeding grounds (late May or early June in B.C.), immediately following courtship and mating. The construction process generally takes 5-10 days and is done entirely by the female. The nest is a small cup (4.5-5 cm across, with an inner diameter of 2.5-3 cm) and is situated near the tip or at a fork of a down-sloping or horizontal branch with a fairly open area underneath and a canopy of leaves above. The nest is often situated near, or even above, water. Nest heights range from 3-6 m, although they can sometimes be found as low as 1.5 m or as high as 15 m. The nest is composed primarily of plant down (thistle, dandelion) and bud scales and is held together with spider webs; it sometimes contains animal hairs and other fibres. The exterior is decorated with lichens for camouflage.
Eggs
Clutches of (1) 2 (3) smooth, non-glossy, white eggs are laid following the completion of the nest, and most eggs in B.C. are likely laid in early or mid-June. The incubation period is 12-16 days, and only the female incubates the eggs. This species produces 2-3 clutches per year in some areas, but B.C. populations (which are at the northernmost portion of the species’ range) likely produce only one or two clutches per year. Most eggs in B.C. likely hatch in mid- to late June, although some may potentially be delayed and hatch in early July (particularly replacement clutches).
Young
Following hatching, the young remain in the nest for 18-22 days and are tended only by the female; they are also tended by the female for an additional 5-7 days after fledging. The nestlings are altricial and nearly naked, with slate-blue skin and a line of yellowish down along the centre of the back; the bill is short and yellow. Nestlings in B.C. are likely present between mid-June and mid-July, and some fledglings may remain into late July or early August before migrating south.
Source: Robinson et al. (1996); Baicich and Harrison (1997); Williamson (2001); Howell (2002)
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As with most hummingbirds, nectar forms a large proportion of the diet of this species. Reported nectar sources that occur naturally in the Peace River region include Wild Bergamot, columbine, honeysuckle, paintbrush, and campion, and it would also be expected to draw nectar from a wide variety of exotic and ornamental flowers and flowering shrubs. It sometimes pierces the base of long-tubed flowers to gain access to the nectar. It also consumes small insects such as mosquitos, spiders, gnats, small caterpillars, aphids, fruit flies, and small bees, and has been known to consume insect eggs from vegetation. Most insects are captured either by “hawking” from a perch or through gleaning of the vegetation, and it is known to glean insects that are attracted to sap wells. It also sometimes consumes the sap that seeps from these wells. Regularly visits feeders. When feeding, the Ruby-throated Hummingbird typically holds its tail closed or slightly fanned and in the same plane as the rest of the body. The tail is occasionally twitched or dipped, but is not habitually wagged as in the similar Black-chinned Hummingbird.
Source: Robinson et al. (1996); Williamson (2001); Howell (2002)
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