The Dusky Hummingbird (Cynanthus sordidus) is a small hummingbird native to western North America. With an average body length of 3.5 inches and weight of 2-3 grams, it is one of the smaller hummingbird species. Despite its tiny size, the dusky hummingbird is known for its feisty and territorial behavior.
The dusky hummingbird gets its name from its overall drab plumage. The male has dark gray-brown plumage on its head, back, and tail. When the sunlight hits just right, faint purplish-brown iridescence can be seen. The male’s throat is a dull white. The female dusky hummingbird is even duller in coloration than the male. She lacks any iridescent feathers and is primarily light brown on the head, back, and tail. Her underside is a pale gray-white. The bill of both sexes is short and straight.
Juvenile dusky hummingbirds resemble the adult female in appearance. As they mature, the males will gradually take on the darker gray-brown plumage of adult males.
Range and Habitat
The dusky hummingbird is found along the Pacific Coast, ranging from southern British Columbia in Canada to Baja California and Sonora in Mexico. Its range extends east into Nevada, Arizona, and New Mexico.
This species is found in a variety of semi-open habitats, including mountain meadows, chaparral, and edges of coniferous forests. It occurs at elevations up to 10,000 feet. The dusky hummingbird migrates north to its breeding grounds in spring and early summer and retreats south to Mexico for the winter.
Food and Feeding
Like all hummingbirds, the dusky hummingbird feeds on the nectar of flowers. It uses its specialized long bill and tongue to lap up the sweet nectar while hovering in front of the flower. Some of its favorite food plants include Indian paintbrush, columbine, larkspur, trumpet vines, and manzanita. The dusky hummingbird will also feed on small insects such as gnats, fruit flies, and spiders to obtain protein.
To fuel its superfast metabolism, the dusky hummingbird must consume up to half of its body weight in nectar each day. Its wings beat up to 70 times per second as it flies between food sources.
Courtship and Nesting
In spring, male dusky hummingbirds return to their breeding grounds ahead of females to establish nesting territories. They perform aerial displays, dive bombs, and whistling vocalizations to attract females and deter intruding males. Once paired, the female builds a tiny cup-shaped nest out of plant down, spider webs, and lichens. The exterior of the nest is camouflaged with bits of bark, moss, and leaves.
The female incubates the two pea-sized white eggs alone for 14-19 days. Once hatched, both parents feed the nestlings with regurgitated food. The young leave the nest at 18-24 days old. The dusky hummingbird produces 1-2 broods per breeding season.
With a large range and estimated population of over 3 million birds, the dusky hummingbird is listed as a species of Least Concern by the IUCN. No major threats to the species have been identified. Providing flowering plants and nectar feeders may help support dusky hummingbird populations, especially in parks, gardens, and backyards. Reduction in pesticide use will also benefit hummingbird food sources.
Fun Facts about the Dusky Hummingbird
– The dusky hummingbird is one of the least colorful hummingbirds in North America, with females being nearly completely brown. Despite this, the males are aggressively territorial.
– Dusky hummingbirds have been observed stealing silk from spider webs and using it to build their tiny nests. The silk helps bind the nest materials together.
– To conserve energy on cold nights, dusky hummingbirds can enter a state of torpor, lowering their metabolic rate by about 50-70%.
– The dusky hummingbird’s wings beat up to 70 times per second, allowing remarkable aerial agility. They can fly backwards, upside down, and hover in place.
– Higher nectar concentrations in flowers along its migration route help provide quick energy to fuel the dusky hummingbird’s long migrations.
– Dusky hummingbird chicks hatch without any feathers. Within a week, they develop a coat of gray down.
– Adult dusky hummingbirds get most of their water from the floral nectar they feed on. They also sometimes drink rainwater collected in tree branches and leaves.
– The dusky hummingbird’s feeding territory is quite small, with males defending an area of about one-tenth of an acre around a prime nectar source.
– This species is known for its pugnacious behavior. Males will zealously chase away other males, larger butterflies, and even hawks that venture too close.
– The oldest known dusky hummingbird was a female who was at least 5 years old when recaptured during banding studies.
– Like most hummingbirds, the dusky hummingbird has specialized hinged ankles that allow it to perch on branches. Other birds have fixed ankles that do not allow grasping.
– Iridescent hummingbird feathers get their rainbow-like color from optically complex arrangements of melanin granules. Adjusting the geometry of the feathers changes the observed color.
– Special visible markings on the tail feathers, known as “flags”, likely help signal territorial boundaries to other males.
– During courtship displays, male dusky hummingbirds climb up to 130 feet in the air before diving down past the female in a U-shaped arc. This ritual is repeated multiple times.
– The dusky hummingbird’s heart rate can reach as high as 1,260 beats per minute while in flight. Even while resting, its heart still beats around 250 times per minute.
– This species prefers flowers with a straight, tubular shape, ideal for accessing nectar with its specialized beak and tongue. Some adapted flowers depend specifically on the dusky hummingbird for pollination.
– Dusky hummingbirds are solitary, coming together only briefly for courtship and mating. Males and females form no lasting bonds and separate soon after mating.
– New feathers molt symmetrically between the two wings rather than in large blocks. This allows the hummingbird to keep flying while molting.
– Predators of the dusky hummingbird include falcons, sharp-shinned hawks, and greater roadrunners. Dragonflies may grab hatchlings still in the nest.
– The metabolic rate of the dusky hummingbird is the highest of any vertebrate animal based on its size and weight. This intense metabolism requires a sugar-rich nectar diet.
In summary, the dusky hummingbird is a remarkable tiny bird adapted to hover in place while feeding on floral nectar across western North America. Despite its small size, it aggressively defends its feeding territory and migrates remarkably long distances each year across a range spanning thousands of miles. This species thrives in a variety of habitats from mountains to deserts thanks to specialized traits like rapid heart and wingbeat rates enabling its active lifestyle. While the dusky hummingbird lacks bright coloration, its tenacity and aerial agility make it a favorite among birdwatchers within its range.