The Black-chinned Hummingbird (Archilochus alexandri) is a small, vibrantly colored bird that is found throughout western North America. With an average body length of only 8-10 cm and a weight of 2-4 grams, it is one of the smallest birds found in North America. Despite its tiny size, the Black-chinned Hummingbird plays an important role in plant pollination and is a favorite among birdwatchers. In this article, we will explore the typical size and dimensions of the Black-chinned Hummingbird including length, wingspan, and weight. Understanding the bird’s petite stature provides insight into its ecology and behavior.
Black-chinned Hummingbird Length
The Black-chinned Hummingbird measures on average between 8-10 cm in total body length. This makes it only slightly larger than a golf ball! The bill itself is quite small, averaging 1.5 cm long and slightly decurved. The tail measures about 4.3 cm. Here is a breakdown of the Black-chinned Hummingbird’s length dimensions:
- Total length: 8-10 cm
- Bill length: 1.5 cm
- Tail length: 4.3 cm
To put its tiny size into perspective, the Black-chinned Hummingbird is only about as long as an average human thumb! It’s no wonder these birds are often confused for large insects as they buzz by. Their small stature allows them to hover in front of flowers to access nectar, with some species beating their wings up to 70 times per second. The diminutive size of hummingbirds is one of their most distinguishing and amazing characteristics.
Wingspan
In addition to having a small body, the Black-chinned Hummingbird has a very compact wingspan that matches its petite proportions. The wingspan ranges from 10-12 cm.
This narrow wingspan allows the Black-chinned Hummingbird to perform its signature hovering behavior. The wings are specially adapted to permit hovering flight, with stronger musculature and bone structures compared to other bird species. When feeding, the hummingbird can maintain its rapid wing beats to stay suspended in front of a flower while extracting nectar with its long tongue.
The short wingspan also provides great maneuverability. The Black-chinned Hummingbird can fly backwards, upside down, and in nearly any direction, allowing it to access flower nectar from different angles. A larger wingspan would make these complicated maneuvers more difficult. Overall, the small wingspan of only 10-12 cm is perfectly suited to the Black-chinned Hummingbird’s feeding behaviors and flight requirements.
Weight
The diminutive Black-chinned Hummingbird weighs an average of only 2-4 grams. For comparison, a penny weighs about 2.5 grams. This makes the Black-chinned Hummingbird the second smallest bird in North America, just barely heavier than the Calliope Hummingbird.
The male and female Black-chinned Hummingbirds exhibit slight sexual dimorphism in size, with males averaging 3-3.5 grams compared to females which average 2-3 grams. Males may utilize their slightly larger size in defending breeding territories or during competitive courtship displays.
This tiny weight is a key adaptation that allows the hummingbird to hover in midair, which requires rapidly beating their wings in a very energy-intensive maneuver. A heavier bird would not be able to sustain hovering flight. The Black-chinned Hummingbird compensates for its small energy reserves by entering torpor at night when temperatures drop, slowing their metabolism to conserve energy.
The diminutive weight is also crucial for agile flight through dense vegetation when seeking food, escaping predators, and migrating. Overall, weighing only as much as two to four pennies allows the Black-chinned Hummingbird to utilize its unique and impressive flight capabilities.
Male vs Female Size
As mentioned previously, there are slight size differences between male and female Black-chinned Hummingbirds. Let’s compare their dimensions:
| Measurement | Male | Female |
|---|---|---|
| Total Length | 8-10 cm | 8-10 cm |
| Wingspan | 10-12 cm | 10-12 cm |
| Weight | 3-3.5 g | 2-3 g |
As shown, the male is slightly larger in weight, averaging about 3-3.5 grams compared to the female’s 2-3 grams. The total length and wingspans overlap between the sexes.
The small but noticeable size difference may provide some advantages to the male. The extra weight may allow males to be more successful defending breeding territories or displaying to potential mates. The minute variation between the sexes is an interesting quirk of Black-chinned Hummingbird biology.
Size Relative to Other Hummingbirds
The Black-chinned Hummingbird is one of the medium-sized hummingbirds found in North America. How does its size compare to other hummingbird species?
The Calliope Hummingbird is the smallest in North America, with a total length of 7-8 cm and weight of 2-3 grams. The Black-chinned is slightly larger.
The Rufous Hummingbird is relatively small as well at 8-9 cm long, but is stockier with a weight of 3-4 grams. The Black-chinned is more delicate in build.
Larger hummingbirds like the Blue-throated Hummingbird measure 10-12 cm in length and 4-6 grams in weight. The Black-chinned is considerably smaller than these heftier species.
Across all hummingbird species found in North America, the Black-chinned falls at the petite end of the size spectrum. It is an excellent example of just how tiny hummingbirds can be, which contributes to their unique lifestyle and ecology.
Young Birds vs Adults
Baby Black-chinned Hummingbirds, like the young of most bird species, are smaller in size compared to adult birds. The nestlings hatch weighing only about 0.6 grams – that’s the same as a single paperclip!
As they grow and develop, the nestlings quickly increase in size, gaining about 0.7 grams per day. After one week, they already weigh 5-6 grams, nearing adult size. By two weeks old, their eyes are open, and feathers begin to emerge. At three weeks old, the nestlings are fully fledged and ready to leave the nest.
Once independent, the juvenile hummingbirds have nearly reached their adult dimensions. Total length, wingspan, and weight will be very close to mature adults. Distinguishing young birds from adults can be tricky. Subtle clues include shorter bills on juveniles and some remaining tufts of down.
The incredible growth rate allows young Black-chinned Hummingbirds to swiftly reach adult proportions where they can take advantage of all the behavioral and flight capabilities that their petite size provides.
Size of Nest and Eggs
In addition to the diminutive size of the adult Black-chinned Hummingbird, the nests and eggs produced by this species are equally tiny.
The nest is approximately 3-4 cm wide and 2 cm tall – smaller than the size of a ping pong ball and remarkably compact for accommodating incubating adult birds. Nests are crafted out of plant down and spider silk, bound with sticky saliva produced by the hummingbird. The external walls are decorated with lichen to help camouflage the nest against branches.
The eggs are quite small as well. Black-chinned Hummingbird eggs measure only 10 to 14 mm long and 7 to 10 mm wide – smaller than a jellybean! The tiny eggs allow the adult bird to cover them while incubating to protect them in the exposed nest. Like the adult hummingbird, the minute eggs and nest structures are exquisitely diminutive.
Size and Flight
The Black-chinned Hummingbird’s small proportions contribute directly to its flight capabilities. The light body weight, short wingspan, and compact size allow this species to perform sustained hovering when feeding on floral nectar.
The energy required for hovering flight is extremely high. As a result, adaptations like a high metabolism and the ability to enter torpor help compensate for the immense energy demands. Migrating Black-chinned Hummingbirds have been recorded flying non-stop for up to 24 hours during journeys between breeding and wintering grounds.
The small body size also permits exceptional maneuverability in flight. Black-chinned Hummingbirds can fly backwards, upside-down, sideways, and in nearly any direction when accessing food sources or avoiding predators. This impressive agility would not be possible with larger body dimensions.
Overall, the tiny size of the Black-chinned Hummingbird facilitates the unique and specialized aspects of its flight, including sustained hovering, high metabolism, long endurance flights, and unparalleled maneuverability. The form and function of its body is exquisitely adapted for life on the wing.
Size and Feeding
The Black-chinned Hummingbird’s feeding behaviors also depend on its compact size. The primary food source is floral nectar. The long, slender bill is specialized for extracting nectar, and the small body size allows the bird to hover right in front of flowers for efficient feeding.
The tongue has also adapted by splitting at the tip to lap up nectar. To fuel its high metabolism, the Black-chinned Hummingbird feeds frequently throughout the day by visiting hundreds or even thousands of flowers. This would quickly deplete food resources if not for the hummingbird’s small appetite – only about half its body weight in nectar daily.
In addition to nectar, hummingbirds utilize their tiny size to prey on small insects such as gnats, aphids, and spiders. Their diminutive stature allows them to maneuver adeptly when hawking insects in midair. The long bill is perfect for precision grasping.
Without its compact proportions, the Black-chinned Hummingbird would not be able to exploit flower nectar or hunt nimble insects quite as successfully. Size plays an essential role in how this species utilizes food resources.
Size and Torpor
The small size of the Black-chinned Hummingbird also facilitates its ability to enter nightly torpor – a state of decreased physiological activity and temperature. To conserve energy when food is limited, hummingbirds can lower their metabolic rate and body temperature. This is crucial for surviving cold nights when floral food sources are inaccessible.
Because of the hummingbird’s tiny body mass and large surface area relative to its size, it loses heat rapidly. By entering torpor, it can prevent excessive heat loss and avoid starvation. Their small size allows hummingbirds to quickly raise and lower their metabolic rate as needed for torpor.
Larger birds do not have this capability. The Black-chinned Hummingbird’s diminutive proportions help drive this essential survival adaptation for conserving energy.
Size and Thermoregulation
In addition to torpor, the small size of Black-chinned Hummingbirds poses challenges for thermoregulation – balancing heat gain and heat loss. The large ratio of surface area relative to their volume makes hummingbirds prone to excess heat loss, even on mild weather days.
To compensate, hummingbirds have an extremely high metabolism that generates internal heat. They can shiver to raise their body temperature when necessary. Black feathers and dark colors also help absorb radiant solar energy. At night, thick plumage provides insulation.
During hot weather, hummingbirds struggle to dissipate excess heat due to their small size. Panting, wing-spreading, and seeking shade provide cooling relief.
Overall, the Black-chinned Hummingbird’s miniscule proportions require exceptional adaptations to maintain a stable body temperature in both cold and hot conditions. Their small size poses thermoregulatory challenges that must be overcome.
Ecological Roles
Despite its tiny proportions, the Black-chinned Hummingbird fills important ecological roles primarily as pollinators and prey species:
Pollination
While feeding on floral nectar, Black-chinned Hummingbirds transfer pollen between flowers, making them important pollinators for many plant species. Their small size allows them to access tubular flowers that cannot be reached by larger pollinators. Migration helps disperse pollen over vast geographic ranges.
Prey
Young hummingbirds, eggs, and even adults are vulnerable prey items for many predators. Common predators include birds, snakes, and insects. Their small size means hummingbirds must constantly be on alert for threats. Predation pressure is likely a driving force in hummingbird evolution.
Despite being tiny, the Black-chinned Hummingbird provides valuable ecosystem services through pollination and serves as an important food source high in the food chain. Its small size underlies these critical ecological roles.
Size Diversity Among Hummingbird Species
There is impressive diversity in size among the over 300 hummingbird species in the world. Some examples of this variation in length and weight:
- Bee Hummingbird: 6 cm long, 1.6-2 g
- Anna’s Hummingbird: 12-15 cm long, 4-6 g
- Giant Hummingbird: 22 cm long, 18-24 g
While small size is a defining trait, different evolutionary pressures have led to a spectrum of sizes. The Bee Hummingbird is the world’s smallest bird, while the Giant Hummingbird is the largest. Black-chinned Hummingbirds fall in the medium-small range of hummingbird sizes.
Factors like food resources, habitat, competition, and predation likely influence optimal body proportions. There is no one-size-fits-all among hummingbirds. This diversity highlights nature’s ingenuity in adapting to different environments.
Conclusion
From beak to tail tip, the Black-chinned Hummingbird is only 8-10 cm long with a 10-12 cm wingspan – remarkably tiny dimensions. Weighing a mere 2-4 grams, these energetic, shimmering jewels are adapted to hover and feed with precision maneuverability.
Their petite size enables remarkable flight capabilities and survival behaviors like torpor. While minute in stature, the Black-chinned Hummingbird and its hummingbird relatives provide essential ecosystem services like pollination across their ranges. Next time you see a hummingbird buzzing by, take a moment to appreciate the perfection of its miniscule size.
