Bumblebee Hummingbird Species

The bumblebee hummingbird (Atthis heloisa) is a tiny hummingbird species found in Mexico and parts of the western United States. With an average length of only 2 to 2.5 inches and weighing less than 0.1 ounces, it is one of the smallest birds in the world. Despite its small stature, the bumblebee hummingbird has a number of interesting traits and behaviors that make it stand out among hummingbirds.

Physical Description

As its name suggests, the bumblebee hummingbird bears a resemblance to a bumblebee in terms of its diminutive size and quick, buzzing flight patterns. Its body is compact with a short tail and a slender, needle-like bill adapted for drinking nectar. The plumage of the male is mostly green above with a golden-red crown and gorget (throat feathers). The female lacks the bright crown and gorget and is more grayish-green overall. In both sexes, the tail feathers are relatively short and forked. The wings are long and narrow as is typical of hummingbirds, allowing the bird to hover and maneuver precisely when feeding on flowers.

Range and Habitat

The bumblebee hummingbird is found predominantly in the mountains of central and western Mexico. Its breeding range extends north into southeastern Arizona, southern New Mexico and western Texas in the United States. It occupies scrubland, woodland edges, and canyon areas rich in flowering plants. This species tends to occupy higher elevations than other North American hummingbirds, inhabiting montane scrub up to 8,500 feet in elevation.

Like most hummingbirds, the bumblebee hummingbird migrates based on the availability of food sources. It winters in the Mexican highlands and migrates northward in spring to breeding grounds in the U.S. The migration routes and wintering grounds of this species are not fully understood.

Feeding Habits

With its high metabolism, the bumblebee hummingbird depends on a constant supply of sugary nectar for energy. It feeds mainly on nectar from tubular flowers such as penstemons, paintbrushes, and various cactus flowers. The long, slender bill allows the bird to delve into blooms and obtain the nectar. As the smallest bird in North America, the bumblebee hummingbird can access nectar from flowers that may be too tiny for larger hummingbird species to feed from. In addition to nectar, it will eat small insects for protein.

The bumblebee hummingbird hovers at blossoms while feeding, lapping up nectar with its quickly moving tongue that darts in and out of the flowers. The wings beat approximately 50-80 times per second, making the characteristic humming noise of the species. The rapidity of the wingbeats generates the aerodynamic lift necessary to allow the bird to hover in place.

Breeding Behavior

During the breeding season, male bumblebee hummingbirds establish and defend small territories centered around prime feeding areas. They perform aerial displays, chasing each other while calling and diving. As part of courtship, males also perform a hovering, butterfly-like flight to impress females.

Once paired, the female builds a tiny cup-shaped nest out of spider webs, lichens, and plant down. She lines the inside with soft plant fibers and attaches it to a downward hanging branch. She then lays two pea-sized eggs and incubates them for about two weeks. Once hatched, the chicks are fed regurgitated nectar and insects by the female. They leave the nest at about 3 weeks old but remain dependent on the female for another couple of weeks.

Conservation Status

With its limited range and specific habitat needs, the bumblebee hummingbird has a small global population estimated at only about 5,000 individuals. However, its numbers appear stable and the species is listed as Least Concern by the IUCN Red List. Threats include habitat loss from development, grazing, and logging within its breeding range. Climate change may also impact the delicate alpine ecosystems this species inhabits. Maintaining protected areas and habitat connectivity in mountainous regions of Mexico and the southwestern U.S. will be important for the continued survival of this diminutive hummingbird.

Unique Traits and Behaviors

– Some key unique features of the bumblebee hummingbird include its extremely small size, making it one of the tiniest warm blooded animals on Earth. Its high-pitched chipping vocalizations are also distinctive.

– It has an exceptionally fast metabolism needed to sustain its tiny body and rapid wingbeats. Its heart rate can reach up to 1,200 beats per minute.

– To conserve energy, the bumblebee hummingbird enters torpor (a temporary hibernation) each night and tolerates lower temperatures than other hummingbird species.

– Despite its small bill, the bumblebee hummingbird has a specially adapted tongue capable of protruding nearly an inch beyond the tip of its beak to reach nectar.

– The bumblebee hummingbird hovers more efficiently than larger hummingbirds. Aerodynamic theory predicts that smaller hummingbirds should waste less energy hovering than larger ones.

– This species engages in a rare behavior called “leg pumping”, moving its legs back and forth while perched, possibly to aid digestion and circulation.

– The bumblebee hummingbird is one of the most heat tolerant hummingbird species. It has been recorded withstanding body temperatures of nearly 45 °C (113 °F).

– It is thought to have shorter migration routes than most other western hummingbirds. This may be an adaptation to save energy due to its extremely high metabolic needs.

– Relative to its size, its eggs are the smallest known bird eggs. Incubation can begin after laying the first egg since the tiny eggs only take up 4-5% of the female’s body mass.

So in summary, while it may be the most diminutive North American bird, the bumblebee hummingbird exhibits many fascinating and specialized traits that aid its survival. Careful resource management will hopefully ensure the continuation of this species and allow continued study of its remarkable adaptations. With its buzzing flight, high-altitude lifestyle, and pint-sized proportions, the bumblebee hummingbird occupies a unique ecological niche among birds.