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Discover the Fascinating World of Buff-bellied Hummingbirds: Systematics Plumages Behavior and More

The Buff-bellied Hummingbird, also known as Amazilia yucatanensis, is a bird species found mostly in Mexico, but with some populations extending to the United States. Hummingbirds, in general, are one of the most fascinating bird species in the world due to their exceptional agility, speed, and vibrant colors.

In this article, we will explore the Buff-bellied Hummingbird, its identification features, plumages, and molts, among other key aspects. Identification:

Field Identification:

Buff-bellied Hummingbirds, as the name suggests, have a buff-colored belly and an iridescent green back.

They have a curved bill and a reddish-pink patch on their throat known as the gorget. The males have a more iridescent green color on their body, while the females have a duller green with a white throat.

These hummingbirds are small, measuring between 9.5 and 11 cm in length. Similar Species:

Buff-bellied Hummingbirds are often confused with other hummingbird species such as the Allen’s Hummingbird and the Rufous Hummingbird.

Allen’s Hummingbirds have a deeper green color on their back and lack a buff-colored belly, while the Rufous Hummingbird has a reddish-brown color all over its body and a less curved bill than the Buff-bellied Hummingbird. Plumages:


Hummingbirds go through several molts in their lifetime, which affects their plumages.

The Buff-bellied Hummingbird goes through two molts each breeding season, one in the spring and another in the fall. During the spring molt, males develop their gorget patch for mating purposes while females molt their dull feathers in preparation for breeding.

Juvenile Plumage:

Juvenile Buff-bellied Hummingbirds have a much duller appearance than the adults, often lacking the buff-colored belly and the gorget patch. The juvenile plumage is more grayish-brown, which helps them blend into their environment better for protection.

As they mature, they develop their adult plumages. Adult Plumage:

The adult plumage of the Buff-bellied Hummingbird has a bright green color on their back and a steel-blue color on their crown.

The males have a striking iridescent green color on their back with a gorget patch that ranges from dull to iridescent reddish-pink. Females, on the other hand, have a green back with a white throat and belly.

Final Thoughts:

The Buff-bellied Hummingbird is a magnificent species that showcases the intricate and marvelous characteristics of hummingbirds as a whole. Their vibrant colors and speedy movements make them a delight to watch.

Identification and plumage are crucial aspects of understanding this bird species, which can help bird lovers appreciate them more. With proper knowledge of these hummingbirds, enthusiasts can easily identify this species and distinguish it from other similar species.

Systematics History:

The Buff-bellied Hummingbird belongs to the Trochilidae family, which encompasses over 330 different hummingbird species. The species was first described by John Gould in 1850, who named it Trochilus yucatanensis.

Since then, the classification and systematics of the Buff-bellied Hummingbird have undergone several changes. Geographic Variation:

The Buff-bellied Hummingbird has a diverse range in terms of its geographic distribution, which contributes to the variation observed in the species.

The bird species is found mostly in Mexico but has been observed in areas within the United States such as Texas and Louisiana. Subspecies:

The Buff-bellied Hummingbird is divided into two subspecies, A.

y. yucatanensis and A.

y. salvini.

The former, A. y.

yucatanensis, is the nominate subspecies and is found mostly in Mexico’s Yucatan Peninsula, Guatemala, and Belize. The latter, A.

y. salvini, is found mainly along the Gulf of Mexico in Texas and Louisiana.

Related Species:

The Buff-bellied Hummingbird is closely related to other hummingbird species, including the Violet-crowned Hummingbird and the Broad-billed Hummingbird. The Violet-crowned Hummingbird has a similar gorget patch, but its back is violet instead of green.

The Broad-billed Hummingbird, on the other hand, has a blue-green back and a broader bill, which differentiates it from the Buff-bellied Hummingbird. Historical Changes to Distribution:

The Buff-bellied Hummingbird’s distribution has undergone significant changes throughout history due to various factors such as climate and habitat changes, human activities, and natural disasters.

Some of the notable changes in the Buff-bellied Hummingbird’s distribution are:

Expansion in Range:

The Buff-bellied Hummingbird’s range has gradually expanded over time. The birds used to be mostly limited to the Yucatan Peninsula in Mexico, but they have since been observed as far north as Texas and Louisiana.

The expansion of the species’ range is likely due to the availability of suitable habitats and food sources. Climate Change:

Climate change has also impacted the distribution of the Buff-bellied Hummingbird.

As temperatures rise, the species has had to migrate to cooler areas to survive. In recent decades, Buff-bellied Hummingbirds have been observed wintering further north than their typical range due to climate change.

Habitat Loss:

Habitat destruction is a major concern for the Buff-bellied Hummingbird. Its habitat is mainly tropical forests, which are under threat from deforestation, agricultural expansion, logging, and urbanization.

These human activities have led to the loss and fragmentation of the forests, making it harder for the Buff-bellied Hummingbird to find suitable habitats. Natural Disasters:

Natural disasters such as hurricanes and droughts have also impacted the Buff-bellied Hummingbird’s distribution.

Hurricanes can destroy the bird’s habitats and food sources, while droughts can deplete the nectar and insect populations, making it harder for the birds to survive. These natural disasters have led to localized declines in the Buff-bellied Hummingbird’s populations.

In conclusion, the Buff-bellied Hummingbird’s systematics history, geographic variation, subspecies, and related species help to provide a better understanding of this fascinating bird species. The Buff-bellied Hummingbird’s historical distributional changes have been impacted by various factors such as climate change, habitat loss, and natural disasters.

By staying informed about these factors, conservationists and bird enthusiasts can help to protect and conserve this beautiful bird species. Habitat:

The Buff-bellied Hummingbird requires a specific habitat to survive.

The bird species is typically found in tropical forests, but it prefers habitats with partially open canopies. The Buff-bellied Hummingbird is often found near forest edges, clearings, and dense shrubbery.

The bird species also prefers habitats with plenty of nectar-rich flowers, especially those with tubular shapes that can accommodate its long bill. In addition to nectar, the Buff-bellied Hummingbird feeds on insects, which it hunts by hovering in front of flowers or foliage.

Movements and Migration:

The Buff-bellied Hummingbird does not migrate long distances like some other hummingbird species. However, the bird species has shown evidence of short-distance movements within its range throughout the year.

The Buff-bellied Hummingbird usually stays within its established range during the breeding season, which is from April to July. During this time, the males establish territories and defend them against other males while attracting females through their courtship displays.

In the non-breeding season, which is from August to March, the Buff-bellied Hummingbird’s movements become more unpredictable. The bird species often follows flowering seasons, moving to different areas depending on the availability of nectar-rich flowers.

However, the Buff-bellied Hummingbird’s non-breeding range still falls within its established distribution range. During the winter season, Buff-bellied Hummingbirds in the northern part of their range move further south, while those in the southern part of their range remain in their established territories.

This seasonal shift is primarily due to the availability of suitable food sources. The bird species is known to feed on nectar from flowering plants, especially trumpet-shaped flowers.

During the non-breeding and winter seasons, Buff-bellied Hummingbirds may visit backyards and gardens that have nectar-producing plants. In some areas, the Buff-bellied Hummingbird may compete with other hummingbird species such as the Ruby-throated Hummingbird for nectar and territory.

However, the Buff-bellied Hummingbird is larger and more aggressive than the Ruby-throated Hummingbird, which gives it an advantage in territorial disputes. Overall, the movements and migration patterns of the Buff-bellied Hummingbird are minor compared to other bird species.

The bird species is a year-round resident of its range, with minor fluctuations in movements driven by food availability. The Buff-bellied Hummingbird, like other hummingbird species, is an important pollinator of flowering plants and helps to maintain the ecological balance of its habitat.

Diet and Foraging:


The Buff-bellied Hummingbird’s primary diet is nectar from flowering plants, but it also feeds on insects, especially during the breeding season when protein intake is critical for growing young. The bird species has a long, slender bill that allows it to access nectar from tubular flowers.

The Buff-bellied Hummingbird hovers in front of flowers or foliage, using its bill to probe the nectar inside. The bird’s tongue also has a brush-like tip that helps it to collect the nectar efficiently.


In addition to nectar and insects, the Buff-bellied Hummingbird also feeds on tree sap, fruit juice, and pollen. The bird species has a relatively larger crop than other hummingbird species, which allows it to store more nectar for later use.

Buff-bellied Hummingbirds also have a fast metabolism that requires constant food intake to maintain their energy levels. Metabolism and Temperature Regulation:

The Buff-bellied Hummingbird’s metabolism is one of the fastest among all bird species, which allows it to maintain its high-energy lifestyle.

The bird’s metabolism is critical in maintaining its body temperature since hummingbirds generate body heat through metabolic processes. The Buff-bellied Hummingbird’s metabolism is so efficient that it can enter into a torpor state at night, which allows it to conserve energy by lowering its body temperature.

Temperature regulation is also critical for the Buff-bellied Hummingbird’s survival. The bird species is found in warm and humid environments, which can lead to overheating and dehydration.

To avoid this, the Buff-bellied Hummingbird takes frequent baths, spreading its wings and feathers to wet them with water. The bird then uses its bill to fluff up its wet feathers, which cools its body as the water evaporates.

Sounds and Vocal Behavior:


The Buff-bellied Hummingbird’s vocalizations are an essential part of its behavior, especially during the breeding season. The bird species has a distinct chipping call that it uses to communicate with other birds.

The most common sound that the Buff-bellied Hummingbird makes is a high-pitched “chirp” or “chip.” The male Buff-bellied Hummingbird also produces a courtship call that is characterized by a rapid series of high-pitched chips. During territorial disputes, the Buff-bellied Hummingbird may produce a harsh, scolding call to warn the intruder.

The bird species may also make an aggressive “squeak” sound to intimidate other birds and defend its territory. In conclusion, the Buff-bellied Hummingbird’s diet and foraging behavior are critical to its survival, with the bird species relying on nectar, insects, and other plant and animal matter to maintain its high-energy lifestyle.

The bird’s metabolism and temperature regulation also play essential roles in its survival, helping it to conserve energy and avoid overheating in warm and humid environments. Vocalizations are also an essential part of the Buff-bellied Hummingbird’s behavior, with the bird species using distinct sounds to communicate, mate, and defend its territory.



The Buff-bellied Hummingbird is an exceptional flier, capable of hovering, flying backward, and even flying upside down. The bird species can fly at high speeds, sometimes reaching up to 25 miles per hour.

The Buff-bellied Hummingbird’s flight is accompanied by a characteristic humming sound produced by its wings’ rapid flapping. Self Maintenance:

The Buff-bellied Hummingbird is a clean bird species, taking frequent baths to maintain its feathers’ health and appearance.

The bird species also spends a significant amount of time preening, using its bill to clean its feathers and remove any dirt or mites. Agonistic Behavior:

The Buff-bellied Hummingbird is a territorial bird species, with males aggressively defending their territories against other males and females.

Agonistic behavior is common during the breeding season, with males engaging in aerial chases and combat to establish and defend their territories. Sexual Behavior:

During the breeding season, the Buff-bellied Hummingbird engages in elaborate courtship displays.

The male Buff-bellied Hummingbird performs mating dances, including aerial acrobatics, to attract females. The males also display their gorget patches, which range in color from dull to iridescent reddish-pink, to impress females.

After mating, female Buff-bellied Hummingbirds build small nests that they use to lay and incubate their eggs. Breeding:

The Buff-bellied Hummingbird breeds during the spring and summer months, with nesting activity peaking in May and June.

The female Buff-bellied Hummingbird builds a small cup-shaped nest that is often attached to a horizontal branch. The nest is typically made of soft plant fibers and spiderwebs and is decorated with lichens to camouflage it from predators.

The female lays one to three white eggs and incubates them for about two weeks. After hatching, the young chicks are fed with regurgitated insects and nectar until they fledge, which typically occurs about three weeks after hatching.

The Buff-bellied Hummingbird produces one or two broods per year. Demography and Populations:

The Buff-bellied Hummingbird’s populations are currently stable, but the bird species faces threats from habitat loss and degradation.

Deforestation and urbanization have led to the destruction and fragmentation of the hummingbird’s habitat, making it harder for the species to find suitable nesting and foraging areas. Climate change is also a concern, as it can alter flowering and migration patterns, affecting the Buff-bellied Hummingbird’s access to food sources.

To conserve the Buff-bellied Hummingbird, habitat conservation and restoration efforts are critical. Conservationists can also protect the bird species by planting nectar-rich plants in backyards and gardens and reducing the use of pesticides and insecticides that can harm the hummingbird’s food sources.

Overall, the Buff-bellied Hummingbird’s behavior, breeding, and demography play critical roles in its survival. The bird species showcases unique flight capabilities, displays territorial and sexual behavior during the breeding season, and produces up to two broods per year.

Conserving the Buff-bellied Hummingbird’s habitat and food sources is crucial for ensuring the bird species’ continued survival. In conclusion, the Buff-bellied Hummingbird is a fascinating bird species that showcases exceptional flight capabilities, a unique lifestyle, and complex behaviors.

The bird species faces threats from habitat loss, degradation, and climate change, making conservation efforts vital for its continued survival. Through learning about the bird’s systematics, diet and foraging, behavior, breeding habits, and demography, we gain deeper insights into the intricacies of this remarkable bird species.

By understanding the Buff-bellied Hummingbird’s important role as a pollinator and its significance to the ecosystem, conservationists can take steps to protect and conserve the species for generations to come.

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