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Discover the Fascinating Behaviors of the Blue-tailed Emerald Hummingbird

The Blue-tailed Emerald (Chlorostilbon mellisugus) is a small, lively hummingbird that can be found in Central and South America. This striking bird is known for its shimmering green plumage and distinctive blue tail feathers.

In this article, we will go into detail about the identification, plumage, and molts of the Blue-tailed Emerald. Identification:

Field Identification: One of the key factors in identifying the Blue-tailed Emerald is its vibrant green plumage.

The male has a dark metallic green head and back that fades into a lighter green towards the bottom. The throat and breast are a bright metallic green, while the blue tail feathers are what really make this bird stand out.

The female Blue-tailed Emerald is similar in appearance but has a duller green plumage on the head and throat, with greyish-brown underparts. Similar Species: The Blue-tailed Emerald can be easily confused with other green hummingbird species.

The Violet-crowned Woodnymph, for example, has a similar green body but lacks the striking blue tail feathers of the Blue-tailed Emerald. Another similar species is the Magenta-throated Woodstar, which can be identified by its magenta-colored throat and shorter tail.


The Blue-tailed Emerald has a beautiful plumage that changes as it molts. After hatching, the juveniles will have a duller, matte green plumage with a less distinctive blue tail.

As they grow and mature, the male’s plumage becomes brighter and more metallic, while the blue tail feathers become more prominent. The females plumage remains mostly the same throughout adulthood.


The molting process of the Blue-tailed Emerald is a fascinating and complex process. Molting is the process by which birds replace their old feathers with new ones.

In the Blue-tailed Emerald, the molting process happens gradually over several months. The old feathers will fall out and be replaced by new ones starting from the head and working its way down to the tail feathers.

As the molting process occurs, birds often have to make an extra effort to maintain their energy levels. Molting requires a lot of energy, and birds may need to increase their food intake to keep up.

During a molt, a bird’s feathers are less effective at trapping heat, which can lead to higher energy requirements. Conclusion:

In conclusion, the Blue-tailed Emerald is a beautiful and vibrant hummingbird species that can be found throughout Central and South America.

Its distinctive green and blue plumage is easily recognizable, and makes it a popular bird to identify among bird enthusiasts. Understanding the identification, plumages, and molting process of this stunning bird can help you to better appreciate and protect this precious species.

Systematics and Historical Distribution of the Blue-tailed Emerald

The Blue-tailed Emerald (Chlorostilbon mellisugus) is a small, lively hummingbird that is found throughout Central and South America. It is known for its shimmering green plumage and distinctive blue tail feathers.

Systematics History:

The Blue-tailed Emerald belongs to the family Trochilidae and the genus Chlorostilbon. Within the Chlorostilbon genus, it is classified in the subgenus Leucippus, and its closest relative is the Festive Emerald (Chlorostilbon viridiceps).

The description and classification of hummingbirds have been continuously under review and revision as new information and scientific methods become available. The Blue-tailed Emerald was originally described in 1848 by the German naturalist Johann L.

W. Schomburgk, who named it Trochilus Mellisugus.

The species was later reclassified into the Chlorostilbon genus and given its current name. Geographic Variation:

There is significant geographic variation in the Blue-tailed Emerald population across its range, including differences in coloration, size, and shape.

This variation has led to the recognition of several subspecies of the Blue-tailed Emerald. Subspecies:

There are currently ten recognized subspecies of the Blue-tailed Emerald.

These subspecies are primarily distinguished by differences in their coloration. 1.

Ch. mellisugus mellisugus: Found in northern Venezuela and the Venezuelan Coastal Range, with a mostly green back and a darker head. The tail is a vibrant blue with black tips.

2. Ch. mellisugus axillaris: Found along the west coast of Colombia, this subspecies is slightly smaller than the nominate subspecies and has a bright green back and a bluer tail.

3. Ch. mellisugus eliciae: This subspecies is found in central Colombia and has a duller green back and a reddish-brown or rusty crown.

4. Ch. mellisugus flavissimus: Found in western Colombia and northwestern Ecuador, this subspecies has a yellowish-green throat and a brighter blue tail.

5. Ch. mellisugus guayaquilensis: This subspecies is found along the Pacific coast of Ecuador and is similar in appearance to Ch. m.

flavissimus, but has a shorter bill and smaller body. 6.

Ch. mellisugus margarethae: Found in eastern Ecuador and northern Peru, this subspecies has a duller green back and a bluish-green tail with black tips. 7.

Ch. mellisugus poecilolaemus: This subspecies is found in eastern Peru, and its green feathers have a yellow tinge. The throat is a bright metallic green.

8. Ch. mellisugus smaragdinus: This subspecies is found in central Peru and has a brighter green back and a blue-green tail with black tips.

9. Ch. mellisugus subfurcatus: This subspecies is found in northeastern Brazil, and its darker green feathers have a golden tinge.

The throat is a bright metallic green. 10.

Ch. mellisugus viridipectus: This subspecies is found in northern Bolivia, and it has a green back and a bright metallic green throat. Related Species:

The Blue-tailed Emerald is part of the Chlorostilbon genus, which includes numerous other hummingbirds, such as the Festive Emerald, the Cuban Emerald, and the Copper-rumped Hummingbird.

Members of the Chlorostilbon genus are generally small hummingbirds with iridescent green or blue-green plumage. Historical Changes to Distribution:

The distribution of the Blue-tailed Emerald has undergone changes throughout history due to natural factors such as climate change and human activity.

The expansion of agriculture and deforestation has led to habitat loss and fragmentation, which can have significant impacts on vulnerable species like hummingbirds. In recent decades, the Blue-tailed Emerald has been observed as far north as Costa Rica, which was previously outside its known range.

This expansion could be the result of changes in climate conditions or possibly due to habitat modifications. Conclusion:

The Blue-tailed Emerald is a beautiful and fascinating hummingbird species with unique characteristics, such as its shimmering green plumage and distinctive blue tail feathers.

Understanding the systematics, geographic variation, subspecies, and historical changes to its distribution helps us to appreciate and protect this fragile species. With continued conservation efforts and responsible human activity, we can ensure that this stunning bird remains a part of the natural world for generations to come.

Habitat and Movements of the Blue-tailed Emerald

The Blue-tailed Emerald (Chlorostilbon mellisugus) is a small but lively hummingbird found throughout Central and South America. This bird is known for its distinctive blue tail feathers and shimmering green plumage.

Understanding the habitat, movements, and migration patterns of the Blue-tailed Emerald is important for conservation efforts and for appreciating this beautiful species. Habitat:

The Blue-tailed Emerald is commonly found in a variety of tropical and subtropical habitats, including humid forests, mangroves, and savannas.

In the Andean region, it can be found in cloud forests up to 2,900 meters in elevation. This species prefers to inhabit areas with a high density of flowering plants, such as heliconias and epiphytes, which provide a good source of nectar.


The movements of Blue-tailed Emeralds appear to be primarily driven by food availability. They will follow the blooming of various plants, migrating to different areas as the seasons change.

During the breeding season, males are known to defend territories of around 0.2-0.3 hectares, while females tend to move around more frequently. This could be due to the need to find a mate or to find new food sources.


There is little information available on the migration patterns of the Blue-tailed Emerald. However, individuals have been observed at higher elevations during the non-breeding season, suggesting that they may move upslope during this time.

Some populations of Blue-tailed Emeralds are known to inhabit areas with a relatively stable year-round climate, so they might not have to migrate long distances to find food. In addition to natural factors, human activity can also impact the migration patterns of Blue-tailed Emeralds.

Habitat loss and fragmentation can make it more difficult for the birds to find suitable food sources, which could indirectly impact their migration patterns. Breeding and Nesting:

The breeding season of the Blue-tailed Emerald varies depending on geographic location.

It starts in May in northern Venezuela and extends from June to November in Colombia. The breeding season lasts about four months and can vary widely depending on altitude and climate variations.

Male Blue-tailed Emeralds aggressively defend their territory during the breeding season and use their bright plumage to attract potential mates. Females will construct their nests on a branch or twig near a food source, usually between 0.5 and 2 meters above the ground.

The nest is made up of plant fibers and spider webs and is decorated with lichens or moss on the outside. Females will lay one or two white eggs and incubate them for around two weeks before hatching.

The young birds fledge about 20 to 22 days later. Threats:

The Blue-tailed Emerald is currently listed as a species of “Least Concern” by the International Union for Conservation of Nature (IUCN).

However, it is still vulnerable to habitat loss due to agricultural expansion and deforestation. Along with habitat degradation, climate change is also making it difficult for the Blue-tailed Emerald to find its habitual food sources.

In addition, the bird’s nests are sometimes preyed upon by predators such as snakes, small mammals, and birds. Conclusion:

The Blue-tailed Emerald is a beautiful and unique hummingbird species that can be found throughout Central and South America.

Understanding the habitat, movements, and migration patterns of this species is important for protecting it from the various threats it faces. By providing suitable habitat and reducing human impact on the environment, we can help protect this species for generations to come.

Diet and Foraging of the Blue-tailed Emerald:

The Blue-tailed Emerald is a species of hummingbird, a group of birds best known for their rapid wingbeats and their ability to hover in mid-air. These birds are known for their unique feeding and foraging behaviors.

Understanding the diet, feeding, and foraging behavior of the Blue-tailed Emerald is crucial for conserving this species. Feeding:

Like other hummingbirds, Blue-tailed Emeralds have a high metabolic rate, which means they need to feed often to keep up with their energy demands.

They can consume up to twice their body weight in nectar and insects daily. To access sources of nectar, Blue-tailed Emeralds hover in front of the flowers while using their long, thin bills to extract the sweet liquid.

Because of their rapid metabolism, they must feed frequently or risk starvation and death. Diet:

The Blue-tailed Emerald is a nectarivore – a bird that feeds primarily on nectar.

They feed on the nectar of flowering plants, often favoring those with red or orange tubular flowers. These flowers are rich in nectar and provide the Blue-tailed Emerald with the needed energy and nutrients.

In addition to nectar, the Blue-tailed Emerald feeds on insects, such as gnats, mosquitoes, and spiders, as their primary source of protein. Metabolism and Temperature Regulation:

The Blue-tailed Emerald, like other hummingbirds, has a remarkable metabolic rate.

Their fast-paced lifestyle means that they need to consume nearly their entire body weight in food every day, with most of it being nectar. This extremely high metabolic rate explains the incredible energy and stamina these birds possess.

On the other hand, Blue-tailed Emeralds have a unique ability to maintain their body temperature through a process scientifically known as thermoregulation. These birds can maintain their body temperature even in cold environments.

Sounds and Vocal Behavior:

Hummingbirds are renowned for their admirable vocalization, and the Blue-tailed Emerald is no exception. Although not as vocal as some other bird species, the Blue-tailed Emerald has a few distinctive vocalization features.


Male Blue-tailed Emeralds produce a series of high-pitched, rapid “sips” during their courtship display. This sound may also help to space out territory boundaries during the non-breeding season.

Female Blue-tailed Emeralds, on the other hand, are relatively quiet. They may give occasional calls when defending their territory or communicating with their young.

The vocalization behavior of the Blue-tailed Emerald is not well understood. Studying and understanding the communication techniques and vocalization behaviors of the Blue-tailed Emerald can provide valuable insights into their life cycle.

Impact of Human Activities:

Human activities, such as habitat loss and fragmentation, agriculture, forest fires, and the introduction of non-native species, can negatively impact the feeding and foraging behavior of Blue-tailed Emeralds. Loss of habitat can mean a decline in flowering plants, reducing the availability of nectar.

The introduction of non-native competitors or predators can affect the Blue-tailed Emerald’s ability to catch insects to supplement their diet. Therefore, it is necessary to conserve and protect the natural habitats of the Blue-tailed Emerald to ensure their survival.


The Blue-tailed Emerald is a fascinating and unique bird species. Its feeding and foraging behaviors are highly specialized, with an over-reliance on nectar as their primary energy source.

They are also highly dependent on insects for protein, making them vulnerable to changes in insect populations. In addition, the vocalization behavior of Blue-tailed Emerald is still not well-understood.

Protecting the habitat of this bird can help ensure that they have enough food and can thrive for generations to come. Behavior, Breeding, Demography, and Populations of the Blue-tailed Emerald

The Blue-tailed Emerald (Chlorostilbon mellisugus) is a small hummingbird species found throughout Central and South America.

These birds exhibit a variety of fascinating behaviors related to their locomotion, self-maintenance, aggression, sexual behavior, and breeding. Understanding these behaviors and their implications is crucial for the conservation of the species.



The Blue-tailed Emerald has a unique flying pattern. They use their powerful wing muscles to flap their wings in a figure-eight motion, allowing them to hover in place and move forwards, backward, and sideways.

They can fly at high speeds and can perform acrobatic maneuvers in tight spaces, such as forests, to reach nectar sources. Self Maintenance:

Like other birds, Blue-tailed Emeralds engage in self-maintenance behaviors, such as preening and bathing.

Preening is when birds use their beaks to clean and arrange their feathers. Bathing helps to remove dirt and parasites and keep their feathers clean and in good condition.

Agonistic Behavior:

Blue-tailed Emeralds exhibit agonistic behavior, which involves aggressive or territorial displays. During feeding, males display their vibrant green and blue plumage and may chase off or even fight other birds that try to access their food source.

In addition, male Blue-tailed Emeralds compete for territory and mates, displaying their physical prowess by flapping their wings and vocalizing during courtship. Sexual Behavior:

During breeding season, males will display their bright plumage and engage in courtship displays to attract mates.

Blue-tailed Emeralds are notable for their brief mating period and promiscuity. Males will vie for the attention of several females throughout the mating period, and females will mate with multiple partners.


Blue-tailed Emeralds are territorial during the breeding season; males will spend most of their time defending areas where they believe they could attract potential mates. While defending their territory, males use their bright plumage to attract females.

Once eggs are laid, both male and female birds take turns incubating them and feeding the hatchlings until they are ready to leave the nest. Demography and Populations:

The Blue-tailed Emerald population size is not precisely known but has been marked as stable and common throughout its range, thanks to its highly adaptive nature.

Like other bird species, it can be affected by habitat degradation, deforestation, and climate change. The Blue-tailed Emerald is currently classified as a species of Least Concern by the International Union for Conservation of Nature.

However, some subpopulations of the species may be vulnerable or declining due to habitat destruction and fragmentation. In recent years, efforts have been made to improve the conservation of the Blue-tailed Emerald, including habitat restoration, conservation, and monitoring.

Further studies on the breeding populations and their behavior can reveal important insights into blue-tailed emerald conservation. Conclusion:

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