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Discover the Fascinating Life of the Ashy-Tailed Swift in South America

If you’re interested in birdwatching, you’ve likely come across the ashy-tailed swift. This small bird, scientifically known as Chaetura andrei, can be seen on the wing in the skies of the western Amazon basin and surrounding regions.

In this article, we’ll be taking a closer look at the ashy-tailed swift, with a focus on its identification, plumage, and behavior. Identification:

The ashy-tailed swift has a distinctive shape, with a short, forked tail, curved wings, and a streamlined body.

Its plumage is mostly dark and glossy, with a ashy-gray rump and tail. It measures approximately 13 cm in length and has a wingspan of about 28 cm.

This species is often seen in small groups, flying in a fast and erratic pattern, then diving and rising again. This flight pattern is one way birders can identify this species from other swifts occurring in the same area.

Similar Species:

Identifying swifts can be tricky, as many species look similar in flight. However, there are a few key characteristics to consider when trying to differentiate the ashy-tailed swift from similar species.

One such species is the sickle-winged guan, which is also found in South America. However, the guan has a larger size and a different flight style, which makes it easy to tell apart from the swift.

Other species that can be confused with the ashy-tailed swift include the chestnut-collared swift, the white-collared swift, and the short-tailed swift. However, upon closer inspection, each of these species has distinct differences in appearance, especially in their plumage.


The ashy-tailed swift has two plumages: breeding and non-breeding. During the breeding season, males have a more extensive ashy-gray rump and tail than the female, and their overall plumage can appear shinier.

Between breeding seasons, the ashy-tailed swift goes through a complete molt, which means that all their feathers are lost and replaced. This molt can take place either in the breeding or non-breeding season.

Juvenile ashy-tailed swifts have a much more muted underbelly, with light spots arranged in patches on their throats. Molts:

Molting is when birds shed old feathers and grow new ones to maintain their health and appearance.

Many species molt just once per year, but some can undergo multiple molts. The ashy-tailed swift is an example of a bird that goes through two molts per year.

They undergo a complete molt in between the breeding and non-breeding season, and a partial molt from the head and body feathers in the non-breeding season. This partial molt gives rise to an overall duller coloration, which helps them blend in with their surroundings better.


Like most swifts, the ashy-tailed swift is an aerial expert. It’s often seen in high-altitude habitats, gliding and swooping at great speeds.

They’re typically social birds, often seen in small flocks of up to 10 individuals during daytime. Their erratic flight behavior is often used to catch flying insects, which they collect with the help of their bristly tongues.

Unlike most birds, swifts drink and bathe in flight, swooping down over bodies of water and dipping their beaks in the water while gliding. Conclusion:

In conclusion, the ashy-tailed swift is a fascinating bird with unique characteristics that make it easy to identify in flight.

With two molts per year and distinct breeding and non-breeding plumages, this little bird has much to offer birdwatchers and bird enthusiasts. Next time you’re scouting the skies, keep an eye out for this swift and take a moment to watch its exciting flight behavior.

Systematics History:

The ashy-tailed swift, or Chaetura andrei, is a bird species that belongs to the family Apodidae, in the order Apodiformes. Its taxonomic classification has undergone several changes due to confusion over its identity and its close resemblance to other swift species.

Geographic variation:

The ashy-tailed swift occurs in the western portion of the Amazon rainforest, with a range that extends into the lowland forests of the Andes. Despite this apparent broad range, patchy distribution due to habitat fragmentation and human activities has caused the species to become locally extinct or endangered.


There are four recognized subspecies of the ashy-tailed swift: Chaetura andrei andrei, C. a.

alpestris, C. a.

eisenmanni, and C. a.

punensis. Subspecies differentiation is mainly based on geographic range, migratory status, morphology, and vocalization patterns.

Chaetura andrei andrei is the nominal subspecies, which is found in central Amazonia in Brazil, while C. a.

alpestris is found in the central Andes from Ecuador to Bolivia. The C.

a. eisenmanni subspecies occurs in the eastern foothills of the Andes, from central Peru to Bolivia.

It’s the smallest subspecies and produces a distinctive high-pitched vocalization, distinct from the other subspecies. C.

a. punensis occurs along the lower eastern slope of the Andes mountain range in Peru, and among its distinct features are its long wings and overall larger size.

Despite much debate, there are still questions surrounding the validity of the subspecies of the ashy-tailed swift. Related Species:

The ashy-tailed swift has a very close relationship to several related species, which often results in confusion among birders.

Some of these related species include the short-tailed swift, the Amazonian swift, and the white-chinned swift. However, despite some similarity in plumage, each species has its unique vocalization and flight behavior, allowing for its identification.

Historical Changes to Distribution:

The distribution range of ashy-tailed swifts has undergone some significant changes in recent years. Habitats such as forests, swamps, and riverside areas along its range have been affected by various human activities including agriculture and deforestation, leading to the decline of major populations.

Amazonian forests provide the majority of the ashy-tailed swifts’ habitat. Widespread deforestation has caused a decline in forest cover, leading to habitat fragmentation, affecting the swift’s population sizes and sustainability.

Deforestation has also influenced the migration patterns of the swifts leading them further from their breeding sites. In addition to the effects of habitat destruction, climate change has also affected the ashy-tailed swift’s distribution range.

Many species migrate based on weather patterns, and if the climate in their breeding area changes to become less hospitable, they may migrate to a different area. The swifts have had to shift their ranges further southward because of the changes in climate.

Moreover, human disturbance in the form of hunting and capture adds to the problem of dwindling population size. Although swifts are protected by CITES, this form of human interference continues to cause distress to swifts leading to a reduction in the size of their populations.


The ashy-tailed swift is an elusive bird that lives deep within the rainforests of South America, and its presence is critical to its ecosystem. Subspecies differentiation helps to distinguish the bird’s unique morphological and vocalization characteristics.

While nothing can quite replace the joy of seeing the swift in person, the ashy-tailed swift has many known behaviors, which have not only proven fascinating to birders but also essential to the bird’s existence and solving the puzzle of its dynamic adaptations. Human activities have impacted the distribution range of the ashy-tailed swift, and through conservation efforts and education, we can work to mitigate potential consequences of future human action and protect this beautiful species.


The ashy-tailed swift’s habitat is primarily in tropical rainforests and surrounding ecosystems. They occupy the upper canopy and sub-canopy heights of forests, often flying in and out of small openings between the trees and vegetation, seeking out insects to feed on.

They are also known to use clearings and areas of forest edge, which they may use as foraging sites. The species has a particular preference for humid areas, and they are seen in habitats with high precipitation levels.

For nesting sites, the ashy-tailed swift uses cavities in trees, crevices in cliffs, or in hollows and ledges in buildings. The species is highly adaptable and able to adjust to locations with varied structural complexity and unpredictability.

Movements and Migration:

The ashy-tailed swift has a historically known range distribution, starting from Central America south through South America to northern Argentina. The species tends to have migratory behavior, moving long distances seasonally to adapt to changes in availability of prey.

The subspecies C. a.

eisenmanni, however, is non-migratory. Some groups of the species may travel up to 5,000 km during their migrations, covering thousands of kilometers daily in their search of breeding sites and suitable habitats.

Not many studies have been done regarding the ashy-tailed swift’s movements, nor have scientists established their migratory routes. However, studies have shown that they make use of wide areas of the forest canopy and habitat types, taking on variations in their migratory journey.

Outside from Brazil, where the bird is found in small numbers, their movement pattern remains a mystery. There are shorter movements of the ashy-tailed swift as they switch their locations within their overall range to match the availability of food resources.

These short migrations are also important, allowing the species to survive and sustain their population. In areas where food is scarce, they will spend much of their energy reserves searching for prey and flying greater distances to other areas

A shift in climate patterns has caused the species to alter its migration routes, often leading to changes in the timing of their movements.

A decrease in precipitation levels affects the growth of the vegetation and insects on which the bird relies, which could prompt them to move to locations that offer better food resources. The ashy-tailed swift is sensitive to habitat disruptions, and changing migration patterns can influence their ability to find optimal conditions.

They are often negatively affected by habitat fragmentation, disturbance from human activities, and the degradation of breeding sites. Conclusion:

The ashy-tailed swift is a fascinating bird species that has managed to survive in the rainforests of South America despite increasing habitat fragmentation.

It has adapted to the changes in its environment, moving over long and short distances to survive and feed. However, human activities have disturbed the habitats of these birds, causing a reduction in their population sizes and range.

Conservation efforts are necessary to prevent further destruction of their habitats and halt the decline of their populations. By protecting the ashy-tailed swift and its habitat, future generations can continue to enjoy the wonders of this unique and important bird species.

Diet and Foraging:


The ashy-tailed swift forages on small aerial insects, which it captures on the wing. It uses its short, broad beak and bristly tongue to collect its prey.

The bird spends most of its daytime hours flying in a small group, swooping and gliding erratically and skillfully, in pursuit of insects like ants, wasps, and beetles. The swifts have adapted to their constant flight patterns and the fact that they have to feed whilst in the air.

They have a high metabolism, which enables them to maintain a high body temperature, and an energetic flight helps to maintain balance regulation in the birds. Diet:

The ashy-tailed swifts’ diet comprises mostly predatory insects, like small ants, wasps, and beetles.

The species has evolved to possess a broad, short beak that has adapted to its diet. The beak is perfect for capturing prey mid-flight since it allows the bird to open and close rapidly, ensuring no escape from their prey.

Also, swifts must consume their food whilst in flight, making the efficiency of their hunting technique a critical factor in successful feed. The bird’s metabolism is also high, and the caloric demand of maintaining their high body temperature is met by a diet of insects with high fat content.

Metabolism and Temperature Regulation:

Ashy-tailed swifts have an extremely high metabolic rate and body temperature regulation, which allows them to thrive in the humid, hot conditions of the Amazon basin. The swifts are warm-blooded, and their high metabolic rate helps them to generate sufficient body heat to maintain a constant body temperature.

This increased body temperature allows them to maintain warmth even during flights that occur at high altitudes, making their aerial hunting more efficient. The diet of the ashy-tailed swift is rich in proteins and fats, which helps improve their metabolism while regulating their body temperature.

During digestion, the swifts’ metabolic rate increases, leading to higher energy production and overall higher temperatures, critically important to a bird that cannot regulate body temperature as people do. In return, this high temperature requirement needs a swift’s high-energy flying to warm the body temperature to a level where they can digest their food.

Sounds and Vocal Behavior:


Ashy-tailed swifts are not known for being particularly vocal. However, they produce a high-pitched, piercing chatter and chattering calls at dawn and dusk, and during flight.

The swifts use high-frequency calls to communicate with their fellows while hunting, and their vocalizations are believed to be primarily instrumental. The vocalizations of the ashy-tailed swift vary by subspecies, with each one producing unique vocalizations that have contrasting levels of intensity and sharpness.

Research indicates the vocalizations of the ashy-tailed swift may be linked to its behavioral and environmental adaptations. During dawn and dusk, swifts will group in social arrangements in preparation for the day’s hunt.

To this end, the sharp calls work to mark territory, coordinate flying patterns, and communicate within a group. When feeding, any high-pitched noises also disrupt the insect’s and startle them, which makes it easier for them to be caught by swifts.

Apart from using sounds for communication and foraging, some birds use sounds evolutionarily to establish an individual’s species, location, family ties, behaviors, and ecological niche. There is little research based on ashy-tailed swifts, but these questions remain relevant in determining their survival, habitat, and evolutionary changes.


The ashy-tailed swift is a fascinating bird, perfectly adapted to life in the dense rainforests of South America. Their ability to maintain high metabolic rates, regulate body temperature in flight, and their unique hunting technique to catch prey has made them one of the key components of the ecosystem.

Their adaptations have also allowed for efficient communication even amongst their group while sounding unsure of their position. The conservation of their habitat is crucial for the survival of this species, as it provides for their primary resource for survival and home for reproduction.

By understanding the bird species and its behavior, we can better protect its habitat, population, and co-existence in the larger ecosystem. Behavior:


Ashy-tailed swifts are small birds with streamlined bodies and short, forked tails that enable them to move quickly through the air.

Their flying abilities are exceptional, and they are well adapted for continuous, energetic flight. When the swifts fly together in groups, they undergo coordinated flight efforts, allowing them to form patterned shapes in the sky that can be impressive to observe.

Self Maintenance:

The ashy-tailed swift is a self-maintaining bird, often using its beak to preen its feathers. Self-cleaning and personal upkeep are important for keeping the feathers of the ashy-tailed swift in their perfect, aerodynamic shape.

Also, due to their high energy requirements and metabolism, the birds ensure they are hydrated via drinking while flying. Agonistic Behavior:

The ashy-tailed swift engages in agonistic behavior, such as aerial chases and disputes, which can be witnessed during periods where territories are established and defended.

They can be competitive and may exhibit dominancy over other birds or species. Sexual Behavior:

Ashy-tailed swift pairs form long-term bonds and are relatively faithful to their partners.

The courtship rituals of the species are still relatively unknown. However, possible markings of their nests or specific groups during the breeding season might indicate males battling for females’ affections.

Research has shown males have larger ashy colored rumps than females, leading to the belief that males with larger rumps may be more successful in attracting females. Breeding:

The breeding season of the ashy-tailed swift varies by location and subspecies.

Usually, they breed between April and August, and the season starts after the completion of the complete molt. Research suggests that their nesting duration, incubation period, and fledgling rate vary among different areas and breeding seasons.

Typically, the species breeds by laying one or two eggs, which are incubated mainly by the females. Little is known about the nesting and breeding sites of the ashy-tailed swift.

Their nests are hidden from sight and hard to locate due to their secretive location in rocks, hollow cavities of trees, or artificial structures like buildings. In addition, their access to food resources and, in some cases, changes in the weather also influence the breeding and nesting behavior of these birds.

Demography and Populations:

The ashy-tailed swift has been listed as a species of least concern, but its population trend is decreasing. Large-scale habitat fragmentation, human activities, and climate change have significantly impacted the species as a whole, and populations are declining in certain areas.

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