Bird O'clock

Discovering the Unique Behaviors of the Bar-Crested Antshrike: From Foraging to Breeding

The Bar-crested Antshrike, scientific name Thamnophilus multistriatus, is a bird species commonly found in South America. This bird belongs to the family Thamnophilidae and is widely distributed in parts of Brazil, Venezuela, Colombia and Ecuador.

Bar-crested Antshrikes can be found in several different habitats, including humid forest edges, scrub and woodland areas. Identification:

When it comes to identifying the Bar-crested Antshrike, there are certain visual and auditory clues to look out for.

The Bar-crested Antshrike stands at around 13-15 cm tall, with males and females possessing distinct plumages. The male has barred black and white feathers on its head, crest and upperparts, whilst the female has more subdued olive-brown feathers with fine white bars.

The wings and tail are blackish in both sexes. The Bar-crested Antshrike has a small, hooked beak and bright red eyes.

In terms of auditory identification, the Bar-crested Antshrike is known for its distinctive call, which is a clear and loud series of whistles that sound like “pew-pew-pew-pew-pew”. Field Identification:

The Bar-crested Antshrike can be distinguished from other similar birds like the White-flanked Antwren by its distinctive black and white crested head and barred upperparts.

It can also be distinguished from the more common Plain-winged Antshrike by its shorter crest and the presence of barring on its upperparts. Similar Species:

The Bar-crested Antshrike has a few different subspecies with slight variations in plumage, but generally, it is quite distinct from other bird species.

However, it can be confused with the closely related Striped Antbird, which also has a black and white striped head, albeit without a crest. The Striped Antbird is larger and has a longer tail.

Plumages:

Bar-crested Antshrikes possess different types of plumage. Juvenile birds will have a brown plumage, which will gradually change into the adult plumage.

Males and females have distinct plumages, as mentioned before. During the breeding season, males will display their crest more prominently, as it is an important part of courtship.

Molts:

Bar-crested Antshrikes generally undergo a complete molt once a year. During the molt, the birds will replace all of their feathers in a sequence that usually starts with the flight feathers and ends with the body feathers.

The process can take several weeks to complete, and during this time, the birds will be less active than usual. Conclusion:

The Bar-crested Antshrike is a fascinating bird species that is found in various habitats across South America.

Its distinctive black and white plumage and clear whistle call make it easy to identify in the field. By knowing more about these birds, we can appreciate their unique characteristics and play a role in helping to protect them and their habitat for future generations.

Systematics History:

The Bar-crested Antshrike, Thamnophilus multistriatus, was first described by the German ornithologist Johann Friedrich Gmelin in 1789. Initially, it was classified under the genus Lanius, which includes shrikes, due to its hooked beak and predatory behavior.

However, in 1927, it was reclassified under the genus Thamnophilus, which includes antbirds, due to its resemblance to other antbird species in terms of its behavior and ecology. Geographic Variation:

The Bar-crested Antshrike exhibits geographic variation across its range.

Birds found in the northern part of its range tend to be larger than those found in the south. Additionally, there are slight differences in plumage between birds from different regions.

For example, birds found in the northern part of its range have more extensive white barring on their wings, while those from the south tend to have less. Subspecies:

There are five recognized subspecies of the Bar-crested Antshrike, each with slight variations in plumage and distribution:

1.

Thamnophilus multistriatus cinereus: Found in Venezuela, this subspecies has a darker grayish-brown plumage with more extensive white barring on its wings. 2.

Thamnophilus multistriatus multistriatus: Found in Brazil, this is the nominate subspecies with a black and white plumage and a bold crest. 3.

Thamnophilus multistriatus pallidiventris: Found in the Amazon basin, this subspecies has a paler plumage with less white barring on its wings. 4.

Thamnophilus multistriatus polygrammus: Found in eastern Brazil, this subspecies has a more extensive white barring on its wings and a slightly broader crest than the nominate subspecies. 5.

Thamnophilus multistriatus putregulus: Found in western Ecuador and northwestern Peru, this subspecies has a grayish-brown plumage with less extensive white barring on its wings. Related Species:

The Bar-crested Antshrike belongs to the family Thamnophilidae, which includes over 200 species of antbirds found in the Neotropics.

Within the genus Thamnophilus, the Bar-crested Antshrike is closely related to other antshrikes such as the Stripe-backed Antbird and the Spot-winged Antshrike. These similar species can be differentiated by their plumage characteristics and geographical location.

Historical Changes to Distribution:

The Bar-crested Antshrike was historically found in a wide range of South American countries, including Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela. However, due to habitat loss and fragmentation, its range has been reduced over time.

In particular, deforestation and agricultural development have led to a decline in suitable habitat for the species. As a result of these changes, the Bar-crested Antshrike has become more restricted in its distribution and is now classified as a near-threatened species by the International Union for Conservation of Nature (IUCN).

Conservation efforts are currently being undertaken to protect the remaining habitat for the Bar-crested Antshrike and other bird species in the Neotropics. Conclusion:

In conclusion, the Bar-crested Antshrike is a fascinating bird species that exhibits geographic variation across its range.

The five recognized subspecies provide slight variations in plumage and distribution, while the species overall is closely related to other antbird species. The Bar-crested Antshrike has experienced historical changes to its distribution due to habitat loss and fragmentation, which has led to conservation efforts aimed at protecting its remaining habitat and preserving this important species for future generations.

Habitat:

The Bar-crested Antshrike is a bird species that can be found in a wide range of habitats. It is most commonly found in forest edges, scrub, and woodland areas, but can also be found in other types of habitats such as tall grasses and second-growth forest.

The species prefers humid areas with dense vegetation and low understory, where it can forage for insects and small invertebrates. Movements and Migration:

The Bar-crested Antshrike is considered to be a non-migratory bird species, meaning that it does not undertake long-distance migrations.

Rather than migrating, the species has been observed to make seasonal movements within its range. During the breeding season, Bar-crested Antshrikes are more commonly found in forested areas, while during the non-breeding season, they may move to more open habitats.

Studies have shown that Bar-crested Antshrikes exhibit some degree of territoriality, which may influence their movements within their range. During the breeding season, males will defend a territory of up to 1.5 hectares, while females may defend smaller territories of up to 0.5 hectares.

Outside of the breeding season, the birds may move outside of their territories in search of food or to avoid competition with other individuals. It is worth noting that while the Bar-crested Antshrike does not undertake long-distance migrations, it may make shorter distance movements to cope with changing environmental conditions.

For example, during periods of drought or forest fires, the species may move to more suitable habitats in search of food and water. Conservation Implications:

The non-migratory nature of the Bar-crested Antshrike has implications for its conservation.

Since the species does not undertake long-distance migrations, it is more vulnerable to habitat loss and fragmentation. If suitable habitat within its range becomes scarce or degraded, the species may have limited options for moving to more suitable areas.

Additionally, since Bar-crested Antshrikes exhibit territoriality, they may be particularly vulnerable to habitat fragmentation since they need large areas of suitable habitat to maintain their territories. Conservation efforts for the Bar-crested Antshrike should focus on preserving and restoring suitable habitats within its range.

This includes protecting areas of intact forest and ensuring that suitable habitat corridors are maintained between forested areas. Given the species’ preference for forest edges and scrubby habitats, conservation efforts should also consider preserving these types of habitats within forested areas.

In particular, the use of sustainable land-use practices that minimize forest fragmentation and deforestation could help to protect the Bar-crested Antshrike and other bird species in the Neotropics. By preserving suitable habitat and minimizing disturbance, we can ensure that these important species continue to thrive in their natural habitats for generations to come.

Conclusion:

In conclusion, the Bar-crested Antshrike is a non-migratory bird species that exhibits seasonal movements within its range. The species is commonly found in forest edges, scrub and woodland areas where it forages for insects and small invertebrates.

Given its non-migratory nature and territoriality, the species is particularly vulnerable to habitat loss and fragmentation, and conservation efforts should focus on preserving and restoring suitable habitats within its range. By doing so, we can ensure that the Bar-crested Antshrike and other bird species continue to thrive in their natural habitats for years to come.

Diet and Foraging:

The Bar-crested Antshrike is an insectivorous bird species, which means it feeds primarily on insects and other small invertebrates. The species has been observed to primarily forage on the ground or on low vegetation, where it gleans insects from leaves and branches.

Occasionally, it may also capture insects in mid-air. Feeding:

Bar-crested Antshrikes are active foragers, meaning they actively search for food rather than waiting for prey to come to them.

They use their keen vision and intelligence to locate and capture insects, which make up the majority of their diet. The birds will often perch near the ground or on low branches, scanning the surrounding area for potential prey.

Once prey is located, Bar-crested Antshrikes will swoop down to the ground or snag the insect from the air. They will then manipulate the prey using their beak and feet, often using nearby branches as a tool to hold the insect while they eat.

The birds have been observed to use their feet to hold down struggling prey while they consume it. Diet:

The Bar-crested Antshrike has a varied diet that includes insects, spiders, and other small invertebrates.

Some of the most common prey items consumed by the species include ants, beetles, caterpillars, and grasshoppers. While the species primarily feeds on insects, studies have shown that they may also eat small vertebrates such as lizards and frogs.

Metabolism and Temperature Regulation:

As an endothermic bird species, the Bar-crested Antshrike has a high metabolic rate and can regulate its body temperature independently of the environment. To maintain its body temperature and energy levels, the species must consume a large amount of food relative to its body size.

During periods of low food availability, such as during droughts or forest fires, the birds may conserve energy by reducing their activity levels and metabolic rate. Sounds and Vocal Behavior:

Vocalization:

The Bar-crested Antshrike is known for its distinctive call, which is a clear series of whistles that sound like “pew-pew-pew-pew-pew”.

The call is typically used by males to advertise their presence and to establish their territory during the breeding season. Females may also use a similar call to communicate with their mate or to call out to young.

Besides its primary call, the Bar-crested Antshrike also has a repertoire of other vocalizations that are used for different purposes. For example, during courtship and nesting, the male may sing a more complex and melodic song to attract a mate.

The birds may also use a variety of other whistles, chirps, and trills to communicate with each other and to maintain social bonds. Interestingly, the Bar-crested Antshrike has been observed to use vocal mimicry to imitate other bird species in its environment.

This ability to mimic the songs of other birds can help the Bar-crested Antshrike to avoid predators or to deceive potential competitors. Conclusion:

The Bar-crested Antshrike is an insectivorous species that feeds primarily on insects and other small invertebrates.

They are active foragers, using their keen vision and intelligence to locate and capture prey. While they primarily feed on insects, they have a varied diet that can include small vertebrates such as lizards and frogs.

As an endothermic bird species, they have a high metabolic rate, and must consume a lot of food to maintain their body temperature and energy levels. The Bar-crested Antshrike is also known for its distinctive vocalization, which includes a clear series of whistles.

Males use this call primarily to advertise their presence and establish territories during the breeding season, while females may use it to communicate with their mate or young. Additionally, the birds have a repertoire of other vocalizations that they use for different purposes.

Overall, these unique behaviors and characteristics make the Bar-crested Antshrike a fascinating species to study and appreciate. Behavior:

Locomotion:

The Bar-crested Antshrike primarily moves on foot, actively foraging for insects and other small invertebrates found on the ground or on low vegetation.

The bird can also take short flights to evade danger or cross small gaps between trees. Self Maintenance:

The Bar-crested Antshrike engages in self-maintenance activities, such as preening and bathing.

Preening is important for maintaining feather condition and hygiene, while bathing helps to remove dirt and parasites from the feathers and skin. Birds have been observed bathing in pools of water or taking a dust bath, where they roll in dry soil or sand to help remove dirt and oil from their feathers.

Agonistic Behavior:

The Bar-crested Antshrike can display agonistic behavior towards competitors or predators to defend its territory or resources. Males may engage in aggressive displays to establish and defend their territory, which can include holding the tail and wings open towards the opponent while making threatening calls.

Birds have also been observed to engage in aerial combat or chase intruders out of their territory. Sexual Behavior:

During the breeding season, males will display their crest more prominently to attract females.

Once a pair has formed, the birds will build a nest together, with both sexes participating in nest building and incubating the eggs. Females typically lay 2-3 eggs, which are incubated for 13-15 days.

The young fledge in approximately 12-15 days after hatching. Breeding:

Bar-crested Antshrikes breed during the rainy season, which varies depending on the location.

Nesting typically occurs between February and May in some parts of Brazil, while in other regions it can occur later in the year. The species is usually monogamous, and pairs will often remain together for several breeding seasons.

The birds build a cup-shaped nest using twigs, grasses, and other plant materials. The nest is typically located in a dense shrub or small tree, low to the ground.

Both sexes participate in nest building and incubating the eggs, which helps to ensure the success of the breeding pair. Demography and Populations:

The Bar-crested Antshrike is considered to have a stable population and is listed as a species of least concern on the IUCN Red List.

However, due to habitat loss and fragmentation, the species may be experiencing declines in some regions. The birds are typically found in low to moderate densities within their range, with specific populations varying depending on the availability of suitable habitat.

For example, populations in fragmented forest habitats may be smaller and more isolated than those found in larger forests. Conservation efforts aimed at protecting the Bar-crested Antshrike and other bird species in the Neotropics should focus on preserving and restoring suitable habitats within their range.

This includes protecting areas of intact forest and maintaining habitat corridors between forested areas to prevent fragmentation. Conclusion:

The Bar-crested Antshrike exhibits interesting and complex behaviors related to self-maintenance, territorial defense, and breeding practices.

These behaviors are vital to the survival and reproductive success of the species. Additionally, the species is considered to have stable populations overall, but threats such as habitat loss and fragmentation may cause declines in smaller populations.

By understanding these behaviors and threats, conservation efforts can be directed towards preserving and restoring suitable habitats within the range of the Bar-crested Antshrike and other bird species

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