Bird O'clock

Fascinating Facts About the Mayan Antthrush: From Plumage to Vocalizations

The Mayan Antthrush, Formicarius moniliger, is a beautiful and unique bird species that inhabits the tropical forests of Central and South America. Although they are not as well-known as some of their more colorful counterparts, like the toucan or macaw, the Mayan Antthrush is a fascinating bird with a rich history and interesting habits.


Field Identification

The Mayan Antthrush is a small bird that measures about 5.5 to 6 inches in length and has a wingspan of 9 to 10 inches. The male and female have similar plumage, dark brown on the upperparts and a rufous tail.

Their underparts are cinnamon-brown with black streaks and a buffy throat. The eyes are large and dark, and the bill is short and curved downwards.

Similar Species

There are several other similar species to the Mayan Antthrush, including the Black-faced Antthrush, the Ruffous-breasted Antthrush, and the Zeledon’s Antbird. However, they have different plumage and body characteristics.


The Mayan Antthrush has two plumages: the basic and alternate plumages. The basic plumage is the basic appearance that the bird takes on upon completion of its post-nuptial molt.

The alternate plumage is the appearance a bird takes on during the breeding season.


Like most bird species, the Mayan Antthrush undergoes two molts: the pre-basic and pre-alternate molt. The pre-basic molt occurs in the fall when the bird replaces its old, worn feathers with new ones before the winter season.

The pre-alternate molt occurs in the spring just before the breeding season begins. During this molt, the Mayan Antthrush replaces its feathers with brighter and more colorful ones.


The Mayan Antthrush is an interesting and unique bird species that is worth learning about for bird enthusiasts. These birds inhabit the tropical forests of Central and South America, and they have a beautiful dark brown plumage with rufous tails and cinnamon-brown underparts.

They undergo two molts, the pre-basic and pre-alternate molt, and have two plumages, the basic and alternate plumage. This information is a starting point for those who want to learn more about the Mayan Antthrush.

Systematics History

The Mayan Antthrush, Formicarius moniliger, belongs to the family Formicariidae, which also includes other antthrushes, antpittas, and ground-antbirds. The species was first described and named by John Gould in 1861.

Geographic Variation

The Mayan Antthrush has considerable geographic variation, with differences in plumage, size, and vocalizations across its range. The variation is likely the result of the isolation of populations in different regions and their adaptation to local conditions.


Currently, there are four recognized subspecies of the Mayan Antthrush:

– Formicarius moniliger moniliger: Found in southeast Mexico and Belize. The largest subspecies, with a rich reddish-brown color.

– Formicarius moniliger forbesi: Found in Honduras, Nicaragua, and Costa Rica. Smaller than moniliger, with a more contrasting dark brown color and less rufous on the tail.

– Formicarius moniliger unicus: Found in northwest Colombia and Panama. The smallest subspecies, with a darker color and more heavily barred underparts.

– Formicarius moniliger passepos: Found in northeast Colombia, Venezuela, and Trinidad. Similar to unicus, but larger and with a more contrasting plumage.

However, the subspecies classification of the Mayan Antthrush is still under debate, and further research is needed to clarify the genetic and morphological differences between populations.

Related Species

The Mayan Antthrush is closely related to other antthrush species in the same genus, Formicarius, including the Black-faced Antthrush, Rufous-breasted Antthrush, and Long-tailed Antthrush. These species share similar morphology, behavior, and vocalizations, and are often found in the same habitats.

Historical Changes to Distribution

The historical distribution of the Mayan Antthrush is not well known, but the species is believed to have a larger range in the past. The species used to be found in southern Mexico, but the rapid deforestation and clearance of habitat have caused a decline in populations and range contraction.

In recent years, the Mayan Antthrush has also faced threats from habitat loss due to conversion of forests to agricultural lands, logging, and development. The species is also hunted for food and captured for the pet trade, which has further contributed to its decline.

Conservation efforts are needed to protect the remaining populations of Mayan Antthrush and their habitats. These efforts include setting aside protected areas, implementing sustainable land use practices, and enforcing wildlife laws and regulations.


The Mayan Antthrush, Formicarius moniliger, is a fascinating bird species with considerable geographic variation across its range. There are four recognized subspecies of the Mayan Antthrush, each with unique differences in plumage, size, and vocalizations.

The species is closely related to other antthrushes in the same genus, and their natural history and ecology are similar. However, the Mayan Antthrush has faced historical changes to its distribution, with range contraction due to deforestation and habitat loss.

Conservation efforts are necessary to secure the future of this important and beautiful bird species.


The Mayan Antthrush is primarily found in humid tropical and subtropical forests with dense understory vegetation. The species prefers mature forests with a closed canopy, but can also be found in secondary forests, forest edges, and shaded coffee plantations.

The Mayan Antthrush occupies a wide range of elevations depending on the geographical location. It is found from sea level to as high as 7,000 feet (2,100 meters) in the Andes of Colombia and Venezuela.

Movements and Migration

The Mayan Antthrush is a non-migratory bird species and thus does not undertake long-distance movements such as migration. Instead, these birds make local movements within their respective habitats in response to changes in food availability, breeding season, and other environmental factors.

During the breeding season, male Mayan Antthrushes establish territories and will actively defend their territory against other males. These territories can range from 3 to 10 hectares in size.

Female Mayan Antthrushes will then visit these territories and mate with the territorial males. Outside of the breeding season, the Mayan Antthrush is not known to form flocks or travel in groups.

Instead, individuals forage for food within their respective territories. The Mayan Antthrush is primarily a ground-dwelling species, although it can also be seen foraging on lower branches and vines.

These birds are active and vocal during the day and roost at night on the ground or in low vegetation. The Mayan Antthrush is also known to have a unique foraging behavior where it will use its bill to flip over leaves, logs, and other debris to uncover insects and other arthropods.

They will also probe the leaf litter with their bills and use their feet to scratch the ground in search of food.

Conservation and Management

The Mayan Antthrush, like many forest-dependent bird species, is vulnerable to habitat loss and fragmentation due to deforestation, agricultural expansion, and urbanization. These activities threaten the quality and availability of habitat, and have led to population declines and local extirpations in some areas.

Efforts to conserve Mayan Antthrush populations and their habitats include the establishment of protected areas, such as national parks and nature reserves, and the implementation of sustainable forest management practices. These practices aim to balance economic development with the preservation of biodiversity and ecosystem services.

Research on the species’ ecology and natural history is also important for effective conservation management. For example, understanding the species’ preferred habitat characteristics, breeding biology, and foraging behavior can inform targeted conservation actions and maximize the effectiveness of management actions.


The Mayan Antthrush is a beautiful and fascinating bird species that primarily inhabits humid tropical and subtropical forests. These birds are non-migratory and make local movements within their respective territories in response to changes in food availability and other environmental factors.

The Mayan Antthrush is primarily a ground-dwelling species and employs a unique foraging behavior to uncover insects and other arthropods. However, this species is vulnerable to habitat loss and fragmentation due to deforestation, agricultural expansion, and urbanization.

Conservation and management efforts are necessary to secure the future of this important bird species.

Diet and Foraging


The Mayan Antthrush is an insectivorous bird that feeds primarily on ants, termites, beetles, and other invertebrates. They use their bills to probe and dig into the forest floor and leaf litter to uncover prey.

They are also known to use their feet to scratch the ground and to flip over leaves and other types of debris to expose hidden prey.


The diet of the Mayan Antthrush varies depending on the availability of prey in their respective habitats. In the Amazon rainforest, for example, their diet is largely composed of ants, termites, and beetles.

In the forests of Costa Rica, they feed on ground-dwelling arthropods such as spiders, centipedes, and millipedes. Recent research suggests that Mayan Antthrushes also consume fruit, which may serve as an additional source of nutrients particularly when insect prey is scarce.

Metabolism and Temperature Regulation

As small birds that are active during the day, the Mayan Antthrush has a high metabolic rate, which is the rate at which they convert food into energy. This high metabolic rate allows them to maintain an internal body temperature that is stable within a narrow range, despite fluctuations in ambient temperatures.

The Mayan Antthrush also has physiological adaptations to regulate its body temperature. The species can minimize water loss through their skin, feathers, and respiratory system.

They also have the ability to reduce their metabolic rate and enter a state of torpor, which is a temporary lowering of their metabolic rate, during periods of extended heat or cold stress.

Sounds and Vocal Behavior


The Mayan Antthrush is a vocal species that communicates through a variety of calls, songs, and other vocalizations. The species has a distinctive voice that is used to attract mates, warn conspecifics of potential dangers, and defend territories against rivals.

The male Mayan Antthrush has a remarkable repertoire of songs, ranging from whistles, trills, and rattles, to more complex sequences of notes that are repeated with consistent structure. These songs can last up to several minutes and are usually heard early in the morning or late in the afternoon.

The female Mayan Antthrush also vocalizes, but her songs are generally less complex than those of the male, consisting of shorter, simpler sequences of notes. In addition to vocalizations, the Mayan Antthrush also communicates with body language.

For example, during the breeding season, males will use posturing, such as puffing out their chest or tail, to intimidate rivals and impress potential mates. Overall, the intricate vocalizations and behavioral displays of the Mayan Antthrush contribute to these birds’ unique and captivating natural history.



The Mayan Antthrush is primarily a ground-dwelling species, and its primary mode of locomotion is by walking and running on the forest floor. However, they also move through the understory and lower vegetation by hopping and climbing on vines and small branches.

Self Maintenance

The Mayan Antthrush maintains its own plumage by preening or cleaning itself regularly. Similar to other birds, it uses its bill to remove dirt, feathers, and parasites, particularly from its head and neck.

Agonistic Behavior

The Mayan Antthrush is territorial during the breeding season and males will defend their territories against other males. Agonistic encounters involve physical and vocal displays, including bill snapping, tail pumping, and loud vocalizations, with the aim to deter rivals.

Sexual Behavior

The Mayan Antthrush typically forms monogamous breeding pairs, with males establishing territories and attracting females to mate via song and display. The breeding season varies slightly throughout its range but generally occurs from March to August.


The Mayan Antthrush typically nests in dense undergrowth or in small trees and shrubs, within its territory. Nests are cup-shaped and constructed of twigs, leaves, and other plant material.

The female typically lays two eggs, and both parents participate in incubating the eggs for approximately 18 to 19 days. After hatching, the chicks are brooded intensively by the parents to keep them warm and protected.

Both parents are also responsible for feeding the chicks, bringing them insect prey for several weeks until they are ready to leave the nest.

Demography and Populations

Despite the Mayan Antthrush’s abundance within some areas of its range, there is little information available on population size, demography, and trends. The bird is generally considered to be of least concern for extinction, as it is common within its range and there have been no reports of significant population declines.

However, the Mayan Antthrush, like many other forest-dependent species, faces significant threats from habitat loss and fragmentation due to human activities. Conserving the natural habitats upon which the Mayan Antthrush depend on is crucial to the long-term survival of this species.

Long-term studies on population demographics, behaviors, and habitat preferences are necessary to better understand the Mayan Antthrush’s ecology and create targeted conservation strategies to protect this species and its habitat.


The Mayan Antthrush is a distinctive ground-dwelling bird species that inhabits humid tropical and subtropical forests in Central and South America. These birds employ a unique foraging behavior to uncover prey, have a high metabolic rate to regulate their internal temperature, and communicate through intricate vocalizations and behavioral displays.

The species forms monogamous breeding pairs, with both parents participating in incubating the eggs and rearing the young. Despite facing threats from habitat loss and fragmentation, the Mayan Antthrush is considered of least concern for extinction.

However, to ensure the long-term survival of this species, more research is needed to better understand its population demography, behaviors, and habitat preferences so that targeted conservation strategies can be created and implemented. In conclusion, the Mayan Antthrush, Formicarius moniliger, is a fascinating bird species with a unique natural history, which has garnered interest among bird enthusiasts.

The article has covered a range of topics, including the Mayan Antthrush’s identification, plumages, geographic variation, movements and migration, diet and foraging, behavior, breeding, demography, populations, and vocalizations. These topics have helped to paint a comprehensive picture of the Mayan Antthrush for interested readers, highlighting the importance of habitat preservation, conservation, and management for a long-term sustainability of the species.

Overall, the Mayan Antthrush is an integral part of the natural ecosystem in Central and South America, and greater awareness and education about the species can aid in protecting it for years to come.

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