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Discover the Fascinating World of the Buff-necked Ibis: Behaviors Populations and Conservation Efforts

Buff-necked Ibis: A fascinating bird speciesNature is filled with wonders beyond imagination, and the world of avian creatures is no exception. One such unique bird species is the Buff-necked Ibis, also known as Theristicus caudatus.

This bird is considered to be one of the most beautiful species in the Ibis family, with a distinctive appearance and captivating presence. In this article, we will look at the key features of the Buff-necked Ibis along with its identification, plumages, molts, and similar species.


Field Identification:

The Buff-necked Ibis species is predominantly found in Argentina, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guyana, Panama, Paraguay, Peru, Surinam, Trinidad and Tobago, and Venezuela. It is a medium-sized bird and measures approximately 87-96 cm in length.

The wingspan of this bird can range from 110 to 120 cm, with a body weight of 1.5 to 2.28 kg.

The Buff-necked Ibis species has a unique appearance, making it easy to identify.

It has a distinctive reddish-brown appearance on its back and a black crow on its head, neck, and chest. It also has a buff-colored neck, a white spot on the wing, and a long, curved beak, which it uses to forage for its food.

Similar Species:

The Buff-necked Ibis shares some similarities with other species of Ibis. The Puna Ibis is one such species as it is also found in the same areas as the Buff-necked Ibis.

However, the Puna Ibis is smaller than the Buff-necked Ibis, and its neck is not buff-colored.


The Buff-necked Ibis will go through a number of plumages as it grows into adulthood.

It is important to understand these plumages as it can help to differentiate between juveniles and adults during bird-watching. Juvenile Plumage:

The juvenile Buff-necked Ibis has an overall darker plumage as compared to an adult.

They have a rufous-buff head with black streaks, a dark brown mantle with white feather tips, and rufous-buff legs. Adult Plumage:

The adult Buff-necked Ibis has a similar appearance to the juvenile, but its plumage is overall lighter in color.

The buff-colored neck distinguishes an adult bird from a juvenile. Molts:

Birds molt their feathers as they grow older, and the Buff-necked Ibis is no exception.

Molting is the process by which a bird sheds its old feathers to facilitate the growth of new feathers. The Buff-necked Ibis molts once a year during the non-breeding season, which can range from June to October, depending on the region.


In conclusion, the Buff-necked Ibis is a magnificent bird species with a unique appearance. Its buff-colored neck and red-brown feathers make it stand out in any bird-watching session.

The identification of the Buff-necked Ibis is relatively simple, and its plumages and molts provide a greater understanding of the bird’s growth cycle. This article serves to educate bird enthusiasts and nature lovers alike about the many wonders of the Buff-necked Ibis.

Systematics History:

The Buff-necked Ibis belongs to the family Threskiornithidae, which also includes other Ibis species. The scientific classification of the Buff-necked Ibis has undergone changes in the past due to various factors such as new data, advancements in technology, and the discovery of new species.

In the past, this bird was placed in the family Ardeidae. However, recent molecular studies have shown that the Buff-necked Ibis is more closely related to other ibis species.

Geographic Variation:

The Buff-necked Ibis is widespread, found throughout South and Central America, and exists in different geographical regions. The variation observed in different geographical regions is often referred to as geographic variation.

This variation can be both physical and behavioral, and different subspecies may have unique traits and characteristics. Subspecies:

The Buff-necked Ibis has several recognized subspecies that are spread throughout its geographical range.

These subspecies are differentiated by their distinct physical traits and behaviors. The recognized subspecies of the Buff-necked Ibis are:


T. c.

caudatus: This is the nominate subspecies and is found in most of the species’ range. It has a long, curved bill, a buff-colored neck, and dark brown feathers on its back.

2. T.

c. albolineatus: This subspecies is found in the Andes, from Bolivia to Ecuador.

It is similar to the nominate subspecies, but with a white collar-like patch on its neck. 3.

T. c.

colombianus: This subspecies is found in parts of northern Colombia. It is similar to the nominate subspecies but has a darker coloration.

4. T.

c. mexicanus: This subspecies is found in western Mexico.

It has a more coppery coloration on its back than the other subspecies and has a smaller bill. 5.

T. c.

derbianus: This subspecies is found in the Guianas and northeastern Brazil. It has a black crown, a white patch on its wing, and shorter legs.

Related Species:

The Buff-necked Ibis has several related species, including the Puna Ibis (Plegadis ridgwayi), Black-faced Ibis (Theristicus melanopis), and Andean Ibis (Theristicus branickii). The Puna Ibis is found at high altitudes in the Andean region of South America, and it is similar in size and shape to the Buff-necked Ibis.

However, it has a more uniform plumage of dark grey, and its neck is not buff-colored. The Black-faced Ibis is found in the high Andean plateau of South America and is smaller in size than the Buff-necked Ibis.

It has dark plumage with a white rump and a black face. The Andean Ibis is restricted to the Andean region and is of a similar size and shape to the Buff-necked Ibis.

It is distinguished by a dark plumage and a white crest on its head. Historical Changes to Distribution:

The Buff-necked Ibis has experienced changes in its distribution due to various factors, including habitat loss, climate change, and human activity.

In the past, this species was mainly found in natural habitats such as forests, grasslands, and wetlands. However, with urbanization and habitat destruction, the Buff-necked Ibis’s population has decreased in many areas.

The Buff-necked Ibis is categorized as a species of “Least Concern” by the International Union for Conservation of Nature (IUCN). In some countries like Brazil, this species is protected by the law and is not considered a game bird.


In conclusion, the Buff-necked Ibis is a unique bird species that has undergone changes in its scientific classification and geographical distribution over time. The variation observed in different geographical regions has led to the recognition of several subspecies.

This species has several related species, including the Puna Ibis, Black-faced Ibis, and Andean Ibis. The Buff-necked Ibis, being a species of “Least Concern,” still faces challenges of habitat loss and population decline in several areas, highlighting the need for conservation efforts to protect this beautiful bird and its habitats.


The Buff-necked Ibis is found throughout South and Central America, inhabiting a variety of open habitats such as forest clearings, grasslands, wetlands, and pastures. This bird prefers areas with open, grassy fields and lagoons since it feeds on invertebrates and small vertebrates in these areas.

The Buff-necked Ibis is also known to perch on trees and sometimes nesting on them as well. In some areas, the Buff-necked Ibis prefers man-made wetlands like agricultural fields and pastures.

Movements and Migration:

The Buff-necked Ibis is a non-migratory bird, meaning that it does not migrate to other areas for breeding or feeding. However, it may undergo nomadic movements within its geographical range.

These movements are often driven by the availability of food and water. For example, in areas affected by drought, the Buff-necked Ibis is known to move to more favorable areas to find food and water.

These movements can be short or long distance and occur throughout the year. Breeding:

The breeding season of the Buff-necked Ibis varies throughout its geographical range.

In southern South America, it can breed from August to February, while in northern South America, egg-laying occurs from April to August. During breeding, Buff-necked Ibises form monogamous pairs, which are maintained throughout the breeding season.

The nest is built high up in trees or palms and can be reused from season to season. Both sexes participate in building the nest and incubating the eggs.

A clutch size of one to four eggs is typically laid depending on the subspecies. The eggs are white and have a textured surface.


The Buff-necked Ibis is an opportunistic forager, feeding mainly on invertebrates like insects, crustaceans, and small vertebrates like frogs, lizards, and rodents. During feeding, they will typically forage in grassland areas, probing the ground with their long, curved bill for food.

Sometimes they feed on planktonic animals, including crustaceans and insect larvae, in water bodies like wetlands, ponds, and lagoons. Conservation:

The Buff-necked Ibis has a significant geographical range, and its population is considered stable by the International Union for Conservation of Nature (IUCN).

However, like many bird species, it is susceptible to habitat loss, predation, and human encroachment on its natural habitats. In some countries like Brazil, the Buff-necked Ibis is protected by law and is not considered a game bird.

Conservation efforts must continue to monitor the species’ population and address any loss of habitat concerns. Conclusion:

The Buff-necked Ibis is a fascinating bird species that is well adapted to various open habitats such as grasslands, wetlands, and pastures throughout its geographical range.

It has unique behaviors like nomadic movements within its range and is known for its feeding, nesting, and breeding habits. While it faces the risk of habitat loss, the Buff-necked Ibis’s population is stable, but continued monitoring of their populations is essential for long-term conservation efforts.

Overall, this bird species is a beautiful display of nature’s diversity and the need for conservation efforts to preserve the species and its habitat. Diet and Foraging:


The Buff-necked Ibis is an omnivorous feeding bird that forages both on land and in the water.

They are opportunistic and will eat a variety of foods, such as insects, crustaceans, fish, and small vertebrates like snakes, lizards, and rodents. Sometimes they will also feed on plant materials like seeds and fruits, especially during the non-breeding season when the food is scarce.


The Buff-necked Ibis relies heavily on invertebrates as a food source, and a significant portion of their diet is made up of insects such as beetles, ants, grasshoppers, and crickets. In water, they feed on amphipods, aquatic insects, crayfish, and fish fry.

Sometimes they feed on earthworms, centipedes, and millipedes. They also feed on small reptiles such as snakes and lizards during the breeding season when they are most active.

Metabolism and Temperature Regulation:

To meet their energy needs, the Buff-necked Ibis has a high metabolic rate, which is necessary for flying, foraging, and thermoregulation. As an active forager, the Buff-necked Ibis needs to maintain a constant body temperature to go about its daily activities.

To regulate its body temperature, this bird has a special adaptation of the circulatory system known as a rete mirabile. This circulatory organ regulates the temperature of the blood of the bird’s legs, keeping them warm and preventing excessive heat loss.

Sounds and Vocal Behavior:


The Buff-necked Ibis vocalizes a lot, especially during breeding season, when they need to communicate and establish territories. It has a distinct vocalization that sounds like a series of grunting calls “gow-wow-wow-wow” that increases and decreases in frequency.

These calls are often heard within the breeding territory and serve to communicate to other individuals in the vicinity. The male will also utter a low-pitched growl during courtship displays to attract a mate.

The Buff-necked Ibis also has a variety of other vocalizations used during non-breeding times such as whistles, squeaks, and high-pitched calls, which it uses to communicate with other individuals in its flock. These calls help to maintain social cohesion and communicate any threat of danger.


In conclusion, the Buff-necked Ibis has a unique foraging behavior that makes it an omnivorous bird species feed. It feeds on both animal and plant matter, with a major portion of its diet being invertebrates such as insects, crustaceans, and small vertebrates including reptiles like lizards and snakes.

Its high metabolic rate and circulatory adaptations allow it to sustain high levels of activity and thermoregulation. The Buff-necked Ibis is also known for its vocalization, especially during the breeding season when it uses a series of grunting calls to communicate with its conspecifics.

The vocalizations of the Buff-necked Ibis serve as a means of communication, socializing, and maintaining a sense of social cohesion within the flock. Behavior:


The Buff-necked Ibis is a bird with a characteristic long neck, a curved bill and belongs to the Ibis family.

It often walks on the ground, moving slowly and deliberately as it searches for food. When in flight, it has a tough, powerful flapping action, which enables it to cover large distances efficiently and speedily.

Self Maintenance:

The Buff-necked Ibis maintains its plumage through preening, which is a vital aspect of its self-maintenance behavior. Preening is carried out by passing its beak over its feathers, removing any dirt or debris that might be there.

It also involves spreading its wings and using its bill to remove any dirt or parasites that might be there. Agonistic Behavior:

Agonistic behavior is a behavior associated with dominance and aggression.

The Buff-necked Ibis’s agonistic behavior is displayed during the breeding season when males establish territories and compete for mates. The display involves the males puffing out their chests, flapping their wings, and bobbing their heads.

This behavior is accompanied by a grunting call that serves as a warning to other males to stay away. Sexual Behavior:

The Buff-necked Ibis expresses sexual behavior during the breeding season when males establish territories and mate with females.

The male displays its feathers, puffing out its chest and brandishing its wings to attract females. Once a pair bond is established, the male performs various courtship behaviors, such as feeding the female and nesting together.


The Buff-necked Ibis breeds once a year, and the breeding season varies within its geographical range. During breeding, the Buff-necked Ibis forms monogamous pairs, which are maintained throughout the breeding season.

The nest is usually built high up in trees or palms. A clutch of one to four eggs is laid depending on the subspecies, and the eggs are incubated by both sexes for approximately 24-27 days.

After hatching, the young Buff-necked Ibises are cared for and fed by both parents. Demography and Populations:

The Buff-necked Ibis is a bird species that is widespread in Central and South America.

Its population is considered to be stable by the International Union for Conservation of Nature (IUCN), but its habitat is increasingly under threat from human activity such as deforestation and urbanization. The Buff-necked Ibis also faces some mortality risks, mainly from hunting, collisions with power lines and wind turbines, and climate change.

Conservation efforts are essential in the long-term protection of the Buff-necked Ibis, and there are several initiatives throughout Central and South America to mitigate threats and conserve populations. For example, the Brazilian government has established a network of protected areas throughout the country, including some for the Buff-necked Ibis and other bird species, providing crucial breeding and foraging habitats.


In conclusion, the Buff-necked Ibis displays unique behaviors during locomotion, self-maintenance, agonistic behavior, and sexual behavior. During breeding, it forms monogamous pairs and builds a nest high up in trees to lay its eggs.

The population of the Buff-necked Ibis is deemed to be stable. However, conservation efforts are necessary to mitigate the threats to its habitat and minimize any risks to its populations.

Overall, this bird species remains a stunning, avian wonder and a vital component of Central and South America’s biodiversity. In summary, the Buff-necked Ibis is a unique bird species found throughout Central and South America, displaying a wide range of fascinating adaptations and behaviors.

It has a varied diet, opportunistic foraging behaviors, and adaptations in its metabolism and

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