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Would you like to know more about the biology of the Hyacinth Macaws and what are the main threats to the species? Click here and check it out.

In this text, we complement our content with such a dear and important subject: we will tell you about the loving universe of these psittaciformes. Understand how they choose their nests, raise their chicks, and what factors affect their reproduction!


A pair of Hyacinth Macaw. / Photo: Octavio Campos Salles.


The arrival of the reproductive season

The reproduction of these birds varies with the climatic-environmental conditions. In the Pantanal, in flood years, it was observed that the breeding season started in July and the young, for the most part, were already flying in December. In drier years, it started later, around September, with flights in March.

Fact is that usually until July the Hyacinth Macaws are seen in flocks, when they begin to separate into pairs and head for the nesting sites. These pairs are formed when they are still young, after reaching sexual maturity between 7 and 9 years of age. 

And, yes! Once bonded, they tend to maintain a faithful relationship for life, and are generally examples of monogamy, cooperation, and bonding in the animal kingdom


Photo: Gustavo Figueirôa.


Choice of nest 

These macaws are very selective when choosing a nesting site, opting mainly for cavities in manduvi trees (Sterculia etriata). In the Pantanal of Nhecolândia (MS), 94% os the nests are in trees of this species. The other 6%, a minority in that region, are found in angico-white (Pithecellobium edwallii).


Tree hollow, egg-laying site / Photo: Hyacinth Macaw Institute.


The nest building height varies with the height of the tree. Active nests have been observed from a height of just over 2 meters up to almost 15 meters. 

For nesting, these birds take advantage of small cavities made by termites, ants, woodpeckers, bacteria, fungi or when branches break. From the small “gap” in the wood, with their strong beaks, they open a larger space to create their nest. Then they use the sawdust they take from the tree itself to line the base. By turning a small cavity into a large nest, they are known as environmental engineers


Photo: Cézar Côrrea.


Besides being loyal to their partners, they are also loyal to their breeding sites, tending to return in the next breeding seasons. But always, by renovating the space. Who doesn’t like a well-kept house?

Although they are devoted to their nests, they are not individual, and may be used by other individuals and even by other species that compete for space. This highlights the importance of the manduvi for the fauna in general. 

Besides the preference for a certain species of tree, these psittaciformes also prefer more open areas, small areas with acuris (Attalea phalerata) or the edge of mountain ranges, where they choose large trees. What facilitates their feeding either by the acuris or the coconuts that are frequent in fields, is the accessibility to these trees, given the size of the macaws and the visibility to protect themselves from disturbances.


Union and cooperation between the couple 

Division of tasks is the key to success for a long-lasting relationship, isn’t it?Along with the building of the nest, copulation begins. And together with the laying of the eggs, the clear division of labor between the couple begins. The female usually lays two eggs (the number varies from one to three), which are incubated for 28 to 30 days by the mother. Meanwhile, the male is responsible for guarding the nest, vocalizing when there is danger, and feeding his mate, foraging 4 to 6 times a day. When alerting the female of a possible threat, she leaves the nest, and together the couple vocalizes to scare the danger away. 


Photo: Fernanda Fontoura.


During this period, especially during the feeding division, it is possible to see feather cleaning behaviors, called alopreening between the pair, and also copulations (learn about other Hyacinth macaw behaviors here). 


Alopreening. Photo: João Marcos Rosa.


A curious thing is that even when there is great human disturbance, the hyacinth macaws do not abandon their nests, remaining faithful to them

Until two days after the birth of the nestlings, the male continues in the task of providing food for the female and protection for the nest. 

With a hatching rate of 90%, the Hyacinth Macaws are very small, on average 82.7 mm and 31.6 g, and start receiving food on the second day of life.

With birth, the female begins to go out in search of food, and then both parents perform the task of feeding their young. As they grow up, the parents spend less time in the nest, but always giving all the necessary support to the offspring. 


Photo: Fernanda Fontoura.


At around three months of age, the activities of watching over the nest and caring for the chicks begin to be done in rotation by the couple. At this stage the flight training also begins – at an average of 107 days old and weighing about 1.2 kg, the macaws fly for the first time.


Photo: Kefany Ramalho.


After they leave the nest, there is a long process ahead. Now they need to improve their flying skills, learn how to feed themselves, find out where to sleep, and how to defend themselves. After a long training period, at about 1 year and 4 months, the young macaws become independent from their parents. 


Factors that affect reproduction


Photo: A. Cecília.


It is known that the reproductive rate of this species is low, and several factors can affect the success of its reproduction. The main factor is that the species does not reproduce every year, new copulations only occur after the care of its young has been completed, which takes a little more than 1 year. 

Another relevant reason is the amount of available cavities: the number of manduvis, the species’ favorite tree, has been decreasing, either due to natural degradation, fires, or deforestation. 


Burned area. Photo: A. Cecília.


Deforestation promotes not only a reduction in the number of manduvis trees, but also a reduction in trees of adequate diameter for nesting in the Pantanal. Add to this the competition: 8 to 19% of the active nests of the hyacinth macaws are occupied by other species

Predation is also another obstacle affecting reproductive success; both eggs and young are preyed upon by a variety of animals. The predation rate on eggs varies from 20 to 40%, with coatis, opossums, toucans, crows, and hawks being some of the predators. Young chicks up to 45 days old can be preyed upon by toucans, hawks, and even ants.

Furthermore, in nests with two chicks, when the time difference between births is more than four days, the second chick usually dies. This is because the younger one has difficulty in competing for food with its brother, suffering from dehydration and severe weight loss.


Two chicks are 90 and 93 days old. Photo: Lucas Rocha.


These factors highlight the importance of the studies about the species, studies that allow us to know them more and more, to better understand all these threats they face and thus be able to work to increase their reproductive success. All these factors highlight the importance of our Hyacinth Macaw Project, which has been carried out since 1990. 


Acting – Hyacinth Macaw Project

Among the various fronts of the project, we are working on one of the main reproductive challenges of the Hyacinth Macaws: the low number of available nesting cavities. There are already more than 880 registered and monitored nests, 400 of them artificial, placed by our team. 


Couple in artificial nest. Photo: João Marcos Rosa.


Artificial nests have also been effective: when assessing nests in the Pantanal of Miranda in the years 2011 and 2012, it was seen that although the reproductive potential was higher in natural nests, the reproduction rate and reproductive success was higher in artificial nests. 


Photo: Cezar Corrêa.


Since the beginning of our work many behavioral and reproductive data have been collected. Not to mention the sanitary analysis, genetics and sex determination of the nestlings, which also provide important data for the conservation of the Hyacinth Macaws.


Photo: Fernanda Fontoura.


If you admire our work and want to contribute to the continuity of our actions, find out how to help here.

Did you learn more about the motherhood and fatherhood of the Hyacinth Macaws? 


Text by: Jéssica Amaral Lara

Reviewed by: Juliana Cuoco Badari