Hyacinth macaw
The hyacinth macaw, or hyacinthine macaw, is a parrot native to central and eastern South America. With a length of about one meter it is longer than any other species of parrot. It is the largest macaw and the largest flying parrot species. While generally easily recognized, it could be confused with the smaller Lear's macaw. Habitat loss and the trapping of wild birds for the pet trade have taken a heavy toll on their population in the wild, so the species is classified as Vulnerable on the International Union for Conservation of Nature's Red List, and it is protected by its listing on Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora.
Taxonomy
It is one of two extant and one probably extinct species of the South American macaw genus Anodorhynchus.English physician, ornithologist, and artist John Latham first described the hyacinth macaw in 1790 under the binomial name Psittacus hyacinthinus. Tony Pittman in 2000 hypothesized that although the illustration in this work appears to be of an actual hyacinthine macaw, Latham's description of the length of the bird might mean he had measured a specimen of Lear's macaw instead. However, Latham's description was based on a taxidermic specimen, which was the only one Latham knew to exist up until 1822. It was prepared from a living animal originally belonging to Lord Orford, and given to the land agent Parkinson for display in the Leverian Museum after it died.
Nonetheless, Latham mentions another bird, which he calls the 'blue maccaw', supposedly the same size. This blue macaw was already described in Latham's 1781 volume of his A general synopsis of birds as merely a variety of the blue and yellow macaw, and was previously figured in the work of Mathurin Jacques Brisson, Patrick Browne and Eleazar Albin as a macaw found in Jamaica. Albin, Browne and Brisson all reference even older authors and state the bird also occurs on the mainland, and Albin states this bird is the female version of the scarlet macaw. Latham mentions that the provenance of parrots in general was often confused by the fact that the birds were much traded across the world for the purposes of sale.
Description
The largest parrot by length in the world, the hyacinth macaw is long from the tip of its tail to the top of its head and weighs. Each wing is long. The tail is long and pointed. Its feathers are mostly blue, lighter above, the neck feathers can sometimes be slightly grey, large parts of the underwing and undertail are black. The ring around the parrot's eyes and the area just underneath the beak are a strong, vibrant yellow.Ecology
The Hyacinth macaw mostly nests in Manduvi trees, which rely on the toco toucan for 83.3% of the tree's distribution of seeds. The toco toucan also feeds on 53% of the hyacinth macaw's offspring as eggs. Eggs are also regularly preyed on by corvids such as jays and crows, opossums, skunks and coatis. The young are parasitized by larvae of flies of the genus Philornis.Behaviour
Food and feeding
The majority of the hyacinth macaw diet is composed of nuts from specific palm species, such as the acuri and bocaiuva palms. They have very strong beaks for eating the kernels of hard nuts and seeds. Their strong beaks are even able to crack coconuts, the large Brazil nut pods, and macadamia nuts. The birds also boast dry, smooth tongues with a bone inside them that makes them an effective tool for tapping into fruits. The acuri nut is so hard that the parrots cannot feed on it until it has passed through the digestive system of cattle. In addition, they eat fruits and other vegetable matter. The hyacinth macaw generally eats fruits, nuts, nectar, and various kinds of seeds. Also, they travel for the ripest of foods over a vast area.In the Pantanal, hyacinth macaws feed almost exclusively on the nuts of Acrocomia aculeata and Attalea phalerata palm trees. This behaviour was recorded by the English naturalist Henry Walter Bates in his 1863 book The Naturalist on the River Amazons, where he wrote that
Charles Darwin remarked on Bates's account of the species, calling it a "splendid bird" with its "enormous beak" able to feed on these palm nuts.
In captivity, the palm nuts native to the hyacinth macaw's natural habitat are often not readily available. In these circumstances the macadamia nut is a suitable, nutritious and readily-accepted alternative. Coincidentally, the hyacinth macaw is one of the only birds with the necessary jaw strength to open the nut, which requires 300 psi of pressure to crack the shell.
Tool use
Limited tool use has been observed in both wild and captive hyacinth macaws. Reported sightings of tool use in wild parrots go as far back as 1863. Examples of tool use that have been observed usually involve a chewed leaf or pieces of wood. Macaws often incorporate these items when feeding on harder nuts. Their use allows the nuts the macaws eat to remain in position while they gnaw into it. It is not known whether this is learned social behavior or an innate trait, but observation on captive macaws shows that hand-raised macaws exhibit this behavior, as well. Comparisons showed that older macaws were able to open seeds more efficiently.Reproduction
Nesting takes place between July and December, with nests constructed in tree cavities or cliff faces depending on the habitat. In the Pantanal region, 90% of nests are constructed in the manduvi tree. The hyacinth macaw depends on the toucan for its livelihood. The toucan contributes largely to seed dispersal of the manduvi tree that the macaw needs for reproduction. However, the toucan is responsible for dispersing 83% of the seeds of Sterculia apetala, but also consumes 53% of eggs preyed. Hollows of sufficient size are only found in trees around 60 years of age or older, and competition is fierce. Existing holes are enlarged and then partially filled with wood chips. The clutch size is one or two eggs, although usually only one fledgling survives as the second egg hatches several days after the first, and the smaller fledgling cannot compete with the firstborn for food. A possible explanation for this behaviour is what is called the insurance hypothesis. The macaw lays more eggs than can be normally fledged to compensate for earlier eggs that failed to hatch or firstborn chicks that did not survive. The incubation period lasts about a month, and the male tends to his mate whilst she incubates the eggs. The chicks leave the nest, or fledge, around 110 days of age, and remain dependent on their parents until six months of age. They are mature and begin breeding at seven years of age.General traits
Hyacinth macaws are the longest psittacine. They are also very even-tempered and can be calmer than other macaws, being known as "gentle giants". An attending veterinarian must be aware of specific nutritional needs and pharmacologic sensitivities when dealing with them. Possibly due to genetic factors or captive rearing limitations, this species can become neurotic/phobic, which is problematic.Distribution and habitat
The hyacinth macaw occurs today in three main areas in South America: In the Pantanal region of Brazil, and adjacent eastern Bolivia and northeastern Paraguay, in the cerrado regions of the eastern interior of Brazil, and in the relatively open areas associated with the Tocantins River, Xingu River, Tapajós River, and the Marajó island in the eastern Amazon Basin of Brazil. Smaller, fragmented populations may occur in other areas.Over the last few decades the known range in Bolivia has grown. It is well known from the far southeast of the country near the tri-national border point with Brazil and Paraguay, where it is considered an emblematic symbol of the region, and locals often feed the macaws maize, like chickens. In the early 1990s it became apparent the species also occurred in the remote Noel Kempff Mercado National Park area a few hundred kilometres northward. Most of the Bolivian population of this macaw is thought to be found in the San Matías Integrated Management Natural Area, an area with extensive pantanal. Censuses conducted in 2008, 2009, 2011 and 2014, revealed stable population numbers: respectively 231, 107, 134, and 166. Bird counts in such swampy and difficult to navigate terrain are inherently inadequate. The censuses were performed by visiting locations with previously reported sightings; however, it was not always possible to visit all sites, and coverage varied. Thus, in 2011 the earlier estimated population of about 300 birds in this area was considered to be largely accurate. A 2014 study which correlated sightings to habitat and extrapolated this over a larger area found the birds occur in the northern part of the Natural Area, and a similar population likely also occurs in an equally sized area to the north of this, outside of the Natural Area. In a 2018 Mongabay Latam article, park rangers relate that there is anecdotal evidence the population was increasing and spreading, as more sightings were being reported by local inhabitants and the bird was now confirmed for the first time in a number of adjacent municipalities.
The hyacinth macaw has escaped or been deliberately released into Florida, US, but there is no evidence that the population is breeding and may only persist due to continuing releases or escapes.
It prefers semi-open, somewhat wooded habitats. It usually avoids dense, humid forest, and in regions dominated by such habitats, it is generally restricted to the edge or relatively open sections. In different areas of their range, these parrots are found in savannah grasslands, in dry thorn forests known as caatinga, and in palm stands or swamps, particularly the moriche palm.
A 2014 Bolivian study in San Matías Integrated Management Natural Area which correlated sightings to habitat found that areas including seasonally inundated savannas, wetlands and anthropogenic areas habitats interspersed with a mosaic of savannas, were the best indicators for the presence of the macaws. The most preferred habitat by far was anthropogenic, which is primarily cattle ranches practising extensive grazing in this area. The authors, however, were not very impressed by these results, and cautioned that the methodology might be flawed.