It is rare with a highly restricted native range, which was only discovered in 1978, although intensive conservation efforts have increased the world population about thirtyfold in the first two decades of the 21st century.

It inhabits a dry desert-like shrubby environment known as caatinga, and roosts and nests in cavities in sandstone cliffs.

The rarely seen bird was not considered a distinct species until 1978, when German-born, Brazilian-naturalised ornithologist Helmut Sick finally located the wild population.

The body, tail, and wings are dark metallic blue with a faint, often barely visible, tinge of green, and the head is a slightly paler shade.

The hyacinth macaw can be distinguished by its darker plumage, lack of greenish tinge, and a differently shaped patch of yellow skin adjacent to the base of the bill.

[9]The primary diet of Lear's macaw are the nuts (as many as 350 per day) of the palm Syagrus coronata, locally known as licuri, but the seeds of Melanoxylon, Jatropha mollissima, Dioclea, Spondias tuberosa, Schinopsis brasiliensis and Zea mays are also eaten, as well as the flowers of Agave.

[6] If it is, then the macaws generally feed directly at the site, tearing the fibrous pulp off the fruit to obtain the extremely hard and thick-shelled nut.

[11] The heavy bills appear to have evolved specifically to crack open the palm nuts with a chisel-shaped edge, being precisely of the correct size and shape.

The prevailing theory is that such mammals once performed these functions, but that Late Pleistocene extinctions of most of these animals had rendered large-fruited plants impotent regarding the spread of their seed, at least until humans introduced livestock.

A study found a significant number of undamaged palm nuts on the ground below the branches or rocks where the birds occasionally carry their harvest.

[11][13] Flocks of Lear's macaws will congregate at cattle corrals and walk around on the bare ground of rumination sites.

Just 11,000 years ago, perhaps these macaws were commensals to one or some of the giant browsing herbivore species of northeast Brazil which traveled in herds, and the palms depended on this relationship for effective dispersal.

[13] Lear's macaw are somewhat of a pest species, and a major problem caused by the animals is their habit of raiding the plots of local subsistence farmers to consume maize (Zea mays).

In order to minimize the chagrin of victims and stop them from shooting at the birds, a scheme was implemented in 2005 to compensate farmers for crops lost to the animals with bags of maize from elsewhere.

[10] A wild population was eventually discovered in 1978 by ornithologist Helmut Sick in Bahia in the interior northeast of Brazil.

[17] It is known from two colonies at locations known as Toca Velha and Serra Branca, south of the Raso da Catarina plateau in northeast Bahia.

[10] From these roosts, the macaws travel throughout the region (the municipalities of Campo Formoso, Canudos, Euclides da Cunha, Jeremoabo, Monte Santo, Novo Triunfo, Paulo Afonso, Santa Brígida and Sento Sé), relying on stands of licury palm to find much of their sustenance.

This palm stand habitat is thought to have once stretched over 250,000 km2 (97,000 sq mi) in Brazil, but has been much reduced due to clearance for agriculture.

[6] Based on this, Birdlife International (BI), which has written the IUCN Red List assessments, gave an estimated population of 150 birds in 2000.

BI states that if these juveniles mature over the next few years and the population grows from 250–500 to over 250 individuals, the species would need to be downlisted in the future.

The 'Threats' section was updated to emphasise reduction of food resources due to habitat loss caused by the historical expansion of agricultural development in the region (criterion B1b(iii)).

[17] As well as habitat loss, Lear's macaw may have historically suffered from hunting,[27] and more recently, trapping for the aviary trade in the 1990s.

[6][21] Fundação Biodiversitas bought and created the Canudos Biological Station in 1991 to protect the sandstone cliffs of Toca Velha used by the macaws to roost and nest.

[3][28][30] Two protected areas,[1] designated by the Brazilian government in 2001, conserve portions of the range: Raso da Catarina Ecological Station (104,842 hectares (259,070 acres), administered by ICMBio),[31] and Serra Branca / Raso da Catarina Environmental Protection Area (67,234 hectares (166,140 acres), administered by the Instituto do Meio Ambiente e Recursos Hídricos, the state agency of Bahia tasked with the environment).