Lear's macaw (Anodorhynchus leari), also known as the indigo macaw, is a large all-blue Brazilian parrot, a member of a large group of neotropical parrots known as macaws. It was first described by Charles Lucien Bonaparte in 1856. Lear's macaw is long and weighs around . It is coloured almost completely blue, with a yellow patch of skin at the base of the heavy, black bill.

Although there are records of the macaw from Britain from the early 1830s, this bird was only generally recognised as an independent species in the late 1970s. 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. It mostly feeds on the nuts of the palm species Syagrus coronata, as well as raiding maize from local farmers. Its ecology also appears linked to cattle ranching.

Taxonomy

Lear's macaw was named after the famous poet, Edward Lear, who was also an accomplished artist. In his teens in the early 1830s, Lear published a book of drawings and paintings of live parrots in zoos and collections, Illustrations of the Family of Psittacidae, or Parrots. One of his paintings in his book strongly resembles this species, and although at the time he titled the work as 'hyacinth macaw' — a larger, darker species with a differently shaped patch of yellow skin adjacent to the base of the bill, which it closely resembles — not everyone agreed, and a quarter century later, in 1856, the illustration was given a species description by the French ornithologist and nephew of Emperor Napoleon, Prince Charles Lucien Bonaparte, who chose to commemorate the poet in the specific name. Most authorities, however, were unconvinced of the distinctness of the new taxon. 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.

upright|right|thumb|Illustration by [[Edward Lear (1812–88) first published in his book Illustrations of the Family of Psittacidae, or Parrots in 1832]]

Description

Lear's macaw is long and weighs around .

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. It has an area of pale-yellow skin adjacent to the base of its beak, and orange-yellow eye rings. It has a large, blackish beak and dark grey feet.

Lear's macaw is similar to the larger hyacinth macaw and the slightly smaller glaucous macaw. 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. The glaucous macaw is paler and has a more greyish head.thumb|Lear's macaw, NE Brazil.

Ecology and behaviour

Feeding

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.

The macaw usually forages in groups. They preferentially feed on the palms where they grow in groves, mixed together with taller trees. At least thirty confirmed feeding localities are known throughout the range. A tall tree is selected by the flock as base to carefully inspect the feeding area. First a pair descends to the level of the palms to assess the suitability, the pair then returns to base, and then the entire flock descends to decide if it is worth staying around. 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. Upon occasion the birds maw fly off to a better perch to consume the nut, sometimes even carrying a branchlet with a few fruit.

A mystery regarding plants in the Neotropics with very large fruit or seeds is which type of animal disperses the seeds. Elsewhere on earth large herbivorous mammals are the dispersal agents for such plants, but these are largely absent in South America today. 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. The Syagrus coronata palm, however, may have found a way to avoid such a fate, despite its large nuts.

Breeding

The mating season starts at the beginning of the summer rains, at the start of the year, and extends up to May, when the young begin to fledge and leave the nest. 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. In 1995, a roosting site holding 22 birds was located at Sento Sé/Campo Formoso, to the west. The estimated global population in 1987 was 70 birds. The wild population was surveyed as some 170 individuals in 2000. The global population was censused at 246 birds in 2001 (Gilardi), 455 in 2003, Barros counted a total wild population of 630 birds in 2006. In the 2008 assessment BI countered that earlier surveys undercounted the birds, and that the population was not actually increasing. BI estimated a population of 250–500 mature wild individuals in 2008, arguing that because the population was probably increasing, most of the birds counted by in recent surveys were probably juveniles and therefore did not count as to the total population. 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 population growth was stated to be uncertain, with BI reasoning that because in the 1990s some 40 birds had been trapped for the pet trade, which had represented a "very rapid decline", it was unclear if the increasing population was increasing. This was not true, it was known that there were two subpopulations, perhaps three since a new discovery of 22 birds at another roosting location in 1995, but BI filled in this information incorrectly in the Population section, despite elaborating on the different subpopulations in the Geographic Range section in the same assessment. The 2016 IUCN assessment continued to give an estimated total population of 250–999 individuals, with the population growth given as uncertain, although it was now clear the population was growing. BI slightly changed the text to state that 228 birds were adults, more than 250, instead of 258.

In 2014 Chico Mendes Institute for Biodiversity Conservation (ICMBio) counted 1,294 birds, this increased to 1,354 in the 2017 ICMBio count, and grew further to 1,694 in the 2018 count. In the 2019 IUCN assessment, BI continued to assert that the population was 250–999 individuals, but now first stated that the population growth was increasing. The map was extended to show the foraging ranges, and not only the roosting sites. 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)). An explanation was also given for reducing the number of mature individuals to 228, a 2014 study published by Pacífico et al. This study stated that although the total population size at some 1,125 birds was well known by 2010, it was unknown how many of these birds were actively breeding. During the 2010 season, 114 nests and probable nests were counted. As each nest represents two actively breeding birds, this indicates that 20.3% of the population was actively breeding each season, which is comparable to other similar parrot species. Canudos Biological Station was expanded in 2007, partially with funding by the American Bird Conservancy, from to .

Two protected areas, and Serra Branca / Raso da Catarina Environmental Protection Area (, administered by the Instituto do Meio Ambiente e Recursos Hídricos, the state agency of Bahia tasked with the environment). This latter area contains both the privately owned Canudos Biological Station where Toca Velha is located, and the privately owned Serra Branca ranch, which contains the majority of the nest and roost sites.

According to the World Parrot Trust, the Lear's macaw is currently extremely rare in captivity and may live for 60 years, It is recommended that this parrot be kept in an enclosure of in length.

See also

  • List of macaws

References

  • Rare Blue Parrot Back from the Brink of Extinction , American Bird Conservancy, 9 June 2009
  • Parrot Encyclopedia – Species Profiles by World Parrot Trust
  • Parrots International
  • The Mystery of Lear's Macaw
  • Blue Macaws
  • images and movies of the Lear's macaw (Anodorhynchus leari) at ARKive