Digital creation of glaucous macaws, by Andrés González (© Andrés González/Wikipedia - CC BY-SA 3.0 licence)
Most ornithologists currently recognise 17 species of living macaw. However, there are varying degrees of evidence to suggest that several additional forms have also existed in modern times but do so no longer. Some of them were confined to various Caribbean islands, and I have previously reviewed those examples briefly here on ShukerNature (I have now conducted and written up a much more extensive investigation of their cases that will be appearing shortly). But the ostensibly lost, highly controversial species under consideration by me right now hailed from continental South America – and, who knows, it may still do so.
Some of the most spectacular of all macaws are unquestionably those breathtaking beauties in blue that belong to the genus Anodorhynchus. Both in size and in colour, the three officially-recognised blue macaw species belonging to this genus exhibit an interesting gradation.
Glaucous macaw (centre) with hyacinth macaw (left) and Lear's macaw (right), on a Brazilian postage stamp (public domain)
The largest of this trio is the hyacinth or hyacinthine macaw A. hyacinthinus, named after its magnificent, exclusively blue plumage. Next in line is the mid-sized Lear's macaw A. leari, in which much of the hyacinth macaw's vivid cobalt shading has been replaced by subdued turquoise.
Then comes the glaucous macaw A. glaucus, slightly smaller than Lear's, with a plumage incorporating (as its name stresses) a subtle range of greenish-blue and sea-green hues - particularly upon its head, belly, and the upper surface of its tail feathers. In addition, its throat is brownish-grey, and the feathers around the lower portion of its face are sooty in colour. Tragically, however, this last-mentioned species is now extinct – or is it?
Glaucous macaw, as painted by Paul Louis Oudart for Louis Pierre Vieillot's work La Galerie des Oiseaux, 1825-1834, appearing in it as Plate 24 (public domain)
The scientific debut of the glaucous macaw took place in 1816, when it was formally described by French ornithologist Louis Pierre Vieillot. Its distribution at that time appeared to encompass southern Brazil, central and southern Paraguay, northern Argentina, and northeastern Uruguay, but by the end of the 19th Century this once-common species had seemingly vanished throughout its entire range. The reasons for this astonishing disappearance are still unknown, because the glaucous macaw had rarely been studied in the wild, although the major felling of yatay palms whose nuts were its staple diet, and the capturing of birds for the pet trade undoubtedly contributed.
Over the years, however, a few specimens had been exhibited in various of the world's major zoos - one of these was received by London Zoo in 1886, and a well-known example lived at Paris's Jardin d'Acclimatation from 1895 until 1905. Indeed, it is often claimed that this Paris specimen was the very last glaucous macaw. Conversely, some authorities confer that sombre distinction upon an individual that arrived at Buenos Aires Zoo in the 1920s and was still alive there in 1936, but there are others who believe that this latter bird was actually a Lear's macaw.
A glaucous macaw (foreground) with a Spix's macaw Cyanopsitta spixii, in a Hamburg animal dealer's premises, snapped by Karl Neunzig in 1895 (public domain)
Yet even if it was a genuine glaucous macaw, there is no certainty that it really was the last one. On the contrary, the published literature dealing with this exceptionally secretive species contains an appreciable number of reports alleging the much more recent existence of glaucous macaws, both in captivity and in the wild. Some of these are very vague, little more than rumours; but certain others are compelling enough to have stimulated cautious expectation within ornithological circles that this controversial bird's formal rediscovery is not very far away.
For instance, in her book Macaws: A Complete Guide (1990), parrot specialist Rosemary Low revealed that in 1970 the late Rossi dalla Riva of Brazil, an occasional breeder of rare parrots and very knowledgeable regarding his local region's avifauna, claimed that glaucous macaws nested there, but he would not name the precise locality, fearing that local collectors would send their hunters to trap them. Low also noted that in 1988, after spending some months in the field (she did not name the area), a very experienced bird trapper came back home and announced that he had spied glaucous macaws, but had not been able to photograph or capture any of them.
Another early glaucous macaw illustration, from Alexandre Bourjot Saint-Hilaire's Histoire Naturelle des Perroquets, 1837-1838 (public domain)
In his own book, The World of Macaws (1985), Dieter Hoppe noted that he had heard tell that during the 1970s a glaucous macaw had apparently been exhibited in a bird park either in Belgium or in the Netherlands, and that another supposed specimen had been alive somewhere in Australia during or around 1960. Hoppe also documented a much more tangible, firsthand encounter. Several years earlier, he had visited an animal dealer who had shown him two very strange hyacinth macaws, much smaller than normal and with atypical sea-green plumage; Hoppe believed that these were glaucous macaws.
In addition, he has published a photo of an odd-looking macaw assumed by the photographer, Tony Silva, to have been a Lear's macaw, but which was principally sea-green in colour instead of deep turquoise - another incognito specimen of A. glaucus? Certainly, there is a very real possibility that there are currently a number of unrecognised specimens of this scarcely-known species hiding 'undercover' in captivity, i.e. erroneously labelled as hyacinth or Lear's macaws.
A glaucous macaw skin, at Huub Veldhuijzen van Zanten-Naturalis Biodiversity Center in the Netherlands (© Huub Veldhuijzen van Zanten-Naturalis Biodiversity Center/Wikipedia - CC BY-SA 3.0 licence)
In 1982, writing in his Handbook of Macaws, Dr A.E. Decoteau claimed to be in regular correspondence with a European aviculturalist (no name or country of abode given) who was supposedly breeding a flock of glaucous macaws, from a tame pair that he had owned for several years. However, I have yet to see any mention elsewhere of this sensational programme of captive breeding.
Perhaps the most promising of the glaucous macaw's many reputed reappearances in modern times took place during February 1992, following the arrival at British Customs of a pair of Lear's macaws imported by parrot breeder Harry Sissen on loan from Mulhouse Zoo, situated near Strasbourg, in France. When he came to Customs to inspect them, Sissen was amazed to find that the female seemed to be a glaucous macaw. On 31 March 1992, London's The Mail on Sunday newspaper contained a fascinating full-page account of this remarkable episode written by Howard Smith, which included an excellent colour photograph snapped by Lynn Hilton that clearly portrayed the sea-green colour of the bird's breast and head, with indications of brown markings present upon its throat.
The Mail on Sunday newspaper's article, featuring Lynn Hilton's colour photo of the Mulhouse Zoo mystery macaw – please click to enlarge for reading purposes (© The Mail on Sunday/Howard Smith/Lynn Hilton – reproduced here on a strictly non-commercial Fair Use basis for educational, review purposes only)
Subsequent to its arrival in Britain, this extraordinary specimen was scrutinised by at least two leading parrot experts, Robin Pickering and Joseph Cuddy – among the very few people to have examined every one of the eight preserved skins known to be from genuine glaucous macaws, housed in various of the major museums across the globe. Neither of them reportedly had any doubt regarding the bird's identity as a bona fide A. glaucus.
Moreover, Peter Colston, then scientific officer at the London Natural History Museum's ornithological department at Tring in Hertfordshire, was shown photos of the bird by The Mail on Sunday, and he agreed that its head was reminiscent of the glaucous macaw's. However, he also pointed out that it did not seem to possess this species' characteristic sooty facial feathers.
A second glaucous macaw skin, preserved as a taxiderm specimen, at Huub Veldhuijzen van Zanten-Naturalis Biodiversity Center (© Huub Veldhuijzen van Zanten-Naturalis Biodiversity Center/Wikipedia - CC BY-SA 3.0 licence)
At present, therefore, Sissen's import remains unidentified. It may yet prove to be nothing more than a Lear's macaw (albeit an aberrant, green-tinged one).
Yet if it really is a glaucous macaw and can be demonstrably shown to be one (perhaps by comparative DNA tests), and if other incognito specimens hiding in plain sight can also be found and unmasked, then the only sizeable species of South American bird believed to have become extinct since this continent's western colonisation will be extinct no longer, and the search for the sea-green scarlet pimpernel of the parrot world will finally be at an end.
Glaucous macaw painting, from Monographia Psittacorum, 1832, authored by Johann Georg Wagler (public domain)
Having said that, expeditions by ornithologists during the 1990s to southwestern Paraguay, a potential hideaway for surviving glaucous macaws, failed to uncover any evidence for its continuing existence. Only the region's oldest residents had any recollection of this species, which was apparently last confirmed there more than a century earlier, back in the 1870s. Conversely, the late George Smith, a naturalist who was very informed regarding the history of the glaucous macaw, believed that it still survived in remote areas of Bolivia, where trappers encountered by him were able to identify it.
Smith also noted that when he had flown over these areas, there were vast stands of palm trees, "as far as they eye could see", but these have still never been scientifically investigated, so who knows what secrets they may be hiding? Tellingly, the IUCN still categorises this enigmatic bird as Critically Endangered rather than as Extinct.
Moreover, if we wish to confirm that the longterm concealment of a brightly-hued parrot species of stature in South America is by no means impossible or even unparalleled in modern times, we do not have to look far to offer a very apposite precedent, no further in fact than one of the glaucous macaw's very own congeners – Lear's macaw.
The existence of this famously elusive species first became known to science in 1831, when Victorian bird painter and nonsense-rhymes writer Edward Lear painted a macaw of unrecorded origin that he believed to be (and duly labelled as) a hyacinth macaw but which was later recognised to be a separate species. In 1856, it was named in honour of him by French biologist Charles L. Bonaparte (although some authorities also refer to it as the indigo macaw).
Edward Lear in 1867, and his exquisite painting from 1831 of the macaw species named after him (public domain)
Yet despite having been represented in aviaries worldwide since 1831, Lear's macaw remained a major conundrum to ornithologists for over a century - because no-one knew where these captive specimens had actually been caught. Not even their country of origin, much less their precise provenance, was known. Indeed, a prevalent view back then was that this species might even be extinct in the wild - always assuming that it was a valid species, and not a hybrid of the hyacinth macaw and the glaucous macaw, as some researchers were beginning to suggest.
In 1964, the late Dr Helmut Sick, a German-born Brazilian ornithologist, began an intensive programme of searches for this mysterious missing macaw in a bid to solve its riddles once and for all. It was a programme that would take 14 years before success arrived, but arrive it did. On 31 December 1978, he spied three Lear's macaws in a little-explored area of Brazil's northeastern Bahia region, called the Raso de Catarina. And in January 1979 he sighted a flock of about 20, proving that it was not a hybrid form. These turned out to be part of a population numbering just over 100 birds.
Moreover, in June 1995, a team of Brazilian biologists discovered a second population of Lear's macaw, several hundred miles from the first one, consisting of 22 birds on a nesting cliff. By 2010, the total wild population was estimated to be just over 1,000 birds, and it is also represented in captivity.
Although only three species of Anodorhynchus macaw are formally recognised nowadays, there was once an alleged fourth, and even a fifth, member of this genus. The fourth, of which more is known, is (or was) the purple macaw, the fifth the black macaw.
As noted earlier here, in terms of plumage colouration this genus's official trio of species can be arranged in a very neat gradation, beginning with, as its name indicates, the intense hyacinth-blue shade of the hyacinth macaw, then moving subtly into the slightly more turquoise-blue hues of Lear's macaw, which then transforms further, yielding a paler, turquoise-green or sea-green shade, in the aptly-named glaucous macaw.
But what if this colour gradation were also extrapolated in the opposite direction? That is, in addition to the hyacinth macaw's striking blue hue faintly greening into turquoise and thence even more so into a glaucous tone, how about deepening it, to yield a macaw whose plumage was a darker, predominantly violet or purple shade?
The purple macaw, as depicted by celebrated bird artist John G. Keulemans in Lord Walter Rothschild's classic work Extinct Birds, 1907 (public domain)
If this quartet of macaws were then arranged in a continuous linear spectrum of transforming colour, running from purple into blue into turquoise-blue into pale turquoise-green, the line-up would be: purple macaw, hyacinth macaw, Lear's macaw, and glaucous macaw. Of course, the purple macaw is purely hypothetical – isn't it?
In reality, such a bird may actually have existed – so if you'd like to read about the purple macaw's fascinating history, as well as that of a possible fifth Anodorhynnchus species, the even more obscure black macaw, as prepared by me exclusively for ShukerNature, all you need to do is click here!
A pair of digitally-created purple macaws discovered online (original source presently unknown to me – reproduced here on a strictly non-commercial Fair Use basis for educational, review purposes only)
This ShukerNature article is very greatly expanded and updated from my original 1993-published coverage of the glaucous macaw contained in my book The Lost Ark, which in turn was the first in my trilogy of groundbreaking, definitive tomes collectively documenting new and rediscovered animals of the 20th and 21st Centuries.
Incidentally, please note that my glaucous macaw coverage did not reappear in either of The Lost Ark's two sequel tomes – The New Zoo (2002) and The Encyclopaedia of New and Rediscovered Animals (2012). So now, and constituting yet another ShukerNature exclusive, this is the first time that it has been reprinted (and updated) in more than 25 years.