An early lithograph of the spotted cuscus – the identity of Cape York Peninsula's mystery monkeys? (public domain)
Zoologically speaking, Australia is most famous for its marsupials (pouched mammals) and monotremes (egg-laying mammals). It does contain a number of native species of placental (higher) mammal too – the predominant mammalian category everywhere else in the world – in the form of various rodents and bats. Since this island continent was colonised by humans, however, many non-native placental mammals have been introduced here as well, such as domestic cats and dogs (notably the dingo during a very early stage of human colonisation), deer, sheep, cattle, foxes, and rabbits. However, there is no official confirmation that Australia has ever been home to monkeys – which is why an outbreak of monkey reports here during the early 1930s is so intriguing, and, although all-but-forgotten today, has never been satisfactorily resolved.
One of the world's last unspoiled wildernesses, boasting a rich abundance of relatively undisturbed habitats including tropical rainforest and wooded savannahs, Cape York Peninsula is a vast, remote triangle jutting northward from northernmost Queensland into the Torres Strait, separating Australia at that point from New Guinea. If mystery animals could exist undetected anywhere in northern Australia, this is where they would be. And sure enough, in autumn 1932, after a party of bold, adventurous gold prospectors had penetrated this secluded realm, they came back home to Townsville with tales of having encountered there some very strange and, for Australia, extremely unexpected creatures – monkeys. And not just a few monkeys either. According to a remarkable report appearing on 19 September 1932 in an Adelaide, South Australia, newspaper entitled the News, "several thousand" of these mystifying creatures had been seen (though this count was reduced to "hundreds" further down in that same report).
The prospectors had journeyed to the region of Cape York Peninsula situated between the Lockhart and Pascoe Rivers, 130 miles south of Cape York and 40 miles from the coast. This area's almost impenetrable terrain, apparently having never before been explored by Westerners, was so densely packed with large trees bearing great quantities of red nuts that they "had to fight their way" through, and it was here where they encountered the monkeys, after having initially being alerted to their existence by natives. The monkeys were inhabiting an area 60 miles long by 30 miles wide, and according to the prospectors they "seemed to be of the Malayan breed, about the size of an average dog, and weighing about 30 lb".
Cape York Peninsula monkeys report in the News (Adelaide), 19 September 1932 - click to enlarge for reading purposes (public domain)
Versions of this report simultaneously appeared in a number of other Australian newspapers too, including one in Queensland's Townsville Daily Bulletin claiming that the monkeys seen by the prospectors were in groups of about 15-20 individuals, and that there were "numerous" such groups. These reports were followed by a second account emerging just a day later, on 20 September, from a gold prospector named R. King. As again covered in a wide range of newspaper reports across Australia, he stated that he had not only encountered some monkeys but had even shot a couple of them while exploring one particular area of Cape York Peninsula. According to a report that appeared in the Maryborough Chronicle on 20 September 1932, documenting King's testimony:
The area in which King located the animals is south-east of the Batavia goldfield, embracing the McIlwraith Range [a rugged granitic plateau], the area being about 30 miles wide and extending along the peninsula for approximately 60 miles. King said today that he journeyed on the western side of the range searching for gold. There was nothing there that suggested human beings had ever been in that locality. Progress was difficult with horses being impeded by sugarcane grass growing to enormous heights, in some instances up to 15 feet. In this scrub the prospector saw mobs of monkeys frequently during his four or five weeks' stay. They were generally in parties from 15 to 25.
But that was not all:
Though he could not get closer than rifle range he shot a couple during his stay. Observations he made seemed to indicate that the male was much larger than the female and the largest would not exceed about 30lb.
If only King had brought back the body of one of the shot monkeys (or at least some portion of it) for scientific examination. Having said that, however, carrying what would have been a rapidly-decomposing, stinking carcase back with him through difficult terrain in the humid conditions prevalent in this locality would not have been the easiest or most pleasant of tasks, so I can certainly understand why he didn't do so, even if such a thought had indeed occurred to him. Equally, as he was not a professional zoologist himself, he probably would not have realised the scientific significance that even just a selection of one of the shot monkey's teeth and/or a single jawbone, for instance, would have held for zoologists examining them,
Nevertheless, according to an article published on 1 October 1932 by a Cairns, Queensland, newspaper entitled the Northern Herald, King was willing to self-finance a two-man expedition, consisting of himself and a scientific representative, back to the location where he'd seen the animals, provided that "a substantial reimbursement were guaranteed on production of the specimens". As far as I am aware, however, no such expedition was ever launched, so presumably King did not receive any such guarantee.
Well worth recalling at this point is that during the second half of the 19th Century, a number of acclimatisation societies sprang up all over Australia. Their shared goal was to introduce into the wild a vast diversity of exotic, non-native species that their members considered would be beneficial for food, for cultural exchange purposes with other countries, or, in some cases, for purely aesthetic reasons (i.e. they were attractive species, or were familiar ones that reminded the societies' members of Europe). In order to achieve this, the societies sought to create captive-breeding colonies from which releases into the wild could subsequently be carried out until self-sustaining populations had established themselves there.
Madagascan ring-tailed lemurs roaming wild in Australia? It nearly happened! (© Dr Karl Shuker)
Among the mammalian species on their lists of proposed releases were such geographically and taxonomically diverse creatures as South American agoutis, African elands, Madagascan ring-tailed lemurs – and several species of monkey. Indeed, in 1861, Edward Wilson, the founder of Victoria's acclimatisation society, wrote to this Australian state's governor requesting that monkeys be released into the Victorian bush: "…for the amusement of the wayfarer, whom their gambols would delight as he lay under some gum tree in the forest on a sultry day". Happily, however, for the survival of Australia's unique, irreplaceable endemic fauna, very few of these alien species bred successfully even in captivity at the societies' various breeding centres (let alone in the wild). Consequently, most of the planned releases never took place, and I am not aware of any record of official monkey releases having occurred anywhere on this continent. But might there have been some unofficial, undocumented, unpublicised acclimatisation efforts involving monkeys that were successful, with Cape York Peninsula being deemed an ideal locality for such creatures to live and thrive (which, indeed, it is)? Yet if not, what other explanations can be offered for the gold prospectors' sightings here?
During the weeks that followed the two prospector accounts being widely disseminated by the Australian media, several additional articles were also published, containing opinions regarding the possible identity of Cape York Peninsula's supposed monkeys, as proffered by a range of scientists and others who were variously interested in or dismissive of this mystifying affair. But once its initial novelty had worn off, however, and (as always happens with ephemeral subjects like this) the media began looking elsewhere for curiosities to publicise, the Peninsula's enigmatic primates vanished from the headlines, and eventually from all but the most tenacious memories within the zoological community too.
Indeed, if referred to at all nowadays (which it seldom is), this entire episode is normally dismissed as the outcome of a regrettable misidentification by the gold prospector eyewitnesses, mistaking one or other of two already-known types of marsupial for monkeys. As will now be shown here, however, neither of these 'official' identities stands up to close scrutiny. Having said that, there seems little doubt that some form of creature was encountered (and in some numbers) amid this peninsula's remote backwaters, so what might it have been?
An 1884 lithograph of Lumholtz's tree kangaroo (public domain)
When the story of the alleged monkeys in the Peninsula broke, two different but equally popular mainstream identities were variously proposed for them by a number of different authorities. One of these identities was some form of tree kangaroo – as suggested, for instance, by Ludwig Glauert, then Curator of Perth Museum.
Two species are native to Australia, and both occur in a small portion of Cape York Peninsula's easternmost basal region. The smaller and more common of these is Lumholtz's tree kangaroo Dendrolagus lumholtzi, a rainforest-inhabiting species predominantly black and grizzled grey in colour, with somewhat short limbs but an exceedingly long tail, and only weighing up to around 20 lb maximum. Larger and rarer here is Bennett's tree kangaroo D. bennettianus, dark chocolate-brown above and fawn below, with longer limbs, a very long tail, and weighing up to 30 lb in adult males (females are much smaller). It inhabits both mountain and lowland tropical rainforest, but is notoriously elusive.
An 1894 lithograph of Bennett's tree kangaroo (public domain)
In terms of dimensions, maximum-sized Bennett's tree kangaroos are comparable to the largest 30-lb alleged monkeys as estimated by King and the other prospectors; but in terms of morphology, neither species of Peninsula tree kangaroo is particularly simian. Moreover, whereas both species have very long, noticeable tails, no mention of tails occurred in either of the two gold prospector reports – indicating, perhaps, that the creatures that they encountered were either tailless or only possessed short, inconspicuous tails?
In addition, whereas all Old World monkeys are strictly diurnal, as the creatures encountered by the prospectors clearly were too, both of these tree kangaroo species are principally nocturnal (exhibiting only limited, spasmodic daytime activity), so they wouldn't have been readily perceived or even met with by their eyewitnesses, and neither species occurs in large groups or parties like the creatures sighted anyway (Lumholtz's occurs in small, loose-knit reproductive groups of just 3-5 adult members). Also, if they had indeed been nothing more than tree kangaroos, the region's native inhabitants would surely have known this, and therefore would not have specifically called the prospectors' attention to them.
Instead, and even before his own first-hand encounter with the alleged monkeys, King had already been informed by aboriginals inhabiting the Daintree River area that monkeys lived in the Peninsula. However, he had discounted their claims, assuming that the creatures that they were referring to were simply tree kangaroos – until he saw them with his own eyes, and realised that they were not. This also demonstrates that King knew what tree kangaroos looked like, and therefore would not have been confused by them.
Ion Idriess (public domain)
At the time of the media reports concerning the Cape York Peninsula monkeys, one of the few Westerners to have explored sizeable portions of this region was Australian writer Ion Idriess. When media reporters asked his opinion as to these mystery animals' possible identity, he speculated that they may have been either a species of tree kangaroo or, his personal preference, a very large phalanger – which brings us to the second popular mainstream identity offered for the Peninsula monkeys.
Phalangers are arboreal marsupials closely related to the possums and sugar gliders, and the largest phalangers are the cuscuses (the biggest species of which is New Guinea's black-spotted cuscus Spilocuscus rufoniger, up to 4 ft long and weighing as much as 15 lb). Although cuscuses are predominantly found in New Guinea and on certain Indonesian islands close by, two New Guinea species also occur in Australia's Cape York Peninsula.
Taxiderm specimen of the spotted cuscus (© Markus Bühler)
Of these two, the species less likely to explain this region's supposed monkeys is the well-named spotted cuscus S. maculatus, because in the male its thick brown fur is indeed handsomely and very noticeably patterned with irregular white spots and blotches, which sometimes are so extensive that the animal appears white with brown blotches (females are unspotted). This striking characteristic is of course conspicuous only by its absence in the prospectors' monkey accounts, yet due to its eyecatching nature it would surely have been reported by them if it had indeed been exhibited by the monkeys (some of them would certainly have been males).
The second cuscus species native to this peninsula is the grey cuscus Phalanger mimicus (which is closely related, and similar in overall appearance, to the more familiar ground cuscus P. gymnotis). Its woolly unpatterned fur is grey-brown dorsally and laterally, and off-white ventrally, with a brown mid-dorsal stripe extending along its spine from its ears to its rump.
Ground cuscus (public domain)
As with the tree kangaroos, however, both of these cuscus species are predominantly nocturnal, do not occur in large groups (they are generally solitary animals), and are so cryptic that they are seldom spied even by the region's aboriginals. They are also sluggish and slow-moving, unlike typically active, agile monkeys. Additionally, neither of them attains anything like a weight of 30 lb; on the contrary, no bigger than typical domestic cats they rarely exceed 8 lb in the wild (sometimes more in captivity), with the spotted cuscus being slightly bigger than its grey-furred relative.
In view of such notable discrepancies between cuscuses and monkeys, I was nothing if not surprised, therefore, to discover, via a brief single-line reference to the Cape York Peninsula monkey saga contained in her book Possums: The Brushtails, Ringtails and Greater Glider (2001), that Anne Kerle considered that the grey cuscus was "undoubtedly" the origin of the monkey reports. Further back in time, but no less surprising, was that in his book Furred Animals of Australia (8th edition, 1965), Australian zoologist Ellis Troughton stated that spotted cuscuses have "a remarkably monkey-like appearance" and that this species may therefore have inspired the Peninsula monkey reports (notwithstanding this cuscus's unmissable spotting?). Moreover, an old, now-obsolete colloquial name for the grey cuscus is 'monkey cuscus', and another, even older (and taxonomically inaccurate!) name for it is 'monkey opossum'. (Taxonomically, the term 'opossum' is restricted to the didelphid marsupials of the Americas.)
I find these allusions to the supposed monkey-like appearance of cuscuses to be very perplexing, even bizarre. For as someone who has seen living cuscuses at close hand in captivity while visiting Australia, I can readily affirm that they do not look like monkeys at all – being far closer in appearance to certain lemurs among the primates. Nor am I alone in that view, because it was also expressed back in the 1930s by various commentators in relation to the possible identity of the Peninsula monkeys.
A decidedly (and accurately) lemurine representation of the spotted cuscus in an 1890s engraving (public domain)
For instance: in an article focusing upon the Peninsula's cuscuses and published by the Queenslander newspaper on 22 August 1935, the columnist 'Wanderer' uncompromisingly stated: "How the cuscus came to be called the "monkey opossum" I cannot say, but the name is not appropriate, for the creature is neither monkey-like in appearance nor habits". Similarly, in an Adelaide Advertiser article of 10 December 1932, its author, Donald Thomson, who was leading an expedition in the Cape York district, bluntly confirmed that when a cuscus is closely examined: "…it does not look at all like a monkey". Amen to that!
Equally, as with the tree kangaroos, the Peninsula aboriginals would have been familiar with the cuscuses living there, so surely they would not have attempted to portray them to the prospectors as anything other than cuscuses. Also of note is that when Australian naturalist-prospector William McLennan suggested to King that what he had seen were cuscuses, King denied this, stating that he was familiar with cuscuses, and that what he had seen were monkeys, not cuscuses.
No other native mammals in Cape York Peninsula look like monkeys either, so if we sensibly choose to dismiss as implausible the premise that not only the prospectors but even the native aboriginals had all been extremely unknowledgeable regarding the animals encountered by them there and even less adept at identifying them correctly, the true nature of these supposed monkeys remains a mystery – unless of course they really were monkeys! Yet if this is true, how can the presence of such blatantly non-native animals in the wilds of Australia be explained?
William H.D. Le Souef (public domain)
During his newspaper account, prospector King opined that these reputed monkeys had come from Malaya during the early days of trading between southeastern Asia and Australia, and had remained in reclusive anonymity ever since within the Peninsula's dense scrub where Westerners had not penetrated prior to the recent forays there by himself and the other prospectors. This notion was echoed by Ion Idriess, who conceded that it was plausible that a few monkeys had originally escaped ashore from trading steamers or from wrecks, had thrived and bred in the Peninsula, and had eventually given rise to a self-sustaining population there. Even the eminent Australian naturalist William H.D. Le Souef from Sydney's Taronga Park Zoo stated that it was quite possible that the prospectors' information was correct.
But even if this were so, what kind of monkey might they have been? King and the party of prospectors variously made comparisons between the Peninsula creatures and Malayan monkeys, and suggested a Malayan origin for them, and it is true that 11 different species of monkey collectively exist in mainland Malaysia and in its two states on Borneo (Sabah and Sarawak). They fall into two categories – very slender, long-limbed, long-tailed langurs or leaf monkeys (7 Malaysian species), and sturdier, shorter-limbed, often only short-tailed macaques (4 Malaysian species, following the recent taxonomic splitting into two of the pig-tailed macaque). Moreover, both of these monkey types socialise in large groups (sometimes extremely large in the case of macaques), just as reported by the prospectors for the creatures that they saw.
An 1800s lithograph of a langur or leaf monkey (public domain)
Confined to Borneo, the largest Malaysian langur, the famous proboscis monkey Nasalis larvatus with its huge grotesque nose in the adult male, can surely be eliminated from consideration straight away. This is because not only is its nasal appearance so distinctive that the prospectors would have assuredly mentioned it specifically in their accounts, but males can exceed 60 lb in weight, i.e. more than double the size estimated by the prospectors for even the largest of the creatures that they saw. Other Malaysian langurs, conversely, such as the silvery (crested) langur Trachypithecus cristatus and the spectacled langur T. obscurus, only attain half the weight claimed by the prospectors for the largest of their alleged monkeys (little more than a third in the white-fronted langur Presbytis frontata), and (like tree kangaroos) they possess extremely long, visible tails.
Macaques native to Malaysia include the crab-eating macaque Macaca fascicularis and the two near-identical pig-tailed macaque species M. leonina and M. nemetrina. Unlike a number of other macaques, however, the crab-eating macaque does have a long tail, and males attain a maximum weight of only around 20 lb. Yet, interestingly, this is a notable invasive species, having been successfully introduced to a number of non-native territories where it now thrives, including New Guinea, which as noted earlier is immediately to the north of Australia's Cape York Peninsula, separated from it only via the Torres Strait.
Crab-eating macaque (public domain)
During the course of history, many large species have spread from one region to another via rafting across stretches of water on floating debris, vegetable mats, etc – could specimens of this macaque species have done the same, from New Guinea to Cape York Peninsula? The pig-tailed macaques have only a fairly short tail, but their males are slightly smaller in size than those of the crab-eating macaque, as are those of the stump-tailed macaque M. arctoides, which has an even shorter tail.
A pig-tailed macaque (public domain)
A third option is also worth a consideration – might these so-called monkeys have actually been apes, specifically gibbons? After all, laymen frequently refer to gibbons (and other apes too) as monkeys. Four species exist in Malaysia, of which the siamang Symphalangus syndactylus is much too big, but the other three – the agile gibbon Hylobates agilis, lar gibbon H. lar, and Müller's Bornean gibbon H. muelleri – are smaller and, like all gibbons, are tailless.
When I first read the two prospector accounts describing the alleged monkeys witnessed by them, however, I immediately thought of macaques, in terms of both their appearance and their large groups. These monkeys also have a much closer affinity with humans than langurs and gibbons, being frequently kept as pets aboard ships, as well as used in scientific research (the famous rhesus monkey Macaca mulatta, a commonly-used laboratory species, is a macaque). Consequently, if we assume that the Peninsula mystery beasts were real, and that they were indeed monkeys, perhaps they were macaques that had escaped or been released there by Malay traders visiting northern Australia, with their body size either exaggerated by the prospectors or, with no notable predators in this secluded region, larger than normal specimens having subsequently arisen. Of course, the prospectors' claim of seeing "several thousand" of these monkeys is worrying with regard to their account's authenticity, but this may well be due to journalistic hyperbole, because "hundreds" was used further down in the same newspaper articles covering their account.
Rhesus monkey (public domain)
Today, approximately half of Cape York Peninsula has been given over to cattle grazing, but much of the remaining half is preserved as a national park, with its virgin wilderness still a haven of largely undisturbed tranquillity for its wildlife. Is it conceivable, therefore, that a colony of monkeys genuinely existed here less than a century ago, having descended from some specimens originating from Malay ships and/or rafting across from New Guinea (or possibly even stemming from some unpublicised, covert acclimatisation-based introductions)?
If so, and, with nothing having occurred during the interim period to have eradicated wildlife in much of this vast, scarcely-penetrable locality, might they still be there today?
An 1890s lithograph of Lumholtz's tree kangaroo (public domain)