The role of circumstantial evidence in the discovery and description of new species of primates since 2000 and conservational implications.
Paper presented to the II° International Congress "Problematic Wildlife - conservation and management". Genazzano, Rome Italy, 2011.
According to Bernard Heuvelmans, the task of cryptozoology consists of demythifing the content of information in an attempt to help make the inventory of the planet's fauna as complete as possible, through the examination of the so called circumstantial evidence, that is those whose are not considered sufficiently viable beyond any reasonable doubt (ancient legends, eyewitness testimony, tracks, damage done to other animals or the environment, photographs, or acoustic recordings...).
At least 12 of the 30 new primate species described in the last decade have been known since a long time by local people, and the history of their discoveries shows us that when the researchers investigated the circumstantial evidence, the process of discovery and description of a species was faster than through the use of standard sampling methods. 48% of the world's 634 primate species and subspecies are classified as threatened with extinction on the IUCN Red List of Threatened Species including 9 of the 30 species discovered in the last ten years (5 of them are considered at low risk, while we lack reliable data for the remaining 16). The correct use of cryptozoology's tools to accelerate the process of discovery and description of new species can therefore play an important role as regards the protection of the yet not discovered primates at risk of extinction. Finally, a list of potential, undescribed new primate species will be provided.
The order Primates includes a large number of taxa that live in the equatorial regions of Africa, Asia and South America. As for many other worldwide mammals, the state of conservation of primates is at risk: according to the 2008 IUCN Red List of Threatened Species, 303 out of the 634 at the time known primate species and subspecies are threatened (64 Critically Endangered, 141 Endangered and 98 Vulnerable). But despite these alarming data new primates are continually being discovered and described, and 3 new species (Callicebus caquetensis, Nomascus annamensis, Rhinopithecus strykeri) were described after the pubblication of the IUCN Red List.
Even though 9 out of 30 species discovered since 2000 (Table 1) are officially in critical danger, for 16 of these reliable data are still lacking, and only 5 are at low risk. The main causes of danger for the primates survival are habitat loss and hunting; therefore the institutions of new wildlife preserves and the approval of new laws will be essential – but maybe not sufficient- to preserve primates biodiversity. However, there is the possibility that many primate taxa will be extinct before their discovery. The case of Rhinopithecus strykeri, the newest primate species discovered despite its considerable size, it's emblematic. In fact, due to its distribution in a small area and the hunting pressure this monkey has immediatly been given the Critically Endangered status by its discoverers (Geissmann et al., 2010).
A legitimate question to ask is if it could exist a way to accelerate the process of discoveries so that a larger number of species may become protected in as little time as possibile. Here I address this issue by examining the tools available by cryptozoology – the controversial discipline founded by zoologist Bernard Heuvelmans – and furthermore, I put them in connection with the discoveries of primates since 2000 in order to determine possible relationships and to estimate whether cryptozoology may be a valid instrument in the quest for primates conservation. Finally, I submit to the attention of primatologists a list of possible new species of primates known only through circumstantial evidence (Appendix).
Cryptozoology: the science of hidden animals.
Although the late International Society of Cryptozoology was founded by many eminent scientists from around the world at the Smithsonian Institutions (Heuvelmans, 1997), cryptozoology is underestimated by the majority of the academic world.
The reasons that led to this exile, as well as the fact that in the eyes of most non-professionals cryptozoology is nothing but a fantastic monsters hunt, have been discussed by several authors (Grison, 1999; Arment, 2004) as well as the need and legitimacy to establish parataxa (Heuvelmans, 1982; Paxton, 2010; Woodley, 2010); but these issues are not addressed here. For the intended purposes of this work it will be sufficient to explain what cryptozoology actually is.
Cryptozoology, from the Greek roots kryptos (hidden), zoon (animal) and logos (discourse) means "the science of hidden animals" (Heuvelmans, 1982). According to Heuvelmans the "hidden animals" are not yet acknowledged animal species on which there are circumstantial evidence (the evidence judged to be insufficient by some), so that a targeted work in the field may allow their eventual discovery (Rossi, 2008).
A review of the cryptozoological literature shows a tremendous array in the variety and quality of these so called circumstantial evidence: tufts of hair, feathers or scales, feces, blood, tracks, damage done to other animals or the environment, photographic or acousting recordings, but also rumours, ancient legends and folklore. It follows that only a little part of the cryptids – the animals studied by cryptozoology – could be real.
Despite this, the records of Natural History are full of episodes of animals discovered decades, and sometimes centuries, after the first rumours about their existence reached the civilized world (Heuvelmans, 1955; Shuker, 1993). Indeed, although unknown to scientists, these animals were generally well known by local populations, so Heuvelmans conceived cryptozoology in an attempt to reduce the gap between the first informations about an animal and its official discovery (Heuvelmans, 2007).
Of course, such attempt is applicable to almost every type of living organism, but here I only consider a possible use of cryptozoology in primates discovery and conservation.
Primates discoveries of the last decade and cyptozoological implications.
Table 1 shows a list of primates described since 2000, but only the half of these are of interest here. Indeed "discovery" do not coincide with "description", and 15 out of 30 species (1, 2, 3, 4, 5, 6, 17, 18, 19, 20, 21, 22, 23, 27, 29) are the result of revisions of already discovered taxa previously ascribed to others species. To dwell up on the validity of these revisions, that did not fail to rise criticism (Tattersall, 2007), is irrelevant here: the concept of "circumstantial evidence" introduced in cryptozoology is strongly connected to morphological and ethological differences that may be identified by the observers (Heuvelmans, 1982), while minor changes in DNA, the imperceptible frequencies of a call or internal microstructure can not be appreciated by the local people or by the scientists, if not on a laboratory table.
The "real" new species of the last decade are the remaining 15 in Table 1, and at least 12 of those were already well known by local people.
Table 1. The description record of the last decade primates.
Discussion and conclusions.
The discovery of 4 out of the 12 species already known to the local population (11, 13, 14, 24) was by standard sampling methods (Sinha et al., 2010, Thalmann and Geissman, 2005; Kappeler et al., 2005, Jones et al., 2005), while in the remaining 8 cases (7, 8, 9, 10, 16, 26, 28, 30) circumstantial evidence played a key role.
All species discovered and described by Roosmalen (7, 8, 9, 10) were located with the help of natives, who reported how in different areas similar monkeys had different colors (Roosmalen et al. 2000; Roosmalen et al. 2002).
(Re)discovery of the Blond Capuchin (Cebus flavius), which required no less than 358 years to reach a final conclusion, is very indicative of how essential to conservation the acknowledgement of a species in the shortest possible time may be. The first information about this monkey named caitaia appeared in 1648 together with its illustration in the Margrave's Historiae rerum naturalium Brasiliae. Then in 1774 von Schreber posited Simia flavia without a holotype. For 232 years the existence of this monkey was not confirmed until Oliveira and Langguth "rediscovered" the species (Oliveira and Langguth, 2006) establishing the accuracy of the old descriptions and naming it Cebus flavius.
In the same year, Mendes Pontes et al., intrigued by the claims of the Queiroz family – landowners who for thirty years had tried to attract the attention of scientists on the presence of golden monkeys in their terrains – decided to investigate. They proved the presence of these monkeys, naming them Cebus queirozi (Mendes Pontes et al., 2006), now considered a junior synonym of Cebus flavius (Oliveira et al., 2008). It is clear that if the academic world had paid more attention to Queiroz familyclaims, this Critically Endangered species would have benefited of conservation measures long before 2006.
Boubli et al. discovered the Cacajao ayresi following the Yanomamo Indians on their hunts along the Rio Aracá, a tributary of the Rio Negro in Brazil. The natives had described to investigators a uakari monkey which was slightly different to the ones they knew, and the scientists searched this new monkey for at least five years before discovering it (Boubli et al., 2008).
The Callicebus caquetensis, known by locals with the name of tonga, was discovered by Defler et al. following the informations of Moynihan (1976). This author had made observations of titi monkeys from the upper Caquetá (the piedmont of Colombia's Cordillera Oriental) referred to them as anomalous when compared to the other known species. In 2008 -2009 Defler et al. explored the area of Upper Caquetá confirming the ideas of Moynihan (Defler et al., 2010).
The most amazing discovery, considering the size of the species and the type of circumstantial evidence about its existence, is also the chronologically most recent. The burmese snub-nosed monkey (Rhinopithecus strykeri), that reach a body length of 55 cm and a tail length of 78 cm, was discovered in Myanmar in 2010 because the researchers decided to investigate a weird local legend. During a gibbon survey in Myanmmar, hunters reported to Geissmann and his team the presence of a monkey with prominent lips and a nose that faced upwards (Geissmann et al., 2010). Locals called this monkey myuk na tok and mey nwoah ("monkey with an upturned nose") and assured researchers that this species was particularly easy to find when it was raining. "The monkeys reportedly tend to get rainwater in their noses, the monkeys allegedly spend rainy days sitting with their tucked face-down between their knees" (Geissmann et al., 2010). Despite these bizarre descriptions the researchers believing that the mey nwoah could be a kind of snub-nosed monkey, belonging to a genus yet unknown in Myanmar, and following the indications of the natives they discovered that these assumptions were correct.
In light of these facts, despite cryptozoology still possesses many controversial aspects that need to be resolved, the story of the latest discoveries in the field of primatology shows that underestimating the knowledge of local populations and the value of circumstantial evidence is an unwise behavior. In a world where habitat destruction is faster then ever, a conscientious use of cryptozoological tools to accelerate the discovery of new species before their extinction could play an important role in the biodiversity conservation.
The table shows a list of potential new primate species, selected among the most reliable, and whose sources are professional researchers.
According to circumstantial evidence so far available, there should exist 20 primate species yet to be discovered, so distributed:
1 bushbaby, 2 lorises, 2 woolly monkeys, 2 tamarin monkeys, 1 uacari, 1 squirrel monkey, 3 titi monkeys, 1 marmoset, 2 spider monkeys, 2 saki monkeys and 2 incerte forms.
For 16 of these, including 14 studied by Roosmalen, there are only descriptions of the natives, while the remaining 4 deserve further study because they are supported by photographs or direct eyewitness of the involved researchers.
It's a cat-sized bushbaby-like primate observed and photogtaphed in Cameroon by an assistent of bushbaby taxonomist Dr. Simmons K. Bearder in 1994 (Bearder, 1997).
Tailed Slow Loris.
It's a form of loris closely resembling slow loris Nycticebus couang, but distinguished from all known lorises by possessing a long bushy tail; indigenous to India's Luashi Hills. Specimens were captured alive, photographed, and exhibited for a time in captivity during 1889 (Annandale, 1908).
Pale slow loris.
It's an unidentified loris superficially resembling the slow loris but much larger and far paler in color, exhibited and photographed in a bird cage on an animal dealer's stall at the new animal market in Hanoi, Vietnam, in december 1994 (Richardson, 1995).
It's a famous cryptozoological animal, that reportedly inhabits remote, mountainous forests on the island of Sumatra. In 1994 Deborah Martyr and Jeremy Holden of Fauna & Flora International described a specimen 120 cm tall and similar to an orangutan. To date, the researches still in progress have not been able to confirm what could be one of the greatest discoveries in the field of zoology.
[/b]Potential new primate species (still to be discovered)[/b]
I thank Marco Signore and Mauro Cella.
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