Brown nosed coati on Auyan-Tepui: Are lowland vertebrates invading the tepuis? Part 1
( Special thanks to Mary Reite, a brilliant young anthropologist who helped get this blog published)
Abstract
It has been stated by a number of authors that the tepuis of the Guayana Highlands are depauperate of large vertebrates. The region in which the tepuis exist have been surveyed to a large extent, although not entirely.1 Known vertebrates include endemic amphibians, some endemic reptiles, birds and a few species of endemic mammals, such as the Roraima mouse Podoxymys roraimae .2 A number of authors have observed and published papers regarding the unusual and apparently infrequent presence of lowland vertebrates on the tepuis. Huber, Linares and Havelkova have all stated that coatis (Nasua nasua) have been observed on the tepui summits, and are certainly present in the highlands of Venezuela.3 Sightings are not limited to journal articles, and appear in popular magazines such as National Geographic and GEO.4 This paper adds an additional sighting of Nasua nasua to the short list of large vertebrates observed on the tepui summits. The sighting was recorded in a Terra-X documentary during the 1990 Terramar expedition to Auyan tepui, and predates photographic evidence of Nasua nasua recorded on Roraima tepui in 2003 and documented by Havelkova et al in 2006. Why larger vertebrates are invading the tepuis is unknown. The phenomena could be completely natural, or it could be the result of human interference with the tepuis themselves. Two hypothesis are suggested, that of increased ecotourism and human activity in the Guiana Highlands (GH) enticing the lowland animals onto the summits, or as an observable result of the anthropogenic climate change discussed in depth by Rull et al in a variety of his published papers on global warming in the Guyana Highlands.
Introduction
The Guayana Highlands (GH) are a unique and extensive formation of ancient uplifted rock in northeastern South America, host to an impressive level of biodiversity and unique endemic organisms. The highlands are distributed between Venezuela and Guyana in the north, and Brazil in the south. The GH is part of the Guyana Shield, an ancient Paleozoic massif which constitutes some of the oldest rock on earth. The defining features of the GH are the numerous towering mesas called tepuis, which form a distinct biogeographical region known as the Pantepui.5 This Pantepui region, contained within Canaima National Park, is recognized as neotropical biodiversity center, a center for plant diversity and is an UNESCO World Heritage site.6 The tepuis themselves form semi-isolated habitats for endemic organisms, although the fauna of the tepuis is considered depauperate. The lack of large vertebrates on the tepui summits is due to a number of factors, including discontinuous and limited surface area, topographical isolation, and heavy precipitation which leads to nutrient poor soil. The tepuis range in surface area from a few square kilometers to 700 square kilometers in the case of the largest tepui Auyan. The Pantepui region was uplifted from the surrounding terrain at the same time as the Andean uplift, a process which begun approximately 30 million years ago.7 This uplift then led to the raising of underlying buried Proterozoic sandstone thousands of feet above the surface. Subsequent weathering and erosion of the softer rock ( such as Mesozoic sediments) cut the Pantepui into a series of isolated mesas. It is theorized that the differentiation of the modern tepuis can be traced to the establishment of the various river systems which now divide them.8 In this environment of isolated rain eroded tepuis, large summit endemic vertebrates are considered absent. Few have been observed, and the ecosystem is in general not considered conducive to the long term establishment of larger vertebrates. Furthermore, lowland species are not recognized to invade the tepuis, due to both topographical isolation as well as a lack of food sources. A few endemic mammal species such as the rodent Podoxymys roraimae have been observed and cataloged on tepui summits, but larger species of commonly occurring lowland animals are not observed in general.9
Despite this, a few sightings of coatis (Nasua nasua) have been reported from the Pantepui, specifically the summits of certain larger tepuis.10 The first published paper with a specific sighting is described by Havelkova et al in the paper “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)”11 The work includes a description of the sighting and location, a diagnosis of the coati, and a brief discussion of why it it may be present on Roraima. The observations of Roraima coatis are summarized below for the purposes of comparison to the Auyan tepui coati described next.
The Havelkova coati
Location: Summit of Roraima Tepui, March 2002, January 2003. (Photographed during 2003 sighting). Both observations occurred during the day. Timing correlates to the end of the dry season.
Description: Individuals were identified as “ having a relatively slender snout and a predominantly yellow-black pattern of pelage. The head is black; no distinct facial light markings, with a singe yellow spot situated on the right side of the left eye. The nose is suspiciously gray. Dorsal side of the ears and fur behind them is orange or orange-brown. Head colored black, with distal portion of the limbs black. Tail coloration with six black rings, twice the width of the light rings, and a black tip. Rest of the pelage is yellow to beige, with black underfur”.12
Behavior: Gregarious and seemingly un-shy around humans. Marek Audy observed two individual coatis behaving aggressively, with one tagging the other. These observations made were due to the fact that the coatis were visiting the authors camp on a number of occasions. Coatis were observed investigating the inside of bromeliads in search of food.
The coati described by Havelkova. Image taken from Virtual Tourist.
An earlier sighting of coatis on the tepui summits went officially undocumented, but was recorded in the Terra-X documentary “Islands Above the Rain forest, part 2”, episode 33 of the Terra-X series. This documentary follows the work of the Venezuelan environmental Non-Governmental Organization (NGO) Terramar, which at the time of filming was conducting field research on two tepui summits, Roraima and Auyan. A series of expeditions were undertaken by Terramar in the late 1980s, which resulted in the publication of the May 1989 National Geographic article “Venezuela's Island in Time” by Uwe George, the December 1990 GEO article “Auf der Suche Nach dem Ungeheuer” (The search for the Monster) by Uwe George, Terra-X episode number 33 “Islands Above the Rainforest” and a book which detailed the expedition entitled “Inslen in der Zeit”, published in 1988. It seems from a review of the GEO article “Auf der Suche Nach dem Ungeheuer” and the Terra-X documentary “Islands Above the Rainforest”, that the two works detail precisely the same Terramar expedition. There is consistency in the two sources regarding details of the expedition, GEO article photographs which are identical to Terra-X film frames, and continuity in expedition members, including Volker Artz, Armando Michelangeli, and Uwe George. Furthermore, the credits of the Terra-X documentary state that the film is a product of GEO-Film, a now defunct documentary producer which was part of the operation of GEO itself. The sighting is recorded on two segments of film from the Terra-X documentary, while the details of the actual encounter between coati and expedition members is unknown in duration and circumstance.
The Terra-X coati
Location: Summit of Auyan tepui. Details from the documentary and GEO article place the sighting to the west and north of Angel Falls, possibly near camp two in an area described as the “Valle Encantador”. Occurred prior 1989 or 1990, toward the end of the dry season, determined by film narration.13 Although two clips of coatis are present in the documentary, these may represent the same individual animal.
Description of clip one: Footage lasts exactly 20 seconds, during which time the coati in question is filmed moving across a clearing in a swampy area bordered by a shallow stream. The coati exhibits a dark brown pelage, with a lighter brown belly. It has no obvious markings on its face; tail rings are difficult to differentiate, but seem present. The snout does seem to be fairly narrow, and resembles in shape the snout of the coati in the photographs in the Havelkova article.
Behavior: This particular coati appears rapidly from behind some vegetation, then looks at the camera before quickly proceeding on its way across the open swampy area. As with the previous sighting, the Coati seems to ignore human presence.
Description of clip two: Clip 2 lasts 25 seconds, and shows a coati which is entering the campsite of the expedition members. This coati has a blackhead and snout, with ligher brown patches on its head. The legs are black, and the belly and back are a medium colored brown. Tail rings are not clearly visibly, and the tail itself is brown. Snout is fairly narrow.
Behavior: This coati was filmed raiding the camp of the expedition members while they were away. It seems undisturbed by the camera man, although it my be unaware of his presence. It climbs down a branch supporting the tarping covering the kitchen tent, and proceeds to search for food. It locates what appears to be left over food and a container of dry food, and consumes it. The coati seems finally startled by the cameraman filing it, and leaves the camp.
Diagnosis
In this case, both clip one and clip two seem to show the same individual; a single coati with a black snout and head, black legs, a brown colored trunk, and a tail with little indication of rings. In both cases the size of the animal, proportions of the legs and slender snout seem to demonstrate that this is the same animal. If other coatis were sighted, they were not mentioned in the film, nor was their presence recorded for the documentary, indicating that no other coati sightings were made. In terms of what species of coati this is, it is clear that this is the South American coati Nasua nasua, based upon its geographical location, as well as parts of its visible anatomy.14 Furthermore, it is possibly a member of the coati subspecies Nasua nasua vittata, based upon the geographical ranges of coati subspecies and physical similarity (although vastly different coloration) to the coati featured in Havelkova et al.15 The coloration of coatis is highly variable; this coati displays a muted brown and black pelage, without the usual distinctive yellow snout hairs, or distinctive rings on its tail. This pelage coloration is well in the range of known coatis, where “the ring pattern of the tail may be scarcely visible”.16 The sex of this individual coati is unknown, but it can be guessed at. First, the coati in clips one and two seem to be the same individual, and no other coatis were recorded. It is known that among coatis, adult males are solitary, and females and juveniles travel in bands of up to 30 individuals.17 Thus, one can infer that the coati recorded is a solitary adult male.
Other Coati sightings
The presence of coatis on tepuis is not without precident. Coatis on Auyan tepui have been mentioned by Omar Linares in his book “Mamiferos de Venezuela”. Otto Huber also mentions the presence of coatis on the tepui summits in his 1988 work “Guayana Highlands versus Guayana Lowlands, a reappraisal”. Toward the end of the article, Huber discusses the relative isolation of tepui biota from lowland biota. He states;
“It must also be born in mind that the concept of isolation is highly conditioned by anthropocentric thinking. A wall 200 m high might well form a serious obstacle for men, but not necessarily so for plants or even higher mammals. As a matter of fact, even from such 'isolated' and inhospitable tepui summits as Roraima, Yuruani, Angasima, etc., a coati (Nasua nasua, Procyonidae) has been reported;...”.18
The author of the 2008 book “Lost World of the Guiana Highlands” Stewart McPherson also writes about coatis present on the tepui summits. McPherson writes;
“The largest vertebrate on the summit of Mount Roraima, and probably the majority of tepuis is the ring tailed Coatimundi (Nasua nasua). Also known as the coati, this relative of the raccoon forages through the spacse vegetation of the tepuis in search of flowers, fruit, leaves and insects. Having been isolated, the Coatimundi of Mount Roraima have little fear of people and so are relatively tame and approchable, a further parallel of animal life of distant ocean islands and archipelagos”.19
Discussion.
The coati sightings backed by photographic evidence seem to be confined to the 2006 paper of Havelkova et al, and the two sightings from the Terra-X documentary. Statements by Linares and Huber should be taken very seriously; both men are renown scientists with a keen observational eye and are heavily published. As for the account by McPherson, it would seem that he implies a population of coatis present on Roraima tepui, which have been isolated from the surrounding population in some way, and are not afraid of humans. This statement does not seem to have any supporting evidence which I can discern. Indeed, in McPherson's book the section detailing the coatis on Roraima utilize the exact photograph of the coati in figure two of the Havelkova article, identified as a coati photographed by Marek Audy in 2003.20
What can be discerned from the sightings of coatis on tepui summits and the amount of literature being written about them seems to be puzzling. As a general rule, scientista are of the opinion that large vertebrates are absent from tepui summit ecosystems, as the summits are considered to lack ecosystems suitable to sustain large animals. The 2006 Havelkova et al paper reflects this opinion, and goes into depth on the issue of coatis photographed on Roraima. After that publication, the presence of Roraima coatis is included by McPherson in such a way as to imply an almost island endemism. Both Linares and Huber seem to regard the issue as akin to a foot note, and do not go into great detail regarding larger mammal presence on the tepui summits. In the case of the Terra-X coati, it would seem that Terramar and its members regarded the presence of a coati on Auyan Tepui as not unusual, though the film crew included it in the German language version of the documentary. To me, this indicates that for Venezuelan scientists the presence of coatis on the tepuis is considered a normal phenomena to some degree. Alternativly, it could be such a rare occurance that it is glossed over, and certainly the Terra-X episode featured Terramar members involved in a much more intense target oriented search of Auyan Tepui.
Historically, Nasua nasua became an indigenous member of the South American faunal community during the Great American Interchange in the Pliocene. Thus, its interactions with the tepui ecosystems occurred during the cyclical glaciations which had a dramatic effect on the vertical migration of lowland organisms into the tepuis, and may have been accompanied by massive extinctions in pre-Pliocene tepui summit biota.21 Summit invading coatis would have been effected by the glacial oscillations, and perhaps entered tepui summits during climatic periods where foraging on the summits was conducive to their survival. It is stated in Gompper et al that “This species (Nasua nasua) is absent from the llano grasslands of Venezuela”, and that the coatis in Venezuela are primarily found in forested areas. This predilection for forested environments means that in the Guayana Shield region, coatis would have been in contact with the GH during periods of glaciation which correlates to the spread of savanna and grasslands.22 The vertical migrations which correspond to glacial oscillations may have affected the habitat and establishment of coatis in the GH. According to Dr. Valenti Rull, major components in the establishment of highland and tepui biota stem from these vertical migrations. As a forest inhabitant, Nasua nasua and its subspecies have been reported from environments ranging from deciduous and evergreen rainforests, gallery forests, and dry scrub forests; from the lowlands to an altitudinal range of 2500 meters in the Andeas.
Coatis are omnivores, allowing them to forage for a wide variety of food sources and persist in environments which would seem devoid of food. On the tepui summits, coatis probably feed on endemic invertebrates and small vertebrates, flowers, leaves and fruits. One foraging behavior which was observed was coatis searching the inside of bromiliads for insects.23 Havlkova theorizes that coatis may also be accessing human foodrests. This theoretical behavior can be verified by clip two of the Terra-X documentary, so it is likely that increased tourism on the tepuis, specifically Roraima, will attract coatis to human foodstuffs in the form of larders and possibly trash. The primary factor which limits coatis on tepui summits is the availability of sources of food. If the availability of food sources changes, then it would seem quite feasible for coatis to enter and establish themselves on the tepui summits. Thus there exist two possible factors which may be encouraging coatis and possibly by extension other lowland vertebrates to invade the tepuis, and both are the result of human activity. The human activities are anthropogenic climate change and increased human presence as a result of ecotourism. These human activities will be set as competing two hypothesis which are based upon the realities of Canaima National Park, which encompass both tepuis for which verifiable photographic evidence of summit coatis exists. In part two, the two hypothesis will be explored in detail, and an attempt will be made to eliminate one so that the realities of lowland invasive vertebrates can be assessed.
1Rull, V. “Is the 'Lost World' really lost? Paleoecological insight into the origin of the peculiar flora of the Guayana Highlands” Naturewissenschaften vol 91, 2004 and Rull “Biotic diversification in the Guayana Highlands: a proposal” Biogeography 32, 2005
2Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006. Havelkova lists well known authors for each faunal subset.
3 1) Huber, Otto “Guayana Highlands versus Guayana Lowlands, a Reappraisal” Taxon, 37, (3) August 1988, 2)Linares, O.J. “Mamiferos de Venezuela” Sociedad Conservacionista Audubon de Venezuela & British Pertroleum. (eds.) Caracas 3) Havelkova, Pavla et al, Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae) Lynx 37, 2006.
4George, Uwe “Venezuelas islands in time”, National Geographic, May 1989 and “Die Suche nach dem Ungeheuer” GEO December 1990.
5Berry, Huber and Holst. “Floristic Analysis and Biogeography” From Flora of the Venezuelan Guayana” vol 1. Berry, Holst and Yatskievtch ed. Missouri Botanical Garden Press, 1995
6UNESCO-World Heritage Convention, Canaima. http://whc.unesco.org/en/list/701 accessed April 6, 2011
7Stewart McPherson “ Lost World of the Guiana Highlands” Redfrern Natural History Productions LTD 2008
8Funk, V.A. & R. Brooks, “Phylogenetic Systematics as the Basis of Comparative Biology” Smithsonian Institution Press 1990. A cladogram was constructed of the tepuis was constructed by the authors, based on the erosion of a single massif into a series of tepuis. The cladogram was then favorably compared to cladograms of endemic flowering plants such as Stenopadus. The results support the vicariance and allopatric speciation model for tepui flora.
9Perez-Zapata et al. “New Data on the systematics and karyology of Podoxymys roraimae (Rodentia, Cricetidae)” Ztschr. Saugetierk 57. Also IUCN Red List Podoxymys roraimae, summary http://www.iucnredlist.org/ 2011
10 1) Huber, Otto “Guayana Highlands versus Guayana Lowlands, a Reappraisal” Taxon, 37, (3) August 1988, 2)Linares, O.J. “Mamiferos de Venezuela”. Sociedad Conservacionista Audubon de Venezuela & British Petroleum. (eds.) Caracas 3) Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006.
11Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006
12Description summarized from the detailed description in Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006
13The 1990 date is tentative, based on the year the documentary came out. It is possible, based on the publication date of the GEO article, that the expedition occurred in 1989 or before.
14There are three species of Nasua. Nasua narica from North America, Nasua nasua from South Amercia, and Nasua nelsoni from Cozumel Island off the Mexican coast. The Red Panda, Olingos, Coatis, Raccoons, and their relatives, Compiled by Angela R. Glatston IUCN 1994.
15This diagnosis is not established by consultation. Classification is based review of coati ranges discussed in “Mammalian species, Nasua nasua” by Mathew E. Gomper and Denise M. Decker, The American Society Of Mammalogists, No 580, June 1998. as well as the elimination of more exotic Nasua species by visual examination. N.n. vittata is the coati subspecies found in the Orinoco, and N.n dorsalis is found in the Andean region in Venezuela, in the east. Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006
16Mathew E. Gomper and Denise M. Decker, The American Society Of Mammalogists, No 580, June 1998.
17Mathew E. Gomper and Denise M. Decker, The American Society Of Mammalogists, No 580, June 1998. The authors remark “Confusion over the status of solitary males led early researchers to designate separate species names, N. solitaris and N. sociabilis...for adult males and for gregarious band members, respectively.”
18Huber, Otto “Guayana Highlands versus Guayana Lowlands, a Reappraisal”l Taxon, 37, (3) August 1988
19 Stewart McPherson “ Lost World of the Guiana Highlands” Redfrern Natural History Productions LTD 2008
20Stewart McPherson “ Lost World of the Guiana Highlands” Redfrern Natural History Productions LTD 2008. Figure 169 “Mount Roraima's Ring tailed Coatimundi (Nasua nasua)”
21Rull, V. “Unexpected biodiversity Loss under global warming in the neotropical Guayana Highlands; a preliminary appraisal” Global Change Biology, 12, 2006.
22V. Rull. Biotic diversification in the Guayana Highlands: a proposal Journal of Biogeography 32, 2005
23Havelkova, Pavla et al, “Brown-nosed coati (Nasua nasua vittata) on the Roraima tepui (Carnivora: Procyonidae)” Lynx 37, 2006
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