Auyan Tepui mammalian fauna review

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Introduction

In my previous blogs post I proposed the creation of a meta-analysis of tepui expeditionary documentation in order to determine the realities the tepui biodiversity. This proposal was based on recent scholarly papers and observations of Nasua nasua vittata on multiple tepui summits, Tamandua tetradactyla on Auyan, and Cerdocyon thous thous on the slopes of Auyan Tepui. The presence of these medium to large sized mammals seems to indicate that Auyan Tepui may contain greater biodiversity than previously thought. When these observations are compared to the scientific literature regarding tepui summit fauna, it becomes apparent that a knowledge gap exists regarding the distribution of fauna on the tepui slopes and summits. This knowledge gap needs to be addressed to avoid labelling or location errors which could mask the presence of >5kg lowland mammals on the tepui summits. 

It is now apparent that global climate change will compromise the survival of Pantepui species and ecosystems. A recent study conducted as part of the PANTEPUI project delineates this threat in great detail (Vegas-Vilarrubia et al 2012 ). For the 26 tepuis included in the study, 42.3% are expected to suffer the complete extinction of their summit floral biota through vertical displacement within the next one hundred years. The remaining vascular plant species will suffer range restriction to the point that the surviving ecosystems may become destabilized.  The paper identifies 4 levels of threats to the tepui ecosystems, based on connectivity, shared flora, and projected area loss. Auyan Tepui and the Eastern District tepuis (as defined in Huber, 1988) are least threatened, and may serve as potential refugia for in situ conservation efforts in the future. Given this situation, establishing the realities of the faunal composition of Auyan Tepui and the large tepuis of the eastern Pantepui sector is of the utmost importance.

In an effort to solve this problem, I have compiled a list of mammal sightings on Auyan detailed in “The mammals of the Guiana Region” by G.H.H Tate, circa 1938. This work is the first published review of mammals observed on or near the Eastern Sector tepuis, and is partly based on the 1937-38 Phelps expedition to Auyan Tepui. A detailed account of the Phelps expedition is described by Tate in “Auyantepui: Notes on the Phelps Venezuelan Expedition” which describes the collection sites and camp locations. The Phelps expedition collected at four camp sites; camp 1 at 460 meters near the Urullen Valley, camp 2 (known as Guayaraca) at 1100 meters, camp 3 at 1850 meters, and camp 4 at 2200 meters (see map below).

The duration of the Phelps expedition on the summit of Auyan Tepui is unmatched to this day. From November 1937 to March 1938 the expedition spent time exploring the southern access point of Auyan Tepui. By comparison, the 1994 expedition of the Robert G. Goelet American Museum-Terramar herpetological expedition to the summit of Auyan Tepui only lasted a month. The 2012 camera trapping expedition of Auyan lasted roughly 14 days, and was conducted at Guayaraca (1010 meters), Penon, (1838 meters), and Naranja (2161 meters); locations roughly identical to the area explored by Tate during the Phelps expedition.
Tate states “the (mammal) fauna of the summit zone of the Guiana Mountains (5000-8000 feet) comprises nine types of animals: Didelphis marsupialis, Marmosa cincera, Marmosa tyleriana, Tamandua tetradactyla, Coendou, near melanurus, Akodon aerosus, Podoxymys roraimae, Thomasomys macconnelli and Nasua Candace dichromatica”. This is a broad generalization, though it remains the most comprehensive characterization of tepui mammal fauna, as subsequent expeditionary work has not expanded on either the survey locations or field time of the Phelps expedition. 

However, this characterizations of the tepui mammal distribution is not entirely precise, as Tate lists 30 species of mammals which were encountered during the Phelps expedition that were not included in his summary. Presented below is a compiled list of the mammals observed or collected during the Phelps Auyan Tepui expedition.

The fauna list

The following list is a reduction of Tate’s "Mammals of the Guiana Highlands" in which only the mammals observed on Auyan are present in the list. This reduction is necessary in order to organize this large document into a manageable size so that an analysis of Auyan Tepui mammal fauna can be conducted. The purpose of this list is to determine which mammals are recorded as normative fauna ( ie established in literature as being present on Auyan from initial exploration) and which mammals are anomalous fauna (ie not recorded as being present on Auyan) so that future mammal sightings will not be misinterpreted.   
"The Mammals of the Guiana Highlands" is at times problematic in that elevational data is inconsistent, referencing is vague for certain species, and taxonomic nomenclature has changed for a number of the species included in the list since its publication in 1939.  I have compiled the data from Tate's work in an attempt to clarify some of these problems with the inclusion of updated nomenclature and current conservation status using the IUCN Redlist as a guide. The scientific names of the species described by Tate are italicized; where the names have been altered I have included the updated nomenclature in parenthesis followed by the common name in bold. After the appellations, the current distribution and IUCN Redlist status of the species are stated. Finally, the description, collection altitude, and details of the species collected are presented enclosed in apostrophe as verbatim by Tate. 

Didelphimorphia

1)Didelphis marsupialis marsupialis: common possum, comadreja grande. Wide distribution across G.S., and into Central America. IUCN status LC. “Material- Mt Duida (6); Mt Roraima (4); Mt Auyan-tepui (9). The affinities of D. marsupialis are with Didelphis of the surrounding lowlands- the Amazonian and Orinoco basins. Animals from the highlands (up to 7000 feet), readily picked out by their denser fur, seem directly derived from the lowland form.”

2) Metachirus nudicaudatus: brown four eyed possum, cuica común . Wide distribution across G. S. IUCN status LC. “Material- Foot of Mt. Duida, 300 feet, juvenile female. Auyan tepui, 1500 feet, 5 specimens, and at 3500 feet 1 specimen. The Duida specimen is considerably browner in general tone, and particularly along the sides, than any of the individuals from farther east. 5 specimens at 1500 feet.”

3) Marmosa Gray: (Taxa name not valid in IUCN): mouse possums “Three of the five principle groups of Marmosa represented in the Guiana highlands:

3.1) Micoureus demararae areiticola: ( sub-species possibly invalid, synonymous with Marmosa demerarae). long-furred woolly mouse opossum, woolly mouse opossum, marmosa grande gris. Wide range for M. demararae, not present west of Venezuela. IUCN status LC. “The original series of eight from Mt. Roraim (1300m) from Auyan Tepui 460 meters (8), 1100 meters (13) 1850 meters (one and an extra skull). The race appears to be morphologically uniform both at Roraima and at Auyan-tepui. At the latter locality through a vertical range of 1390 meters no definable difference can be seen.”

3.2)Marmosa murina roraimae: (possibly defunct subspecies) murine mouse opossum. Wide distribution across G.S. IUCN status LC. “Roraima; Material: the original series of 14 from Roraima (1400 meters); from Auyan-Tepui 460 meters (8) 1100 meters (only 1). The Auyan-Tepui material conforms precisely with that from Roraima, differing from M. m duidae and M. m. klagesi by characteristics given previously ( loc, cit) probably, however, it integrates with the latter.”

3.3) Marmosa tyleriana phelpsi: (subspecies of M. tyleriana). Tyler's mouse opossum. Endemic to G.H., Estado Bolivar and Estado Amazonas, stated as being restricted to three isolated tepuis (Duida-Marahuaca, Jaua-Sarisariñama, and Auyantepui) at elevations between 1,300 and 2,200 m. (IUCN ver. 3.1 2011). IUCN status DD. “(new sub species) type: No 130502, AMNH adult female, Auyan-tepui plateau, 1850 meters. Collector G.H.H Tate. General characteristics- a dark race of the somewhat rufous M. tyleriana. Description- color dorsally near Prout's brown, ventrally with the identical fawn shade of true tyleriana. Quality of pelage, characteristics of the tail and ears as tyleriana but feet rather darker. Skull not distinguishable from that of tyleriana... Besides the holotype the collection from Auyan-tepui includes seven paratypes and an additional specimen from 2200 meters. Duida, Auyan-Tepui.”

3.4) Marmosops parvidens: delicate slender opossum. Present in Guiana, Surinam and French Guiana, limited records from Estado Bolivar, known in Columbia and Peru, may be synonymous with M. pinhreroi. IUCN status LC. “Material- two adults female and male from Auyan tepui 460 meters and one adult female from 1100 meters. The rediscovery of this interesting species known hitherto only by the type specimen which was collected in 1906 is of great interest. The animals were all trapped in tropical to lower forest in traps set under logs.”

4) Monodelphis brevicaudata: northern red sided possum. Endemic to the G.S. IUCN status LC. “Material: The type of M. b. dorsalis Allen and two paratypes-all three young; a series of specimens from Mt. Auyan-Tepui 460 meters (one from 1100 meters)...17 from Duida...seven from Roraima , 3800 feet.” … well defined buffy facial area, extending usually from the rhinarium to the top of the head in eastern subspecies.”

Xenarthra

5) Cabassous unicinctus: southern naked tailed armadillo, cabasú de orejas largas. Wide distribution from G.S into Brazil. IUCN status LC. “Material -British Guiana, several specimens. At Mt Auyan -Tepui many small holes, probably the work of this armadillo, were observed in open, sandy places. Neither we, nor he Indians who were offered a substantial bonus for specimens, ever managed to secure one.”

6)Tamandua tetradactyla: southern tamandua, southern anteater, brazo fuerte, hormiguero de collar, oso melero. Wide range and distribution across the Neotropics. IUCN status LC. “Material: Mt. Roraima (1) Mt Auyan-Tepui (4) Mt Duida (4). This form of anteater is quite common on the plateaus of Duida and Auyan-tepui between 6000 and 8000 feet as it is at altitudes between 2000 and 3000 feet. The Roraima specimen was brought in by an Indian to base camp, and consequently was probably taken at about 4000 feet.”

7) Myrmecophaga tridactyla: giant anteater, hormiguero gigante, oso caballo. Wide distribution, but probably extinct across previous ranges in Belize, Costa Rica, and Guatemala. Extinct in Uruguay. IUCN status VU. “Material- Mt Roraima (1) ; Mt Auyan-tepui (1 and a pick-up skull). A full grown giant anteater was seen at the “Tree Savanas” foot of Mt Duida, but not captured. These animals apparently range all over the guianan savanna region up to 5000 feet. They are met with in the forest, though usually near savannah. Thomas records a specimen from 'Mount Roraima, 5000 feet' ”.

Rodentia

8) Proechimys cayennensis: (official scientific name is Proechimys guyannensis, synonym with Proechimys warreni. Molecular phylogenetic may result in split of species into several different species). Cayenne spiny rat. Distributed in the lowlands of the G.S, supposedly restricted to 500 meters. IUCN status LC. “Material: Mt. Roraima, 3500 -4200 feet (32) Mt Auyan Tepui, 1500 feet (44), R. Cotinga savannas 500 feet (64) R. Yuruan approx 1500 feet (6) lower R. Caura 1000 feet (9) Esemeralda Mt Duida 300 and 00 feet (67), lowlands of British Guiana (10).”

9) Dasyprocta cayanus: ('cayanus' seems defunct, scientific name Dasyprocta leporina) red rumped agouti. Range from Caribean Islands, Trinidad and Tobago into the G.S., from Estado Bolivar into French Guiana and Surinam. IUCN status LC. “Material: B.G. Lowlands R. Yuruan (1) Mt. Auyan Tepui 2000 feet (1) 3500 feet (1) El Llagual mouth of the Cura River (1).”

10) Cuniculus paca: (formerly Agouit paca). spotted paca, paca, tepezquintle. Range is all across South America. IUCN status LC. “Material Mt Auyan tepui, 1500 feet (1) British Guiana several, Mt Duida several.”

11) Cavia pallas, Cavia guianae: (C. guianae is not a recognized taxa, most likely Cavia aperea) guinea pig. Animal is wide ranging across South America. IUCN status LC. “Material Mt. Auyan tepui, four females at 1500 feet, type venezuelae.”

12) Chalcomys aerosus saturates:  (Chalcomys is an archaic synonym for Akodon, currently recognized genus, genus renamed Calomys. Dubious classification, it could be Akodon aerosus ). vesper mice “new subspecies no 131020, AMNH adult female Auyan tepui plateau, 6000 feet. Four paratypes and three specimens also found at 7500 feet on Auyan...Much of the material from Mt. Duida (4500 to 7000 feet) is referable to saturate form just described. From the ‘Savanna Hills Camp,’, 4500 feet, in the center of the table land the material becomes slightly more aerosus –like, though it by no means approaches the gray-brown shade of our material from Auyan-Tepui at 3500 and 2000 feet. From the Duida plateau we have 45 specimens.”

13) Zygodontomys microtinus: (sub-species of Zygodontomys brevicauda) short-tailed cane mouse. Range is from Central America into Venezuela and north of the Amazon river. IUCN status LC. “Material- Auyan- Tepui , 3500 feet (7), 2000 feet (48). Mt Duida Esmeralda Savannas, 350 feet.”

14) Oryzomys macconnelli maconellis: (Sub species of Oryzomys macconnelli, taxonomically complicated genus.) Macconnell's rice rat. Wide distribution. IUCN status LC. “Material: Auyan tepui, 3500 feet (15), 2000 feet(5). “In our Roraima-Duida-Auyan-tepui series, as well as those from British Guiana and Cotinga River, in north Brazil, all colour variations can be found. Juvenile animals are slate coloured, gradually assuming the rufesent hue of maturity.”

15) Oryzomys laticeps: (Currently Hylaeamys laticeps as of 2006). large-headed rice rat. Range is limited, confined to the Atlantic forest in Brazil, fragmented habitats with a decreasing population trend. IUCN status NT. “Material- Mt. Roraima (35), Kartabo, British Guiana (22); Mt. Auyan-Tepui (95); Mt Duida (33) this is the commonest of the forest dwellers among the Guiana oryzomine mice , 9 forms listed from Colombia to Venezuela to Trinidad.”

16) Oligoryzomys delicates: delicate pygmy rice rat. Current taxonomic status and IUCN status not found. “Material- Mt Roraima, 3500 to 6500 feet (41); Mt. Auyan Tepui 3500 feet (27) 2000 feet (1) . These mice were found most commonly in rather open environments where shrubs grew instead of threes. Occasional specimens, however, were met within the forest.”

17) Oecomys phelpsi: (taxanomic status under revision, see also Oecomys auyantepui news species No. 131156 AMNH, ) arboreal rice rat. “new subspecies No 131164 AMNH Young adult male, South slopes of Auyan Tepui 3500 feet comments 'A peculiarly aberrant mouse with external features, except the mark on the dorsum of the foot, common in Rhipidomys. It is unfortunate that this unusual mouse if founded upon a single individual. It was trapped in heavy forest.'”

18) Thomasomys macconnelli: (scientific name Rhipidomys macconnelli) MacConnels climbing mouse. Range is restricted to the Guiana Highlands in Venezuela, Guiana, and Brazil. IUCN status LC. “Material- Mt. Roraima (summit) (21); slopes 6000 feet (27); Mt Duida (summit) 4500 feet to 7600 feet (135) Mt. Auyan-tepui (summit) 1800 to 2200 feet (35). “I have been unable to distinguish between the above listed series from the summit of the three mountains studied. …the few individuals taken on the much lower levels (3500 feet) at Roraima and Auyan Tepui are paler and have considerably shorter pelage than the typical form.”

19) Rhipidomys venezuelae: Venezuelan Climbing Mouse Distribution in north and west Venezuela and Colombia, eastern distribution unclear. IUCN status LC. “Our Guiana highlands collections include chiefly specimens of milleri, of which we have the type in the American Museum for comparison. They were taken at Auyan Tepui, 3500 feet, and Roraima at the same altitude. Subspecies Rhipidomys nitela found on Auyan Tepui at 3500 feet. This mouse was taken in the forest at Auyan tepui, in the gallery woods about Roraima and Limao.”

20) Nectomys peters: (Broad classification, probably Nectomys palmipes. Nectomys is a genus of rodent in the tribe Oryzomyini of family Cricetidae. It is closely related to Amphinectomys and was formerly considered congeneric with Sigmodontomys). Trinidad water rat. Ranges from Trinidad into mainland Venezuela, distribution analysis considered incomplete. IUCN status LC. “Material-Mt Auyan-Tepui, 3500 feet (6), Mt Roraima 3500 feet (2)... The Duida (Nectomys) specimens have somewhat smaller teeth than those from Roraima and Auyan-Tepui. We may therefore refer to them, respectively, as N. s. rattus and N.s palmipes (= melanius).”

Carnivora

22) Nasua candace dichromatica: (Nasua nasua vittata; dichromatica is synonomyous with vittata). South American Coati, Coatamundi, Achuni, Coatí, Tejón. Extremely wide distribution, vittata subspecies found in Venezuela. IUCN status LC. “New sub species type No 131166 AMNH Adult female Plateau of Mt Auyan Tepui, at approximately 6000 feet….The type is a pick up skeleton with relatively few parts missing, the skull complete expect certain teeth.” See discussion for further details.

23)Mustela linnaeus: (Either M. africana or M. frenata, most likely the latter). Long tailed or Amazon weasel, Comedreja Andina, or Comedreja Amazónica. Wide distribution, both present in Venezuela but not widespread there. IUCN status LC for both subspecies. “ Material- one skull taken from a ledge near the summit of Mt. Duida at 7000 feet; one skin (with out skull) from the lower terrace of Mt. Auyan tepui (3500 feet).”

24) Felis concolor: (Puma concolor) Mountain lion, Puma, Cougar, León Americano, León Bayo, León Colorado, León De Montaña. Wide range, population and subspecies vary from region to region, extensive hunting and range reduction in certain areas; localized extinctions. IUCN status LC. “Material- At Auyan tepui, the Indians reported pumas as of rare occurrence. At Roraima they seem altogether ignorant of these animals.”

Primates

25) Cebus apella: ( Sub species C. a. apella, C. a. margarita) Black-capped Capuchin Monkey. Wide ranging species, depending on resolution of species taxonomy which is complex. Sub species C. a. Margarita restricted to Margarita Island, Venezuela. IUCN status LC. “A large number of specimens from the Mt Duida region taken by the Tyler Duida expedition, a small series from Mt. Auyan Tepui, middle Rio Caroni.”

Perissodactyla

26) Tapirus terrestris: South American tapir, danto. Wide range, but extirpated from numerous areas. Population dynamics require study. IUCN status VU. “At Mt. Auyan Tepui tapir tracks were abundant as high as 3500 feet. Probably they go higher when the terrain is suitable, for on the eastern slopes of the Andes near the Pastaza Rover I found tracks of tapir above 7000 feet.”

Artiodactyla

27) Tayassu tajacu: (now classified as Pecari tajacu). collared peccary, báquiro cinchado. Extremely wide distribution, including North America. IUCN status LC. “Material- Mt Duida area (3); Mt Auyan Tepui (1).”

28) Tayassu pecari: white-lipped peccary, cariblanco, chancho de monte, pecari de labios blanco. Wide distribution, extirpated in El Salvador. IUCN status NT. “Material- Mt Auyan tepui (7); British Guiana (the series of 10 or more representing T. p. beebi Anthony); mouth of Rio Uaupes (2). Also studied; material from Suriname, Colombia, Peru and Brazil. The skull of the type and several individuals of beebi differ from our material from Auyan-tepui in possessing considerably wider molars and larger premolars. … Meanwhile, for the purposes of this paper we can state only that the white-lipped peccaries of the east and south of the Guiana region are chiefly large toothed; those of the west and north (including Auyan-tepui) are essentially small toothed.”

39) Cervidae- “I (Tate) saw but failed to secure a fully antlered buck at Mt. Auyan Tepui, 3000 feet”

30) Mazama nemorivaga Amazonian Brown Brocket, Amazonian Brown Brocket Deer, Small Brown Brocket Deer, Matacán Grisáceo, Soche Gris. Wide distribution across northern South America. IUCN status LC. “Material Thirteen specimens from British Guiana; Mt Auyan tepui (1) (small teeth), Mt Duida (3); the type of Murelia from Caqueta.

Analysis

The total number of mammal specimens collected by Tate during the Auyan-Tepui expedition is approximately 750 individual animals (Musser and Patton 1989), making the Phelps expedition the most authoritative survey of the mammalian fauna of Auyan Tepui to date. Of the 134 species of nonvolant mammals known from the G.S., 29 are present from 450 to 2200 meters on Auyan Tepui. Rodents make up the majority of mammals found on Auyan Tepui, with 12 species in four families; roughly 20% of the  total number of rodent species found across the G.S. The majority of these rodents were collected at 2000 to 3500 feet, or 600 to 1000 meters, in the low to mid altitude slopes of the Auyan dominated by mountain forests. Of the 12 species of rodent recorded, all are designated IUCN Least Concern (LC) except 4: Chalcomys errosus, Oligoryzomys delicates, Oecomys phelpsi and Oryzomys laticepts. Of these four species, only O. laticepts is listed as Near Threatened (NT) while the other three species are not listed as they are either taxonomically invalid or have not been taxonomically resolved. O. laticepts has been reclassified as Hylaeamys laticeps as of 2006 (Weksler et al 2006), and is listed as being restricted to the Brazilian Atlantic forest, by the IUCN (Percequillo, A. & Weksler, M. 2008, Patton et al 2000). Tate mentions that 95 specimens of Hylaeamys laticeps ( former Oryzomys laticepts) were taken during the Auyan-Tepui expedition. If this reclassification of Tates “O. laticepts” into Hylaeamys laticeps is accurate, this could mean that a population of H. laticeps in the GH could act as a buffer to the extinction of the Atlantic forest population. Regarding the status of O. phelpsi, it would seem that the species' taxonomic status is under revision due to an error in classification regarding the mismatch of the the initial sample. Tate collected only one specimen of this species, and produced a mismatch holotype by combining the skin of Akadon with the skull of O. phelpsi. Tate restricted the holotype and species name phelpsi to the skull alone after recognizing his mistake, but latter analysis revealed more problems with the species. It was discovered that the skull was a composite of a mismatched cranium and mandible, which was subsequently rematched, placing the species name phelpsi with a single mandible. The authors of the work detailing the re-evaluation of this species state that O. phelpsi is not a synonym of O. guianae, or O. auyantepui, but represents a species unsuccessfully collected by Tate similar in appearance to O. bicolor. Currently, O. phelpsi is temporarily placed with O. bicolor until the nature of the Auyan Tepui population is established (Musser and Patton 1989). There seems to be some confusion over the status and resolution of the Muridae family on the slopes and summits of Auyan Tepui, as only two of the 9 species present as reported by Tate remain valid.

Didelphimorphia

The next most abundant family present on Auyan Tepui are the Didelphids, or opossums, with four of the six represented by marsupial mice in the supergenus Marmosa. Marmosa demerarae (formerly Micoureus demararae) was the most abundantly found species, with 22 taken from Auyan Tepui up to 1850 meters. All opossums were distributed from the low altitude camp into the higher elevations, though their density did decrease with altitude. From a conservation stand point, all members of Didelphimorphia are listed as IUCN Least Concern, with the exception of Marmosa tyleriana phelpsi, which is restricted to three tepui summits and listed as being Data Deficient (DD). Marmosa marina roraimae may be a defunct sub-species, in which roraimae is no longer valid, and Micoureus demararae has since been reclassified as Marmosa demararae (with Micoureus being a sub genus of Marmosa). Since the collecting expedition by Tate, the phylogenetics of the mouse opossums has been reviewed and certain change to their taxonomy has been made. Analysis of mitochondrial DNA of Marmosa and the sub-genus Micoureus supports an increased diversity of species recorded thus far, most notably from wide ranging species in Central America. In the South American species, Marmosa demerarae in French Guiana, (present on Auyan Tepui), shows marked genetic differentiation from the M. demerarae in Peru, supporting a division of the species into subspecies. The study also confirmed the status of M. tyleriana, where its closest relatives were M. murina and M. waterhousi. Based on this study, there is some strong evidence to break up the genus into cis vs trans Andean species, with significant differentiation in cis Andean species such as M. demerarae and M. lepida.

Carnivora

Four members of Carnivora are present on Auyan Tepui, with the coati "Nasua candace dichromatica" (now Nasua. nasua vittata) being the most abundant. Tates observations of this animal are interesting, as they may be used to resolve the unusual coloration of coatis observed on Roraima and Chimanta Massif mentioned in Havelkova (2006) and Ronvinsky (2007). Tate calls “dichromatica” a new sub species, based on smaller dentition and what he reffered to as “sexual dichromatism” in observed coatis. He believed that the males were buff colored, where as the females were rufous . He observed 8 individual animals, each with a markedly different pelage arrangement and coloration. This observation has been disregarded, though the variation in coati pelage coloration was noted in Havelkova et al (2006) with regard to unusually colored coatis on the summit of Roraima Tepui, and again in Robovsky et al (2007) on Churi Tepui, in the Chimanta Massif. Observed Auyan Tepui coatis seem to lack this color variation, and appear uniformly brown-black in coloration, as apparent from the Terramar expeditions in the late 1980s, and recent photographs of a black coati taken in 2008 by Pomares and crew (images below) during an expedition to the Auyan Tepui. Based on this body of work, it now apperas that coatis are residents of the large tepuis in the eastern pantepui sector. In the Canid family, only Cerdocyon thous thous the crab eating fox was sighted by Tate, although no altitudinal data was given in his report. Tates observations were confirmed in 2012, and currently C. t. thous is known to range to at least 1010 metres in the southern terrace of Auyan Tepui. Though a span of nearly 80 years separates these reports, it is likely that crab eating foxes were not observed by subsequent expeditions due to their nocturnal modality. 

Juvenile coati photographed in near Libertador, 2009

 

Adult coati filmed by Terramar expedition members in 1990

With regard to felids, Tate makes it clear in his text that mountain lions and large cats are considered rare on Auyan and unknown on Roraima by the indigenous Pemon people. Recent sightings of what has been described as a large felid (Panthera leo) comes from two sources; Gorzula (1991) and George (1989). Gorzula describes a (probably) stray solitary mountain lion, while in George (1989) Armando Michelangeli (at the time the leader of a Terramar expedition to Auyan Tepui) observed a female mountain lion with two cubs exiting a cave along a dry river bank on the eastern portion of Auyan Tepui (i.e. east of Canyon del Diablo.). The 1989 sightings were not reported in academic literature, though the concept of large mammals inhabiting the tepui summits is presented in the book “Tepuys, Colossos de la Tierra”, published in 2005 by Terramar expedition mmbers. With regard to the amazon weasle Mustela linnaeus I have been unable to find any further mention of it on a tepui, and I therefore assume that it was observed at the base camp placing it more toward the lowlands than the talus slope of Auyan.

Xenarthra

I have detailed the distribution of Pilosa on this blog before, and that post will serve as the primary reference for this order. I have since investigated the IUCN distribution report of Brdaypus tridactyla which states that this sloth is present on tepui summits. At this time this distribution can not be confirmed or negated, as the reference material for this statement can not be found. Thus, T. tetradactyla is a tepui resident (at least on Auyan), Myrmecophaga tridactyla has yet to be verified, and B. tridactylus requires further investigation.

Primates, Perissodactyla and Artiodactyla.

The reference to Cebus apella is the only reference to primates near Auyan I have encountered. According to the IUCN Redlist, the name C. apella is no longer valid, suggesting either C. a. apella or C. a. margarita, where  C. a. apella is not known to range into Venezuela.  Alternativly, the Smithsonian publication "Checklist of the Vertebrates of the Guiana Shield" list Cebus apella as a valid name, and list this primate as distributed throughout the GS. I do not think this monkey is near the summit or talus slopes, as it is mentioned by Tate as being observed in the middle of the Rio Caroni. This distribution does require more scrutiny, though it is probably irrelevant to studies of tepui summit and slope fauna. The only member of Perissodactyla (odd-toes ungulates) in the G.S is the tapir Tapirus terrestris, Tate remarks that tapir foot prints were observed at 3000 feet (approx 1000 metres), though he suspects that Tapirs are present on the summit. This observation is also made in George "1989", and by Huber in his 1988 paper. The 1989 source relates to sightings of tapir footprints made near campo Dragon and Second Wall on Auyan Tepui, and were also sighted in the western regions of the tepui in valleys, which contained dense gallery forests. During the course of the Terra-X documentary “Islands above the Rainforest” (Artz, 1991) certain expedition members proposed at one point that sightings of three unknown animals swimming in a lagoon were in fact misidentified tapirs. This would make sense, as tapirs would probably be present on Auyan along riparian gallery forests foraging for food, however this is still speculation. Tracks of tapirs have been observed by Terramar expedition members on Auyan Tepui in the mid 1980s (George, 1989). These sightings confirm Tataes observations; whereas tapirs in Venezuela are mostly confined to the lowlands, according to Tate “Mt. Auyan-tepui tapir tracks were abundant as high as 3,500 feet”.

Both species of peccary, Tayassu pecari (Pecari tajacu) and Tayassu pecari lack altitudinal data for their collection points, thus I have assume that they were collected at around 450 metres. The lack of any documentation of peccarys on any tepui summit seem to support this, although this is in no way conclusive. An unknown member of Cervidae (indicated in the text as an adult male) was spotted at 1000 metres, as was an Amazon brown brocket Mazama nemorivaga, though no collection altitude was provided. All members of Cervidae represented in the G.S. are wide ranging as is M. nemorivaga, although M. nemorivaga is not recorded as being present in the G.S. This raises the question as to what deer Tate observed, as the only listed G.S species are Mazama americana, Mazama gouazoubira, and Odocoileus cariacou.

Discussion

Establishing the realities of tepui faunal distribution is critical for further developing successful conservation strategies in the pantepui, and furthering human understanding of global biodiversity. The threat posed by global warming to the endemic flora is too extreme to be ignored, and the resultant extinctions and vertical displacement will alter the tepui summit ecosystems. This is a scientific and ethical dilemma; there is no way to reverse this extinction process and humans must decide what get saved from extinction and what does not. In order to design effective conservation strategies for the preservation of tepui summit organisms and ecosystems, the interplay of lowland fauna with the tepui summit communities must be established. The development of these strategies require that trends in current tepui biodiversity (defined as faunal/floral interaction in an extinction scenario as a result of upland displacement caused by rapid climate change) are assessed with regard to current and predicted lowland faunal interactions. As an example of complex potential interaction, some of the animals observed on the tepui summits and talus slopes such as Cerdocyon thous thous and Tapirus terrestris act as primary seed dispersers. As the climate envelope for vascular plants shifts, these two animals may facilitate the movement of lowland plants onto the tepui summits. At this point the interplay between lowland frugivores and summit flora is not understood as large lowland organisms are still considered to be absent on the tepui summits. In fact, the distribution mechanics of tepui summit flora is not completely understood in and of itself (Rull 2010).

This gap in the understanding of tepui ecosystems dynamics and paleoecology is only now being addressed. Current molecular phylogenetic analysis of tepui fauna indicates that the herpetofauna of the tepuis is far younger than previously expected (Salerno et al 2012). While the paleofauna thesis has long been dismissed, it appears as though gene flow between summit reptile and amphibian communities stopped sometime between the Pleistocene and Holocene, leading to little genetic variation in the "isolated" tepui summit herpetofauna (Kok et al, 2012). This is a very recent date for the isolation of tepui summit herpetofauna, and indicates that the current ecosystem composition is much younger than previously thought. This is interesting; when the the niche of tepui summit herpetofauna is examined it tends to be highly specific, implying a lack of plasticity in niche breadth which would indicate long term isolation. However, it is quite possible that the colonization of the tepui summits by small vertebrates was extremely difficult under glacial conditions during the Pleistocene, when the hypothetical tepui paramos existed, and the current tepui like ecosystems were distributed in lower elevations. The other alternative to explain the recent date of the herpetofaunal assemblage of pantepui is a kind of "waif dispersal", in which amphibians and reptiles spread to the various summits by being displaced there, possibly by birds. Such an explaination defies the patterns of herpetofaunal assembalges (in which greater summit area equates to greater species richness), and treats the tepuis as true "sky islands", which seems at odds with the observed patterns of tepui paleoecology. We can see from the mammalian fauna that the tepuis can host a variety of large lowland vertebrates; they are not as isolated as they appear to be. 

Thus, I am in favor of climate and substrate related constrains on tepui ecosystem establishment as the determining factor, as opposed to limited and long term waif dispersal as a mechanism for explaining tepui summit vertebrate fauna composition. In light of palaeoecological realities, this would explain why tepui summit herpetofauna lacks genetic tepui to tepui differentiation and genetic diversity, and explains both the lack of tepui specific endemic rodents and the continued sightings of lowland mammals on the summits, as the same animals were interacting with tepui floral assemblages at lower altitudes during the Pleistocene and have simply followed these assemblages to higher elevations.

Conclusions

When looking at tepui summit fauna, there is a complex interplay of climate, elevation, ecosystems, endemism, and gene flow. The normative view of tepui dynamics and biogeography has changed over the years. Initially considered a “lost world” of paleofauna in isolation, tepui ecosystems are now considered to be the result of the complex interplay of climate change, recent colonization, and extinction events. Limiting factors such as climate and substrate play a greater role than topographical isolation, and barriers to colonization are reduced. In the case of the largest tepuis, floral assembaleges are diverse, and carrying capacity may be larger than previously anticipated. Auyan Tepui maintains five distinct vegetational zones, and is unique in that grassy savannah is present in the south and centre of the tepui, creating a possible migration corridor. Auyan is partly topographically connected with the Chimanta Massif, leading to the creation of a large complex of migration routes between these areas.

Tates list of fauna can provide the basis for studying the interactions between lowland species and tepui summit species, on all levels of analysis. Using this list, it is possible to address the concepts of normative vs anomalous fauna. Normative fauna is defined as low density, small bodied, and confined to didelphimorphia and rodentia. Anomalous fauna is broadly classified as comprising medium to large bodied wide ranging G.S species. The two groups can merge in a synthesis which was implied in Robovsky and Havelkova with their review of tepui summit coatis; lowland species physically able to access the tepui summits may find an available ecological niche and exploit it. This phenomena has probably not been recognized as research gaps produced by limited expedition duration and long periods of time between expeditionary work have skewed sampling efforts. Equally, the lack of different sampling methods (i.e. diurnal transect surveys v.s. nocturnal camera-trapping) have produced an imperfect understanding of tepui summit biota. Normative fauna can now include all rodents and opossums mentioned by Tate, as well as coatis and tamanduas. Anomalous fauna includes unidentified animals/new species, deer, anteaters, tapirs and carnivores (Panthera leo), with crab eating foxes not yet observed on the highest elevations of plateaus, and not yet outside of Auyan. My recommendations to continue this synthesis are continued literature reviews to determine proper notation and referencing of tepui fauna (as with Bradypus tridactylus), and the implementation of a future camera trapping regime on the slopes and summits of the eastern sector tepuis.

Biblography

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