Camera Trapping Of Auyan Tepui: January 2012

In the beginning of this year, from January 6th to January 13th, a unique experiment took place. Working with Alberto Pomares and members of his expedition team, a camera trapping pilot study took place which followed a transect line survey of an area on Auyan Tepui known as the Laime trail. The positive results of this experiment demonstrate that camera trapping on the summit of Auyan Tepui is not only possible, but can be used to obtain images of the unique fauna of the summit. The application of such a study can be used to monitor invasive faunal elements entering the tepui. I am deeply indebted to the entire expedition crew for the realization of my pilot study; Alberto Pomares, Vittorio Assandria, Daniel Abgrall, Cedrig Abgrall, Dr. Douglas Olivares, Nelson Gonzalez, Richard Dittmar, Ana Cristina Fernandez, Dr. Carlos Acevedo,and Paul Stanley. I would also like to especially thank the Pemon guides who assisted with the completion of the camera trap: Santos Ugarte (the principle guide), Arturo Berti ( Guide and Camera Trap assistant) and Nixson (Camera trap assistant). Currently Alberto Pomares and his fellow team members are setting up a website for this and other work on Auyan Tepui.


Camera trapping is becoming a widespread practice in wildlife biology. It is minimally invasive and when employed en mass over a large area can be an effective tool in monitoring biodiversity, carrying capacity, and species density.1 It has been used to identify new species and identify cryptic species.2 In this instance, a camera trap pilot study was utilized during an expedition to the summit of Auyan Tepui in Venezuela. The methodology of the pilot study differed from that of traditional camera trapping in that it followed the progress of a transect walk across a defined path in the southern access point of Auyan Tepui, known as the Laime Trail. While not a traditional camera trapping study due to its differential methodology, it did produce positive results of multiple captures of the fox Cerdocyon thous. The implications and data returned can be used to launch a larger more comprehensive project to study an area of the world which may be subject to significant ecosystem change over the next 100 years due to anthropogenic climate change.

The Laime Trail and Auyan Tepui

At roughly 700 square kilometers in summit area and 200 square miles of tallus slopes, the Auyan Tepui in Venezuela is the largest tepui (flat topped sandstone mesas) in the Guiana Highlands. Officially discovered in the mid 1930s and first explored in 1937, the summit hosts the greatest diversity of ecosystems and animal life when compared to the other tepui summits. The tepui summit has never been completely surveyed over time, and its sum total biodiversity has not been completely assessed. Auyan Tepui is host to four types of vegetational assemblages; pioneer assemblages, tepui summit meadows and woody scrub, evergreen forests (mostly along river systems and areas with large soil deposits) and mountain forests on the tallus slopes.3
The Laime Trail is the southern access point on the tepui summit used by Alexander Laime to access the summit of Auyan Tepui. Alexander Laime was a well known explorer and local celebrity in Canaima. He was the first westerner to reach Angel Falls by foot, and participated in the 1955 expedition to the summit of Auyan Tepui. He spent substantial time on the summit of Angel Falls, and made numerous observations regarding the fauna of the tepui summit, including observations of undescribed animals on the summit. His extensive knowledge of the Auyan Tepui allowed him to access the southern portion of the plateau, which turned out to be a trail which with minimal climbing allows for easy hiking access to the tepui summit. Mr. Laime has been featured in a variety of travel logs and documentaries pertaining to the Auyan Tepui. Sadly, this famous explorer died in 1994, a recent documentary detailing his life can be found following this link4. The 2012 Laime Trail expedition intended to set out from the bottom of the trail and end in the central point of Auyan Tepui, where the a series of rivers empty into the southern end of the Canon Del Diablo, and the approximate location of the Salto Churun-meru. This trip would cover a variety of habitats and floral assemblages, ending near the collection camp of the 1994 AMNH-Terramar herpetological expedition.5 Thus, the camera trapping would have followed this trail to its conclusion, and time was set aside to scout a new camp site. The intended course of the expedition is detailed below in figure 1.

Figure 1. Satelite image of Auyan Tepui with the positions of intended camera trapping points for the 2012 Laime Trail expedition represented by yellow pins.
Rationale for camera trapping on the tepuis

Camera trapping has not been documented as a research tool in the study of tepui fauna this far. Although Auyan Tepui has been partly surveyed since its formal discovery in the late 1930s, inconsistent information regarding its vertebrate fauna has never been reconciled. The vertebrate fauna of the tepui summit ecosystems is considered to be composed of mostly small reptiles, amphibians, birds, and a limited number of small endemic mammals. However, numerous sources indicate that Auyan Tepui may be host to larger vertebrates. Havelkova and Robovsky have documented the presence of coatis (Nasua nasua) on the tepui summits.6 My previous blog posts deal with the presence of coatis on the summit of Auyan, and Havelkova and Robovsky have detailed them on Roraima and the Chimataná Massif, respectively. Other authors have mentioned the presence of Panthera onca on the summit of Auyan Tepui, and members of the Terramar expedition society have reported seeing mountain lions on the summit of Auyan, in the eastern section of the tepui.7 Tapirs have been reported on the summit of the Auyan Tepui by both Otto Huber and Armando Michelangeli.8 Tamanduas were observed and documented by Tate, and photographed by Alberto Pomares, as well as coatis.9
However, the general consensus on the summit vertebrates of the tepuis is that they are extremely scarce, and can be considered absent. This is primarily due to the limited carrying capacity of the tepui summits. The standard characterization of the tepuis can be summed up by the eminent Dr. Valenti Rull:
The diversity of herpetofauna (frogs and reptiles) is about half that of birds, but the level of endemism is higher, reaching 60% in some tepuis. Mammals, most of them small, are also represented by even lower number of species, mainly of bats, rodents, and some marsupials (opossums). So far, felids, monkeys, and medium to large herbivores have not been observed atop the tepuis. Insects have not been studied systematically, but recently, a new genus of damselflies was described (Tepuibasis), with all its seven species being endemic to Pantepui”10

The difference between the reported sightings and observations of medium to large animals represent something of a knowledge gap in our understanding of the tepuis in general, and their ecological carrying capacity. I have addressed this in my previous blog posts by stating:

The presence of coatis and large vertebrates on the tepuis is now a question natural range extension or climate change induced invasion. Solutions to this question can be answered with increased monitoring and scientific surveys. However, there is an admitted research gap in the study of the Tepuis, stated in both Rull et al 2009 and in Robovsky et al 2007. In Rull et al 2009 the authors state “Scientific expeditions to the GH started 170 years ago and continued in a regular fashion, until the late 1980s”, a statement which mirrors Robovsky et al 2007 with the statement “The aim of this paper is to bring new observations concerning the distribution of this species (Nasua nasua) on the Chimanta Massif after 15 years (sic) long gap and also partially describe its external appearance”.”

The primary concern is that the inconsistent reporting of tepui vertebrate fauna is hiding a phenomena which may be catastrophic to tepui summit life; vertical migration and extinction caused by anthropogenic climate change.11 Such a phenomena would be a devastating loss to local and global biodiversity, and needs to be researched in depth and addressed with the proper conservation strategies.
While research methodologies to determine the realities of habitat loss on the tepui summits are multidisciplinary and diverse, camera trapping can be one tool used to determine elements of the current faunal diversity of the tepuis. Thus a kind of impromptu pilot study was initiated to test the use of camera traps following a single transect walk across the Auyan Tepui. The theory behind this impromptu study is that camera trapping is capable of producing more data regarding cryptic animals (such as felids and tapirs) than the traditional survey techniques used thus far. This experiment had four major objectives:
  • To record images of medium sized vertebrates, if encountered, along the Laime Trail.
  • To conduct a reconnaissance of the Laime Trail for future camera trapping exercises on Auyan Tepui.
  • To test the camera trapping equipment for durability in the tepui summit environment.
  • To use the data collected to asses the feasibility of future tepui summit camera trapping activity

Survey area
The summit and escarpments of Auyan Tepui are the areas surveyed, starting at a southern entrance point at camp Uruyen and proceeding north into the interior of the summit. The area is interesting to examine as it is a major entrance to the interior of Auyan Tepui; the sloping topography allows for humans to enter the summit of the tepui. The trail moves through a variety of different ecosystems from the base of the tepui up the slopes to the summit; from mountain forests to tepui meadows, leading into a slight increase of elevation at the second wall near camp Dragon in the center of the tepui. The tepui vegetational cover varies with altitude: submontane forests exist up to 1200 meters, montane forests, scrub and swamp exists from 1200 to 3000 meters in elevation. The summit in the south is rocky and filled with meadows and bogs, with the terminal point of the Laime Trail composed of peat bogs, sandstone bluffs and some dense forests following the river that drains into the Canon Del Diablo, just east of the Salto Churun-meru. This portion of Auyan Tepui is also subject to periodic tourist activity, so the location can be useful in analyzing the impact of human presence on the tepui ecosystems. Equally, it may act as an access point for invasive animals entering the tepui summit, either as part of their natural range or vertical migration due to global climate change.

Trapping locations, tools and and methods
The expedition occurred from 6th to the 13th of January, 2012. The expeditions' intended route was to proceed from Uruyen in the Kamarata Valley to Campo Guayaraca, and proceed north on the summit of Auyan Tepui, moving past camp Dragon and the second wall of Auyan Tepui to scout out a new camp site, as presented in figure 1. Inclement weather limited the expeditions' progress and forced them to end early at camp Naranja (2146 meters in elevation) detailed in figure 2. While this represents only a small part of the entire trail, the team did move through ecosystems ranging from the lower elevation (approx 1000 meter) forests into the rocky and meadow dominated portions of the Auyan Tepui summit. Unfortunately, the gallery forests and dense vegetation which characterizes the the northern portion of the trail after the second wall was left unvisited. 

Figure 2 (A and B) Figure 2A is a satelite map of the Auyan Tepui with the camps and camera trapping locations on the Laime Trail indicated by yellow pins. Figure 2B is a close up of the camp and camera trap locations.

Camera traps specifications and notation

Two D55IR GameSpy digital cameras manufactured by Moultrie were utilized with SD memory cards valued at 4 gigs each. Desiccant packs had been placed within the housing to absorb moisture. The cameras were set with the following custom modes:
Camera name: biokpt01           Camera name: biokpt02
Capture mode: video               Capture mode: multiple stills
Quality: low                            Quality: medium
Delay: 15 seconds                   Delay: 15 seconds
Temperature: Celsius              Temperature: Celsius
IR test: off                               IR test: off
Info Strip: On                          Info Strip: On
Default settings: No                Default settings: No
Delete All : No                       Delete All: No
Flash: On.                               Flash: On

The second camera (biokpt02) was set with a capture mode of multiple stills, with a quality (resolution) setting placed at medium. In all other respects the settings were identical. These cameras utilize a temperature sensor which triggers the camera when an object with a higher temperature than the background ambient temperature passes with in its range. The effective detection range of the camera is 35 feet +/- five feet, with a 52 degree field view. The camera system was selected due to weight, price and and capture mode. Primarily, a camera system using an infrared trip sensor would not have been effective to use in an opportunistic manner without establishing specific sites for long term trapping.

The method utilized for the camera trapping study was a nocturnal set up and use of the traps at each camp location, effectively preforming a photographic nocturnal survey of the Laime Trail in multiple locations. While the expedition team moved from camp to camp, they preformed a default transect survey of the south of Auyan Tepui, noting and recording vertebrates observed and recording possible locations for future camera trapping exercises. The GPS coordinates and elevation of each camera trap site was recorded, as were the precise location of vertebrates observed, and suitable locations for future camera trapping. The cameras were retrieved and deactivated when camp was abandoned, and set up at the next camp location to record from approximately dusk to dawn. The intention of this method was to monitor faunal elements along the transect during time periods which have never been monitored before. As the majority of camera time was in indifferent locations, the data obtained produced a limited account of nocturnal life along the Laime Trail during the course of the expedition. The traps were set at approximately 60 centimeters from the ground, and attached to sufficiently large trees or appropriate natural features. They were artificially triggered after set up to verify they were functioning. The expedition crew attempted when possible to set the traps along a trail or open area which would tend to encourage animals to walk into the capture zone.

Results (as delivered verbatim from Alberto Pomares)
First Trap setup: GUAYARACA
Food: Vegetables
Operator: Alberto Pomares
Assistant: Arturo Berti (Pemón Guide)
Location: At 50 m from Guayaraca Camp on a forest trail
Fotos and Videos: DROPBOX\2012\CAMERA TRAP\2012-01-06-NEAR GUAYARACA
Date: From 2012 Jan 06, 17:20 to 2012 Jan 07 07:16 (Local Time)
Position: N 5º 41.084' & W62º 31.483'
Altitude: 1010m (over sea level)
Height position: aprox 2 feet from ground
Noted: Easy to position due to the trees in the forest

Second Trap setup: Peñón
Results: Negative (Cameras not fired at all)
Food: Dinner leftovers
Operator: Alberto Pomares
Assistant: Arturo Berti (Pemón Guide)
Location: At 10 m from Peñón Camp in the bushes (no forest)
Fotos and Videos: NO IMAGE RECORDED
Date: From 2012 Jan 07, 19:14 to 2012 Jan 08 06:41 (Local Time)
Position: N 5º 44.665' & W62º 32.452'
Altitude: 1838m  (over sea level)
Height position: aprox 1 feet from ground
Noted: Difficult to position, no trees, just small logs and rocks. Camera belts are adequate just for tree setting up and not good for anything else. (Don´t know why no images were taking during setups?)
Recommendations: Next time there is the need for a pre-build support for bush setups.

Third Trap setup: Naranja (Orange)
Results: Negative (Cameras fired just during setup)
Food: First Cereal, then Dinner leftovers, 3rth day vegetables
Operator: Alberto Pomares
Assistant: Arturo Berti (Pemón Guide)
Location: At 264 m south from Naranja Camp in a trail among the bushes (no forest)
Fotos and Videos: DROPBOX\2012\CAMERA TRAP\2012-01-10-NARANJA
Date: From 2012 Jan 10, 16:17 to 2012 Jan 13 15:22 (Local Time)
Position: N 5º 46.415' & W62º 31.969'
Altitude: 2161m  (over sea level)
Height position: aprox 2 feet from ground
Noted: Difficult to position, no trees, just small logs and rocks. Camera belts are adequate just for tree setting up and not good for anything else.
Recommendations: Next time there is the need for a pre-build support for bush setups.

Fourth Trap setup: Naranja Camp (Orange)
Results: Negative (Cameras fired but no capture)
Food: Dinner leftovers
Operator: Alberto Pomares
Assistant: Arturo Berti (Pemón Guide)
Location: Right at the camp near the fireplace were we saw small mice eating leftovers
Fotos and Videos: DROPBOX\2012\CAMERA TRAP\2012-01-13-NARANJA-CAMP
Date: From 2012 Jan 10, 16:17 to 2012 Jan 13 15:22 (Local Time)
Position: N 5º 46.528' & W62º 32.075'
Altitude: 2130m  (over sea level)
Height position: aprox 2 feet from ground
Noted: Difficult to position, no trees, just small logs and rocks. Camera belts are adequate just for tree setting up and not good for anything else.
Recommendations: Next time there is the need for a pre-build support for bush setups, including placement on rocks.

Fauna Sighting:
In this expedition we had the opportunity to see:
2 Birds (maybe a couple) at the Naranja Camp. They were all day long lurking for food left overs
1 black vulture (Zamuro) all black, flying over the Naranja Camp in several days
1 Royal vulture (Zamuro Real), black with white and red head, flying over the Naranja Camp in several days
1 frog on a tree at Guayaraca Camp
1 Small Lizard at Orange camp.
1 Spider at Oso camp
1 Little frog at Naranja camp

Images above are of animals photographed during the expedition.
summary of results
Biokpt 1 was equipped to record still images and 5 seconds of video. Out of 45 shots, seven are of fauna (Cerdocyon thous), and four appear to be misfires of the camera. The remaining images are of expedition members setting up the cameras or moving around them. Biokpt 2 was configured to capture still images and no video. Of 81 images, 6 are of fauna, again Cerdocyon thous. 34 shots are misfires (three appear blank, and may be a mechanical failure), and the remaining shots are of expedition members. These results indicate that the video function of the cameras is far superior in producing images of wildlife, whereas the still image setting alone produces more misfires, and records less usable data. Each camera was operational for 166 hours in the field, producing 332 camera hours, or approximately 13.8 camera days (a “camera day” is the number of cameras multiplied by the number of days they are operational.) This information is summarized in chart 1 below.

Total number of shots
Number of captures
Number of misfires
Expedition members recorded
Positive capture rate
Capture in Photo/hour
Chart 1; summary of the results of camera trapping the Laime Trail.

Camera trapping results analysis

The camera trapping experiment was successful; it recorded images of the fox Cerdocyon thous, and images from the summit (expedition members moving in front of the camera). It was, however, not perfect. At camp Penon from the 7th to the 8th of January, the cameras failed to fire, and subsequent capture of images were mostly of expedition members. The failure of the cameras to properly fire at the second location may be due to a variety of factors. The most obvious factor is that the no animal of sufficient size to trigger the cameras passed in front of the cameras. Given the limited time the traps were active, their failure to capture further images of larger vertebrates at camp Pemon and Naranja is not entirely surprising. Furthermore, the inclement weather and extremely heavy rain which halted the expedition at Naranja may have discouraged animals from moving around at night during the time the cameras were active. The rain may also have produced interference which prevented the cameras from operating by drowning out the temperature variations which trigger the operation of the camera. The expedition members who set up the camera traps noted the presence of moisture build up around the lenses and infrared lens; this phenomena is known to interfere with camera traps.
At Penon, the trap failed to fire from the initial set up. Though it remains unknown what caused the failure, the problem was temporary and the traps fired at the Naranja camp, although they apparently did not capture anything other than their own initial set up. In effect, after photographing a fox at on the forested talus slopes, the cameras did not capture any other animals. At both Penon and Naranja, the expedition team had difficulty setting up the cameras due to a lack of suitable locations to attach the units. The D55IR Gamespy cameras come with straps to attach the camera unit to tree trunks- an optimal set up to both camouflage the cameras and properly anchor them. On tepui summits, suitable trees are generally restricted to gallery forests which exist along stream margins, or are located in slime forests. In open tepui meadows, there are few suitable trees to attach the cameras to. The expedition crew noted that the traps were “Difficult to position, no trees, just small logs and rocks. Camera belts are adequate just for tree setting up and not good for anything else”, and recommend that “Next time there is the need for a pre-build support for bush setups, including placement on rocks.” This lack of mounting structures may have contributed to the lack of camera trap captures on the tepui summit.
This assessment is defiantly accurate; for the topographically complex and floristically diverse tepui summits, future camera trapping efforts will require specialized pre-built structures for mounting camera traps. Such structures, perhaps similar to tripods, can be disguised with local plants, placed in dense herbaceous settings, or covered in camouflage material to make them inconspicuous to local wildlife. During the course of the experiment, (though the expedition crew made an effort to position the cameras where they would intercept wildlife) camera placement near the camp and in human traveled areas may have had resulted in a decreased likelihood of encounters with local fauna. In future camera trapping endeavors on tepui summits pre-built structures would have to be used and the cameras would be placed for maximum encounter possibility in appropriate environments, for longer periods of time.
Some literature indicates that camera trapping can be more successful than transect line surveys for a variety of reasons, and more appropriate in conducting long term surveys.12 The viability of camera trapping vs transect line surveying for recording medium sized or larger vertebrates is evident with regards to the fauna encountered on the the Laime Trail during the expedition. In this case, we have a clear dichotomy between the effectiveness of a transect survey and a camera trap survey during a short expedition: a medium sized carnivorous mammal was camera trapped but not physically observed. The transect survey managed to produce observations of a limited number of organisms: two small birds, two species of vultures, two amphibians, one small reptile and one spider. What is interesting to note is that at the Guayaraca camp, only a spider was observed, whereas the camera trap managed to photograph Cerdocyon thous. Thus, it appears that camera trapping is possibly a more effective method of recording and surveying the larger vertebrates of the Guiana Highlands, particularly over longer periods of time. Transect survey methods are by definition useful in recording smaller organisms or arboreal animals which the cameras may miss, although possible solutions to this may be found with strategic camera placement and proper use of bait.13 Based on the success of this camera trapping pilot study, it would seem that there is some strong evidence to propose the use of camera trapping in future surveys of certain tepui summits. Larger tepuis that maintain a greater diversity of summit ecosystems and that a have topographical connection to the lowlands should be the primary focus.

Cerdocyon thous Analysis

1) Description and ecology

At Campo Guayaraca, the camera traps successfully recorded images of a Venezuelan fox, identified in this case as Cerdocyon thous, the crab eating fox. The images and video below are from the camera traps at Guayaraca. The fox enters the capture area of the camera traps presumably to feed on the food scraps that have been left as bait.


The classification of the fox is based upon the physical features of the fox, as well as the known distribution of foxes in this region.14 A medium sized canid, Cerdocyon thous is known as the zorro comun, zorro de monte, or zorro sabanero in Spanish. Cerdocyon thous weighs on average 5-7 kg, and is identifiable by a moderately bushy tail with a black or dark tip, narrow pointed head, dark pelage from the dorsum to the midline, and generally light colored ventral pelage, although significant pelage color variation is known. Five subspecies are known, the Venezuelan subspecies being C. t thous. The range and distribution if Cerdocyon thous is shown below.

(The map of the distribution for Cerdocyon thous can be found here and at the IUCN website.)
Cerdocyon thous has been noted as being sympatric with several other species of fox, including the pampas fox Pseudalopex gymnocercus, Pseudalopex culpaeus and P. vetulus in Brazil.15 The population density varies depending on location and environment; in the scrub mosaics of Brazil the average population density is 0.55 animals per square kilometer, whereas the population density for C. thous in the Venezuelan llanos is 4 animals per square kilometer. The population density is not known in the Venezuelan highlands, Suriname, French Guiana, or the lowland Amazon forests. Habitat varies considerably throughout the animals range, from scrub to woodlands and forests, and C. thous has been recorded up to 3000 meters. Range varies with abundance, season, and availability of prey items as well as social status of individual foxes. Range varies greatly across south America, from an estimated 5.3 km2 in Marajo Brazil to 1km2 in the Venezuelan llanos, with dry season ranges greater than wet season ranges. C. thous is hyopcarnivorous, and omnivory is well established. Prey items vary with availability; in the Venezuelan llanos, the majority of prey items were small mammals, followed by fruit, amphibians and insects. In Argentina, aquatic birds made up the majority of the prey items, and in Colombia vertebrates were the favorite food items, while in Marajo Brazil insects appear to be the primary food item. Foraging behavior of C. thous is characterized by individual or pair hunting, with adults accompanied by 1 to 3 grown offspring. Hunting method of C. thous is primarily pouncing when hunting vertebrates, and lateral head movements when hunting insects. C. thous may act as a seed disperser of Acacia aroma, Celtis tala, different varieties of fig species, and presumably other cultivated and wild plants. Studies conducted on the feeding habits of C. thous found that the majority of ingested food was plant based (fruits and leaves), followed by insects and finally vertebrates.16
Social behavior is categorized by monogamy and social interactions in small groups of offspring. Dispersed offspring form territories in proximity to their parents ranges. Breeding pairs produce a litter of approximately 2.6 offspring between December and February. Parents and offspring are sociable throughout their lives, and there is no sexual division of labor in cub rearing. With such a comparatively large population density, the presence of foxes in the areas around the tepui talus slopes is not surprising. An fairly high population density of C. thous (at 0.78 individuals per square kilometer) was found in Itapua National Park in Brazil. This population density was partly attributed to the variety of feeding habitats in the area, where diverse ecosystems offered a myriad of feeding opportunities.17 The GH and the tepui ecosystems (including the talus slopes) offer an high diversity in ecosystems; potential feeding opportunities should abound for C. thous in the region. Therefore, while the precise population density of C. thous is not recorded for tepui slopes, it should be fairly high. Only future studies using methods like long term camera trapping will determine the reality of this assertion.

2) Discussion of C. thous in proximity to the tepuis

In the Guiana Shield (GH), there are two primary species of Canids; Cerdocyon thous and Speothos venaticus, commonly known in English as the bush dog.18 The order Carnivora is represented in the Guiana Shield by two canids, six felids, five mustelids, and four procyonids.19 In terms of our present knowledge of the mammals of the region, the first systematic efforts to collect the mammals of the GH were undertaken by Robert and Richard Schomburgk in the 1840s.20 Analysis and collecting of both the flora and fauna were later conducted between 1937 and 1938 with the famous Phelps/ American Museum of Natural History expeditions, funded by W.H Phelps and led by G.H.H Tate. A comprehensive list of the mammalian fauna of the Guiana Shield was latter compiled by Tate based on these expeditions and previous work, while Phelps Senior and Junior continued ornithological expeditions in the tepuis of Venezuela.21 Further comprehensive inventories and species lists were made by the Smithsonian Venezuelan Project, and by Ochoa et al in 1993, with complete inventories of Canaima National Park.22 In the region as a whole, (ie the entire Guiana Shield) the vast majority of mammalian diversity is made made up by chioptera (bats), which represent 148 out of the 282 known mammal species. This is followed by Rodentia at 58 described species, Didelphimorphia (opossums) with 22 species, and Carnivora at 17 species. Given the body sizes and behavior of these groups, one can assume that the majority of the mammalian fauna in the Guiana Highlands and the Guiana Shield will be difficult not only to camera trap, but also to identify and classify during a short term expedition or transect survey, particularly for non-specialists.
To my knowledge there exists no study of the general capture frequency for crab eating foxes in the Guiana Highlands. There are some studies involving camera trapping that did included C. thous captures that were carried out in other parts of South America. In the Bolivian Chaco, four years of camera trapping (2001-2005) resulted in 215 photos of Cerdocyon thous .23 A similar study in the Emas National Park in Brazil, again over an extended period of time and with multiple camera traps, recorded a capture rate of 93 captures out of 157968 camera trap hours, with a calculated photographic rate defined in photographs/hour at between 0.000106 to 0.000980 depending on habitat.24 My capture per camera hour rate is comparatively impressive at between 0.0421 and 0.0361 for the two cameras, though the brevity of the study makes any statistical comparison with other studies virtually irrelevant. Only a longer study or series of short term studies would yield enough data to make valid and useful comparisons. It is unfortunate that this is the first instance of camera trapping and investigation into the fox population of the tepui slopes; a contemporary analysis would give at least a baseline to compare my results to. Despite the knowledge gap regarding the distribution of larger carnivores on the tepui summits, C. thous has been noted as being a resident of the area by Tate in the late 1930s, in his report the “Mammals of the Guiana Highlands”. Regarding the foxes of the Auyan Tepui Tate writes that they have certain features which differentiate them from the foxes of the Colombian Andes:

The audital bullae, though fuller, more rounded and deeper than those of the high Andean fox reissi, are far less full than those of the foxes of Mt. Auyan-Tepui and the Cotiga savannas north of the Rio Branco.”
He differentiates the Auyan tepui foxes further from foxes found in other parts of the highlands, stating that:
The specimens from the Cuyuni are slightly aberrant-perhaps transitional with Auyan-Tepui specimens-in the reduction of the black dorsal hairs of their tails to a small area at the tip. The audital bullae, however, differ from those of Auyan-Tepui.”25

Speaking specifically about the morphology of Auyan Tepui foxes, Tate makes several anatomical observations:

The foxes from the Auyan Tepui area and those of the Cotiga savannas differ markedly from Orinoco foxes in the enlargement and proportional approximation of their bullae and in the accompanying narrowness of the basi-occipital. In animals from the Auyan-Tepui the teeth are slightly smaller…Auyan Tepui specimens, furthermore, differ Cotinga animals in possessing small, short haired tails with black markings limited to the tip….”26

Tate asserts that C. thous can be differentiated by the size of their dentition; where the Auyan Tepui animals representing a transitional form between the northern Brazilian foxes and those found in the Venezuelan llanos. Although this camera trapping experiment did not obtain enough information to verify Tate's observations regarding the derivation of foxes across Northern South America, it does confirm his observations regarding the distribution of foxes into the upper elevations of Auyan Tepui. Interestingly, Tate's investigations of the fauna of Mt. Duida failed to produce evidence of foxes, and upon further investigation he confirmed with the indigenous people that C. thous is unknown in the region. This could speak to the fact that higher elevation tepuis do not maintain the same levels of faunal diversity, possibly due to their carrying capacity. If this is the case, then the distribution of C. thous in the Pantepui region should include the Chimantá Massif, and other large tepuis with lower elevations, greater surface area and diversity of ecosystems. Establishing the range and populations of C. thous in the Pantepui region is extremely important for a variety of reasons, but for our purposes here the role of C. thous in the ecosystem need to be established as it effects not only the endemic fauna, but also the flora. C. thous is a potential seed disperser, and its gut may encourage the germination of certain plant seeds. 27 Similar phenomena has been observed in coatis, which should be considered as regular members of Tepui summit biota.28 This could effect the potential change in tepui summit floral composition if global climate change effects the tepui summits as disastrously as predicted. C. thous and N. nausa may change the distribution of current and future floral assemblages by introducing non-endemic or indigenous plant species by acting as seed dispersers.

From an epistemological stand point, the photographic capture of C. thous is not surprising, but its lack of documentation on the tepui summits is. As of the writing of this paper, I have been unable to find records of C. thous on the tepui summits or talus slopes with the exception of the 1939 work by Tate previously referenced. This is unusual, as C. thous seems to be highly adaptable predator and is present in the Guiana Highlands and Canaima National park. Despite the fact that the animal was recorded on the slopes leading up to the summit rather than the summit proper, the altitude of the capture was still within the higher elevations of the tepuis. At 1010 meters in elevation, the camp Guayaraca photo and video captures place C. thous in the proper location and niche to be present on the summits of low-lying tepuis. The feeding behavior of C. thous is consistent with what would be expected from a tepui summit invasive animal; omnivory, adaptability and the capability of feeding on a variety of available food sources. The diet and niche of C. thous compares favorably to that of Nasua nasua; a mesopredator already known to range into the summits of low elevation tepuis,.29 I covered in detail the phenomena of coatis on the summit if Auyan Tepui; the presence of these animals on Roraima and Chimantá was considered noteworthy enough to generate two short scholarly articles, which did a great deal to illuminate the carrying capacity of the tepuis and the biogeography of Nasua nasua.30 The lack of scholarly information on the presence of C. thous on the tepui summits presents something of a mystery, given the relative ease of camera trapping these animals on the slopes of Auyan Tepui. It could be that there have been no sightings of C. thous on the tepui summits as a result of summit avoiding behavior. Perhaps there is a lack of long term food sources on the summits, or maybe the topography of the tepuis represents a challenge to C. thous. This seems unlikely, as the area in which the fox was photographed grants humans relatively easy access to the summit; it seems logical that an agile fox could make the hike from camp Guayaraca to the summit of Auyan Tepui. It could also be that the absence of C. thous on the summit is the result of a sampling error; C. thous is mostly active during the night and at dawn, and therefore unlikely to be encountered during a transect walk or under the usual conditions of daytime scientific field activity. In this case, when a survey methodology was used that was biased towards nocturnal organisms, (ie nocturnal camera trapping), the presence C. thous was recorded successfully. In all likelihood this nocturnal carnivore would have not been recorded without the camera trapping experiment. Finally, as I mentioned in part 1 of the Auyan Tepui coati post, it may simply be that local scientists and foreign scientists do not have a identical understanding of the precise distribution of vertebrates in the Guiana highlands.

Projecting forward- future endeavors

This camera trapping experiment was a successful proof of concept. Given that the methodology differed from standard camera trapping, and taking into account poor weather and extremely limited duration, this experiment was wildly successful. Based on this fact alone, it would seem that camera trapping the Auyan Tepui and its sister tepuis would be useful in deducing the sum total biodiversity of the tepui summits, bearing in mind that camera trapping would be biased toward larger bodied endothermic vertebrates to trigger the camera. Camera trapping has worked all over the world to catalog known species and has managed to uncover new species.31 Traditional transect surveys and site collection methodologies should be used in conjunction with camera trapping. An excellent methodology for integrating theses systems can be found in the Tropical Ecology Assessment and Monitoring Network (TEAM), with specific guidelines on camera trapping systems and procedures. There are a few general recommendations that can be made based on this work:

  1. A mapping analysis of Auyan Tepui focusing on both key regions of interest and entrance points along the talus slopes which can be camera trapped.
  2. An increase in both the number of camera traps used and and their duration of time in the field. TEAM methodology recommends 32 cameras per survey, 2 per site with a total of 16 sites. Such as large number of cameras would only be possible with a well funded expedition, in cooperation with local organizations in Canaima and Venezuela.
  3. Complete georeferencing of all camera locations, as well as specimens photographed or collected by recognized scientists.32
  4. Proper post camera trapping data analysis, again following TEAM protocols. Protocols are outlined and available for download at
  5. Following the recommendations of Captain Pomares and his expedition team ( waterproofed housing, use of tripods or prebuilt mounts, moisture control).

These five recommendation are just a few things that need to be done in order to camera trap the tepui summits successfully and competently. The recommendations are easily enough implemented in future camera trapping experiments. At this point in time, based on what was learned from this camera trapping experiment, Auyan Tepui needs to be the focus of a new, more involved and more detailed camera trapping study. The time for such studies is now, as we come to understand that global climate change will alter the tepui ecosystems forever.

1Carbone, C. et al “The use of photographic rates to estimate the densities of tigers and other cryptic mammals” Animal Conservation # 4 2001.
2 “First images of newly discovered primate”
3 McDiarmid and Donnelly, “The herpetofauna of the Guayana Highlands; amphibians of the lost world”. Ecology and evolution in the tropics: a herpetological perspective. pp. 461-560 Donnelly, Maureen A., Crother, Brian I., Guyer, Craig, Wake, Marvalee H. and White, Mary E. (eds.)
5Myers & Donnelly, “The summit herpetofauna of Auyantepui, Venezuela: report from the Robert G. Goelet American Museum-Terramar expedition” Bulletin of the AMNH # 308, 2008
6Havelkova et al, “Brown-nosed coati (Nasua nasua vittata on the Roraima tepui, (Carnivora: Procyonidae)” Lynx (Praha) 2006, Robovsky et al “Additional report of the brown-nosed Coati (Nasua nasua vittata) on the tepuis- the Chimantá Massif, Churi Tepui Venezuela” Lynx (Praha) 38, 2007
7 1)Havelkova et al, “Brown-nosed coati (Nasua nasua vittata on the Roraima tepui, (Carnivora: Procyonidae)” Lynx (Praha) 2006, Havelkova summarizes limited sightings and reports of larger mammals on tepui summits. 2)Uwe, George “Tepuis, Venezuelas Islands in Time” National Geographic, May 1989.
8 Huber, Otto “Guayana Highlands versus Guayana Lowlands, a reappraisal” Taxon, 37 1988 , Michelangeli, Armando “Tepuis, los colossus de la tierra”, Uwe, George “Tepuis, Venezuelas Islands in Time” National Geographic, May 1989
9Tate G.H.H “Mammals of the Guiana region”. Bulletin AMNH vol 79 1939
10 Rull, V “Pantepui” Encyclopedia of islands Rosemary Gillespie and David Clague eds University of California Press, 2009. This is the opinion of a variety of scientists regarding the general level of tepui summit fauna. See also Ochoa & Gorzula “Los Mamiferos del macizo de Chimantá. Con algunos comentarios sobre las comunidades de las cumbres tepuyanas” in Huber (ed) El Macizo del Chimantá, Escudo de Guayana Venezuela, Un Ensayo Ecologico Tepuyano, Caracas, 1992
11Rull, V. et al (2006)  “Unexpected biodiversity loss under global warming in the neotropical Guayana Highlands: a preliminary appraisal”   Global Change Biology 12: 1-6, Rull, V(2007)  “The Guayana Highlands: a promised (but threatened) land for ecological and evolutionary science”   Biotropica 39: 31-3,Rull, Villarrubia,, Nogue, Huber, (2009)  “Conservation of the unique neotropical vascular flora from the Guayana Highlands in the face of global warming”   Conservation Biology 23: 1323-1327
12 Trolle, M. et al “Brazilian Tapir Density in the Pantanal: A Comparison of Systematic Camera-Trapping and Line-Transect Surveys” Biotropica, vol 40, issue 2 2008, Silvera, L et al “camera trap, line transect census and track surveys: a comparative evaluation”. Biological Conservation, 114, 2003
13 Schipper J “Camera trap avoidance by Kinkajous Potos flavus, rethinging the “non-invasive” paradigm”, Small carnivore conservation vol 36April 2007
14 Identification based upon long bushy tail, appearance of black line on the dorsum, as well as the known canids of the Guanyana highlands. See 1)“Checklist of the Terrestrial Vertebrates of the Guiana Shield” Bulletin of the Biological society of Washington no 13, December 2005 2) Berta A “Cerdocyon thous” Mammalian species # 86, 1982 3) IUCN Canid Specialist Group “Crab-eating fox (Cerdocyon thous)”
15 IUCN Canid Specialist Group “Crab-eating fox (Cerdocyon thous)”
16 Rocha, V. J et al “feeding habits of the Crab eating fox Cerdocyon thous in a mosaic area with native and exotic vegetation in Southern Brazil,” Revista Brasileira de Zoologica, 24(4) Dec 2008
17 Faria- Correa, M, et al “Activity, habitat use, density, and reproductive biology of the crab-eating fox (Cerdocyon thous) and comparison with the pampas fox (Lycalopex gymnocercus) in a resting area in the southern Brazilian Atlantic Forest” Mammalian biology 74, 2009
18Burton K et al “Mammals: Checklist of the Terrestrial Vertebrates of the Guiana Shield” Bulletin of the Biological Society of Washington # 13 2005
19Burton K et al “Mammals: Checklist of the Terrestrial Vertebrates of the Guiana Shield” Bulletin of the Biological Society of Washington # 13 2005
20 Burton K et al “Mammals: Checklist of the Terrestrial Vertebrates of the Guiana Shield” Bulletin of the Biological Society of Washington # 13 2005
21Myers, Charles W. “A history of Herpetology at the American Museum of Natural history”, Bulletin of the AMNH no 252, 2000.
22Ochoa et al “Inventario y estudio communitario de los mamiferos del Parque National Canaima, con una lista de las especies registradas para la Guayana Venezolana Acta Cientifica Venezolana # 44, 1993
23 Maffei et al 2007 Home range and activity of two sympatric fox species in the Bolivian Dry Chaco. Canid news 10.4
24De Almeida Jacomo A.T. Et al “Niche separation between the maned wolf (Chrysocyon brachyurus), the crab-eating fox (Dusicyon thous) and the hoary fox (Dusicyon ventulus) in central Brazil” London Journal of Zoology, 262, 2004. It should be noted that Dusicyon thous is a synonym of Cerdocyon thous.
25Tate G.H.H Mammals of the Guiana region. Bulletin AMNH vol 79 1939
26Tate G.H.H Mammals of the Guiana region. Bulletin AMNH vol 79 1939
27 1)The Crab-eating Fox (Cerdocyon thous) as a secondary seed disperser of Eugenia umbelliflora (Myrtaceae) in a Restinga forest of southeastern Brazil Biota Neotrop., vol. 9, no. 2 Eliana Cazetta1,2,3 & Mauro Galetti12) Seed dispersal of Solanum thomasiifolium Sendtner (Solanaceae) in the Linhares Forest, Espírito Santo state, Brazil Acta bot. bras. 23(4): 1171-1179. 2009 João Vasconcellos-Neto et al
28 Cecília P. Alves-Costa “Seed dispersal services by coatis (Nasua nasua, Procyonidae) and their redundancy with other frugivores in southeastern Brazil” Acta Ecologica, vol 32 issue 1 2007
29 Aguiar, Lucas M et el “Diet of brown-nosed coatis and crab-eating raccoons from a mosaic landscape with exotic plantations in southern Brazil” Studies on Neotropical Fauna and Environment vol 46, issue 3 2011.
30 Havelkova et al, “Brown-nosed coati (Nasua nasua vittata on the Roraima tepui, (Carnivora: Procyonidae)” Lynx (Praha) 2006, Robovsky et al “Additional report of the brown-nosed Coati (Nasua nasua vittata) on the tepuis- the Chimanta Massif, Churi Tepui Venezuela” Lynx (Praha) 38, 2007
31Rovero, F. “A new species of giant sengi or elephant-shrew (genus Rhynchocyon) highlights the exceptional biodiversity of the Udzungwa mountains of Tanzania” Journal Of Zoology 274 2008.
32See Garcia and Funk “Improving the use of information from museum specimens: Using Google Earth (c) to georeference Guiana Shield specimens in the U.S. National Herbarium” Frontiers of Biogeography 2.3 2010


  1. Great work on this post Laszlo. It was a pleasure participating in this pilot study. We are ready to help you out for the next one on the Auyan Tepuy.
    Alberto Pomares


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