Review of Part 1
In the previous blog "Brown nosed coati on Auyan-Tepui: Are lowland vertebrates invading the tepuis? Part 1", I discussed and diagnosed two coati sightings on Auyan Tepui and Roraima, which represent the unusual phenomena of large vertebrates entering and living on tepui summits. The blog post ended with a discussion as to why these animals are present on tepui summits which are supposedly devoid of large vertebrates. The post ended with
"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"
Part 2 continues with the two competing hypotheses, the elimination of the weakest hypothesis, and a discussion as to what impact the presence of large vertebrates such as coatis may have on the Guiana Highlands (GH) in general, and tepui summit life specifically.
Are the coati sightings a indication of the invasion of the highlands by lowland organisms? The displacement of lowland organisms into the global highlands is a documented phenomena.1 The extinctions of butterflies and frog species as a result of range restriction has been noted in connection with lowland temperature increase and migration toward the poles.2 In the tropics, the displacement of lowland organisms is less oriented toward the poles as it is toward the highlands.3 This situation is compounded by the fact that lowland areas are under extreme stress, and may face extinction of their indigenous organisms in the near future.4 The threat of extirpation of lowland animals depends heavily on a given species' thermal adaptability. There is a good indication that increasing temperatures will generate extinction in lowland ecosystems, as many species currently exist at their thermal maximum.5 If this is the case, then the migration of lowland species into the highlands will occur followed by the replacement of current lowland ecosystems with entirely new and novel assemblages of flora and fauna. This vertical displacement of lowland organisms towards the highlands with accompanying highland extinctions leads to habitat fragmentation. The extinction of large predators associated with this fragmentation can lead to the proliferation of smaller omnivores, a phenomena termed mesopredator release.6 Coatis are noted among the opportunistic mesopredators which take advantage of these open niches and lack of competition to expand their range and increase in population.7 Coatis are known to range into high altitudes; there are no factors which should preclude them from entering the tepui summits as the kinds of vertical displacements described by Rull occur. These new coati sightings on the tepui summits may be a part of the phenomena of global climate change effecting the tepui ecosystems.
Hypothesis 2: Coatis are entering the Tepui summits in response to human tourist activity.
Canaima National Park in Venezuela encompasses the majority of Tepuis in Venezuela. As a national park, it was established to preserve the tepui ecosystems and to provide watershed for the Guri Dam. The creation of the park is based on natural beauty and human derived benefit, a synthesis of which drives the conservation of wild places.8 Roraima receives 3000 tourists per year, who climb the slopes to the summit of the tepui.9 There is a cut off of 50 tourists climbing the summit at any given time. A number of travel agencies and companies book excursions to Roraima, which is accessible to tourists. As an example, the company Mountain Travel Sobek currently offers tours of Roraima and Angel Falls. Their previous travel itinerary included a trek to the summit of Auyan Tepui, with an entire day reserved to explore the summit of the Tepui. This itinerary, dated to the year 2000, has since been abandoned due to the arduous and difficult nature of hiking to the summit of Auyan Tepui.10 Thus, it seems feasible that coatis may be attracted to human camps, and may be enticed to the Tepui summits by human tourism. Private citizens and exploration societies are also able to summit Auyan, and camp on the summit for a period of time. This process is expensive, and difficult to accomplish for foreign tourists. Despite this fact, Canaima National Park and the unique and beautiful tepuis are an ideal travel destination for Eco-tourists and adventure seekers.
Testing the hypotheses
These two hypotheses designed to explain the presence of coatis on the tepui summits can not be fully tested or negated without field work or further detailed study, but instead can be investigated with a rational examination of the two alternatives. First, the timing of the sightings is important. The Havelkova sightings on both Roraima and Chimanata have occurred during the present century, during which tourism on the tepuis has been steadily increasing. The Terra-X Auyan Tepui sighting occurred during the mid to late 1980s, during which tourism was significantly reduced compared to the current rates. Tourism on Roraima is fairly consistent, but the refuse collection on the summits at least seems to be advanced to the point of being zero-impact. Roraima tourism is undertaken on foot, through a fairly steep hike through a passable route. Current Auyan Tepui summit expeditions are limited to a scant few days at most on the summit, and do occur through an arduous climb. However, the Terra-X sighting was made by an expedition team that made summit with a helicopter, and did not establish themselves in such a way as to entice opportunistic lowland animals to the summit. Even given the presence of foraging coatis on the summit of Auyan Tepui, the expedition team was located in the north of the tepui, on the opposite side of the tourist paths which lead to the summit in the extreme south.11 (See fig 1)
Figure 1 A map of the tourist camps and trails available. Tourist trails are located in the more accessible south of the tepui, where guided tour groups enter via a difficult hike and bouldering. The 1990 Terramar expedition entered Auyan Tepui via helicopter, in the north of the plateau. .12
The 1990 Terramar expedition summited Auyan Tepui utilizing helicopters, and set up two base camps: one a few kilometers to the south and west of Angel Falls, and another in the extreme west of the tepui, in a region known as the Valle Encantador. It is logical to conclude that the coati on Auyan Tepui was present prior to the arrival of the expedition team, and ventured into their foodstuffs in an act of opportunistic browsing. In this instance, given the circumstances of the 1990 expedition, it would seem that the presence of coatis on the summit of Auyan Tepui represents a case of the invasion of a large tepui summit ecosystem by a lowland mesopredator. On Roraima tepui, the situation is more complicated, and may represent an interplay of the effects of both tourism and global climate change. In June of 2010, a colleague of mine from San Francisco State University traveled to Canaima National Park, and collected observational data regarding tourism in the park. She categorized the level of tourism as being relatively low, and restricted primarily to Roraima. She attempted to obtain a tour to the Summit of Auyan Tepui, but was unsuccessful. She observed that a number of tours were unavailable, and that the Tepui summits are restricted to tourists in order to maintain their pristine condition. Tours are typically low impact, restricted to established trails, and involve minimal time hiking. Unguided tourist activity is practically nonexistent. Given this situation, it is unlikely that coatis are being enticed by tourism to the tepui summits. They may take occasional advantage of opportunistic food sources, but nothing indicates that their behavior has been changed by tourism. In 2007, Havelkova, Robovsky, Audy, Schlogl and Diaz De Pascual published a follow up paper to the Roraima coati sighting, which details sightings of coatis on Churi tepui, Chimanta Massif. In the abstract the authors state in relation to the coatis distribution “The dense vegetation with a relatively good food resources (sic) allows coati's natural distribution on Chimanta Massif where they are certainly not facilitated by the touristic activity”.13 I agree with this assessment. Coatis sighted on Chimanta, Auyan, and Roraima appear to be indigenous or naturally invasive, and the mechanism of their establishment should omit tourism due to a lack of pervasive tourism, as well as a lack of evidence indicating that tourism acts to entice coatis into these areas.
Ultimately, the mechanism which entices coatis on to the tepui summits is currently unknown, in terms of the notion of range extension via natural processes or as a reaction to climate change. What can be eliminated from the testing of the two hypothesis is the notion that tourism alone is responsible for the coati sighting on the tepui summits. The Auyan Tepui sighting is certainly not the result of tourist activity, as access is restricted, and the sighting occurred away from the location of potential tourist trails. While Havelkova et al mentions tourism as a possible factor and brings up the notion of food rest exploitation, coati behavior on Roraima was seemingly focused on bromeliad scavenging. The follow up 2007 paper of the Churi Tepui coati band sighting proves that tourism is not enticing coatis to Churi Tepui. Given these facts, it seems as though the phenomena of coatis present on tepui summits needs to be framed in terms of natural range expansion versus unnatural (human induced climate change) range expansion, and not as a result of tourist activity.
Analysis of Results
As I have mentioned in my literature reviews, current evidence points toward vertical migration as the key factors in the establishment of GH biota. The mechanism behind this vertical migration is the oscillation of glacial cycles which changes the global temperature and precipitation rate. In summary, during the glacial periods which predominate the Pliocene and Pleistocene, GH organisms migrated down into the lowlands, creating communities which were a mixture of tepui and highland organisms. After repeated glacial cycles, some summit biota adapted to lowland conditions to establish tepui derived vegetational assemblages in the lowlands.14 This migration was contained at an altitude of approximately 1100 meters, effectively isolating regions which were above this elevation from the lowlands and biotic exchange. Due to the topography of the tepuis, the higher tepuis engendered vicariance and speciation development in their isolated ecosystems, whereas lower altitude tepuis and tepui slopes were engaged in a process of hybridization with the lowlands during the glacial periods. It is theorized that during the glacial periods, tepui summits played host to a series of ecosystems which are now totally extinct, and have no modern counterparts.15 Rull theorizes that, based on similarities between the Andean paramos and the paramoid shrub-lands on the Chimanta Massif, tepui paramos would have existed during glacial periods on the higher elevation summits.16
During the interglacial periods, lowland biota migrated upwards, leading to vicariant evolution and extinction of highland biota. The cut off for lowland upward migrations is likewise placed at approximately 1100 meters. Rull estimates that the interglacials were a period of extinction for the hypothetical tepui paramos, as the temperature was not suitable for their continued existence. Remnants of the glacial communities are represented by Andean organisms on the tepui summits which have adapted to persist in the current interglacial. He also cites the Chimanta paramoid shrub-lands as a survivor of the glacial tepui paramos.17 As isolation is based upon altitude, and in general mixing of lowland biotas does not occur historically past 1100 meters, higher altitude tepuis such as Auyan and Roraima maintain a higher degree of endemic species which have theoretically adapted to the cyclical glaciations to an unknown extent.
The effects that this pattern of vertical migrations alternatively occurring during cyclical glaciations has on the distribution of Venezuelan coatis is not known. If the coati subspecies is truly N.n. vittata, then its presence in higher altitudes may constitute a new distribution for coatis. A known and little studied species of coati Nasuella olivacea is known to inhabit higher altitudes in the North Andean Highlands, though it is a smaller species and does no match either of the coatis reviewed in this paper. Nasua nasua does have a distribution over a wide range, from its preferred habitat of forested environments to dry scrub forests, and has an observed altitudinal range of up to 2500 meters.18 Due to the lack of a detailed fossil record on the tepui summits, it is unknown if Nasua was present on the summits during the last glacial period.19 What is certain is that coatis have come into contact with tepuian ecosystems during the glacial periods when tepui plants made their way into the lowlands. This could indicate that coatis are adapted to enter into tepui ecosystems, and may be accustomed to interacting with the current endemic flora and fauna, which has been isolated due to interglacial conditions.
As I discussed in my blog reviewing selected works of Dr. Rull, anthropogenic climate change is anticipated to cause massive extinctions in tepui summit ecosystems by eliminating their climatic envelope. The preliminary appraisal for the Pantepui is a reduction of 70-90% of tepui summit area, and an extinction of 80% of vascular plants and 30-50% of pantepui endemics by 2100 A.D.20 As predicted by the climate change and diversification models, the upward movement of lowland species into the tepuis is anticipated to contribute to this extinction event, although it is unclear if the lowland invasion will precede or coincide with the extinction in taxa. What is certain is that current warming trends exceed the maximum natural interglacial warming by 10 fold.21 Given that this current rate of warming is expected to increase in the next 100 years, the acceleration of lowland invasion and tepui summit extinction should be noticeable on a human timescale. The vertical displacement of lowland organisms towards the highlands, at its current rate, should be noticeable now. It is possible that the observation of mesopredators such as coatis on the tepui summits is a visible effect of climate change induced vertical migration of larger lowland vertebrates.22
The two sightings of coatis is seemingly unique in the history of the tepuis. It is the general consensus among the scientific community that the tepuis are devoid of large mammals due to unsuitable habitat and lack of resources to maintain their populations. All endemic highland mammals are relatively small, a pattern which they share with the reptiles of the GH and tepui summits.23 Given that this seems to be the accepted consensus for tepui summit vertebrates, it puzzles me that the 1990 Terramar expedition sighting and video of coatis went unreported in scholarly literature. I can surmise two possible reasons why a coati would be filmed on a tepui summit yet go unreported in scholarly literature: either its presence on the summit was not considered unusual by the expedition crew, or it was not considered unusual enough to warrant a report. Either of these two scenarios are possible in light of the fact that such sightings are already established in scientific literature. Huber wrote in 1988 that coatis have been sighted on the tepui summits, theorizing that the sighting may represent lone individuals. Is there a knowledge gap between Venezuelan scientists and U.S scientists concerning the fauna of the tepui summits?
In 2007, Audy, Havelkova and three other authors published their follow up sighting of coatis on Churi Tepui in the Chimanta Massif in an effort to determine the status of coatis on the tepui summits.24 In a review of literature concerning the mammalian fauna of the massif, the authors identified an number of coati sightings in the highlands and the tepui summits. These documented sightings include an observation made in; 1) 1955 of a female on Torono Tepui, 2) 1984 on Apakara Tepui, 3)in 1983 and 1986 on the summit of the central west portion of Chimanta Tepui, 4) in 1985 the remains of a coati found on Torono-Tepui.25 These sightings demonstrate that not only have coatis been sighted on the tepui summits, but they have been consistently sighted over time, and are known to Venezuelan scientists. This factor may have contributed to the absence of literature regarding the Terra-X coati video and sighting.
The Churi Tepui sightings themselves were made by Marek Audy and Jan Schlogl in February of 2007. The climatic conditions at the time were unseasonably dry, and the habitat where the sightings occurred was and open area composed Brocchina, Stegolepis, Orecanthe and Chimantaea. The first sighting was of an individual coati, with a pelage coloration “identical with the pelage coloration of the N. n. vittata observed on Roraima...”.26 Schlogl observed at a latter time a group of four coatis which “has a brown-orange-brown pleage with predominant orange colour on the belly and inner side of the legs”.27 The authors identified these coatis as being a group of juveniles, due to physical characteristics, pelage coloration, known coati social behavior (ie adult males are solitary, females and juveniles form groups). The behavior observed was one of foraging for food among Bonnetia and inside bromeliads. This new 2007 sighting of a group of individuals indicates a potentially new phenomena. Where as Huber in 1988, and both the 1990 Terramar and 2006 Havelkova atricle detail lone coatis, the Schlogl sighting demonstrates that groups of coatis range within the tepui summits.
The implications of this observation are complicated, and support the thesis of climate change based vertical migration. It was previously believed that the coatis observed on the tepui summits are simply wide ranging solitary males engaged in opportunistic browsing. This was considered the case by a variety of authors such as Huber, Gorzula and Ochoa in explaining intermittent contacts with these animals. However, with the 2007 sighting by Schlogl and the 1955 sighting of a female described in Ochoa and Gorzula in 1992, we must consider the possibility that coatis may be established on certain tepui summits at this time. If this is the case, then it may be possible to estimate the population density of coatis on or near the tepui summits. There is an average population density of 6.2 individuals per square kilometer in deciduous forests, and 13 individuals per square kilometer in gallery forests.28 However, it is noted that these population densities “may represent a dry season concentration near water”.29 Certainly, the 2007 sighting of a group of coatis on Churi Tepui was noted as occurring during an unusually dry season in the region, which may have played a part in enticing a group of coatis to range outside of their usual territory. However, with sightings ongoing for such a long period of time for a known animal, on the Auyan Tepui and on its sister tepuis, the likelihood that coatis are simply out of their home range is unlikely. It should also be mentioned that while the Chimanta Massif and Auyan Tepui are considered distinct tepuis, they are continuously connected at the 1000 meter contour, are separated by approximately 50 km at 2000 meters in elevation, and may share a similar origination.30 In effect, their faunal elements may be connected.
It seems that the issue of coati presence on the tepuis can be now resolved with the sucessful identification of individual and bands of coatis captured photographically, on video, and observed over time in a consistent manner. A history of sightings, photographic and video evidence with diagnostic characteristics, and finally a sighting of group of animals has been produced. This body of evidence meets that standards for proving the existence of species believed to be absent from a certain area, or considered extinct.31 Through analysis of the circumstances of the sightings, the notion that increased tourism is the sole mechanism enticing coatis or other lowland fauna to the tepui summits can be dismissed. The situation of coatis present on more densely vegetated tepuis is interesting, in that it indicates a much greater ecosystem richness than theorized and reported for the tepui summits. Tepuis with dense gallery forests along river and streams, and dense Bonetia forests should be capable of sustaining a community of larger animals. This may be the case with Auyan Tepui, with an approximate area of 700 square kilometers, gallery forests, shrub-lands, and Stegolepis marshes. Auyan Tepui also maintains a series of micro-habitats which harbor unique endemics, which could be exploited by omnivorous generalists like coatis. If this is an accurate assessment, and tepui summits can maintain in theory a rich diversity of ecosystems, then this situation needs to be analyzed both in terms of cryptic biodiversity, as well as future developing diversity based on vertical migration, invasive, and predicted extinctions.32
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”.33 The period of time in which this 'research gap' occurred roughly corresponds to the time in which the Terra-X documentary was being produced, and the same period of time in which the majority of the summit coati sightings mentioned in Robovsky et al were made i.e. 1984-86. This distribution of sightings of coatis and other large lowland vertebrates on the tepui summits could be the result of observer bias; perhaps more attention was focused on the tepui summits due to the advent of helicopter utilization to get scientists to the summits. If this is the case, then it is possible that large vertebrates naturally range onto some tepui summits, and previous expeditions simply missed this fact due a lack of technologically advanced survey methodologies. Alternatively, it could be that the phenomena of vertical migration proposed by Rull and other scientists is taking effect, and more recent expeditions to the Tepui summits and GH are observing this new and potentially devastating trend. This trend of lowland invasion is not confined to mammals or highly mobile vertebrates. Reptiles and amphibians are known to invade tepui summits. Myers and Donnely commented that while reptiles and amphibians invade the tepuis, it is difficult to establish which species will do so, and what their expected successful rate of population establishment may be, if any at all.34 Thus far, eight species of lowland reptiles have been reported to invaded the tepuis. Of these species, Anolis chrysolepis has been determined to be a regular invader by Myers and Donnelly in their 2008 expedition report. The lowland racer snake Mastigodryas boddaerti has been established on Auyan Tepui for the past 60 years, and Leptoderia annulata has been recorded on both Auyan and Chimanta Tepui( see Fig 2).35 This indicates that new invasive reptiles from the lowlands are invading the tepui summits, and have been observed doing so within the past few decades. If this is part of a natural process, or is a response to climate change, is not known. This situation represents a gap in our current understanding of faunal establishment on the tepui summits, and complicates the issue of establishing the realities of Pantepui endemic life.
Figure 2. An image of Mastigodryas, taken from reptile-database.reptarium.cz 36
The authors of the 2007 Robovsky et al paper state that the sightings and collection of the Churi Tepui represent an approximate 15 year research gap. The Guiana Shield Initiative (GSI) complain of similar gaps in analysis, exploration and collection.37 The GSI describes that Auyan Tepui as being at a relative medium exploration level, although its is clear from published sources that further research is necessary to determine the sum total biodiversity of the tepui summit, and the relationships between adjoining summit biota.38 Complicating this issue of gap analysis on the tepui summits is the global warming phenomena discussed by Rull and others, indicating that the summit biota of the tepuis is anything but static, and indicates that ecosystem changes will occur as a result of lowland vertical migration to the highlands.
If coatis are present on certain tepuis as an established population, then the reports of other animals form the 1990 Terramar expedition to Auyan Tepui need to be taken seriously, as video evidence from this expedition predicted to some degree the 2006 and 2007 paper by Havelkova and Robvsky. Any investigation of these reports should be undertaken to include sightings of previously undescribed animals, animals outside of their known ranges (such as coatis, torrent ducks, and other lowland fauna), and needs to be based on the precautionary, to avoid errors in cataloging or errors of omission.39
The implications of global climate change has a dramatic impact on how we need to view tepui summit ecosystems. Detailed topographic models need to be created for each tepui which show the effects of predicted climate change on the habitats present. Climate envelope models also need to be developed for the present endemic fauna and flora, as well as for potential lowland invaders to discern their future ranges. Surveys will need to be conducted, and monitoring systems will need to be developed, probably using both advanced GIS techniques and horizontal field studies. Only after the sum total of the fauna and flora have been surveyed can the recommendation that Rull, Vegal Villarrubia, Nogue and Huber propose in their 2009 manuscript be implemented.40
The realities of the composition of tepui fauna must be addressed in concert with the conservation recommendations detailed in Rull et al 2009, including increasing the exploration and surveying of tepuis as well as developing ex situ conservation strategies for tepui flora. This recommendation mirrors the GSI Paramaribo Declaration number 19, which states the “Recognition of the need to guarantee long term conservation of the unique tepui ecosystems of this (Guiana Shield) region.”.41 Conservation strategies in the GH must focus on the sum total biodiversity as much as possible, to avoid the omission of keystone species or undocumented species in future conservation efforts. Before the sum total biodiversity can be assessed, research gaps such as those indicated by Rull and Robovsky must be filled, and the potential destructive actions of lowland invaders needs to be considered.
The presence of supposedly “anomalous” fauna ( larger lowland invasive organisms, observed but unclassified vertebrate species) needs to be investigated within reason, and survey methodology needs to be focused on new species discovery. There is in the GH a trend for species discovery, particularly with herpetofauna, which shows a positive linear increase in the number of new species discovered.42 Although this trend is may not continue indefinitely, it does indicate that more fieldwork needs to be done to determine what the actual level of biodiversity in the GH is.
Based on the work addressed in Audy et al 2006 and Robovsky et al 2007, and in light of the Terra-X documentary footage, it is now reasonably certain that coatis should be considered members of the fauna of resource rich Tepuis with large surface areas. Individual coatis have been documented and filmed on Auyan tepui, two individuals have been observed and photographed on Roraima, and a group of coatis have been observed on the Chimanta Massif. The mechanism for the establishment of coatis on tepui summits is range expansion, either as a result of previously unobserved natural behavior or as an adaptation to anthropogenic climate change. Other mechanisms for invasion such as foraging around human food-rests and rubbish have been ruled out due to the wide range of Tepuis hosting coatis, as well as the limited nature of tourism in Canaima National Park, specifically the absence of tourism on Auyan and Chimanta.
The tourism hypothesis was ruled out using basic deduction, confirmation from the work of published by Robovsky et al, interviews with agencies which offer tours of the Tepuis, and field observations by my colleague Alexandra Goodman, while she visited and extensively traveled in Canaima National Park in July of 2011.
The implications of coatis ranging into the tepuis reveals that these ecosystems may be more versatile and rich than previously thought, and implies that the observations made by Armando Michelangeli and the Terramar expedition group in the late 1980s regarding other lowland animals on the tepuis (tapirs and mountain lions) and well as cryptic large fauna, (the status of which is undetermined) are accurate .43 If this assessment is correct, I predict that other lowland vertebrates will be sighted on the Tepui summits, and in larger concentrations over time. First, organisms which can carve out a niche on the summits will be recorded, such as insectivores and omnivores. Herbivores will follow the vertical migration of flora, and predators will follow the herbivores. The impact on the summit ecosystems will be dramatic and potentially catastrophic.
11)Pauli, Gottfried and Graebhrr “Effects of Climate Change on mountain ecosystems- upward shifting of alpine plants” World Resources Reviews, 8, 1996, 2)Rull, V. “Unexpected biodiversity Loss under global warming in the neotropical Guayana Highlands; a preliminary appraisal” Global Change Biology, 12, 2006.
2Thomas et al, “Range retractions and extinction in the face of climate warming” Trends in ecology and evolution, vol 21 no 8, 2006
3Colwell, Robet k. et al “Global Warming, Elevational range shifts, and lowland biotic attrition in the wet tropics” Science, vol 322 October 2008
4Colwell, Robet k. et al “Global Warming, Elevational range shifts, and lowland biotic attrition in the wet tropics” Science, vol 322 October 2008
5Colwell, Robet k. et al “Global Warming, Elevational range shifts, and lowland biotic attrition in the wet tropics” Science, vol 322 October 2008
6Terbourgh, “Maintenance of diversity in tropical forests” Biotropica 24, 1992
7William F. Laurance, “Theory meets reality, how habitat fragmentation research has transcended island biogeographic theory” Biological Conservation 141, 2008
8Barkoczy, Laszlo “Globalizing a Lost world: Beauty or Benefit, what drives conservation? The International Relations Journal, San Francisco State University, Vol 28, 2009.
10I am deeply indebted to Karen --- at Mountain travel Sobek for providing me with the current and previous itinerary, and well as information regarding the Sobek excursions. According to her, the Auyan Tepui summit trek was difficult to undertake and was scraped. Their current package, dated from 2009 to the present, includes only a Roraima summit trek.
111)The Auyan Tepuy Trek, Venezuela http://www.lostworldadventures.com/ . Tours are offered by Lost World Adventures. A detailed tepui summit excursion is entitled “Auyantepui”, and can be found at http://www.venezuelatuya.com/gransabana/auyantepuieng.htm
13Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
14O. Huber, “Flora of the Venezuelan Guayana Vol. 1.” Berry, Holsy and Yatskievych eds. Missouri Botanical Gardens Press, 1995
15V. Rull. “Biotic diversification in the Guayana Highlands: a proposal” Journal of Biogeography 32, 2005
16V. Rull. “Biotic diversification in the Guayana Highlands: a proposal” Journal of Biogeography 32, 2005
17V. “Rull. Biotic diversification in the Guayana Highlands: a proposal” Journal of Biogeography 32, 2005
18Mathew E. Gomper and Denise M. Decker, “Nasua” The American Society Of Mammalogists, No 580, June 1998.
19While tepui sediments are generally restricted to peat bogs, I recall a documentary in which the bones of a coati were recovered from a cave in Roraima. With out the documentary footage or other references, I am not comfortable stating the coati remains were uncovered.
20Nogue, Rull & Vegas-Vilarrubia “Modeling biodiversity loss by global warming on Pantepui, northern south America: projected upward migration and potential habitat loss” Climate Change 94, 2009
21 Rull and Vegas-Vilarrubia “Unexpected biodiversity loss under global warming in the neotropical Guayana Highlands; a preliminary appraisal”. Global change Biology, 12, 2006
221) Terbourgh, “Maintenance of diversity in tropical forests” Biotropica 24, 1992, 2) William F. Laurance, “Theory meets reality, how habitat fragmentation research has transcended island biogeographic theory” Biological Conservation 141, 2008
23Myers and Donnelly “ The Summit Herpetofauna of Auyantepui, Venezuela: Report from the Robert G. Goelet American Museum-Terramar Expedition”. Bulletin of the American Museum of Natural History, No 308 March, 2008.
24Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
25Ochoa J & Gorzula S. “Los Mamiferos del macizo de Chimanta, con algunos comentarios sobre las comunidades de las cumbres tepuyanans” In El Macizo del Chimanta, Escudo de Guayana, Venezuela: Un Ensayo Ecologico Tepuyano. Ed Otto Huber, Caracas 1992. For the detailed summary of sightings, see Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
26Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
27Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
28Mathew E. Gomper and Denise M. Decker, The American Society Of Mammalogists, No 580, June 1998.
29Mathew E. Gomper and Denise M. Decker, The American Society Of Mammalogists, No 580, June 1998.
30Myers and Donnelly “ The Summit Herpetofauna of Auyantepui, Venezuela: Report from the Robert G. Goelet American Museum-Terramar Expedition.” Bulletin of the American Museum of Natural History, No 308 March, 2008.
31McKelvey et al “Using Anecdotal occurrence data for rare or elusive species: the illusion of reality and a call for evidentary standards”. Bioscience, vol 58 # 6 June 2008.
331)V. Rull, T. Vegas -Vilarrubia, S. Nogue, O Huber “Conservation of the unique Neotropical Vacular flora of the Guayana Highlands in the Face of Global Warming” Conservation Biology, Vol 25, no 5 2009 and 2)Robovsky et al, “Additional rsport if the Brown nosed Coati (Nasua nasua vittata) on the tepuis- The Chimanta Massif, Churi Tepui, Venezuela” Lynx (Praha) 38, 115-117 2007.
34Myers and Donnelly, “Herpetofauna of the Yutaje-Corocoro Massif, Venezuela”. Bulletin of the American Museum of Natural History, 261, 1-85 2001.
35Myers and Donnelly “ The Summit Herpetofauna of Auyantepui, Venezuela: Report from the Robert G. Goelet American Museum-Terramar Expedition” Bulletin of the American Museum of Natural History, No 308 March, 2008
37Guiana Shield Initiative, “Recommendation” http://www.guianashield.org/site/en/psw-workshop
38Myers and Donnelly “ The Summit Herpetofauna of Auyantepui, Venezuela: Report from the Robert G. Goelet American Museum-Terramar Expedition”. Bulletin of the American Museum of Natural History, No 308 March, 2008.
39This matter will be addressed in a latter blog posting. For relevance and evidential standards of new species or species in expanded ranges, see 1)McKelvey et al “Using Anecdotal occurrence data for rare or elusive species: the illusion of reality and a call for evidentary standards”. Bioscience, vol 58 # 6 June 2008. 2) Roberts et al “Identifying anomalous reports of putatively extinct species and Why it matters” Conservation Biology, vol 24, # 1 2009.
40Rull et all, “Conservation of the unique neotropical vascular flora of the Guayana Highlands in the face of global warming” Conservation Biology, vol 23 # 5 2009
41 Guiana Shield Initiative, “Recommendation” http://www.guianashield.org/site/en/psw-workshop
42“Checklist of the Terrestrial Vertebrates of the Guiana Shield”. Bulletin of the Biological Society of Wahsington. # 13, 2005. Hollowell and Reynolds, ed. Specifically, Teresa C.S. De Avila Pires refers to the species accumulation graph of reptile discoveries over time ( 1748 to 1998) “clearly shows a an ascendant curve”. page 36.
43Mountain lions and tapirs sightings were documented in National Geographic May 1989 article “Tepuis; Venezuela's Island in Time” by Uwe George. Other unknown animals were sighted around the same time as the National Geographic article. These are documented in GEO 1990 “Die Suche nach dem Ungeheuer” by Uwe George. Possible alternative identities for the unusual animals sighted includes wayward torrent ducks, and long necked otters.