After a series of editing and alterations, the article detaining the 2012 camera trapping expedition of Auyan Tepui is now available for download from Canid Biology and Conservation. The publication of this article validates the scientific necessity of continuing both this blog and this line of inquiry into the ecology of the Pantepui region. As I have stated before, a tremendous amount of research and analysis is needed in order to determine the sum total biodiversity of the tepuis of Venezuela.
What is needed is a detailed and systematic series of field studies on the summits of the 50 or so individual tepuis which comprise the Pantepui region. The Pantepui suffers from a series of research gaps, depending on the tepui and sector being analyzed. Pertinent and general research gaps in the Pantepui can be summarized as follows:
1) 30% of the Eastern Chain tepuis lack
any herpetological surveys.
2) Surveyed tepuis lack consistent and
long term field studies.
3) Transect surveys are limited or
non-existent on the majority of tepuis.
4) Temporal biases skew tepui
expeditionary research data (all expeditions occur during the dry season,
January-April).
5) Basal altitudinal data for a number
of smaller tepuis are unknown.
6) Reporting of faunal sightings is
minimal; animals sighted outside the target field of study are often omitted.
7) Expeditionary research does not
cover the entire surface area of a tepui summit, and redundant
surveying has occurred in more accessible areas.
8) The biodiversity of the talus slope environment is under-sampled; the ecological interaction between these areas and the summits are poorly understood.
8) The biodiversity of the talus slope environment is under-sampled; the ecological interaction between these areas and the summits are poorly understood.
A variety of factors contributed to
these survey gaps. The primary factor is the remote location of the
tepui plateaus and the difficulty in accessing their summits. Though
tepuis such as Auyan and Roraima have limited trails which allow for
hiking access, exploring the summits by foot takes a
considerable amount of time and resources. The most efficient method
of gaining access to a tepui summits is by helicopter, which
is expensive and has only become possible recently. The expense in
long term tepui survey expeditions translates to limited time on the
summit, and encourages expedition teams to conduct field work in
comparatively easily navigated trails, which have been surveyed in
the past. Areas which are difficult to survey tend to be ignored, as
the discontinuous terrain makes establishing new trails and camps
extremely difficult and inefficient during limited duration surveys.
The Eastern Sector tepuis tend to be the most thoroughly surveyed in
terms of tepui topography and faunal and floral composition, and the
western sector tepuis are in need of detailed topographical and
biotic analysis.
The vascular plant communities of the tepuis are highly endemic, and are in danger of extinction driven by vertical displacement of climate envelopes caused by global climate change. The complex interplay between the plant communities, avifaunal, herpetofaunal, and mammalian species of the tepuis is unknown. Unless systematic long term survey work is conducted, it is possible that these ecosystems will vanish in the next 100 years (Rull 2006, Nogue et al 2009, Vegas-Vilarrubia et al 2012). Strategies for ex situ conservation of the plant diversity (assisted migration, seed banks) have been briefly discussed by various experts, as have in-situ assisted migration (inside the Chimanta Massif). No conservation actions pertaining to these strategies have been implemented thus far, and remain at the discussion phase. Absolutely no plans for integrating the faunal components of the tepui ecosystems have been addressed at all, and complex interactions between fauna and flora (such as seed dispersal) are virtually unknown.
Conducting this effort on Auyan offers a number of advantages.
First and foremost, Auyan is pristine yet accessible, without suffering from the tourist caused degradation which has affected Roraima. Located in Canaima National Park, Auyan Tepui is comparatively assessable for a tepui, and has been the location of numerous expeditions since its initial exploration under the leadership of G.H.H Tate in the late 1930s. As its herpetofauna and avifauna is comparatively well sampled for a tepui, any RBA effort conducted there will have a relatively accurate baseline from which to make comparisons and test field methodologies which can be used on more remote tepui summits. Auyan Tepui contains a microcosm of tepui environments, ranging from rocky terrain to tepui meadows and gallery forests. This makes it ideal for a camera trapping expedition which samples a variety of its summit ecosystems. Finally, Auyan itself is host to a number of research gaps which can be closed with RBA combined with camera trapping, ranging from the presence of lowland invasives, indigenous coatis, and undescribed animals such as the rodent Oecomys phelpsi.
Although Auyan Tepui is world renown for Angel Falls and one of the
largest of the tepuis, it is no exception to the
norm in terms of data gaps and bias. Auyan Tepui
is primarily surveyed in the southern portion of the tepui, which is
the most accessible portion of the massif. The first expedition to
Auyan conducted form 1937 to 1938 surveyed the southern access point
from the base altitude of 450 metres to 2200 metres, and produced
records of 30 species of mammals, none of which have since been
systematically studied or verified on the summit of this tepui. The
first herpetological survey of Auyan took place in 1956, followed by
an expedition in 1958, then 40 years latter in 1994 and 1998.
Herpetological surveys occurred in the 1990s in 14 locations, though
the combined duration was far less than the total field time of the
Phelps expedition. If mammal or avifaunal sightings did occur during
these expeditions, they were not reported. Significant survey gaps on
Auyan Tepui exist in the north and east of the tepui, along densely
forested areas composed of low lying bonnetia trees which compose
slime forests and bogs. The smaller tepuis of the Auyan Massif, Cerro
del Sol and Cerro del Luna, remain for the most part completely
unexplored due to the difficult of making summit, limited surface
area, and the expense and danger of landing a helicopter on their
summits.
In an effort to close some data gaps, I
undertook a review of Tates Mammals of the Guianas, to
determine a base line of mammal species present on the summit of
Auyan Tepui. The results showed a lack of precise elevational notation for mammalian species observed. Subsequent literature
analysis from different sources filled in some gaps in current faunal
distribution, but many issues remain. Small carnivores such as Nasua
nasua vittata have been verified on the summits of Roraima and
the tepuis of the Chimanta Massif (Torno and Churi Tepuis), and
expeditionary work has verified Tates observations of coatis on Auyan. Tamandua tetradactyla has been
verified on the summit in bogs and tepui meadows,
and Cerdocyon thous thous is present on at least the slopes.
Of the other 28 species of mammal recorded, little is known of the
distributions of the disulphide and rodentia and they remain poorly
studied. The status of tepui endemic rodents is not yet resolved, and molecular phylogenetic analysis of tepui species is confined to a few species of amphibians and reptiles. Reports of Tapirs terrestris exist dating back to the initial explorations of Auyan Tepui, as do
sightings of Panthera onca, though these sightings have
not been verified photographically.
Camera trapping Auyan Tepui can be used to close these data gaps and verify earlier faunal sightings if they are conducted in an organized manner. The 2012 camera trapping expedition was a proof of concept conducted in an ad hoc manner which demonstrated that it is possible to produce scientifically relevant results on a tepui summit environment with a low budget expedition. The next study will utilize more camera traps, placed across a broad spectrum of tepui ecosystems. The critical element will be selection of appropriate target areas to maximize species surveillance and detection. The traps should be placed in the following three areas on Auyan: 1)forested talus slopes, 2)accessible human used trails and 3)remote locations on the tepui summit which reflect ecosystem diversity.
 |
| Three images showing different camera trap placements on Auyan Tepui in 2012. The top image is camera trap placement on forested talus slopes, the bottom two show camera trap placement in herbaceous assemblages on the summit. Future efforts will require tripod mounts for areas without suitable trees to attach the traps. |
Talus slope monitoring will create a distribution map of the lowland animals which can range into higher elevation mountain forests with tepui-like floral assemblages. As global warming pushes the climate envelope some 500-700 metres toward the summits, animals photographed on the slopes may become future invasives within the ascending climate envelope. Any seed dispersers (such as Cerdocyon thous or Nasua nasua) photographed on the talus slopes may contribute to the movement of lowland plant species upwards to the summit. Understanding where these animals are spatially and extrapolating their requirements and behaviors can help to produce effective conservation strategies.
Monitoring faunal distribution along human trails and rest sites can be useful in determining if human activity is having an impact on the behavour of tepui mammals. This phenomena is discussed in both Havelkova et al (2006) and Robovsky et al (2007) in regard to the presence of coatis on the tepui summits. Although both authors eventually dismiss the notion of human enticement in tepui coati distribution, the phenomena has been photographically documented in two separate species. Long term trail monitoring will be helpful in determining the impact human activity has on tepui summit fauna.
Camera trapping in the inaccessible locations on Auyan holds the greatest potential for species discovery. The vast majority of Auyan has never been surveyed by scientists due to a variety of factors including expense and the harsh tepui summit environment. Some of these regions have been visited only for short periods of time by expedition teams in the form of temporary camps, raging in operation from 1 to 5 days. During these periods, sightings of large lowland animals have occurred which have never been investigated in detail. Verification of these reports would change our understanding of tepui summit biology, as large mammals are considered absent from the tepui summits. Target areas include the northern portion of Auyan, the Valle Encantado in the west, and gallery forests on the eastern portion of Auyan. Getting to these locations will require the use of a helicopter, or the establishment of new temporary trails during which transect surveys can be conducted.
Camera trapping Auyan Tepui will be a massive undertaking. It will require a multidisciplinary team, working in concert to establish the realities of tepui faunal distribution. Luckily, camera trapping can reduce both the expense of such an endeavor, as well as the human impact on the tepuis. Once a successful survey methodology is established on Auyan, it can be used on the other, more remote tepuis. The data gathered will be invaluable in the coming conservation efforts to preserve tepui ecosystems. The technology is available, affordable, and ecologically sustainable. It is time to implement such a survey.
Resumen en Espanol (con Google translate)
Después de una serie de la edición de y las alteraciones, el artículo deteniendo a la 2012 mil expedición de trampeo del cámara a la cierro Auyan Tepui es ahora disponible para su descarga desde Biología Cánido y Conservación de. El publicación de este artículo valida la necesidad científica de continuar tanto este blog y esta línea de investigación sobre el ecología de la región Pantepui. Los tepuis de Venezuela y la Guayana representan una frontera ecológica y científica, una frontera que se ve amenazada por el cambio climático global y se enfrenta a la amenaza de la extinción antes de que puedan ser plenamente comprendido.
Lo que se necesita es una serie detallada y sistemática de estudios de campo sobre las cumbres de los 50 o así tepuis individuales que comprenden la región Pantepui. El Pantepui sufre de una serie de lagunas en la investigación, en función de la tepui y el sector que se analiza.
Lagunas de investigación pertinentes y generales en la Pantepui se pueden resumir de la siguiente manera:
1) el 30% de los tepuis Cadena Oriental carecen de cualquier encuesta herpetológica.
2) tepuis encuestados carecen de estudios consistentes y de largo plazo sobre el terreno.
3) transectos son limitados o inexistentes en la mayoría de los tepuyes.
4) los sesgos temporales de datos de investigación expedicionarias tepuyes sesgar (todas las expediciones se producen durante la estación seca, de enero a abril).
5) datos de altitud basales para un número de tepuyes más pequeñas son desconocidos.
6) Presentación de informes de avistamientos de fauna es mínima, los animales avistados fuera del ámbito objeto de estudio a menudo se omiten.
7) La investigación expedicionaria no cubre toda la superficie de una cumbre tepui y topografía redundante se ha producido en las zonas más accesibles.
8) La diversidad biológica del medio talud es menor en la muestra, la interacción ecológica entre estas zonas y las cumbres, son poco conocidos.
Para resolver estas lagunas en la investigación, le recomiendo una amplia encuesta cámara trampa del Auyan Tepui como prueba para futuros estudios de los tepuyes. La realización de este esfuerzo en Auyan ofrece una serie de ventajas. En primer lugar, Auyan es prístino y accesible, sin sufrir el turista degradación causada que ha afectado a Roraima. Situado en el Parque Nacional Canaima, Auyan Tepui es relativamente valorable para un tepui, y ha sido escenario de numerosas expediciones desde su exploración inicial bajo la dirección de GHH Tate a finales de 1930. Como sus herpetofauna y avifauna está relativamente bien muestreados para un tepui, cualquier esfuerzo RBA realizado allí tendrá una base relativamente precisa de la que efectuar comparaciones y metodologías de pruebas de campo que se pueden utilizar en más cumbres tepuyes remotas. Auyan Tepui contiene un microcosmos de ambientes tepuyes, que van desde el terreno rocoso de tepuyes prados y bosques de galería. Esto lo hace ideal para una expedición de trampeo fotográfico que las muestras de una variedad de sus ecosistemas cumbre. Por último, la propia Auyan es sede de una serie de lagunas en la investigación que puedan cerrarse con RBA combinado con trampeo fotográfico, que van desde la presencia de especies invasoras de tierras bajas, coatíes indígenas, y los animales no descritas como el roedor Oecomys phelpsi.
Captura la cámara es mínimamente invasiva, reduce los costos de operación de campo y es particularmente útil para la topografía remota y de difícil acceso. Cuando se usa durante un período prolongado de tiempo, la cámara captura sistemática de las zonas de destino puede proporcionar datos suficientes para producir un estudio horizontal. En última instancia, la cámara captura en las cumbres tepui ya ha trabajado, simplemente debe aplicarse a mayor escala, en combinación con estudios de campo horizontales.Cámara atrapando Auyan Tepui se puede utilizar para cerrar las brechas de datos y verificar avistamientos de fauna antes si se realiza de una manera organizada. La cámara captura la expedición de 2012 fue una prueba de concepto realizada de manera ad hoc, que demostró que es posible producir resultados científicamente relevantes en un entorno cumbre tepui con una expedición de bajo presupuesto. El siguiente estudio será utilizar más cámaras trampa, colocados en un amplio espectro de ecosistemas tepuyes. El elemento crítico será la selección de áreas de destino apropiadas para maximizar la vigilancia y la detección de las especies. Las trampas deben colocarse en las siguientes tres áreas en Auyan: 1) las pistas forestales talud, 2) accesibles senderos usados humanos y 3) áreas remotas en la cumbre tepui que reflejan la diversidad del ecosistema. Estas tres ubicaciones de los sitios te ayudarán rastrear las especies invasoras, controlar los cambios causados por el hombre en los tepuis, y podrían ayudar a encontrar especies raras y nuevas.Una vez que una metodología éxito de la encuesta se establece en Auyán, que puede ser utilizado en los otros tepuyes, más remotas. Los datos obtenidos serán de gran valor en los esfuerzos de conservación para preservar los ecosistemas próximos tepuyes. La tecnología está disponible, asequible y ecológicamente sostenible. Es el momento de poner en práctica dicha encuesta.
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