Tepui tinamou and 2016-2017 results


Since August 2016, Biokryptos camera traps have been on the summit of Auyan Tepui in the northern lagoon areas and in Campo Lecho, far to the south of the lagoons along the Laime Trail. Due to a variety of factors occurring in Venezuela, accessing these cameras and re-supplying them has been impossible from February 2016 to the current date. As a result, we have been unable to install new batteries in the cameras, new SD cards, nor check and service the cameras. We have also been unable to send new equipment to Arturo, although we have equipment in country with our board members.

In August, 2017, the decision was made by myself and the board to pull the cameras from their current locations and take them back into Kamarata for service. This represents the largest interruption in our activities in the history of our project Tepui Watch.We now have zero active cameras on the summit.

We recovered the data from the summit traps after we pulled them from the field, and processed them. While the results are mixed, it is important to focus on the success we have had thus far, and one of those is capturing photos of one of the most understudied birds in the world, the Tepui Tinamou. A detailed review of the performance of the camera traps will be the subject of a future blog post, once data analysis has been completed on the recorded images.

What stands out in this case is the number of captures we have of a small bird known as the Tepui Tinamou Crypturellus ptaritepui. Tepui Watch cameras have recorded this bird from Lecho to the Northern Lagoons, and the highest concentration of photos seems to be in the densely forested lagoon area.

Tepui Tinamou, found 2.5 km west of Angel Falls

Crypturellus ptaritepui

The Tepui Tinamou was first described in 1945 by Zimmer and Phelps. It is a medium sized tinamou, first found on Ptari Tepui. Since its formal discovery, this species of tinamou has been found on neighboring tepuis, including Sororopan Tepui and Auyan Tepui. Tentatively, it has been found on Chimanta Tepui, based on a tinamou vocalization recorded there. Its range is assumed to be spread throughout the eastern tepui range. From the available documentation, it seems that the tinamous population on Auyan was documented in Barrowclough et al. 1997, and assessed at being stable. The IUCN upgraded the Tepui Tinamou from vulnerable (VU) to least concern (LC) in 2004, based on a lack of pressure on its population and protected status of its ecosystem.

In terms of the habitat of the Tepui Tinamou, it is restricted to mountain ecosystems on the tepui summits, between 1500 and 1700 meters. It is not recorded from the talus slopes on Auyan, and it is a strict tepui summit endemic, which was verified by Tepui Watch camera traps in Guayaraca and Penon, along the talus. How this distribution effects the genetic diversity of individual populations is unknown, but on smaller tepuis with less summit area I would expect this bird to either be absent or in danger of localized extirpation eventually. It is unknown if there is any gene flow between separate tepui summit populations. On Ptari and Sororopan the topography is less disjunctive, and C. ptaritepui must range across the entire Ptari massif.

On Auyan, this bird is common. It is known to the Pemon as Gallina de la Montana, (mountain chicken) and is considered a normal sight on Auyan. We have recorded images of the tinamou from Campo Lecho to the northern lagoons, and can infer that its population is distributed across the entire tepui summit, some 700 square kilometers. Most of what we know of the Tepui Tinamou is from inference based on the behaviour of other tinamou species spread across South America. No one has ever seen a nest of Crypturellus praritepui, and nor have their eggs been encountered and photographed. We can guess that the color will match that of a related tinamou, so they may range from teal in colour to dark black, or possibly white, with a porcelain like sheen. Based on the breeding behaviour of other tinamou species, the females will lay eggs onto leaf litter on the ground, in tree root bundles, without a complex nest. Males will then incubate the eggs for approximately seventeen days. As the tepui environment is tropical mountain forests with year round precipitation, I would expect that the animals may breed whenever convenient. We have not observed more than one individual tinamou at a time in any single photo, so their gregariousness can not be ascertained.
Tepui Tinamou searching leaf litter

Crypturellus praritepui research agenda

The Tepui Tinamou knowledge gap exemplifies a common problem in the study of tepui fauna: we know its there, but we don't know much about it. Crypturellus praritepui is the least known tinamou in South America. The reason for our knowledge gap is simple: it is expensive and difficult to get to a tepui, and expeditions are severely limited in field time. This is exactly the reason Biokryptos developed Tepui Watch- to get around these problems using minimally invasive camera traps and utilize indigenous knowledge. Here are the research priorities for the Tepui Tinamou according to the Cornell Lab of Ornithology:

"Tepui Tinamou is one of the least known species of tinamou. This species is difficult to see, and much of the small known range of this species is inaccessible; therefore this would be a difficult bird to study. Almost all aspects of its life history are unknown, including the diet and reproductive biology, as well as topics such as age at first breeding, life span and survivorship, dispersal, population regulation, molts, territoriality and population density, and sexual behavior. Further research also is warranted to investigate the geographical range of Tepui Tinamou."

What is not included in this far encompassing list of unknowns is how this animal is distributed across Auyan, how this species will react to vertical climate envelope displacement, nor what its possible predators are.

While the effects of climate change on tinamou species remains unstudied, on Auyan Tepui we can expect climate envelope shifts of between 500 to 700 meters by 2100. If the Tepui tinamou is sensitive to climate change, or is dependent on particular species of vascular plants in its diet, we can expect stress on the population. On tepuis smaller than Auyan, vertical displacement of climate envelopes may render the summits uninhabitable to this species. On the other hand, the species maybe adaptable to lowland environments, as its derived daughter species C. berlepschi and C. cinereus inhabit lowland ecosystems (C.  praritepui is determined to be the basal species of  C. berlepschi and C. cinereus).  Compounding factors and hidden variables plague climate change predictions, including altered weather patterns and ecosystem mixing. At this time, with our limited knowledge of the exact ecological, spatial, and dietary needs of C. praritepui, it is impossible to predict with any precision how climate change will effect this tepui summit endemic. Simply put, it should be assumed that most endemic tepui summit fauna is in danger of extinction over the next one hundred years, based on predicted climate change models and the precautionary principle.

There are numerous predators which consume various species of tinamous across South and Central America. These include opossums, coatis, foxes, tayras, and big cats. Before Tepui Watch verified the presence of medium sized mammals on the summit of Auyan, these species were assumed to be absent from tepui summits. We now know that several species of larger predators are present or reported from the summit of Auyan. It can be assumed from a list of known tinamou predators throughout South America that the tayras, coatis, and weasels present on Auyan may hunt adult and juvenile tinamous, and certainly will consume eggs when presented with the opportunity. In the Ptari Massif and Sororopan Tepui topographic connectivity to surrounding highlands and lowlands is more prevalent, and C. praritepui almost certain faces the same predators. The fact that this has yet to be recorded is probably due to the fact that no one has placed camera traps on Sororopan or the Ptari Massif yet.

Same individual tinamou, active at night

Agenda Setting

The most obvious way to proceed in attaining relevant data regarding C. ptaritepui is to follow the agenda set out by the Cornell Lab of Ornithology. This would require additional equipment: microphones for recording their calls, spotting scopes, and possibly thermal cameras. We would also need a team of trained professionals and sufficient field time to track, observe, and collect samples from this bird. However, as implied earlier in this post, we simply do not have the resources at this time to launch such an expedition.
What Biokryptos is good at, and currently designed for, is getting into under explored and unexplored areas and setting up camera traps. As we continue our project, no doubt we will continue to encounter this bird as we enter new ecosystems on the tepui summit.
We have one additional resource which so far is under utilized: access to dozens of Pemon guides and experts who frequent Auyan Tepui and are familiar with this animal. They may have the knowledge to answer the C. ptaritepui research questions; we simply have to ask them. Therefore, we will design a questionnaire about C. ptaritepui for distribution among our experts as part of Tepui Watch. The questionnaire will be distributed both in printed form and will be available electronically. When we have the answers to our research questions, we will make that information available to the public. Until then, based on the frequency of encounters between the Tepui Tinamou and Biokryptos camera traps, we will simply have to be content having the worlds most extensive and recent library of photos of this unique and mysterious bird.