Thirty-two year-old Angela Andrea Camargo Sanabria was one of six young scientists to receive a research grant from UNESCO’s Man and the Biosphere Programme in May 2013. A Colombian who is completing her PhD at the National Autonomous University of Mexico, Angela is using her grant to assess over the coming year just how effectively Montes Azules Biosphere Reserve in the State of Chiapas near Guatemala is managing to preserve its populations of large-bodied herbivores.
A biodiversity hotspot, Montes Azules is part of the Mesoamerican Biological Corridor. Stretching over 331 000 ha, it is the largest remnant of tropical rainforest in Mexico and one of the last refuges of the emblematic jaguar.
Why focus your study on Montes Azules Biosphere Reserve?
Montes Azules Biosphere Reserve protects 60% of the Lacandon forest, the largest and most diverse remnant of tropical rainforest in Mexico. The mammalian species found in the forest are historic species that have always lived in this part of Mexico.
In spite of the consensus that Montes Azules is one of the few remaining strongholds in Mexico for terrestrial mammals, in general, and large-bodied herbivores, in particular, no detailed inventory has ever been made of these elusive species. My research will set out to rectify this, at least in the southern part of the biosphere reserve.
Why only the southern part?
The forest is so dense in the central and northern parts of the biosphere reserve that animals are not very accessible, unlike in the southern part. There is quite a lot of documentation about the incursion of people from neighbouring villages into the reserve through the south, so there is quite a lot of interaction between local communities and wildlife. This area will thus be a good vantage point from which to assess the reserve’s effectiveness in protecting its herbivore species.
Rodrigo Medellín published an assessment in Conservation Biology in 1994 that was also restricted to the southern part of the biosphere reserve. The central part has hardly ever been explored, owing to its inaccessibility. According to Medellín, the biosphere reserve is home to about 112 mammal species, a high number that is comparable to parts of the Amazon Basin. Bat species represent more than half of all the mammal species. Others include the white-lipped peccary (Tayassu pecari) and collared peccary (Pecari tajacu), which resemble wild pigs, the Harpy eagle (Harpia harpyja), scarlet macaw (Ara macao), a parrot, the howler monkey (Alouatta palliata), Baird’s tapir (Tapirus bairdii), the jaguar (Panthera onca) and red brocket deer (Mazama temama).
We shall be able to compare our data with those of Medellín and with the data collected by Dirzo and Miranda in 1991, to see how the populations of the larger mammals have changed over the past 20 years. We shall focus on four endangered herbivores: Baird’s tapir, the white-lipped and collared peccaries and the red brocket deer, all of which are important consumers of forest seeds and fruits. Studies using camera trapping in Thailand, South Africa and elsewhere have shown that, by dispersing seeds through their faeces, herbivores help the forest to regenerate itself. In the biosphere reserve, the tapir, peccaries and deer are all threatened by hunting and habitat loss. Their habitat is either being destroyed or fragmented by logging or by the spread of human settlements.
How are you inventorying these elusive species?
We are using camera-trapping, a technique which dates back to the turn of the century. It has since become popular among scientists, as it allows them to record elusive species and study their behaviour from a distance without disturbing the animals. As animals pass in front of the camera, the movement is picked up by a sensor which triggers the camera.
What are your initial findings?
We have just started collecting field data. During July and August 2013, we set camera traps in five tree species known to be popular with tapir, peccary and deer. The cameras are used to record the rate at which seeds are removed from specific trees over a two-week period. We have already obtained amazing photos of different mammal species using the fruits of Brosimum alicastrum, Licania platypus and Pouteria sapota.
We have also set camera traps at 17 randomly selected locations, with a minimum distance between each camera of 0.5 km to maximize our chances of recording different individuals. Every three months over the coming year, we shall be checking the cameras to recover images and change the batteries. We have already caught nine mammal species on camera, including two which are very typical of this forest, the jaguar and red brocket deer (see images).
We have also laid sand beds to record tapir, peccary and deer tracks. This methodology was used by Dirzo and Miranda in 1991 in this same area.
At the end of the project, we shall be able to compare our findings with those of an ongoing project implemented outside the biosphere reserve by the Marques de Comillas municipality.
How do you plan to make your findings known?
We plan to compile a database with photos and estimate the population density of each of the four focal herbivorous species. This information will then be presented to a national scientific meeting in 2015 organized by the Sociedad Cientifica Mexicana de Ecologia. We also plan to write an article for the general public to publicize our findings and raise awareness of the need to preserve healthy mammal populations.
Camera-trapping has been used before in the reserve to study the general mammal population and specific species like the jaguar. We plan to propose a permanent monitoring programme for the biosphere reserve using camera-trapping and to enroll young scientists in this initiative. In fact, a student from the University of Michoacán in San Nicolás de Hidalgo is already devoting her undergraduate thesis to this topic.
Once the project is over, we would also like to continue assessing how disturbances such as small-scale logging, the harvesting of non-timber plant products, or climate change, as well as the way in which these factors interact, affect the capacity of the biosphere reserve to protect functional populations of mammals.
What advantages do you see in the biosphere reserve’s zoning approach?
The management model proposed by biosphere reserves – with core zones that are strictly protected and buffer zones and transition areas where sustainable human activities are permitted – is the most viable model for conserving biodiversity, particularly in tropical countries. In parallel, it offers local communities a dignified existence that is also environmentally friendly. In the tropics, we cannot adopt a hermetic model with a natural park cut off from the surrounding area and off-limits to the local population. On the contrary, we need a model that can adapt to local conditions and propose a dual approach: conservation and the development of sustainable production.
This implies monitoring to enable the biosphere reserve to adjust to changing circumstances. UNESCO ensures continual monitoring via its expert committees and proposes adjustments to the model when the situation demands. UNESCO also fosters research and the exchange of knowledge, both of which form the basis for establishing scientific criteria for the management of biosphere reserves.
Interview by Susan Schneegans and Paula Santos