The herpetofauna of the Yucatan Peninsula is diverse and contains a high percentage of endemic species that have evolved to adapt to the unique forest habitat. Despite this, the herpetofauna of the Calakmul Biosphere Reserve is poorly studied. There is a notable rainfall gradient from the north to the south of the reserve, which significantly affects tree diversity and forest structure. This variation in habitat is likely to have a notable effect on the abundance and distribution of herpetofauna within Calakmul. Moreover, the only source of water in the reserve comes from lakes known as aguadas. Some are permanent, but the majority are temporary that form on low lying ground during rainy season. Due to increasingly longer dry seasons, many of these aguadas are drying up, which is expected to have a catastrophic effect on herpetofauna especially the aquatic and semiaquatic species. Herpetofauna surveys will be conducted at 5 different research locations within the reserve that have notable differences in habitat type. Within each location, herpetofauna will be surveyed using diurnal and nocturnal active searching along transects. Students will also assist with habitat surveys in which tree diversity, tree DBH, understorey vegetation, leaf litter and sapling density are recorded in a selection of 20m x 20m forest plots at each survey location. Research projects could therefore investigate differences in herpetofaunal species assemblages between different sites and in relation to distance from aguadas. These projects could incorporate a wide range of species or could focus on specific groups (e.g. anurans, lizards, snakes). Alternatively, projects could focus on herpetofauna community structure in aguadas of varying sizes and permanence. These projects would involve timed searches of the aguadas for amphibian species combined with trapping surveys for lizards, snakes, turtles and crocodiles.
The Calakmul Biosphere Reserve (CBR) in Mexico is an UNESCO World Heritage Site of Culture and Nature and is part of the largest expanse of neotropical forest north of the Amazon, filled with ancient Mayan ruins and supporting one of the highest biodiversity levels in the world. The CBR is also an extremely important wildlife corridor that is crucial for migrating birds and animals with extensive ranging patterns such as jaguar and Baird’s tapir. Over the last 10 years the reserve has experienced a notable reduction in rainfall. Monitoring data on birds, bats, herpetofauna, butterflies, ungulates, felids
and primates are being used to evaluate the impact of climate change and changing rainfall patterns on the abundance, ranging and diversity of fauna to help determine when and where mitigation should be used to restore water sources. Data are also used to assess the efficacy of a range of sustainable development projects with buffer zone communities designed to minimise forest encroachment. In addition, there are specialist studies on jaguar and their preferred prey, behaviour of spider monkeys and population levels of Morelet’s crocodiles.
In Mexico it is hot and humid. Temperatures rarely drop below mid 20s even at night. It is unlikely to rain much, but you do get occasional heavy showers during the season.
Fitness level required
Medium in the forest, low on the marine site. There are some reasonably long walks through the forest, terrain varies by camp with some being almost completely flat and others more undulating. On the marine site lower levels of fitness are required (although you will likely be very tired at the end of the day after the in-water sessions).
Facilities in the forest are basic (sleeping in tents or hammocks in a camp site), with a mixture of dry and trench toilets. There are freshwater showers but water conservation is particularly important to bear in mind. There are some limited opportunities to buy snacks at some forest camps and there is no phone signal at any of the sites. On the marine site the facilities are a little less rustic – you sleep in bunk beds in dormitories about 10 minutes drive from the beach. There is good phone signal and the site is well supplied with shops.