The tropical semi-deciduous forest in Calakmul Biosphere Reserve (CBR) largely consists of low to medium canopy forest with limited fruit production, with pockets of high forest containing large fruiting trees. The limited distribution of high canopy forest. appears to be closely related to the location of Ancient Mayan ruin sites. Over 2,000 years ago the Mayans cultivated large fruiting trees such as Ramon (Brosimium alicastrom) as a food supply and other fruiting trees such as Chicozapote (Manilkra zapota) and Mora (Maclura tintoria) were cultivated for extraction of resins and dyes, but also produce abundant fruit. These cultivated trees were generally planted near water sources and irrigated to enable them to grow as large as possible. Remnants of these forest gardens are still found today adjacent to ruin sites and result in areas of forest with high fruit production containing trees that are notably larger than elsewhere in the forest. There are two species of primate in CBR, Geoffroy’s spider monkey (Ateles geoffroyi) and the black howler monkey (Alouatta pigra). Operation Wallacea monitoring data has indicated that they are not evenly distributed across the reserve and occur in high densities in some areas while being virtually absent from others. The aim of the primate monitoring project is to investigate the relationship between habitat characteristics, water distribution and vicinity to Mayan ruins and the abundance and distribution of primates. Primate abundance data will be collected along a series of forest transects across different locations in the reserve with varying distances from ruin sites using distance sampling (based on visual sightings). The survey transects are distributed across a wide range of forest habitat types and each transect contains a number of 20m x 20m habitat survey plots. In each of these plots, the distance to water and Mayan ruins is recorded, saplings and understory vegetation are measured, and for each tree, the DBH will be measured and the species will be identified. Primate distribution in relation to habitat will be assessed using the same transect data combined with opportunistic sightings of primates along transects. Floristic predictors of primate distribution can then be determined by linking each primate sighting to the nearest habitat plot, providing a corresponding set of habitat variables for each primate record suitable for statistical modelling.
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 mammals 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 demographics 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.