The Calakmul Biosphere Reserve has extremely high bird diversity with over 360 bird species, many of which are endemic. Due to the traditional farming methods of the ancient Maya and their direct descendants living in the buffer zone of the reserve, Calakmul contains a large expanse of old growth forest in the core zone and old growth forest and regenerating forests of various ages in the buffer zone. In addition, there is a notable rainfall gradient from the north to the south of the reserve that results in a gradual change in forest structure and tree species composition. Diversity of forest dwelling birds generally decreases with forest disturbance, yet a study from one buffer zone community in Calakmul unexpectedly found that both bird abundance and diversity remained constant across regenerating forests of various ages and old growth forest. As the first Mayan settlers arrived in Calakmul region before the forest appeared (the climate was too dry to support forest until relatively recently), it is possible that the bird population has evolved with the Mayan farming methods and thus the birds have adapted to using all forest types. The abundance and diversity of birds in Calakmul can be monitored using point counts and mist netting at multiple research locations in the reserve. These data will be collected across a range of transects in the reserve that encompass different habitat characteristics. Each transect contains a number of 20m x 20m habitat survey plots that provide detailed information of the forest characteristics in the area. In each of these plots, tree species will be identified, tree DBH, understorey vegetation, canopy openness, and the number of saplings will be measured. Bird data from each transect can then be related to mean habitat characteristics for the transect and comparisons between bird diversity and habitat variables may be investigated.
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.