2025 Dates

2 weeks: 1 week terrestrial & 1 week marine – 28 July – 10 August 2025
4 weeks: 2 weeks terrestrial & 2 weeks marine – 16 June – 13 July 2025
4 weeks: 3 weeks terrestrial & 1 week marine – 16 June – 13 July 2025
4 weeks: 3 weeks terrestrial & 1 weeks marine – 30 June – 27 July 2025
6 weeks: 3 weeks terrestrial & 3 week marine – 16 June – 27 July 2025
6 weeks: 3 weeks terrestrial & 3 week marine – 30 June – 10 August 2025

For those booking onto the 4 week course beginning on 16 June, please email expeditions@opwall.com to indicate if you would like to do 2 or 3 weeks terrestrial.

Calakmul Biosphere Reserve Forest Site

Research is completed at a series of forest camps across the Calakmul Biosphere Reserve. Arrivals on this programme first complete an introduction to the Ancient Maya and Mayan jungle ecology course alongside practicals in survey techniques. Following this you will be helping teams of field biologists completing standardised surveys on a series of key taxa. These surveys are aimed at assessing the importance of the unique aguada habitats for fauna (aguadas are the only water bodies in the reserve) and understanding the relationship between Ancient Mayan manipulation of the forest and current biodiversity. There are several thousand Ancient Mayan ruin sites in the reserve and the forest adjacent to these areas contains the remnants of 7^th century agroforesty resulting in very high abundance and diversity of fauna. If you stay on site for multiple weeks you can travel to different forest camps to see how the forest changes and to assist with biodiversity surveys.

Key Activities:

• Bats: Mist netting long into the night for bats, where morphometric measurements and measurements relating to body condition and reproductive status of captured bats are taken and species identified. Additional data for insectivorous bats that cannot be caught in mist nets will be collecting using acoustic recorders at mist net locations
• Birds: Mist netting is also conducted early in the morning for birds to capture individuals so that morphological measurements and measurements relating to body condition can be taken and individuals marked for population studies. Student can also help collect bird recordings for development of the Calakmul bird vocalization library
• Large mammal surveys involve recording primate sightings (distance sampling) and terrestrial mammal tracks (patch occupancy sampling) encountered along forest transects during morning surveys accompanied by an afternoon session analysing camera trap data.
• Herpetofauna are surveyed using diurnal and nocturnal visual encounters surveys along line transect. As many herpetofauna aggregate around aguadas (the only water bodies in the forest) diurnal and nocturnal timed searches of for herpetofauna will be conducted at aguada habitats.
• Frugivorous butterflies are surveyed using baited traps in the canopy and understory of different forest types. Forest structure is an essential dataset for the project and you will also assist with carrying out quadrat samples.
• Habitat: Habitat plots will be carried out at set intervals along each survey transect to enable a better understanding of the forest structure and tree species composition across different locations in the reserve and to complement the data collected for all other taxonomic groups.
• Guided tour of the Calakmul archaeological site
• Maya forest ecology lecture series covering: Biodiversity monitoring in the Calakmul Biosphere Reserve, Forests of the Maya and their importance for primates, Aguadas and their importance for herpetofauna, Birds, bats and butterflies as indicators of ecosystem health in the Neotropics, Felids and ungulates of Calakmul, and Conservation Management.

 Marine Site

The marine site is in Akumal, part of the Mexican Caribbean Biosphere Reserve. If you are not already dive trained, you can spend your first week at this centre completing a PADI Open Water dive training course, before moving onto the Caribbean reef ecology course in your next week. This course consists of lectures, morning and afternoon in-water practicals, and trains you in some of the survey techniques used in the marine environment to assess the status of reefs and their associated fish communities. If you are already dive trained or just wanting to snorkel your first week is on the Caribbean reef ecology course and the second would be spent working with different researchers on site. Projects you will join include monitoring of sea turtle abundance, sea turtle grazing of seagrasses and seagrass biomass in Akumal Bay.

Key Activities

• PADI Open Water dive training course: This course involves a combination of theory lessons, confined water dives and Open Water divers to gain an official SCUBA qualification.
• Caribbean marine ecology course: This course consists of lectures and in water practicals either by diving (if a qualified diver) or snorkelling. The lectures cover an introduction to the Akumal and the Mexican Caribbean Biosphere Reserve, marine survey techniques, diversity of coral reefs, threats to coral reefs, mangroves and seagrasses, and the future of coral reefs
• PADI Open Water referral course; For this option, students need to arrive having already completed their theory and pool training components with PADI.
• Seagrass quadrat surveys: 1m quadrats are used to assess the coverage of the three different species of seagrass in Akumal Bay, assess turtle grazing and coverage of epiphytes growing on the seagrasses (indicators of water quality)
• Turtle and tourist abundance transects: a series of belt transects are used to assess the distribution of sea turtles in Akumal Bay in relation to tourists
• Reef monitoring: skills learned during the reef ecology course are used to monitor reef ecosystem health using transect surveys for coral, fish and invertebrates. For this option students need to be dive trained and have completed the Caribbean reef ecology course