text and images by MATT HAMER @entohamer

Cloud forests are some of the most biodiverse ecosystems on the planet, being sites of high endemism that are heavily threatened from human-caused pressures. Cusuco National Park (CNP), located in Honduras, is no exception. The park holds considerable biodiversity and has been designated as one of the 137 irreplaceable protected areas in the world (Le Saout et al., 2013). Cusuco was allocated protection after a sweeping decree issued by the Honduran Government in 1987 that gave all mountainous habitats above 1800 m protection. In reality, however, the park is heavily threatened by illegal logging, deforestation and encroaching agriculture. 

Relatively little is known of the insect biodiversity of CNP, particularly the ant (Formicidae) diversity. Ants are an ecologically dominant group, comprising of species scattered throughout the food web from herbivorous leaf-cutting ants (Fig 1) to the highly predaceous army ants (Fig 2) that consume huge numbers of arthropods and vertebrates on the forest floor. Ants are also fantastic indicators of habitat change because many species are highly sensitive to ecological alterations allowing for the study of fine scale diversity and community patterns throughout an ecosystem (Underwood and Fisher, 2006; Tiede et al., 2017; Lessard, 2019). It is therefore important to document this rich community and the impact of occurring human-associated pressures.

MyrmEcoDex, the ant work group of BINCO, investigates the ant diversity present in CNP using inventories from previous expeditions to the park, alongside museum reference specimens and further sampling in collaboration with Operation Wallacea. Five members, based in Belgium, are currently involved in mounting, identifying, and databasing of the specimens. At this time, the team has prepared 251 specimens on point mounts and identified the majority of these, at least eight of them being new to the park already. These samples originate from opportunistic sampling by MyrmEcoDex volunteers in 2018 and 2019 and are also collected from pitfall samples from by-catch during dung beetle monitoring surveys conducted by Operation Wallacea. 

Ants occupy a variety of habitats throughout CNP and so multiple collecting methods will be needed to sample their biodiversity effectively. A significant number of species occupy the leaf-litter layer between the soil and vegetation – this diversity has previously been explored by the LLAMA project in 2010 (Longino et al., 2014). However, further surveys in areas not sampled by the LLAMA project may reveal new records and potentially new species. Additionally, it will be interesting to document whether ants found during the LLAMA project are recovered during current survey work. Ants also reside above ground where particular species dominate over others; it can be easy to overlook more subtle and secretive species, therefore methods such as bait-trapping together with more extensive pitfall trapping could be used to broaden our knowledge on ant diversity. 

MyrmEcoDex hopes that this initial survey work will galvanise further ant surveys in other remote and threatened parts of the world allowing for the inventories of these ecological important organisms and help to understand and document the impacts of anthropogenic pressures.

References

Lessard, J. P. (2019) ‘Ant community response to disturbance: A global synthesis’, Journal of Animal Ecology, 88(3), pp. 346–349. doi: 10.1111/1365-2656.12958.
Longino, J. T., Branstetter, M. G. and Colwell, R. K. (2014) ‘How ants drop out: Ant abundance on tropical mountains’, PLoS ONE, 9(8). doi: 10.1371/journal.pone.0104030.
Le Saout, S. et al. (2013) ‘Protected areas and effective biodiversity conservation’, Science, 342(6160), pp. 803–805. doi: 10.1126/science.1239268.
Tiede, Y. et al. (2017) ‘Ants as indicators of environmental change and ecosystem processes’, Ecological Indicators. Elsevier Ltd, 83, pp. 527–537. doi: 10.1016/j.ecolind.2017.01.029.
Underwood, E. C. and Fisher, B. L. (2006) ‘The role of ants in conservation monitoring: If, when, and how’, Biological Conservation, 132(2), pp. 166–182. doi: 10.1016/j.biocon.2006.03.022.