Terrestrial invertebrate topics - Operation Wallacea

Terrestrial invertebrate topics

Country codes: HO (Honduras), IN (Indonesia), MA (Madagascar), ME (Mexico), PE (Peru), SA (South Africa)

HO02 Dragonfly distribution in cloud forest rivers over an elevational gradient

A high diversity of dragonflies are found in rivers intersecting the cloud forested mountain top in Cusuco National Park (CNP). Including many endemics and cloud forest specialist, dragonfly communities are diverse assemblages sharing river ecosystems. From cryptic forest damselflies (genus Palaemnema) to powerful flyers (Aeshna williamsonia), this study looks into characterizing ecological niches and generating insights in the elevational distribution of dragonflies in CNP. Larval and adult stadia are collected with standardized surveys. A wide range of ecological data on the river habitat is collected and provides the base for the first ecological dissection of dragonfly communities in these mountains.

 Extended Project Summary

HO03 Dung beetle ecology in the Honduran cloud forest

This topic allows students to work on one of the longest-running large-scale invertebrate ecology research projects in the Neotropics, studying the fantastically diverse dung beetles of Cusuco. The project could focus on how diversity and community structure changes over a complex matrix of elevational and habitat gradients, by adapting our existing sampling programme to set up experimental plots. There may also be the opportunity to investigate aspects of ecological genetics, or to utilise GIS in analysing local biogeography of dung beetles. Projects could involve analysing community data from the sampling programme in relation to the habitat structure measurements, or working with data from multiple teams to assess the role that dung beetles play as an indicator for forest quality or the occurrence of other species. Dung beetles also play a vital role in decomposition in the forest and in seed dispersal and the impact and effectiveness of these roles could be tested using various experimental designs. Alternatively, a project could focus on finding out more about some of the beetle species to assess how far they travel to their food source, via mark and recapture methods, or to study aspects of dung beetle ecology such as diet activity or feeding preferences.

 Extended Project Summary

HO04 Ecology of moths in the tropical cloud forest of Honduras

The moths of Cusuco are among the strangest and most beautiful in the world. This project would take advantage of the network of new high-intensity mercury vapour collecting lamps installed throughout Cusuco National Park to study the incredible diversity of moths attracted to light. Currently, two families (Sphingidae and Saturniidae) are well-studied and identifiable to species in Cusuco, but many others are also attracted to light and their diversity is poorly known. Projects could focus on establishing the diversity of the lesser known families (based on morphology or using DNA barcoding) or on increasing our understanding of the better studied species of Saturniid and Sphingid using mark recapture (for example to assess population size and dispersal, or morphological variation within and between species). There would also be scope to improve our knowledge about the process of light trapping, by studying little-known aspects such as the effects of surrounding habitat structure and the attractive radius of traps. Alternatively, studies could take advantage of collaboration with canopy access experts to undertake light trapping above the forest floor, to assess possible variation in captures and moth diversity over a vertical gradient.

Extended Project Summary

HO05 Aquatic invertebrate communities in tank bromeliads

Several hundred species of aquatic organisms can be found living in the unique habitats of bromeliad pools. This project aims to gain insight into some of the deep ecological mechanisms driving diversity patterns. Building on a detailed study of the aquatic invertebrates in bromeliads carried out over the last seven years, a series of experimental setups will be used to look into metacommunity dynamics and how dispersal affects alpha, beta and gamma diversity of invertebrates. Cusuco National Park has the highest diversity of passive dispersers (invertebrates that need a vector to move between bromeliads) recorded, and the presence of both these and active dispersers allows projects to be developed that study how dispersal strategies affect community assemblages and diversity patterns. In this project students will use small plastic cups as artificial bromeliads strategically placed in the forest to experimentally test hypotheses concerning the impact of factors such as metacommunity size (the number of bromeliads) and patch size (bromeliad size) on the aquatic invertebrate diversity. This can help us to better understand the relationships of tank bromeliads with a wide variety of other organisms.

 Extended Project Summary

ME51 Frugivorous butterfly abundance, diversity and distribution patterns in relation to habitat characteristics of Mayan forest

Frugivorous butteflies from the Charaxinae family are often used as indicators of forest disturbance as their abundance and diversity is directly impacted by changes to the forest environment and the only persist in high numbers in primary forest. However, in Calakmul, these butterflies appear to behave differently. A pilot study indicated that Charaxinae abundance and diversity does not vary in relation to disturbance factors, but does appear to vary considerably across different locations in the forest. This unusual behaviour is likely an artefact of the unique forest in Calakmul created by Ancient Mayan agroforestry. The relationship between forest structure and tree species composition with butterfly community structure will be investigated by placing a series of conical traps in different forest locations. Traps will be made from mosquito netting rolled into a large cylinder with a plastic plate hung from the bottom. The plastic plate will be baited with rotten bananas and other fruit each morning at 10-11am and then checked in the afternoon between 3-4pm. Traps will be hung from suitable trees in different areas of the forest and a 20m x 20m habitat plot (using the previously described methods) will be conducted around each trap in order to record forest structure variables and tree species composition. A total of 10 traps (5 understorey and 5 canopy) will be used in each of the research camps. Each butterfly caught in the trap will be identified to species level and will then be released.

PE58 Tropical butterfly diversity and environmental gradients

The forest of the Pacaya-Samiria Reserve is awash with a diversity of bright and colourful butterflies and moths (Lepidoptera), notably including species of the beautiful blue morpho. Lepidoptera make excellent indicators of environmental change due to their variety of life-history strategies and their rapid life cycles. The Lepidoptera of the Pacaya-Samiria are monitored using baited catch-andrelease traps containing fermenting fruit, sugar water or salt water, each attracting a different suite of species. This allows a number of research questions to be examined. Projects could investigate the niche-partitioning of butterflies and moths according to food source and food availability within forest types; alternatively the diversity and community composition changes along the natural environmental gradients from forest edge to centre could be studied; temporal niche-partitioning between butterflies and moths and whether the response to forest edges differs between day and night is also of interest; additionally, there is an opportunity to study the vertical stratification of the Lepidoptera community between the understorey and the mid-canopy. Permission is not granted to collect specimens, but as a diverse and abundant study group, the Lepidoptera project can be tailored to address any number of environmental questions, whilst also contributing to the long-term climate change data set.

Extended Project Summary