The island of Sulawesi has remarkably high levels of endemism due to its complex tectonic history and geographic barriers from neighboring islands. While there have been assessments of biodiversity in lowland habitats, the many large mountains on the island are mostly unexplored. Given the alarming anthropogenic deforestation and the effects of ongoing climate change on the island, there is an urgency to collect biodiversity data from these previously unexplored elevational gradients.  Of special interest are symbiotic microbial communities, both parasitic and commensal, due to the potential to expand the limited understanding of their relationships with vertebrate hosts. Specifically, these endemic communities provide an opportunity to assess the community dynamics of blood parasites of the order Haemosporida and their relationships with commensal microbes living in the gastrointestinal tract. These commensals, collectively called the gut microbiome, contribute to vital host functions including immune response to pathogens; changes in microbiome structure are indicative of a compromised immune system.  My dissertation research tests this relationship in birds on the islands of Sulawesi.