Why bats matters: A critical assessment of bat-mediated ecological processes in the Neotropics

New World bats play a significant role in ecosystem functioning and are imperative for maintaining environmental services. Nevertheless, human-caused environmental changes are jeopardizing bat communities, which results in the loss of functional roles provided by them. It is important, therefore, to assess ecological processes performed by bats in the Neotropics to define priorities in further research for better conservation planning. In this systematic review, I identify general trends, advances, bias, and knowledge gaps in bat-mediated ecological processes across Neotropical ecosystems. I have conducted an extensive search on Google Scholar, Scopus, Web of Science, and Bat Eco–Interactions Database resulting in 538 references, of which 185 papers were included in the review. The papers were published in 76 peer-reviewed journals, with the highest peak between 2006-2010. From the six biomes recorded, Moist broadleaf tropical forest was the most researched, contrary to Montane biomes (>2000 m), where few studies have been conducted. Seed dispersal was the process with more studies (44%), followed by pollination (38%), nutrient cycling (10%), and arthropod suppression (8%). Seed dispersal and pollination displayed large bias on specific bat-plant systems (Artibeus-Ficus, Sturnira-Solanum, Carollia-Piper, Pachycereeae tribe-Leptonycteris) and ecoregions (Ithsmian-Atlantic moist forest, Cerrado, Tehuacan Valley matorral), thus being important to explore other bat and plant species as well as other ecosystems. Arthropod suppression and nutrient cycling were largely overlooked despite constituting essential functions in ecosystem resilience; particularly, more research is needed to know cascading effects on plant fitness in different agroforestry systems, but also is key the understanding of how bats can be pivotal mobile links in terrestrial ecosystems and cave environments. I highlight the importance to consider bats with multiple roles and functional trait-based approach to gain a comprehensive understanding of their functionality. Even though functional studies have increased in the last two decades, several aspects of bat roles are still obscured, and is necessary to keep evaluating their ecological and economic importance to provide useful information for major decision-makings in Neotropical ecosystems’ conservation. Bat extirpations are likely to affect their ecological roles, therefore, mitigating major threats of bats are urgently needed to sustain ecosystem integrity in the Neotropics.