Leo Ohyama, Douglas B. Booher, Joshua R. King
This is a plain language summary of a Functional Ecology research article which can be found here.
Trait-based approaches in ecology focus on quantifying and assessing the traits of an organism. These traits are usually tied to ecological fitness and ecosystem function and can often be a product of the environment affecting the organism or the organism affecting its environment. For example, a trait that is often studied is body size as it often associates strongly with an organism’s physiology, metabolism, trophic position and ecology.
One problem with trait-based approaches is that they are often used at the scale of individual organisms. This leads to problems when assessing organisms that may be social, eusocial or group living, where traits could potentially be measured and evaluated at varying scales. For example, with ants, one could quantify body size as the size of individual workers, individual queen(s), or the total number of individuals within a colony. Given that eusocial organisms like ants or termites make up a large proportion of living biomass on this planet, understanding how to assess and analyze their traits in a more holistic manner is critical to moving the field of trait ecology forward.
In our study we collected trait data spanning different components of ant species from the Florida ant assemblage, one of the best studied assemblages in the world. These data included worker, queen, and colony traits as well as natural history information such as dietary preferences and nesting niches. With these data we assessed several ecologically relevant hypotheses on the expectations of how these different traits as well as their differences amongst each other should vary with one another. For example, we expected and observed that species with larger colony sizes tended to be species with larger size differences between the queen and worker groups (QWD). Higher QWDs can be indicative of a more pronounced division between the reproductive (queen) and labor components (worker) of an ant colony. Therefore, species with more individuals per colony are also likely those that have more morphological specialization between different roles.
Ultimately, we found that emergent traits like QWD not only tie together individual- and colony-scale traits but they also differ based on natural history, where omnivorous ants tend to show much higher QWD relative to arboreal ants. As such, traits like QWD serve as a nexus for other traits from differing scales to associate with.
This study helps extend our understanding of trait ecology and approaches with eusocial organisms and provides the basis for a data-informed step towards a more holistic conceptual framework surrounding ants. We hope that researchers who not only study social insects, but other social organisms, find this to be informative for their own lines of work.
Functional Ecology: Plain Language Summaries 