ongoing projects

microbial transmission dynamics in social groups

​​​Tracking bacterial transmission in social groups

To track the transmission of resident microbes between exposed and naive hosts, we collect and isolate bacteria from individuals in situ, label them with fluorescence plasmids, and expose individuals of known behavioral types. This allows us to track horizontal transmission in social groups in the absence of infection-induced sickness behaviors. We have found that transmission is a product of the phenotypes of both interacting individuals, and the phenotypic composition of social groups can have far-reaching consequences for transmission dynamics. Further, interaction network structure appears to be the underlying mechanism explaining horizontal transmission patterns.

Collective behavior and disease susceptibility

Social groups are can be confronted with multiple ecological stressors simultaneously. How, then, can groups optimize their phenotypic composition to cope with multiple challenges like foraging, navigation, and disease? Here, we study the relationship between groups' collective behaviors, like foraging and brood care, and susceptibility to infectious disease. Since many of these outcomes share underlying mechanisms, we aim to test whether groups regulate collective traits to optimize group success while minimizing the costs associated with disease.

One focus of the lab is the degree to which variation among individuals generates group differences in disease prevalence via multiple transmission modes. We study microbial transmission using fluorescence-labeled cuticular bacteria in social spiders and fungal pathogens in acorn ants and fruit flies.

Individual and social determinants of disease risk

Social aggregation of individually marked fruit flies. (inset) Fly infected with  entomopathogenic fungus

For many infectious diseases, individuals vary immensely in their risk of infection and in their severity of disease symptoms. This variability is influenced not only by hosts’ traits, but also that of the conspecifics with whom they interact. Another branch of my research focuses on identifying the degree to which individuals’ infection risk is attributable to their own traits vs. factors of their social environment

          Representative publications:

           Keiser et al. 2018; Behavioral Ecology

           Keiser et al. 2019; Royal Society Open Science