In an upcoming paper in the journal Animal Behaviour titled “Infection impairs problem-solving performance in American crows,” Townsend and co-authors Erik W. Johansson '19, Annie C. Danielson '22, Amelia Boyd '20, Elizabeth Egey '19, and Ryn C. Winner '19 report that American crows infected with Campylobacter, a common food-borne pathogen, did not perform or did not perform as well as uninfected crows on a problem-solving task than uninfected crows. This difference appeared to be due to both a willingness to attempt the task and an ability to solve it: all uninfected birds attempted and succeeded in the task, whereas only about half of the infected birds attempted the task, some of which failed. The paper is currently available online here.
“An unwillingness or inability of sick animals to engage in cognitively challenging tasks could have negative consequences for wild animals, if, for example, their ability to exploit novel resources is impaired,” says Townsend. “The results of this study might seem obvious, but we actually know surprisingly little about how disease affects the cognitive abilities of wild animals.”
This study suggests that weakened cognitive performance could be a subtle, indirect cost of infection that worsens the direct physiological consequences of disease for wild animals. This disease-driven damage could become increasingly important with the accelerated emergence and spread of infectious disease.
Townsend also recently published a book chapter, “Behavior Shapes Infectious Disease Dynamics in Birds,” that reviews the many other ways in which disease can affect the behavior of birds, from sickness behavior and parasite deterrence to mate choice, food preferences, social behavior, and migration patterns. The chapter, co-authored with Professor Dana Hawley from Virginia Tech, is published in Infectious Disease Ecology of Wild Birds (Oxford University Press).