New dimensions in animal communication: the case for complexity

- Animal communication research must embrace multiple dimensions of complexity.
- New developments help to quantify and conceptualize individual variability in signaling.
- New research on sensory/perceptual/cognitive biases provides insight into signal form.
- Systems theory holds promise for unifying approaches to understanding communication.

Animal communication has multiple dimensions of complexity - signals may be variable over time and space; signals may have multiple components interacting with each other and with the receivers' perceptual and cognitive systems; and signalers and receivers may adjust their behavior with changes in their environment. There is an increasing appreciation that understanding animal communication - especially the diversity of signal form - requires us to examine complexity per se. We review recent methods and conceptual frameworks that address the complexity of communication with a specific focus on new developments in quantifying and explaining signal variation, new advances in understanding receiver psychology, including perceptual and cognitive biases, and new unifying frameworks, such as systems theory, which provide a holistic view of complex communication systems.