Dynamic changes in display architecture and function across environments revealed by a systems approach to animal communication*

Abstract

Animal communication is often structurally complex and dynamic, with signaler and receiver behavior varying in response to multiple environmental factors. To date, studies assessing signal dynamics have mostly focused on the relationships between select signaling traits and receiver responses in a single environment. We use the wolf spider Schizocosa floridana to explore the relationships between courtship display form and function across two social contexts (female presence vs absence) and two light environments (light vs dark). We use traditional analytical methods to determine predictors of copulation success (i.e., signal function) and examine these predictors in a structural context by overlaying them on signal phenotype networks (Wilkins et al. 2015). This allows us to explore system design principles (degeneracy, redundancy, pluripotentiality), providing insight into hypotheses regarding complex signal evolution. We found that both social context and light environment affect courtship structure, although the predictors of mating success remain similar across light environments, suggesting system degeneracy. Contrastingly, the same display traits may serve different functions across social environments, suggesting pluripotentiality. Ultimately, our network approach uncovers a complexity in display structure and function that is missed by functional analyses alone, highlighting the importance of systems-based methodologies for understanding the dynamic nature of complex signals.

Book review of Prum, R. O. 2018. The evolution of beauty: How Darwin's forgotten theory of mate choice shapes the animal world-and us (2017), Doubleday, 428 pages, ISBN: 9780385537216

“…; Hebets ; Hebets and Papaj ; Rosenthal and Hebets ; Taylor and Ryan ; Rosenthal et al. )—just the opposite of “individualized utilities.” Moreover, many hypotheses explaining the function of multimodal signaling are agnostic with respect to the indicator value of signals and are fully consistent with the notion of arbitrary signals (Hebets and Papaj ). For example, display components that alert a receiver to another component can have no hypothesized “meaning” themselves (see Alerting and attention‐altering; Hebets and Papaj ).…”

Digest: Context matters: The effects of light environment and female presence on the structure of wolf spider courtship displays*

“…In this issue, Rosenthal et al. () apply a framework for considering the relationships between components within a display network and comparing these whole‐network displays across different contexts.…”

“…In this issue, Rosenthal et al. () apply the signal phenotype network to study the courtship display of male wolf spiders across both social and environmental contexts.…”

“…In the dark treatment, the only source of light was the laser vibrometer itself, which the authors indicate would be outside the spiders' perceptual sensitivities (Rosenthal et al. ).…”

“…Classic approaches for assessing multimodal signals have typically studied these behaviors by determining the particular function of a single component and asking whether the same * This article corresponds to Rosenthal behavioral response (the "function" of the signal) can be generated using different signal components (referred to as "redundancy") (Partan and Marler 2005). In this issue, Rosenthal et al (2018) apply a framework for considering the relationships between components within a display network and comparing these whole-network displays across different contexts.…”