Social mates dynamically coordinate aggressive behavior to produce strategic territorial defense

Negotiating social dynamics among allies and enemies is a complex problem that often requires individuals to tailor their behavioral approach to a specific situation based on environmental and/or social factors. One way to make these contextual adjustments is by arranging behavioral output into intentional patterns. Yet, few studies explore how behavioral patterns vary across a wide range of contexts, or how allies might interlace their behavior to produce a coordinated response. Here, we investigate the possibility that resident female and male downy woodpeckers guard their breeding territories from conspecific intruders by deploying defensive behavior in context-specific patterns. To study whether this is the case, we use correlation networks to reveal how suites of agonistic behavior are interrelated. We find that residents do organize their defense into definable patterns, with female and male social mates deploying their behaviors non-randomly in a correlated fashion. We then employ spectral clustering analyses to further distill these responses into distinct behavioral motifs. Our results show that this population of woodpeckers adjusts the defensive motifs deployed according to threat context. When we combine this approach with behavioral transition analyses, our results reveal that pair coordination is a common feature of territory defense in this species. However, if simulated intruders are less threatening, residents are more likely to defend solo, where only one bird deploys defensive behaviors. Overall, our study supports the hypothesis that nonhuman animals can pattern their behavior in a strategic and coordinated manner, while demonstrating the power of systems approaches for analyzing multiagent behavioral dynamics.Author summary: Understanding how individuals organize their behavior to accomplish specific goals is an ongoing question in animal behavior. One major challenge centers on measuring and comparing how different behavioral traits relate to each other. This becomes even more difficult when multiple individuals are working together toward a shared goal. Here, we investigate the complex dynamics by which animals organize defensive behaviors to protect territories. We find that social mates show signs of coordinating their activities, especially when it comes to fighting off strong intruders. We also find that population-level patterns of defense vary widely based on the type of challenger, with more threatening intruders triggering more complex defense from territorial residents. Our results demonstrate the unique insights available through a systems-based network approach to studying territoriality. We contribute to an emerging literature focused on using computational approaches to better illuminate the complex ways that animals can work in unison to tackle problems they face in the wild.