Lecture H1 (2024-11-14): Self Defense and Aggression

In this lecture, we discuss fundamentals of self defense from predators. We start with an introduction to mimicry, which allows prey with significant defenses to converge on signals that are easier for larger predators. We also describe prey that do not have significant defenses but can deceptively mimic those organisms that do in order to make themselves appear to be less palatable than they are. This gives us an opportunity to discuss the how mimicry can lead to mimicry complexes embedded in ecological communities. We also discuss other forms of crypsis, including camouflage and hiding, and strategies for providing more time to evade a predator, such as startle behavior and vigilance. We close with an exploration of agonism more broadly and how individuals in agonistic interactions may sometimes choose to fight and other times choose to flee. We use the Hawk–Dove game from game theory to illustrate the balance in such choices and explore a special case of predator–prey oscillations related to a similar negative frequency-dependent selection phenomenon.

Topic highlights:

• mimicry and crypsis
  • Batesian mimicry, Müllerian mimicry, mimicry complexes, camouflage
  • hiding
• startle behavior and vigilance
• agonistic behavior
  • correlated and uncorrelated asymmetries in interactions
• negative frequency-dependent selection
  • evolutionary oscillatory cycles
• Hawk–Dove game
• pure and mixed Nash equilibria in the Hawk–Dove game
• three basic categories of self-defense strategies: avoiding detection, evading capture, and fighting back

Important terms: mimicry, mimic, model, Müllerian mimicry, Batesian mimicry, mimicry complex, aposematism/aposematic signaling, crypsis, camouflage (a form of crypsis), startle behavior, vigilance, agonistic behavior, correlated asymmetries, uncorrelated asymmetries, negative frequency-dependent selection, Hawk–Dove game ("game of chicken"), pure Nash equilibrium, mixed Nash equilibrium, co-evolutionary arms race, three different categories of self-defense strategies