Simulation of movement that potentially maximizes assessment, presence, and defense in territorial animals with varying movement strategies

Abstract

Brown et al. (2011) published a simulation model that could be used as a sub-model for larger simulations (e.g. at the population level) to investigate how individuals may optimize territorial movements while sampling a territory for resources. In their example, a male fish guards a territory against neighbor males while interacting with a mate (the resource), but all individuals employed the same, matching (relative-movement), strategies. We contrast the results of this model with a model that allows individuals to use independent movement strategies. Using mean encounter rate (MER) between individuals, and the coefficient of variation (CV), as metrics, we found that in all but the smallest territories, of all aspects (length-to-width ratios), variant relative-movement strategies are not determinant in maximizing territorial presence (male–neighbor male interactions) or minimizing its variation. Directed movement (low-movement angle strategies) appears to accomplish this, regardless of behavior relative to others. In contrast, in small territories, directed movement does not optimize territorial presence, regardless of territory aspect, and mismatched relative-movement strategies are typically optimal. Social presence (within territory male–female interactions) is more complex. In larger territories, again a general pattern of a low-movement angle strategy was optimal. However, aspects and steps sizes (distances between movement decisions) became influential. Once again, directed movement appears to take on lesser importance in smaller territories. Concerning optimizing relative-movement strategies, matching, or no strategy, is optimal except for small, high aspect, territories. We conclude that a prudent approach in future efforts with the model will be to utilize a “top-down approach” by only removing the complexity involving varying movement strategies from simulations if they are found to be unnecessary for the situation simulated.