Sand dune dwelling gerbils interact with foxes, owls, and horned vipers in an environment in which resource patches renew and deplete daily. There, gerbils face tradeoffs of food and safety and must use the tools of time allocation and vigilance to manage risk. Predators must contend with gerbil behavior and manage fear using the tools of time allocation and daring. For gerbils, this means optimal patch use and optimal vigilance levels in a depleting environment over the course of the night, i.e, their harvest rates in resource patches must balance energetic, predation, and missed opportunity costs throughout the night, and their vigilance levels must balance predator encounter rate, predator lethality, and the effectiveness of vigilance and decline throughout the night as resources deplete. For predator, this means that they must choose their activity to equalize opportunity throughout the night. The consequences of these are that gerbil activity declines throughout the night in lock-step with predator activity and the apprehensiveness of the gerbils. Furthermore, a complete theory the predator-prey foraging game in gerbils needs to account for the following. 1. Foraging decisions of gerbils are responsive to their own state and that of their predators; owls are responsive only to their own state. 2. The state of a gerbil affects it foraging decisions, and it foraging decisions affect its state. This feedback is necessary to understand risk management by gerbils over a lunar cycle. 3. Gerbils enjoy safety in numbers, and gerbils show density-dependent patch use and habitat selection. This creates a 'risk pump' across habitats as gerbils carry safety with them as they alter habitat use. 4. Sight lines affect the quality of vigilance and risk management in response to different predators. Mechanism of species coexistence with GP??? Empirical field behavior from Kotler et al 2002 Numbered List of experimental results a complete theory must include Feedback of state and behavior Full state. Gerbils respond to own state and that of the owls; owls respond only to own Temporal month, night Spatial including risk pump Sight lines Owls and activity