Just to elaborate (for clarity’s sake), by standing up and looking directly at the fox, the rabbit is changing the fox’s expected utility calculation. If the rabbit doesn’t see the fox, the fox will have the advantage of surprise and be able to close some of the distance between itself and the rabbit before the rabbit begins to run. This makes the chase less costly to the fox. If the rabbit does see the fox, when the fox begins the attack the rabbit will see it and be able to react immediately, neutralizing any surprise advantage the fox has. So if the fox knows that the rabbit knows that the fox is nearby, the fox may well not attack because of the amount of extra energy it would take to capture the rabbit.
The rabbit standing up and staring at the fox is an effective signal of awareness of the fox because it is difficult to fake (costliness is only one way that a signal can be difficult to fake). The rabbit can stand up and stare in a random direction if it wants to, but the probability of a rabbit doing that and being able to randomly stare directly at the fox is pretty slim. So if the fox sees the rabbit staring at it, then the fox can be pretty certain that the rabbit knows where the fox is at.
Just to elaborate (for clarity’s sake), by standing up and looking directly at the fox, the rabbit is changing the fox’s expected utility calculation. If the rabbit doesn’t see the fox, the fox will have the advantage of surprise and be able to close some of the distance between itself and the rabbit before the rabbit begins to run. This makes the chase less costly to the fox. If the rabbit does see the fox, when the fox begins the attack the rabbit will see it and be able to react immediately, neutralizing any surprise advantage the fox has. So if the fox knows that the rabbit knows that the fox is nearby, the fox may well not attack because of the amount of extra energy it would take to capture the rabbit.
The rabbit standing up and staring at the fox is an effective signal of awareness of the fox because it is difficult to fake (costliness is only one way that a signal can be difficult to fake). The rabbit can stand up and stare in a random direction if it wants to, but the probability of a rabbit doing that and being able to randomly stare directly at the fox is pretty slim. So if the fox sees the rabbit staring at it, then the fox can be pretty certain that the rabbit knows where the fox is at.
Very clear. Thanks.