Bells are most needed for what primary purpose?

Bells serve multiple important purposes in the context of falconry, directly contributing to the effective management of the hawk during different scenarios. The primary purpose of bells is to keep track of the hawk, particularly when it is out of sight in trees or the sky. Since hawks can fly high and become difficult to visually monitor, the audible sound of the bells helps the falconer locate their bird without the need to focus intensely on it.

Additionally, when the hawk is on a perch, bells can signal its position, making it easier for the falconer to understand where the bird is situated. This can be especially important when managing multiple hawks or when in a crowded area.

Furthermore, when the hawk is down with quarry, bells can serve to alert the falconer to its location, ensuring that the handler knows where to approach and can assist or retrieve the hawk effectively.

Given that bells play a crucial role in all these situations — when the hawk is perched, when it's out hunting, and when it has captured its prey — it is accurate to state that they are most needed for the collective benefit they provide in each of these scenarios. Thus, selecting all of the above as the answer encapsulates