In falconry, what is the significance of the term 'passager'?

The term 'passager' has a specific meaning in falconry, referring to birds that are capable fliers, typically young birds that have not yet completed their first molt. This stage indicates that the bird is in a prime condition for training and hunting, possessing the requisite flight skills but still in its juvenile plumage. The importance of this stage lies in the bird's adaptability and potential for training, making them a popular choice among falconers seeking an effective hunting partner.

In contrast, the other options do not accurately capture the essence of what 'passager' signifies. Young birds in training, trained birds, or mature hawks carry different implications regarding the bird's age, training status, or maturity, which do not align with the specific definition of 'passager' within the falconry context.