What is the purpose of using a weighted lure line for an American Kestrel?

The purpose of using a weighted lure line for an American Kestrel primarily involves preventing the bird from carrying the lure during flight. When training raptors, it is essential to ensure that they focus on the lure and do not attempt to fly away with it. A weighted lure line provides the necessary resistance to keep the lure grounded, encouraging the bird to return to the handler rather than attempting to carry it off. This technique is critical for developing the bird's ability to associate the lure with a reward, such as food, thus aiding in the training process.

In this context, using a weighted lure line allows trainers to effectively engage the kestrel without the risk of losing the lure in the surrounding environment, ensuring a productive training session. The other options relate to aspects of behavior and training but do not directly address the specific primary function of the weighted lure line.