I would say that depends on the point you are at in training, you agree Toby?
IME, when establishing the CR, the reward needs to be given quickly. As training progresses, the time delay can increase once there is a level of understanding established with the bird/dog etc. They know they performed the right action because it was marked with the CR and you can take more time to get a reward. The time gap will be dependent on many thing, I doubt raptors have as long of a gap as dogs given their mental processing speeds.