The technology is still young clearly, but: 1. Drones don't need to always be flying. Flocks of birds turn up on radar quite a lot and I don't see some early d

The technology is still young clearly, but: 1. Drones don't need to always be flying. Flocks of birds turn up on radar quite a lot and I don't see some early detection system for birds as impossible. 2. The flight paths for migrating birds can be predicted, reducing the need for a high presence in some directions. 3. 15 minutes of flight time is low, with some super big LiPo batteries for high performance drones you're easily getting an hour. The benefit of these large batteries is that they can be charged quickly too (charge rate based on power offered). 4. They are relatively fail safe, if the drones stop functioning you just go back to not having any real support. 5. It's likely that with some additional work, they could work on calculating the conditions that cause flocks of birds to fly towards scary sounding planes. I imagine it to be quite likely that they will only fly from certain directions given wind conditions, etc.