An idea not touched upon yet is **flying in a group around the target**. 

While flying light can easily bounce off the wings and make the whole idea of focusing the light into the target hard. Standing on the ground to do the same is also just as hard due to threat from predators. 

So my take on it would be: the **back and tail feathers are reflective and this focuses the light onto the target as they circle it**. So, no hovering is involved and all light should, if at the correct angle, focus into the target as they go around it.