today i was on the right time and place and saw them mating :)
Camera Info
Device: Nikon D7100
Lens: VR 150-600mm f/5-6.3G
Focal Length: 600mm
Focus Mode: AF-C
AF-Area Mode: Single
VR: ON
AF Fine Tune: OFF
Exposure
Aperture: f/6.3
Shutter Speed: 1/320s
Exposure Mode: Manual
Exposure Comp.: 0EV
Exposure Tuning:
Metering: Spot
ISO Sensitivity: Auto (ISO 500)