On arriving at Reifel to help out in the afternoon I learned that there was a little entertainment this morning. Over the centre dyke area the Northern Goshawk was actively engaged with some Northern Harriers.
I made my way out to the centre dyke trail and was unable to locate the Northern Goshawk. The Northern Harriers, however, were actively coming and going to the trail leading the bird blind.
Turns out they were feeding on a drake mallard. The duck was probably killed by the Goshawk and all the fuss noticed earlier was the Harriers harrassing and chasing it away for a free lunch.