Did the kingfisher grasp the fish, or spear it as if intending to eat it?

OMC's pond had water in November, so the fish needed to be spawning size when it arrived, in order to explain the offspring currently being caught. That's a lot to ask of a bird the size of a kingfisher?

"Forget pounds and ounces, I'm figuring displacement!"

If we accept that: MBG(+)FGSF(=)HBG(F1)
And we surmise that: BG(>)HBG(F1) while GSF(<)HBG(F1)
Would it hold true that: HBG(F1)(+)AM500(x)q.d.(=)1.5lbGRWT?
PB answer: It depends.