This is a picture of Northern Goshawks mating. When the male balances on top of the female, rubbing of cloaca each other, transporting sperm quickly during two or three seconds and the mating is complete. When I took the picture, I could see the female's cloaca very well because she remained her tail up for a short time after finishing the mating, the male moved her side. I guess the male must bent his belly in order to do their cloacal kiss with easy balance.