We will quite often stop at the sight of lions on a kill and one can not ignore the fact that they are quite aggressive during the feeding, not to long ago I had a case where one of the nine month old cubs actually struck at its mother over a peace of skin. This is not something you would often see in other species, so why are lions so aggressive?
Well it comes down the bare basics, food supplies the lion with energy and a chance of survival. So once a animal is caught it has to supply the whole pride with meat, one can imagine that if you have six lions and one impala that this is not possible for the impala is not big enough to supply them all with a descent meal. Then the survival instinct takes over and it comes down the survival of the fittest.
The level of aggression can relate to how hungry the lion is, the hungrier ones would fight harder for a pieces of meat than the ones that had a good meal the last time.
For the male, it is not about sharing, his theory is, it is mine and you will now wait until I am finished. So the male is the only individual that will have the sole right until his appetite is satisfied, if there are more than one male it that pride it will also result in aggressive behavior.
Kapama Main Lodge