Well, Honestly There is no right here, but everything wrong. But then given a situation where you need to choose between saving a human or an animal, whether we like it or not, whether we think or not, we will save the human and kill the animal.
This is the natural instinct in action. When you see a human vs an animal, you see yourself in that human and instantly the animal becomes the one to go. We don't think. Imagine a situation, you have a rifle in your hand and in front of you, there's a man facing a Tiger. You wouldn't spend time thinking whether to shoot the man or Tiger. You would simply shoot the Tiger. That's human instinct and millions of years of gene conditioning. If it's between 2 humans that you need to choose, then there could be some trepidation, but if it's an man vs animal and it's your call to save one, the animal will always get killed. Man is higher than an animal in the food chain and you identify yourself with that person, your survival instincts trigger and you kill the poor animal.
As humans,we think it is right to kill animals. I beg to differ though. But then people like us are always a minority.