I think I understand your question, but you question has so many errors in it that it doesn't really make sense.
After reading the above information, one reason different members of crow populations have a different rate of survival is there is always a chance that that some other variation will also effect some of the crows ability to survive. Another reason is that the vision, muscle strength and size can influence survival.
Nonliving characteristics include the fact that they are not cells, have no cytoplasm or cellular organelles, and carry out no metabolism on their own and therefore must replicate using the host cell's metabolic machinery. Viruses can infect animals, plants, and even other microorganisms.
