Many people enjoy feeding wildlife because it allows them to have closer contact with these animals. Often they think they are helping the animals to survive, they could not be more incorrect. When wild animals begin to depend on humans for food, their foraging skills diminish. When young wild animals learn to depend on humans for food, they become less experienced in foraging and consequently less likely to survive. Furthermore, wild animals that are accustomed to food provided by humans commonly lose their fear of people. Animals that are unafraid of people will approach them for food and are sometimes mistaken for as rabid, or otherwise ill and subsequently killed for the perceived threat. They also become easy targets for people who mean them harm. An instinctive wariness of people is important for a wild animal’s survival.
Colorado Parks & Wildlife also shares many insights on why feeding wild animals is a bad idea: https://cpw.state.co.us/learn/