If you see such signs, you're too close, back away slowly and quietly. Always keep a low profile. The parent may reject the baby if it smells human odors on its young or in the nest. Never feed or bait wildlife to lure them closer. Many species can be dangerous if surprised, fed, or controlled, not to mention the fact that some species carry deadly diseases such as hanta virus, rabies, or bubonic plague.
Wildlife watching can be an exciting, lifelong pastime.