To rescue or not

Today, when I was coming back home from the university, I saw a baby bird (I have no idea which species was it) which was sitting under the stairs near my block of flats. He was squeaking in a way that everybody would be concerned if everything is ok with him. I had no idea what to do, I even thought of taking him with me and give him some food and water but I decided to look for some information on the internet and I found an article which said that really, we shouldn't try to be a hero. It might seem like a baby bird needs our help but the truth is that his mother is definitely near him, looking for some food and if we take her baby with us, well, it's bad. Of course there are some cases in which a bird, a cat or any other animal won't survive without our help, so we should be careful in distinguishing both of this situations.