Here's a summer time question. Do parent birds abandon their baby birds if they detect the presence of a human near the nest at any time in the past? This is a fairly common question that has a fairly common misconception. You've likely heard that if you walk up to a nest of baby birds and touch it or linger too long, the mother bird will smell your previous presence and abandon the nest and the birds.
Fortunately for those of us that care about the survival of baby birds, this isn't true. Mother birds take very good care of their offspring. Their sense of smell is not that well developed to flee if they smell a human.
The moral of this story is to not believe everything you hear, but to also not to fear getting too close to a nest of baby birds. Your close presence will not prevent the mother from returning. You should still be careful touching the nest or birds. You don't want to poke them too hard, crack an egg, or knock the nest out of the tree.
For more details, check out this snopes.com entry on this topic.
A Bird in the Hand