Well, yes, pink eyes can just be caused by birds. Generally speaking, pink eye is also named as conjunctivitis. In daily life, there are many ways which can result in pink eye. For example, viruses, bacteria, allergens can be the most common causes. Also, contact lens use, especially the extended-wear type can lead to it too. On the other hand, according to some experts, a virus that infects birds but that can also cause conjunctivitis in humans if you are exposed to infected birds. And that is why there is much flu in world. For the symptoms, pink eye will just cause redness, watery eyes, and itchy eyes. If you do not take some measures to treat it, it can just develop into serious problems.