1. In my opinion the most beautiful bird is colibri or humming bird, because it's bright and colourful creature.
2. I think the most intresting bird is penguin because it live in very cold places.
3. Yes, we can, for example, raising money for their protection in some organisation like Greenpeace, I sure it can help. (Слово protection можно поменять на другое, подходящее по смыслу, если вдруг в теме ранее упоминалась конкретная проблема)