You need to remember what they look like and where they were, as you need to find two more on the opposite side(these two are not under the bridge though).
To find the Bronze Giant Chicken,*Must be Marcus,but can have friends around to help you after the small regular chicken appears.Continue reading for more information on this message.* begin Act 1,Chapter 2 and play the game normally until spoiler]you reach the door that starts the cut-scene of Adam Fenix (Marcus's father) telling you he needs help,that he has been captured by the locust, knows how to stop the lambent, and that Sera's dyeing Then turn around and go backwards(walking back to the place you started) until you see a,long,thin pipe, with two big open pipes beside of it on each side(they are under the bridge that was blown up).