The One and Only Ivan
Katherine Applegate
Harper Collins

This would be a great read aloud for Grade 4 students especially when they are studying their science unit about habitats. It address the problem with captive animals without preaching. It was inspired by a true story-my favorite way to learn new things and although this is fiction there are many opportunities for discussion with a class about the issues presented. The emotions in this book are very real and will reach all students. I think my older students would also enjoy this book too especially if they have already read Half Brother by Oppel.