My DD (almost 6) loves Wild Kratts. She's also a big fan of Mythbusters, and some of the Imax movies.
Her favorite book right now is My First Question and Answer Book. There are quite a few animal sections in it, and lots of science. The categories are Space, Planet Earth, Oceans, Weather, Science, Inventions, Human Body, Dinosaurs, Bugs, Reptiles & Amphibians, Birds, Mammals, Ancient Egypt, Ancient Rome, Vikings, Knights & Castles, Pirates and Explorers.
We also buy quite a few of the non-fiction supplement books in the Magic Treehouse series. There are so many that involve animals: Rainforests, Sabertooths and the Ice Age, Dolphins and Sharks, Polar Bears and the Arctic, etc.
If she likes birds, I would recommend the Backyard Bird Song guide.
We also use Magic Schoolbus books as a jumping off point, and then explore topics further with library books.
