Derek Miller 
Hair, Fur, and Spines [PDF ebook] 

How do bears keep warm in the winter? How does a porcupine protect itself from predators? Early readers will learn about adaptations that have developed on animals’ skin to help them regulate temperature and keep safe, as well as how these adaptations change with the seasons and with an animal’s environment. This book introduces beginning readers to some fascinating creatures with unique hair, fur, or spines that help them adapt to the challenges of life in different habitats and climates.