Picture trying to survive in tropical rainforests in central Africa. For many animals, a habitat like this would be impossible. Yet the gorilla, a mammal up to 1.8 meters tall when standing, thrives there, thanks to features that scientists call adaptations: traits that help a living thing survive in its environment.
Consider long, strong arms: this adaptation help it climb and walk on its knuckles. Equally important is hands with thumbs that can grip, which let it peel stems and hold food. Without these traits, the gorilla would struggle to last a single season.
As a herbivore, the gorilla is an animal that eats only plants; it depends on leaves, stems and fruit. Its behavior matters as much as its body: it lives in a group led by a large adult male called a silverback. Behaviors like this are adaptations too, even though you cannot see them in a photograph.
The next generation faces the same challenges. Young gorillas, called infants, depend on their surroundings and on adult care. An infant rides on its mother's back until it is about three years old.
Perhaps most remarkable of all: gorillas build a fresh nest of leaves to sleep in almost every night. Facts like this remind us that every animal's body tells a story about the place it lives.