Emperor penguins are specialized birds that eat fish. Emperor penguins have
developed many special characteristics
that help them survive in the ocean
environment. The picture below shows
two emperor penguins swimming in
the ocean.

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems