Chapter 51

Animal Behavior

Migration

• Animals migrate in response to environmental stimuli, like changes in the day length, precipitation and temperature. The environment also provides cues to navigate.– Some track their position relative to the sun. Even

though the sun’s position changes they use their circadian clock to help them track position.

– Nocturnal animals keep track of position using the North star.

– Pigeons track their positions relative to Earth’s magnetic field.

migration

• Gray whales migrate seasonally between the Bering Sea and the coastal lagoons of Mexico.

• They do this by knowing and remembering elements their environment. Orienting by landmarks is called piloting.

Animal Communication

• Animals mark their territory with chemical signals called pheromones.

• These chemicals can also act as alarm signals.• For example, if a catfish is injured, a substance

is released from its skin that disperses in the water and induces a fright response in other fish.

• Visual signals—waggle dance