Animal Movement

Three kinds of movements are commonly found among animals:

1. Kinesis (plural, kineses) is an undirected (without direction) change in speed of an animal’s movement in response to a stimulus. The animal slows down in a favorable environment or speeds up in an unfavorable environment. As a result, the animal remains longer in favorable environments.

• When a log or rock is lifted, animals will suddenly scurry about. These movements are kineses in response to light, touch, air temperature, or other stimuli recognized as unfavorable.

2. Taxis (plural, taxes) is a directed movement in response to a stimulus. Movement is directed either toward or away from the stimulus. Movement toward light is called phototaxis.

• Moths move toward lights at night.

• Sharks move toward food when food odors reach them by diffusion or by bulk flow (ocean currents).

• Female mosquitos find mammals (on which they feed) by moving toward heat.

3. Migration is the long-distance, seasonal movement of animals. It is usually in response to seasonal availability of food or degradation of environmental conditions (they usually occur together).

• Whales, birds, elk, insects, and bats are examples of animals that migrate to warmer climates.