18. A system of communication that uses meaningful sounds, symbols, or gestures according to specific rules is called

    1. behavior.

    2. language.

    3. competition.

    4. a signature.

19. Because a highway has been constructed through a forest, many of the animals that once lived there have had to move to a different wooded area. Is their move an example of migration? Explain your answer.

20. Identify two ways in which social behavior can benefit an animal.

21. Explain how aggression and territorial behavior are related.

22. What are pheromones? Give an example of how they are used.

23. What is kin selection?

Think Critically

24. Interpret Graphs When temperatures are low and food is scarce, some mammals enter into a state of dormancy. Dormancy is an energy-saving adaptation in which metabolism decreases and, therefore, body temperature declines. The graph below tracks a ground squirrel's body temperature over the course of a year.

    1. Describe the pattern that you observe.

    2. What can you infer about the squirrel's behavior at different times of the year?

       

25. Form a Hypothesis Although the members of many animal species derive benefits from living in social groups, members of other species live alone. What might be some of the advantages of solitary living?



solve the CHAPTER MYSTERY



ELEPHANT CALLER ID?

Elephants can communicate with loud calls. But they can also communicate with vibrations that can travel for several kilometers. They do so by drumming on the ground with their feet and by making low rumbling calls that contain very low frequency sounds called “infrasound.” The air vibrations can travel up to 16 kilometers while the in-ground vibrations can travel up to 32 kilometers.

Elephants detect these vibrations with specialized pads of fat in their feet and receptor cells in their feet and trunks. By standing motionless and pressing their feet and trunks to the ground, the elephants are better able to sense the vibrations. Particular patterns of vibrations can even identify individuals—like caller ID for elephants!

The vibrations can contain greetings, locations of food, and warnings of danger. The elephants at the watering hole had detected a message from another herd of elephants far away: “Warning! Lions!”

1. Compare and Contrast How do vibrations in the ground compare with airborne sounds as a means of long-distance communication?

2. Form a Hypothesis When researchers play back sounds and vibrations from elephant groups living far from Etosha, the elephants in Etosha don't always react. Why might this be the case?

3. Connect to the How do elephants' responses to low-frequency vibrations in their environment affect their survival?

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