BIOLOGY
CONCEPTS & CONNECTIONS
Fourth Edition
Neil A. Campbell • Jane B. Reece • Lawrence G. Mitchell • Martha R. Taylor
CHAPTER 37
Behavioral Adaptations to the
Environment
Modules 37.8 – 37.12
From PowerPoint® Lectures for Biology: Concepts & Connections
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
ECOLOGICAL ROLES OF BEHAVIOR
37.8 An animal's behavior reflects its evolution
• Behavior is an evolutionary adaptation that
enhances survival and reproductive success
• Behavior evolves as natural selection finetunes an animal to its environment
– The hunting and reproduction behaviors of
jaguars
– Nest location by digger wasps
– Imprinting of goslings
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37.9 Biological rhythms synchronize behavior with
the environment
• Animals exhibit a great variety of rhythmic
behavior patterns
• Circadian rhythms are patterns that are
repeated daily
– Sleep/wake cycles in animals and plants
• Circadian rhythms appear to be timed by an
internal biological clock
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• In the absence of environmental cues, these
rhythms continue
– But they become out of phase with the
environment
Figure 37.9A
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• Long-term isolation has been used to study
human circadian rhythms
• Body rhythms affect our general well-being,
work efficiency, and decision-making ability
Figure 37.9B
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37.10 Animal movement may be oriented to stimuli
or landmarks
• Movement in a directed way enables animals
to
– avoid predators
– migrate to a more favorable environment
– obtain food
– find mates and nest sites
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• A simple type of animal movement is kinesis
– Random movement in response to a stimulus
• Another simple type of animal movement is
taxis
– A more or less automatic movement directed
toward or away from some stimulus
– Examples include rheotaxis, chemotaxis, and
phototaxis
• Some animals use landmarks to find their way
within an area
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37.11 Movement from place to place often depends
on internal maps
• Many animals formulate cognitive maps
– Internal representations of spatial relationships
among objects in their surroundings
• Some animals undertake long-range
migrations
– Examples: whales, birds, monarch butterflies
• Animals navigate using the sun, stars,
landmarks, or Earth's magnetism
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• Migrating gray whales use coastal landmarks to
stay on course
Arctic Ocean
FEEDING
GROUNDS
Siberia
Alaska
NORTH
AMERICA
Pacific
Ocean
Atlantic
Ocean
Baja California
BREEDING GROUNDS
Figure 37.11A
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• The indigo
bunting learns
a star map and
navigates by
fixing on the
North Star
Paper
Ink pad
Funnelshaped
cage
Figure 37.11B
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
37.12 Behavioral ecologists use cost/benefit
analysis in studying feeding behavior
• Animals are generally
selective and efficient
in their food choices
– Some animals, such
as gulls, are feeding
“generalists”
– Other animals, such
as koalas, are feeding
“specialists”
Figure 37.12A, B
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• The mechanism that enables an animal to find
particular foods efficiently is called a search
image
• Natural selection seems to have shaped feeding
behavior to maximize energy gain and minimize
the expenditure of time and energy
– This is the theory of optimal foraging
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• Whenever an animal has food choices, there are
a number of tradeoffs
– A bass can get more usable energy from
minnows, but crayfish are easier to catch
– However, it may take more time to eat a
crayfish because of its tough exoskeleton
Figure 37.12C
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• Jaguars in Belize have many prey options
– Armadillos, only
about 5kg of food for
the jaguar, are
abundant and easy to
catch
– 200 kg tapirs are less
abundant and run
quickly
– In optimal foraging,
the armadillo is the
preferred prey
Figure 37.12D
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• The kangaroo rat selects high-energy foods
(seeds) in a manner that reduces time spent
above the ground, where it is exposed to
predators
Figure 37.12E
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings