1. Chapter 32 Lecture Outline Behavioral Ecology
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2. 32.1 Nature versus Nurture: Genetic Influences
Behavior
Any action that can be observed and described
Genes, to a degree, control behavior

3. 32.1 Nature versus Nurture: Genetic Influences
Experiments with Lovebirds, Snakes, and Snails
Lovebird Nesting Behavior
Fischer lovebirds, Agapornis fischeri, cut strips from leaves and carry them to their nest site
Peach-face lovebirds, Agapornis roseicollis, also cut strips but tuck them into their rump feather and carry them that way
Hybrid lovebirds exhibit intermediate behavior. They cut strips and try to tuck them into feathers, but are unsuccessful
These studies support the hypothesis that behavior has a genetic basis

4. Nest Building Behavior in Lovebirds
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a. Fischer lovebird with nesting material in its beak
b. Peach-faced lovebird with nesting material in its rump feathers.
© Joe McDonald, Courtesy Jeff and Wendy Martin, Refuge for Saving the Wildlife, Inc.

5. 32.1 Nature versus Nurture: Genetic Influences
Experiments with Lovebirds, Snakes, and Snails
Garter Snake Experiments
Genetic role in food preference
Inland populations of garter snakes are aquatic and feed in the water on fish and frogs
Coastal populations are terrestrial and feed on slugs
In the laboratory, inland snakes refused slugs, while coastal snakes readily accepted them
Hybrid snakes exhibited intermediate acceptance of slugs as food
This study suggests a genetic basis for feeding preference

6. 32.1 Nature versus Nurture: Genetic Influences
Experiments with Lovebirds, Snakes, and Snails
Garter Snake Experiments
Determined that sensory receptors are specific for prey
Researchers presented baby snakes with slug extract on cotton swabs and then counted the number of tongue flicks
Coastal snakes had a higher number of tongue flicks than inland snakes
Apparently, coastal snakes have many receptors on their tongues for taste and smell of slugs, inland snakes do not
A genetic difference between the two populations results in a physiological difference in nervous systems.

7. Feeding Behavior in Garter Snakes
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inland
coastal 20 15
Inland garter snake does not eat slugs.
Percentage of Snakes 10 5
Coastal garter snake eats slugs.
Tongue Flicks per Minute
(coastal): © John Sullivan/Monica Rua/Ribbitt Photography; (inland): © R. Andrew Odum/Peter Arnold

8. 32.1 Nature versus Nurture: Genetic Influences
Experiments with Lovebirds, Snakes, and Snails
Snail experiments
Show role of endocrine system in behavior
ELH - egg-laying hormone was isolated in Aplysia snails
ELH controls all aspects of egg laying behavior
After mating, snail pulls egg string with mouth, winds it in a loose ball, and attaches it to an object
When given ELH, snail exhibits all behaviors even without mating

9. 32.1 Nature versus Nurture: Genetic Influences
Experiments with Humans
Twin Studies
Look at characteristics of twins raised apart
Many share common preferences in food, activity patterns, and mate selection
Lend support to the hypothesis that at least certain types of behavior are primarily influenced by nature (i.e., genes)

10. 32.2 Nature versus Nurture: Environmental Influences
Environmental influences (nutire) also affect behavior
Fixed Action Patterns (FAP): specific behaviors elicited by a sign stimulus
Learning: A durable change in behavior brought about by experience

11. 32.2 Nature versus Nurture: Environmental Influences
Learning in Birds
Appears to be a FAP but involves learning
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Pecking
accuracy
of newborn
Pecking
accuracy of
two-day old b.
Mean accuracy of pecking model for all chicks tested
100 75
a. Laughing gull adult and chick, Leucophaeus atricilla
Hits (percent) 50 25
Days in Nest c.

12. 32.2 Nature versus Nurture: Environmental Influences
Learning in Birds
Imprinting: a simple form of learning
Young birds follow the first moving object they see
Sensitive period: time during which imprinting may occur
Social interactions between parent and offspring during the sensitive period are important
Young birds are sensitive to parents vocalization even before hatching

13. 32.2 Nature versus Nurture: Environmental Influences
Learning in Birds
Song Learning
White-crowned sparrows: species-specific song with different dialects; experiments show learning plays a role
Birds that heard no songs: sang an undeveloped song as adults
Birds that heard species song: sang in that dialect as long as tape was played during a sensitive period
Birds that had adult tutor: sang the tutor’s song even if a different species and no matter when tutoring began

14. 32.2 Nature versus Nurture: Environmental Influences
Associative Learning
A change in behavior that involves an association between two events
Classical Conditioning
The presentation of two different types of stimuli at the same time causes an animal to form an association between them
Operant Conditioning
A stimulus-response connection is strengthened
Training an animal by rewarding it

15. Classical Conditioning
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saliva at
sight of food
(unconditioned
response)
saliva at
sound of bell only
(conditioned response)
sound of bell
(conditioned
stimulus)
food
(unconditioned
stimulus)
apparatus to
measure saliva

16. 32.3 Animal Communication Communication
An action by a sender that influences the behavior of the receiver
Chemical Communication: Pheromones
Powerful chemical signals passed in low concentration
May be released into the air or used in territory marking
Auditory Communication
Very rapid and can be modified for specific situations

17. Use of a Pheromone (Chemical Communication)

18. Frequency (kilocycles Frequency (kilocycles
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Frequency (kilocycles
per second)
Frequency (kilocycles
per second) 4 4 3 3 2 2 1 1
0.5 Seconds
Eagle
0.5 Seconds
Leopard a. b.
(main): © Arco Images/GmbH/Alamy; (inset): © Fritz Polking/Visuals Unlimited

19. 32.3 Animal Communication Communication Visual Communication
Most used by diurnal species - must be able to be seen
Plumage, courtship “dances”, aggressive displays, firefly flashes
Tactile Communication
Occurs when one individual touches another
Laughing gull chicks peck at the parent’s beak to induce the parent to feed them
Waggle dance of honeybees

20. A Male Baboon Displaying Full Threat

22. Communication Among Bees (Tactile Communication)
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a: © OSF/Animals Animals

23. 32.4 Behaviors that Affect Fitness
Assume that most behavior is subject to natural selection
Much of the behavior we observe must have adaptive value
Territoriality
Defending a portion of the home range
More likely during reproductive time period
Cost – takes energy to sing and fight
Benefits outweigh the cost

25. 32.4 Behaviors that Affect Fitness
Foraging For Food
Animals need to ingest food that will provide more energy than the effort expended acquiring the food
Optimal foraging theory
Animals face trade-off of foraging for food or avoiding predators

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6.0 6 5
4.0 4
Energy Gain (J/s)
Number of Mussels Eaten per Day 3
2.0 2 1 10 20 30 40 50
Length of Mussel (mm)

27. 32.4 Behaviors that Affect Fitness
Reproductive Strategies and Fitness
Usually, primates are polygamous
Males monopolize multiple females
Females invest more in offspring
Adaptive for females to be concerned with good food source – clump around food source
Males are expected to compete with other males for the limited number of receptive females available

29. 32.4 Behaviors that Affect Fitness
Sexual Selection
Form of natural selection that favors features that increase an animal’s chances of mating
Features are adaptive in the sense that they lead to increased fitness
Often results in:
Female choice – limited number of eggs to fertilize
Male competition – fertilize as many eggs as possible

31. 32.4 Behaviors that Affect Fitness
Mating in Humans
Human Males Compete
Women invest more time and energy in a child biologically
Nine month pregnancy and then lactation
Men only need to contribute sperm during sex act
Result: men are more available for reproduction than women
Because more men are available, they must compete
Humans are dimorphic: men are larger and stronger perhaps as a result of past selection by females
Males pay a price. The average life span is seven years less than females

32. 32.4 Behaviors that Affect Fitness
Mating in Humans
Females Choose
In one study, the ability to achieve financial success was found to be the most preferred trait by females
Other studies have shown that facial body symmetry is important
Men Also Have a Choice
Men prefer youthfulness and attractiveness in females, signs that their partner can provide them with children.
By choosing younger women, older men can increase their fitness.

34. 32.4 Behaviors that Affect Fitness
Societies and Fitness
Sociobiologists hypothesize that societies form when living in a society has a greater reproductive benefit than reproductive cost
Group living does have its benefits
Avoid predators, rear offspring, find food
Group living also has its disadvantages
Disputes, illness

35. 32.4 Behaviors that Affect Fitness
Sociobiology and Human Culture
Humans live in organized societies
The culture of a human society involves a wide spectrum of customs
The earliest organized societies may have been the “hunters-gatherers”
A predatory lifestyle likely encouraged the evolution of intelligence and the development of language

36. 32.4 Behaviors that Affect Fitness
Altruisms versus Self-Interest
Self-sacrificing behavior for the good of another member of the society
Kin selection
Close relatives share many of your genes, it may make sense to self-sacrifice to save them
Inclusive fitness
An individual’s personal reproductive success, as well as that of his or her relatives, and thus to an individual’s total genetic contribution to the next generation

37. 32.4 Behaviors that Affect Fitness
Reciprocal Altruism
Minimal short-term reproductive sacrifice made to maximize future reproductive potential
Benefits
Helper contributes to survival of kin
Helper more likely to inherit territory

38. Inclusive Fitness
A meerkat acts as a babysitter
for its siblings.