Chapter 35Behavioral Adaptations to the Environment

http://kevinspear.com/category/computers/

Animal Behavior Vocabulary

Ethology = study of animal behavior

Behavior = action performed in response

to stimulus

What Is Behavior?• Behavior

– Is what an animal does and how it does it

– Includes muscular and non-muscular activity

Figure 51.2

Dorsal fin

Anal fin

Stimulus = something that elicits a response

External Stimulus = Something outside the animal e.g.

sound, sight, smell, etc, presence of another animal

Internal Stimulus = something inside the animal

e.g. hunger, fatigue, feeling cold, hormones

Proximate and Ultimate Questions• Proximate, or “how,” questions about behavior

– Focus on the environmental stimuli that trigger a behavior as well as internal mechanisms

– Focus on the genetic, physiological, and anatomical mechanisms underlying a behavioral act

• Ultimate, or “why,” questions about behavior

– Addresses the evolutionary significance of a behavior

This explanation of an animal's behavior is based on evolution. It requires that behavioral traits, like physical ones, are genetically heritable, and then explains behavior using an explanation of why this specific behavioral trait was favored by evolutionary mechanisms such as natural selection.

Proximate and Ultimate QuestionsIn philosophy a proximate cause is an event which is closest to, or

immediately responsible for causing, some observed result. This exists in

contrast to a higher-level ultimate cause (or distal cause) which is usually

thought of as the "real" reason something occurred.

Example: Why did the ship sink?

Proximate cause: Because it was holed beneath the waterline, water

entered the hull and the ship became denser than the water which

supported it, so it couldn't stay afloat.

Ultimate cause: Because the ship hit a rock which tore open the hole in the

ship's hull.

In most situations, an ultimate cause may itself be a proximate cause for a

further ultimate cause. Hence we can continue the above example as follows:

Example: Why did the ship hit the rock?

Proximate cause: Because the ship failed to change course to avoid it.

Ultimate cause: Because the ship was under autopilot and the autopilot's

data was inaccurate.

Separating proximate from ultimate causations frequently leads to better

understandings of the events and systems concerned.

Behaviors are categorized as follows:

1. Instinct is behavior that is innate, or inherited. In

mammals, care for offspring by female parents is

innate.

“in most mammals, care for offspring by female parents is innate”

2. Fixed action patterns (FAP) are innate behaviors

that follow a regular, unvarying pattern.

3. Imprinting is an innate program for acquiring a

specific behavior only if an appropriate stimulus is

experienced during a critical period (a limited time

interval during the life of the animal). Once acquired,

the behavior is irreversible.

Fixed Action Patterns• A fixed action pattern (FAP)

– Is a sequence of unlearned, innate behaviors that is unchangeable

– Once initiated, is usually carried to completion

A FAP is triggered by an external

sensory stimulus

Known as a sign stimulus

• In male stickleback fish, the stimulus for attack behavior

– Is the red underside of an intruder

Figure 51.3a

(a) A male three-spined stickleback fish shows its red underside.

• When presented with unrealistic models

– As long as some red is present, the attack behavior occurs

Figure 51.3b

(b) The realistic model at the top, without a red underside, produces no

aggressive response in a male three-spined stickleback fish. The

other models, with red undersides, produce strong responses.

• Proximate and ultimate causes for the FAP attack behavior in male stickleback fish

Figure 51.4ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreases

the chance that eggs laid in his nesting territory will be fertilized by another male.

BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting

territory.

PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus

that releases aggression in a male stickleback.

Imprinting• Imprinting is a type of behavior

– That includes both learning and innate components and is generally irreversible

http://www.familycourtchronicles.com/philosophy/attachment/

• There are proximate and ultimate causes for this type of behavior

Figure 51.5

BEHAVIOR: Young geese follow and imprint on their mother.

PROXIMATE CAUSE: During an early, critical developmental stage, the young

geese observe their mother moving away from them and calling.

ULTIMATE CAUSE: On average, geese that follow and imprint on their mother

receive more care and learn necessary skills, and thus have a greater chance of

surviving than those that do not follow their mother.

4. Associative learning (association) occurs when an animal

recognizes (learns) that two or more events are connected.

A form of associative learning called classical conditioning

occurs when an animal performs a behavior in response to

a substitute stimulus rather than the normal stimulus.

5. Trial-and-error learning (or operant conditioning) is

another form of associative learning.

6. Habituation is a learned behavior that allows the

animal to disregard meaningless stimuli.

7. Observational learning occurs when animals copy the

behavior of another animal without having experienced

any prior positive reinforcement with the behavior.

About half a century ago, a juvenile Japanese macaque

developed sweet-potato washing on the island of Koshima.

The habit spread to the rest of the population. None of these

monkeys is still alive today, but their descendants are still

washing potatoes.

8. Insight occurs when an animal, exposed to a new

situation and without any prior relevant experience,

performs a behavior that generates a desirable outcome.

Wolfgang Köhler

The use of tools to gain access

to food – Problem Space

Types of Behavior

1. Foraging = feeding e.g. locate, obtain & consume

food

2. Parental Care = ensuring survival of young e.g. carrying,

nursing, cuddling, holding young

3. Courtship = attracting a mate

e.g. courtship displays, bright feathers, songs, other

vocalizations, head butting, fighting

4. Reproductive = e.g. mating, giving birth

5. Offensive/Defensive = aggression, submissive behavior,

defense from aggressors e.g. hiding, fighting, escape,

threatening

6. Territorial = protect a resource for exclusive use

e.g. scenting / marking, birdsong, protection of mate /

offspring, space, food or water source

7. Social = work to create alliances, help the group e.g.

grooming, babysitting, defense of musk ox young, play, play

fight

8. Migratory = movement to a more suitable environment

as seasons change e.g. dry vs. rainy seasons, winter vs.

summer range for browsers & birds e.g. salmon upriver to

spawn, artic tern – 1800 m from Arctic to Antarctic, 2x/year

9. Communication = signaling between one animal & another

•Greeting e.g. sniff, hug, kiss “bite”

•Aggression e. g. charge, bite, hit, fight, etc.

•Non-aggression e.g. patting, head butting, stroking

•Grooming (bonding, alliances,keeping clean)

•Group hunt ( e.g. hyenas, lions)

Vocalizations

e.g. bark, growl, snort, howl, hoot, chirp, whinny, alarm sound,

other language

Non-verbal signaling

e.g. body, head, ear, & / or tail position showing teeth, smiling,

looking away, looking directly at, gesturing, thumping, beating

chest, raising hackles or hood, drumming, tail slap, snort,

scenting, pheromones, sign language

10. Curiosity = investigating new stimulus in environment

e.g. approach, sniff, chew, bite, mount

11. Elimination = defecation, urination

12. Resting = apparent inaction e.g. lying down, sitting,

basking, sleeping, loafing

13. Play Purpose = training for life (defense, hunting,

etc)

Cognition = Knowing, including awareness and judgement.

It is difficult to determine if animals are aware of themselves

and their surroundings. The method used, behaviorism, does

not test for cognitive functions.

Behaviorism = A mechanistic approach which describes

behavior in terms of stimulus and response.

Cognitive ethnologists think cognitive ability arises through

natural selection and forms a phylogenetic continuum

stretching into evolutionary history.

Cognitive ethology = A view that sees conscious thinking as

an inherent part of animal behavior.

• Behavioral traits can evolve by natural selection

• Because of the influence of genes on behavior

– Natural selection can result in the evolution of behavioral traits in populations

http://misslorisbiohome.com/we/evolution/thenatsel.html

• Natural selection favors behaviors that increase survival and reproductive success

• The genetic components of behavior

– Evolve through natural selection

• Behavior can affect fitness

– Through its influence on foraging and mate choice

Biston betularia f. typica,

the white-bodied peppered

moth

http://en.labs.wikimedia.org/wiki/Animal_Behavior/Evolution

In 1955, H.B. D. Kettlewell published his study on

pepper moths: Selection Experiments on Industrial

Melanism in the Lepidoptera. Kettlewell hypothesized

that the dotted whitish form of the peppered moth were

more likely to be eaten than the melanic form because

they could be easily detected against the soot covered

trees.

Howlett and Majerus further examined this hypothesis in

their study: The Understanding of Industrial Melanism in the

Peppered Moth, published in 1987. They tested it by pinning

50 of both forms of the peppered moths on pale and dark

tree trunks.

Calculations: Moths in Polluted (dark) Woodland

Dotted Whitish Form: (30/50) x 100 = 60% Melanic Form:

(20/50) x 100 = 40% 60% - 40% = 20%

The Dotted Whitish form is predated on 20% more than the

melanic form in the polluted woodland.

Moths in Non-polluted (pale) Woodland

Dotted Whitish Form: (15/50) x 100 = 30% Melanic Form:

approx. (30/50) x 100 = 60% 60% - 30% = 30%

The Melanic form is predated on 30% more than the dotted

whitish form in the nonpolluted woodland.

Foraging Behavior• Optimal foraging theory

– Views foraging behavior as a compromise between the benefits of nutrition and the costs of obtaining food

The Foraging Paths of the Male Grain Beetle and a Web User

http://www.websiteoptimization.com/speed/tweak/information-foraging/theory.html

Energy Costs and Benefits

• Reto Zach

– Conducted a cost-benefit analysis of feeding behavior in crows

• The crows eat molluscs called whelks

– But must drop them from the air to crack the shells

Zach's first experiment, he selected a collection of

whelks and sorted them according to size (small,

medium, and large). He then dropped these whelks from

various heights until they broke, and recorded how many

drops at each height were required to break each whelk.

A graph of his results is shown below.

http://www-rohan.sdsu.edu/~jmahaffy/courses/f00/math122/lectures/optimization/opt.html

• Zach determined that the optimal flight height in foraging behavior

– Correlated with a fewer number of drops, indicating a trade-off between energy gained (food) and energy expended

Figure 51.22

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50

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Avera

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Average number of drops

Drop height preferred

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Total flight height

Tota

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of dro

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dro

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Height of drop (m)

• In bluegill sunfish– Prey selection behavior is related to prey density

Figure 51.23

Low prey density High prey density

33%33%

33%

32.5%32.5%

35%

2%40%

57%

100%

50%35%

14%

33%33%

33%

Small prey

Medium prey

Large prey

Small prey

Medium prey

Large prey

Small prey

Medium prey

Large prey

Percentage available

Predicted percentage in diet

Observed percentage in diet

Large prey at

far distance

Small prey at

middle distanceSmall prey at

close distance

Social Learning• Social learning

– Forms the roots of culture

• Culture can be defined as a system of information transfer through observation or teaching– That influences the behavior of individuals in a

population

http://folksonomy.co/?permalink=1612

• No other species– Comes close to matching the social learning and cultural

transmission that occurs among humans

Figure 51.38

Evolution and Human Culture

• Human culture

– Is related to evolutionary theory in the distinct discipline of sociobiology

• Human behavior, like that of other species

– Is the result of interactions between genes and environment

• However, our social and cultural institutions

– May provide the only feature in which there is no continuum between humans and other animals

The End