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Chapter 35
Behavioral 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
Dorsal fin
Anal fin
Figure 51.2
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 Questions
In 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
(a) A male three-spined stickleback fish shows its red underside.
Figure 51.3a
• When presented with unrealistic models
– As long as some red is present, the attack behavior
occurs
(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.
Figure 51.3b
• Proximate and ultimate causes for the FAP
attack behavior in male stickleback fish
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.
Figure 51.4
ULTIMATE 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.
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
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.
Figure 51.5
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
food
e.g. locate, obtain & consume
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
125
60
40
Average number of drops
30
Total flight height
20
Drop height preferred
by crows
10
0
2
Figure 51.22
3
Height of drop (m)
5
7
Total flight height (number of drops  drop height)
Average number of drops
50
15
100
75
50
25
• In bluegill sunfish
– Prey selection behavior is related to prey density
Small prey at
middle distance
Small prey at
close distance
Large prey at
far distance
Low prey density
Small prey
Medium prey
Large prey
High prey density
14%
33%
33%
33%
35%
50%
Percentage available
Small prey
Medium prey
Large prey
33%
33%
33%
100%
Predicted percentage in diet
Small prey
Medium prey
Large prey
Figure 51.23
32.5%
32.5%
35%
2%
40%
57%
Observed percentage in diet
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