animal behavior

Animal BehaviorBy:saif BS zology

• Behavior is what an animal does and how it does it.

What is Behavior?

• Animal behavior asks what, why, and how.

• Animal behavior is also referred to as ethology.

– Scientists who study animal behavior are called ethologists.

• Animal behavior is centered around the ability to move.– Animals seek

food, water, shelter.

– Animals play with each other.

– Animals seek mates.

Introduction

Introduction • Why do animals do what they

do?– Why do birds sing?

– How do sea turtles navigate the ocean to lay their eggs on the same beach where they were hatched?

– How do honeybees know when the hive needs more food?

Image from http://www.nps.gov

Image from http://www.scottcamazine.com

Introduction• Behavior results as a reaction

to a stimulus.– A stimulus is a detectable

change in the animal’s internal or external environment.

– Hunger.– Sound.– Pain.– Visual cues(stimulus).– Hormonal changes.

Image from http://www3.nau.edu/biology/

Introduction• Ethologists do not attempt to describe WHY

an animal does a behavior before describing WHAT the animal is doing.– This removes as much bias as possible – good

scientists don’t want to just “see what they want to see”.

– Need to make objective observations of animal behaviors, analyze the data statistically, then come to conclusions about WHY an animal behaves a certain way.

Introduction

• For example, you see two cubs interacting with each other, rolling and hopping around, running to and from each other.– As a behavioral ecologist, you would first state

the behavior you are observing. – Once you made the observations about WHAT

was happening, you could begin to determine WHY they are behaving that way.

Introduction

• The behavior you observed could have been many different things.– Play.

– Mating rituals.

– Aggression, defending territory.

How to determine WHY – action patterns.

• Action patterns are complex behaviors that are always repeated the same way by a species of animal.– We say that action patterns are stereotyped, since

they occur the same way each time, and through to completion.

– After repeatedly observing action patterns, an ethologist can analyze the data statistically.

– (Statistics is the study of the collection, organization, analysis, interpretation and presentation of data)

– Only then do we attempt to determine WHY a behavior is being done.

– Fixed Action Patterns (FAP) are INNATE

http://en.wikipedia.org/wiki/Data

Niko Tinbergen(Dutch)

• Niko Tibergen(noble prize

holder) was a pioneer(first

to do something) in the field of ethology and ornithology.– He observed animals in

their natural conditions, then manipulated(handle

something), or varied the conditions to see how the animals responded.Image from http://nobelprize.org/

Niko Tinbergen

• Tinbergen observed how a wasp called the beewolf finds its nest among other beewolf nests.– He observed that the beewolf would

circle its nest in an ever-widening circle before flying away to hunt.

– This behavior was an action pattern – it was performed exactly the same way each time.

Image from http://www.sciencenews.org

Niko Tinbergen

• After the beewolf flew off, Tinbergen would move certain landmarks around the nests.

• When the beewolf returned, it was disoriented.– So, by manipulating the beewolf’s

environment, Tinbergen came to the conclusion that the beewolf commits landmarks to memory to be able to find its nest when it comes back from hunting!

Image from http://www.earthlife.org

Niko Tinbergen

• Tinbergen had to describe and investigate WHAT the organism was doing before attempting to explain WHY.

More on Action Patterns

• The egg-rolling behavior of the greylag goose is a good example of an action pattern.

• Niko Tibergen and another pioneer in ethology, Konrad Lorentz, originally observed this behavior.

Image from http://www.grayimages.co.uk

More on Action Patterns• The goose will roll an egg that

is outside the nest back into the nest in the same manner every time.– Interestingly, the goose will do

this with any round object placed outside the nest!

– Every time this action pattern is initiated, it is carried through to completion.

Proximate vs. Ultimate Causes

• The question of “WHY” can have different answers.• Proximate causes are related to internal changes in the

animal.– Hormones.– Messages from the nervous system.

• “Proximate” means close.

• Ultimate causes are related to the survival and reproductive success of the animal.

• “Ultimate” means furthest, or utmost.

Proximate vs. Ultimate Causes• An example incorporating both

proximate and ultimate causes: Belding’s ground squirrels.– When males reach about two months

old, they leave the burrow where they were born.

• It is an increase in testosterone, or a hormonal change that triggers this behavior.

• So, the proximate cause of the nest-leaving behavior involves the increase in testosterone levels in the squirrel.

Proximate vs. Ultimate Causes• There is more to the story than just hormones!

– When males leave the nest, they avoid inbreeding with sisters or cousins, etc.

– Their offspring are therefore healthier.– The male offspring inherit the same genetic

information that induces them to leave their nests at a young age.

– So, this behavior is passed on genetically, and it makes for a healthier population of squirrels.

– Avoiding inbreeding is therefore the ultimate cause of this “early nest-leaving” behavior.

Ecology:Interaction between organisms and the biotic and

abiotic environment• Abiotic- non living; e.g., temperature, light,

dissolved gas, water• Biotic- living; e.g., predators, prey, mates

Behavioral EcologyThe study of the behavior of organisms within an

evolutionary framework.• e.g., communication, finding food,

protection from predators

Mechanistic basis for behavior:A. Identify the stimuli that triggers the behavior or B. Study the psychological, neuronal, and

hormonal changes that underlie the behaviorE.g., MIGRATION

Hawaii

Distribution & Migration Map of Pacific Golden Plover

Proximate causes

• External stimuli- changes in day length and temp

• Internal stimuli - hormone levels

Winter plumage Breeding plumage

Ultimate causes - address the evolutionary significance for a behavior and why natural selection favors this behavior.

• Why did a behavior evolve?

• Is it adaptive?

• Does it contribute to reproductive success?

Example: birds that migrate have a selective advantage over birds that don't/didn't, selected for over time, could be due to long term climate changes, glaciation, disease, taking advantage of food sources, etc.

Nature versus Nurture:Revisiting an Old DebateNature

Behaviors are: • Innate • Hard-wired • Instinctual • Genetically

determined

Nurture

Behaviors are: • Learned • Flexible • Not genetically

determined

Behavior results from both genes and environmental factors

A. Behavior - What an animal does and how it does it.- some behavior is learned, some behavior is

inherited

B. To some extent ALL behavior has a Genetic Basis

1. some is totally genetic - which implies heritable2. some is learned but relies ENTIRELY on

genetically based mechanisms

C. In general, behavior is a response to some environmental stimulus

Innate Behaviors – inherited, instinctiveA. programmed by genes; B. highly stereotyped (similar each time in many individuals)C. Four Categories

1. Kinesis2. Taxis3. Reflex4. Fixed Action Pattern

1. Kinesis: "change the speed of random movement in response to environmental stimulus“

2. Taxis: "a directed movement toward or away from a stimulus; positive and negative taxes

3. Reflex: "movement of a body part in response to stimulus".

4. Fixed Action Pattern (FAP): "stereotyped and often complex series of movements, responses to a specific stimulus", hardwired, however, not purely genetic, may improve with experiencea. programmed response to a stimulusb. stimulus of FAP = "releaser", sometimes called "sign

stimulus“c. examples:

- courtship behavior- rhythms - daily (circadian); annual

(circannual)

D. Characteristics of Innate Behaviors - especially FAPs:

1. The behavior is performed correctly the 1st time without prior experience (no opportunity to learn)

2. Triggered by some external stimulus 3. Once started, run to completion with no

further input4. Breeding crosses produce hybrid behaviors

• Ethology is the study of how animals behave in their natural habitat.

– Karl von Frisch: bee communication

– Niko Tinbergen: herring gull experiment; digger wasps

– Konrad Lorenz: imprint in geese

Classical ethology presaged an evolutionary approach to

behavioral biology

Karl Von Frisch- communication in bees

Herring gull experiment by Niko Tinbergen

Releaser Stimuli- stimuli that release FAPE.g., Chick and red dot on gull parents beak triggers feeding response- parent regurgitates food

Laysan albatross feeding chick

Niko Tinbergen

Hypothesis: digger wasps use visual landmarks to keep track of her nests

Move pine cones

Visual cue is arrangement pattern rather than objects themselves

Egg rolling behavior in geese is a Fixed Action Pattern

Male three-spined stickleback shows aggression at models with red undersides

Life-like model

• Songbird repertoiresprovide us withexamples.

– Why has naturalselection favoreda multi-songbehavior?

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Fig. 51.5

• It may be advantageous for males attracting females.


Fig. 51.6

• Cost-benefit analysis of foraging behavior.

– Foraging is food-obtaining behavior.• The optimal foraging theory states that natural

selection will benefit animals that maximize their energy intake-to-expenditure ratio.

Height ofDrop (m)

Average NumberOf Drops Required

to Break Shell

Total Flight Height(Number of Drops

Height per Drop)

2 55 110

3 13 39

5 6 30

7 5 35

15 4 60


Fig. 51.7

• The behavior is adaptive - signs that natural selection is at worka. survival may depend on behavior, learning not an option (one chance only)

b. animals with simple NS may not have capacity to learn

- not strictly true, "simple" animals learn

c. social interactions dependent on survival require rigid performance of roles

mating rituals, termite mounds

Learning - Learned Behavior: Five Categories

A. Imprinting

1. a strong association learned during a specific developmental period

a. "sensitive period" or "critical period"b. imprinting of baby geese on mother - Lorenz

baby geese imprint on mother within hours of hatchingwill imprint on any object during that period

2. learning a releaser for an innate FAP

Goose imprinting by Conrad LorenzGeese imprint on the first moving (with sound) object that they see after birthThere is a selection of a specific period of time (critical period) for social attachment and mate recognition in geese (to ensure geese imprint on the same species)

Imprinting in conservation biology:Need to minimize/eliminate human presence while raising California Condors

B. Habituation

1. decline in response to a harmless, repeated stimulus

filter - prevents animal from wasting energy/attention on irrelevant stimuliadaptive

C. Conditioning - laboratory setting

1. classical conditioning animals make associations - Pavlov's dog associates bell with food, begins to salivate, can be extinguished and later followed by recovery (unconditioned stimulus - meat, unconditioned response - salivation, conditioned stimulus - bell, conditioned response - salivation)

a. animal learns to perform an "old" response to a new stimulus

b. Pavlov's dog- place dried meat powder in dog mouth - salivation- associate with bell - salivation to bell

c. Stimulus first, behavior second (but of course there is an expectation of reward second)

2. operant conditioning a. perform behavior to receive reward or avoid punishment

b. Skinner Box - levers, reward - self training elaborate protocolsc. behavior first, reward second (but of course there is a stimulus, if only a thought of reward)

• Operant conditioning.

– This is called trial-and-error learning - an animal learns to associate one of its own behaviors with a reward or a punishment.

D. Trial and Error Learning - nature setting

1. natural operant conditioning2. modify responses to specific stimuli (releasers) - making both more adaptive3. modify releaser to specific FAP - making both more adaptive

Observational learning - social imitation

Octopus opening jar with crab

Trial & Error & Observational Learning

• Play as a behavior has no apparent external goal, but may facilitate social development or practice of certain behaviors and provide exercise.

Practice and exercise may explain the ultimate bases of play

E. Insight, reasoning

1. manipulating concepts in the mind to arrive at adaptive behavior

2. mental trial-and-error

3. internal memory stores are used as additional sensory/information source

All examples of tool-using:

• chickadees/tits and opening milk bottles

• Egyptian Vulture - uses rocks

• Cocos Finch - uses splinters of wood

• North American Gulls, Northwestern Crow - smash clams on sandy beaches

• Cognition is the ability of an animal’s nervous system to perceive, store, process, anduse information gatheredby sensory receptors.

The study of cognition connects nervous system function with behavior

• Migration Behavior.

– Migration is theregular movementof animals overrelatively longdistances.

– Piloting: an animalmoves from onefamiliar landmarkto another until itreaches its destination.

Whale Migration Routes

• Orientation: animals can detect directions and travel in particular paths until reaching destination.– Navigation may use cues including the earth’s

magnetic field, the sun, and the stars.

starlings

Adults who made the trip before

Juv. went W & SW

Normal Migration

Transport adult and juv.

• Social behavior is any kind of interaction between two or more animals, usually of the same species.

Sociobiology places social behavior in an evolutionary context


Orcas chasing Dusky DolphinOrca and Weddell Seal

Social Behavior in VertebratesA. Predator Avoidance Behavior-mimicry- schoolingB. Reproductive Behavior-competition

-territoriality- displaysC. Parental BehaviorD. CommunicationE. Cooperative Behavior-warning alarms

• Sometimescooperation occurs.

Competitive social behaviors often represent contests for resources


Fig. 51.18

• Agonistic behavior is a contest involving threats.– Submissive behavior.– Ritual: the use of symbolic activity.– Generally, no harm is done.


Fig. 51.19

• Reconciliation behavior often happens between conflicting individuals.


Fig. 51.20

• Dominance hierarchies involve a ranking of individuals in a group (a “pecking order”).

– Alpha, beta rankings exist.• The alpha organisms control the behavior of

others.


• Territoriality is behavior where an individual defends a particular area, called the territory.

– Territories are typically used for feeding, mating, and rearing young and are fixed in location.

– Drawbacks are that territoriality uses a great deal of an individual’s energy.• In addition, an individual might be defending a

territory and die or miss a reproductive opportunity.

– Spraying behavior is where an individual marks its territory.

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin CummingsFig. 51.22

• Courtship behavior consists of patterns that lead to copulation and consists of a series of displays and movements by the male or female.

Natural selection favors mating behavior that maximizes the quantity

or quality of mating partners

Vogelkop Bowerbird

Fig. 51.23

• Parental investment refers to the time and resources expended for raising of offspring.– It is generally lower in males

– Females usually invest more time into parenting (fecundity, egg size, care of offspring)

– Females are usually more discriminating in terms of the males with whom they choose to mate.• Females look for more fit males (i.e., better genes),

the ultimate cause of the choice.


• Mating systems differ among species.– Promiscuous: no strong bond pairs between

males and females.

– Monogamous: one male mating with one female.

– Polygamous: an individual of one sex mating with several of the other sex.• Polygyny where a single male mates with many

females.

• Polyandry one female mates with several males.


• Certainty of paternity can influence mating systems and parental care.

– If the male isunsure if offspringare his, parentalinvestment islikely to be lower.

– Exceptions doexist.

Male sea spider cares for eggs

Mimicry

monarch viceroy

Bastian Mimicry- palatable species resembles an unpalatable one

Mullerian- two or more unpalatable species resembles one another

monarch queen

blenny (Aspidontus taeniatus) mimics Hawaiian cleaner wrasse

shortnose wrasse mimics Potter's angel which sports a defensive spine

Mimicry

Schooling Behavior

• Defining animal signals and communication.– A signal is a behavior that causes a change

in the behavior of another animal.

– The transmission of, reception of, and response to signals make up communication.

– Examples include the following:• Displays such as singing, and howling.

• Information can be transmitted in other ways, such as chemical, tactile, electrical.

Social interactions depend on diverse modes of communication


– Pheromones are chemicals released by an individual that bring about mating and other behaviors.• Examples include bees and ants.


Fig. 51.26

• Most social behaviors are selfish, so how do we account for behaviors that help others?– Altruism is defined

as behavior that mightdecrease individual fitness, but increase the fitness of others.

The concept of inclusive fitness can account for most altruistic behavior


Fig. 51.28

Altruism


Fig. 51.29

– Inclusive fitness: How can a naked mole rat enhance its fitness by helping other members of the population?• How is altruistic behavior maintained by

evolution?• If related individuals help each other, they

are in affect helping keep their own genes in the population.

• Inclusive fitness is defined as the affect an individual has on proliferating its own genes by reproducing and helping relatives raise offspring.


– Hamilton’s Rule and kin selection.• William Hamilton proposed a quantitative

measure for predicting when natural selection would favor altruistic acts.

• Hamilton’s rule states that natural selection favors altruistic acts.

Worker bees

• The three key variables are as follows:–B is the benefit to the

recipient–C is the cost to the

altruist– r is the coefficient of

relatedness, which equals the probability that a particular gene present in one individual will also be inherited from a common parent or ancestor in a second individual


Fig. 51.30

–The rule is as follows:

Formally, such genes should increase in frequency when

rB > C

The more closely related two individuals are, the greater the value of altruism.


– Kin selection is the mechanism of inclusive fitness, where individuals help relatives raise young.

– Reciprocal altruism, where an individual aids other unrelated individuals without any benefit, is rare, but sometimes seen in primates (often in humans).

Sociobiology connects evolutionary theory to human culture

Fig. 51.32

animal behavior

Education

introduction behavior

species of animal

niko tinbergen tinbergen

proximate causes

ultimate causes

fixed action patterns

animals internal

proximate means