Ecology, Exam 1, Ch 6: Behavioral Ecology

Front 1

Alarm calls

Back 1

Warn other colony members of a predator’s presence

Increase the probability that the caller will fallprey

Front 2

altruistic

Back 2

showing a disinterested and selfless concern for the well-being of others; unselfish.

Front 3

How can such apparently altruistic behavior evolve?

Back 3

This behavior can evolve simply so that the individual can ensure that their genes are passed on either by their genes or by their relatives genes.

Front 4

How Does Behavior Evolve?

Back 4

Behaviors contribute to fitness

Behaviors that are genetically controlled are subjectto natural selection

Like other traits, each behavior has both a fitnesscost and benefit

Selection favors behaviors for which the benefitsoutweigh the costs

Front 5

Behaviors areresult of?

Back 5

Behaviors are result of genetic make-up, environment,and experience of an individual

Few behaviors are purely genetically fixed or purelythe result of the environment

Behavioral plasticity is itself an adaptation

Front 6

plasticity

Back 6

the adaptability of an organism to changes in its environment or differences between its various habitats.

Front 7

Stimulus-response

Back 7

Stimulus-response: a specificbehavior is elicited by a specific stimulus

Stimulus-response behaviors are highly invariant

Courtship displays in birdsEach action of a male and a female is fixed and elicits a precise response; any variation breaks down the courtship

Front 8

FundamentalMechanisms of Behavior Interaction

Back 8

Stimulus-response & Communication

Front 9

Communication

Back 9

Communication: action byone individual alters the behavior of another

Visual, auditory, olfactory, or tactile signals

Used to convey discrete or graded information.

Alarm calls of chickadees can warn about the presenceof a raptor and communicate potential threat (raptor size)

Front 10

Sexual Selection

Back 10

Sexual dimorphism indicates that different selective forces operate on males and females

One sex (typically the female) can constitute an important selective force on the other

Selects for what is good for a female and the environment

Front 11

Sex-dependentReproductive Physiology

Females

Back 11

Females

High energetic costs of reproduction (egg laying,incubation, lactation)

Energy is a limitingfactor

Fitness increases as a function of the quality of theprogeny

Front 12

Sex-dependent Reproductive Physiology

Males

Back 12

Males

Low energetic cost of reproduction (sperm is cheap)

Females are alimiting factor

Fitness increases with the number of femalesinseminated

Bateman’s principle: malesexperience greater variation in reproductive success than females.

Front 13

Why do males experience greater variation in reproductive success than females.

Back 13

Males are able to reproduce with multiple mates using low amount of energy in comparison to females. There main goal is to pass on their genes whether regardless of how 'bad' their genes are for the environment. Not very picky.

Front 14

Sexual& Natural Selection

Balance hypothesis

Back 14

Balance hypothesis

Male traits are exaggerated by female choice untiltheir overall fitness cost is too high

Example of the evolutionary trade-off

Front 15

Sexual & Natural Selection

Good genes hypothesis

Back 15

Good genes hypothesis

Elaborate or exaggerated phenotypic traits of malesare an indicator of overall fitness

Help females choose a superior male, therebyincreasing the quality of the progeny

Front 16

FactorsInfluencing Mating Systems

Back 16

The mating system is a set of relationships betweenmales & females during reproduction

Number of mates during the breeding season

Contribution of males & females to parental care How long relationship between mates lasts

Front 17

Typesof Mating Systems

Back 17

1. Monogamy: 1 male w/ 1female

2. Polygamy: 1 sex more than 1 mate

a. Polygyny: 1 male more than 1 female

(Most common of polygamy in vertebrates )

b. Polyandry: 1 female more than 1 male

(Very Rare: mostly in shorebirds)

Front 18

Monogamy

Back 18

1. Monogamy: 1 male w/ 1 female

Front 19

Polygamy

Back 19

2. Polygamy: 1 sex more than 1 mate

a. Polygyny: 1 male more than 1 female

(Most common of polygamy in vertebrates )

b. Polyandry: 1 female more than 1 male

(Very Rare: mostly in shorebirds)

Front 20

Polygyny

Back 20

a. Polygyny: 1 male more than 1 female

(Most common of polygamy in vertebrates )

Front 21

Polyandry

Back 21

b. Polyandry: 1 female more than 1 male

(Very Rare: mostly in shorebirds)

Front 22

EcologicalDeterminants of Monogamy

Back 22

If successful rearing of the young requires bothparents, monogamy is advantageous for both sexes

If reproduction is highly synchronous w/ seasonalityand resource availability, providing parental care is more advantageous to amale than seeking additional copulations

Front 23

EcologicalDeterminants of Polygyny

Back 23

Spatial distribution of females

The potential for males to ensure access to more thanone female is dependent on the spatial distribution of females

Spatial distribution of critical resources

If critical resources are distributed such that malescan easily defend them, males may obtain a territory that attracts multiplefemales

Front 24

BehavioralDeterminants of Polygyny

Back 24

Lek-matingspecies

Males display together on traditional sites known as leks

Females choose a mate based on the displays

Few males obtain the majority of the copulations

Front 25

EcologicalDeterminants of Polyandry

Back 25

Rarest of the mating systems

Fitness benefits to females

Nuptial gifts: packages ofenergy or nutrient rich resources increase female reproductive success

Reduces the probability of mating w/ a poor qualitymale (e.g., infertile, closely related, or genetically inferior)

Front 26

Nuptial gifts:

Back 26

Nuptial gifts: packages of energy or nutrient rich resources increase female reproductive success

Front 27

HabitatSelection

Back 27

Home range

Territory

Front 28

Home range

Back 28

Home range: portion ofthe habitat used on a regular basis

Front 29

Territory

Back 29

Territory: exclusiveuse and active defense of a portion of the home range

Front 30

Territoriality

Back 30

Territory size is related to sexual selection

A male with a larger territory may attract morefemales

Front 31

Dispersal types

Back 31

Dispersal

Philopatry

Saturationdispersal

Pre-saturationdispersal

Front 32

Dispersal

Back 32

Dispersal: one-way movement of an individual from the natal area. To reduce competition.

Front 33

Philopatry

Back 33

Philopatry: lack ofdispersalEndFragment-->

Front 34

Saturation dispersal

Back 34

Saturation dispersal: occurs toavoid shortage of important resources

Front 35

Pre-saturation dispersal

Back 35

Pre-saturation dispersal: occursbefore resources become sparse

Front 36

Whatare Fitness Benefits of Pre-Saturation Dispersal?

Other than food or space limiting.

Back 36

Resources other than food or space are limiting

Potential mates

Genetic benefits

Avoidance of inbreeding

Front 37

SocialSystems, why have them?

Back 37

Evolutionarily optimized so that group benefitsoutweigh the costs of group-living

Depends on the abundance, distribution and type ofresources

Sociality is common in harsh environments

Front 38

Cooperationin Social Groups

Back 38

Cooperative hunting

Shared care for young

Altruistic behaviors

Division of labor

Front 39

InclusiveFitness

Back 39

Inclusive fitness: relativeability to transfer one’s genes, or copies of them, into the next generation

Fitness is based on either personal reproductivesuccess or that of individuals that carry copies of one’s genes

Front 40

Kin selection

Back 40

Kin selection: evolutionarystrategy that favors the reproductive success of an organism's relatives, evenat a cost to the organism's survival & reproduction

Front 41

InclusiveFitness & Relatedness

Back 41

Relation & coefficient of relationship

Parent-Offspring: 0.5

Full siblings: 0.5

Grandparent-Grandchild: 0.25

Aunt/Uncle; Niece/nephew: 0.25

First Cousins: 0.125

Front 42

Behavioral plasticity

Back 42

Can modify behavior due to enviromental conditions

Front 43

Phenotype Plasticity

Back 43

Can modify physical ability due to environmental conditions

Front 44

Discrete Information

Back 44

One level of significant communication.

Front 45

Graded information

Back 45

Different levels of a signal low to high less significant to more significant.

Front 46

Run-Away-Selection

Back 46

Based on female selection a trait may over exaggerate over time. Females choose elaborate or exaggerated phenotypes because this shows the survival rate/fitness of an individual and has access to the energy to grow the phenotype. So female wants to join the male who has access to the energy. Antlers are an example.