chapter 8 ecology

Behavioral ecology

The study of social relations and interactions between organisms and their environment mediated by behavior

Sociobiology

The branch of biology that studies social behavior such as dominance, cooperation, and reproduction

Fitness

The number of offspring an individual contributes to future generations

Male vs female gametes

Females produce larger, costly gametes; males produce smaller, less costly gametes

Hermaphrodite

An organism with both male and female reproductive functions

Sexual selection

Differences in reproductive success due to variation in mating success

Intrasexual selection

Competition among individuals of the same sex for mates

Intersexual selection

Choice of mates by individuals of the opposite sex

Why female guppies prefer bright males

Bright coloration signals good genetics and health

Cost of bright coloration

Increased risk of predation

Endler's experiment result

Reduced predation leads to more brightly colored males

Scorpionfly mating strategy

Males offer food or saliva to attract females

Which scorpionfly males are most successful

Those offering larger prey items

Benefit to female scorpionflies

More food leads to increased egg production

Nonrandom mating

Some individuals have a higher chance of reproducing than others

Wild radish mating trait

Cannot self-pollinate due to self-incompatibility

Sociality

Living in groups and cooperating with others

Eusociality

A complex social system with division of labor and reproductive hierarchy

Inclusive fitness

Helping relatives survive and reproduce

Kin selection

Natural selection that favors helping relatives

Cooperative breeding

Individuals help raise offspring that are not their own

Why helpers help in cooperative breeding

Increase inclusive fitness, gain experience, inherit territory

Philopatry

Staying in the area where an organism was born

Why female lions cooperate

They are related (kin selection)

Why male lions form coalitions

To defend and take over prides

Factor affecting male lion success

Coalition size and rank

Eusocial species examples

Leaf-cutter ants and naked mole rats

Eusocial characteristic 1

Division of labor

Eusocial characteristic 2

Reproductive hierarchy

Eusocial characteristic 3

Cooperative care of young

Haplodiploidy

Males are haploid (1 set of chromosomes), females are diploid (2 sets)

Why relatedness matters in eusociality

High relatedness promotes cooperation

Tinbergen's framework

Mechanism, development, evolution, and function of behavior

Why captive-bred animals fail in the wild

Lack of natural survival behaviors

Environmental enrichment

Increasing complexity of captive environments to improve survival skills

Mate choice vs predation trade-off

Traits that increase mating success can increase predation risk

Resource provisioning in mate choice

Females choose males that provide food or resources