Social Behavior in Animals

Social Behavior

• Social behavior is any interaction between individuals of the same species
• Continued group interactions include social groups (prolonged aggregations of individuals of the same species) and family groups (related individuals where offspring interact with parents into adulthood)

Social Groups

• Living in a group has advantages and disadvantages
• Example of animals that live in groups are European goldfinches and sharp-shinned hawks

Vigilance

• The amount of head jerks per minute (vigilance) of a bird increases as the size of the bird flock increases
• As flock size increases, birds spend more time looking for predators

Feeding Time

• Handling time decreases as flock size increases
• The flight interval time increases as flock size increases

Cost-Benefit Analysis

• Used to determine if social interactions in a population should evolve
• Interactions are analyzed based on costs to a donor, benefits to a recipient and relatedness (r).

Interactions within Species

• Various interactions are displayed in an interaction matrix. Positive, negative, altruism, cooperation, selfishness and spitefulness are some examples.

Selfishness

• Territoriality: defending resources from other individuals (of the same or other species)

Mate Choice and Mate Competition

• Males defend territories with food 2-5x larger than needed
• Mating success depends on nectar content in territories

Altruism

• Altruism reduces fitness but may evolve through kin selection

Kin Selection

• Inclusive fitness = fitness of an individual plus fitness of relatives
• Kin selection describes an interaction that depends on the cost to the donor, benefits to the recipient and relatedness.
• Relatedness refers to genetic similarity which can be quantified by the coefficient of relationship (r)

Altruism through Kin Selection

• Behaviors are possibly widespread among family groups
• Limited dispersion increases relatedness
• Individuals can sense relatedness through chemical or behavioral cues which may not require prior experience.

Adopting Kin

• Red squirrels defend territories through vocalizations
• Adoption often happens between kin (5 of 2230 litters)

Kin Selection and Cooperative Courtship in Wild Turkeys

• Data is provided from a study investigating Kin Selection and cooperative courtship in wild turkeys.
• Data includes relatedness coefficient of subordinate and dominant male pairings.

Kin Selection and Selfishness

• The mean age (days) at which predatory morphology develops is correlated with the concept of kin selection and selfishness.

Insect Societies

• Eusociality involves multiple adults living together, and cooperation in nest building and brood care
• Reproductive dominance is held by one or few individuals and sterile castes of daughters are commonly observed (=altruism)
• Ants, bees, and wasps (Hymenoptera) and termites (Isoptera) are examples

Haplodiploidy

• Males are haploid, while females are diploid
• Sisters share 75% of genes

Will Altruism Evolve among Unrelated Individuals?

• This questions whether altruism would evolve among unrelated individuals.

Reciprocal Altruism

• Blood meals and vampire bats are analyzed for instances of reciprocal altruism.

Will Cooperation or Selfishness Evolve More Frequently?

• The question of whether cooperation or selfishness evolves more frequently is analyzed by various researchers

Game Theory

• Game theory is used to determine the optimal strategy of decision-making among interacting individuals considering costs and benefits
• Evolutionarily Stable Strategy (ESS) refers to the optimal strategy which will evolve and will not be 'invaded' by other strategies.

Game Theory: Hawks and Doves

• Hawks are selfish and fight always for resources
• Dove tactics are cooperative and share resources evenly

Average Payoff per Interaction

• The payoff to hawks always exceeds that to doves
• Calculations are often used to estimate which interaction are beneficial.

Evolutionary Stable Strategy (ESS)

• A society of all hawks is an ESS strategy. However, mixed strategy is often evolutionary stable.
• Cost varying strategies also need to be looked at.

Higher Cost

• When cost is greater, then mixed strategy of hawks and doves is often evolutionary stable.

Explore the intricacies of social behavior among animal species, including interactions within groups and families. This quiz delves into the advantages and disadvantages of group living, vigilance during feeding, and the cost-benefit analysis of social interactions. Test your knowledge on how these dynamics affect survival and behavior in the animal kingdom.