Social Behaviour and Sociality - Part2

Introduction to Social Behavior

• Overview of social behavior focusing on helping behaviors in animals.

• Introduction of the Belding ground squirrels and alarm calling as a form of helping behavior.

Alarm Calling in Belding Ground Squirrels

• Alarm calls signal danger from predators (e.g., hawks, bobcats).

• Benefits of calling: communication of danger to others.

• Costs: individuals making alarm calls are more likely to be preyed upon.

Female vs. Male Calling Behavior

• Females are twice as likely to make alarm calls compared to males.

• Males generally leave the natal colony for reproductive opportunities, while females remain.

• Alarm calling by females helps warn related individuals (sisters, cousins) within the colony.

Inclusive Fitness Concepts

• Inclusive fitness: fitness measure that includes direct and indirect benefits of helping

• Supporting kin contributes to the survival of shared genes.

• Belding ground squirrels demonstrate both direct fitness (protecting own offspring) and indirect fitness (helping relatives).

Reproductive Strategies in Animals

• Example of the pied kingfisher and its male offspring's reproductive strategies.

• Options for young males during breeding season:

  • Reproduce successfully.

  • Become a primary helper (assist parents with siblings).

  • Become a secondary helper (assist unrelated breeding pairs).

  • Delay reproduction and wait for next season.

Costs and Benefits of Helping Behaviors

• Primary helpers (helping parents): high cost but also high potential indirect fitness benefits.

• Secondary helpers (helping unrelated pairs): lower costs but lower potential benefits.

• Delayers face the risk of not breeding without gaining indirect fitness.

Measuring Parental Care in Kingfishers

• Males do most of the foraging for their offspring; helpers exert similar effort to breeders.

• Primary helpers show significant investment, risking their own reproductive success for family.

• Secondary helpers have lesser commitment and thus softer costs/lower benefits.

Inclusive Fitness Analysis of Helper Behavior

• Examination of fitness outcomes over the first and second years of helpers:

  • Primary helpers yield indirect benefits due to kin support.

  • Secondary helpers enjoy higher mating success due to perceived parenting capabilities.

  • Delayers show low success due to lack of demonstrated commitment.

Long-term Fitness Outcomes

• Cumulative fitness over two years shows:

  • Primary helpers yield higher total inclusive fitness than secondary helpers and delayers.

  • Career paths of helpers depend on mating opportunities and environmental contexts.

Impact of Environmental and Habitat Factors

• Discussion of how habitat quality influences helping behavior evolution.

• Inherited territories: male helpers gain motivation to remain when they expect to inherit.

• Replacement of parents reduces helper motivation, especially among males.

Phylogenetic Comparisons of Helping Behavior

• Evidence shows cooperativeness in African starlings occurs primarily in savannah habitats.

• The environmental challenges in savannahs encourage the evolution of helping behavior.

• Non-savannah habitats have more resources, leading to less cooperative behavior.

Conclusion

• Summary of social behavior evolution: driven by fitness benefits and contextual environmental factors.

• Understanding animal social relationships and aiding behaviors in the context of reproductive success and kin survival.