Polygamous Mating Systems
What is polygyny?
A mating system where one male associates with multiple females
Identify the hypothesis: When resources are evenly distributed in space, but females form groups to better access those resources or to help dilute the risk of predation, males will follow and guard a group of females
Female defense polygyny hypothesis
What is a lek?
Clustered mini-territories
Name one cost and one benefit of the polygamous lifestyle. (bonus of 100 points if all 4 costs and benefits are named)
Costs: Reduces genetic diversity of the community (increased inbreeding), can create conflict, polygyny: a disadvantage to female fitness, and polyandry: a disadvantage to male fitness
Benefits: Greater increase in fitness, greater reproductive success, polygyny: advantage to male fitness, and polyandry: advantage to female fitness
What polygamous mating system do gorillas follow?
Polygyny
What is polyandry?
A mating system where one female associates with multiple males
Identify the hypothesis: When resources are clumped, attract multiple females, and are easily defensible, males will guard the resources and by extension the females by setting up a territory.
Resource defense polygyny hypothesis
Identify this lek hypothesis: Males cluster in places called hotspots, where the routes frequently traveled by receptive females intersect
Hotspot hypothesis
Identify the term: A defended group of females associated with one male.
Harem defense polygyny
Do male or female gorillas initiate mating once matured?
Females, but males do their fair share
What is polygynandry?
A mating system where both males and females have multiple mates and stay together to rear the young
Identify the hypothesis: When resources are distributed heterogeneously and females are widespread and do not form groups, males will wait for females to come to them
Lek polygyny hypothesis
Identify this lek hypothesis: Males cluster because females prefer sites with large groups of males, where they can quickly or safely compare the quality of many potential mates
Female preference hypothesis
Identify the term: Both sexes meet for a short-lived highly synchronized mating period
Explosive breeding assemblage
Give three reasons why gorillas are endangered. (Bonus of 100 points if all 5 are named)
Habitat destruction (deforestation and encroachment), the Rwandan Civil War, poaching, diseases, global warming
What is promiscuity?
A mating system where both males and females have multiple mates but leave after sperm transfer
What is the scramble competition polygyny hypothesis
When resources are distributed heterogeneously and females are widespread and do not form groups, males will seek out females
What is the hotshot hypothesis
Subordinate males cluster around highly attractive males to have a chance to interact with females drawn to these hotshots
When does convenient polyandry occur?
Occurs under the assumption that there is a greater cost for females when refusing male mating attempts than in choice mating
What hypothesis(es) do gorillas exhibit?
Female defense polygyny hypothesis and resource defense hypothesis