Mating System

Question 1

Female defense polygyny

Answer 1

One male directly defends several females

Question 2

Resource defense polygyny

Answer 2

One male acquires several mates that are attracted to resources he controls

Ex:African cichlid fish

Question 3

Scramble competition polygyny

Answer 3

One male acquires several scattered mates by finding them before others do

Ex: male ground squirrels + polar bears

Question 4

lek polygyny

Conditions favor evolution of lek?

Answer 4

Groups of mates gather at common display sites (lek) where females select them

Conditions:
-Hot spots: males gather at sites where females more likely to congregate
•females prefer to choose mates from aggregations of males

Question 5

Polyandry more commons that thought

Answer 5

• direct assessment of paternity: advances in molecular tech. Revealed more cases of polyandry than behavioral observations
• mono birds, 15-20% are sired through extra pair copulations

Question 6

Polyandry genetic benefits

Answer 6

Fertility assurance: more likely to get preggers

Good gene hypthosis: more males will have more surviving offspring

Question 7

Polyandry material benefits

Answer 7

More resources:

Better protection: more mates when they feel more harassment

Infanticide reduction: copulate with more males when they’re not ovulating. Infanticidale males leave offspring alone.

Question 8

Monogamy

Mate assistance:

Mate guarding:

Female enforced monogamy hypothesis:

Answer 8

Mate assistance: Mate help rearing offspring assistance

Mate guarding: In bank swallows: males will be most attentive to their mates when they are fertile

Female enforced: monogamy is not adaptive for males (burying beetles)

Question 9

Oppurtunity of sexual selection is influenced by…

Answer 9

Breeding sex ratio. Ratio of receptive females to sexually active males which varies with particular ecological setting

-intensity can vary between closely related species, among populations or within a population over time