Mating Systems And Parental Care

Question 1

What are the forms of Polygamy

Answer 1

1. Resource defence = makes control critical resource
2. Female defence = male control group of females
3. Lek polygamy = males congregate in one area and fight or display. Often defend areas with little or no resources

Question 2

Types of Polyandry

Answer 2

1. Classical = one female with >1 male. Females will compete

2. Cooperative = >1 male associated with single female

Question 3

Consequences of Polygamy

Answer 3

• high variance in lifetime reproductive success of males but not females
• partially predictable

Question 4

Advantages of monogamy

Answer 4

• reproductive success equal
• no cost of courtship
• begin mating earlier
• efficient foraging

Question 5

Define parental investment

Answer 5

Any behaviour towards existing offspring that increases the offspring survival

Question 6

What are the costs of parental investment

Answer 6

• energetic
  > reduced feeding opportunities
• survival
  > starvation or increased susceptibility
• reproductive
  > cost future opportunities of breeding

Question 7

Three strategies of Parental Investment

Answer 7

1. Maternal care
   
   • male can desert
   • depends on probability of young survival
2. Parental Care
   
   • female can desert
   • example of neo tropical harvestman spiders
3. Biparental care
   
   • equal investment, neither deserts

Question 8

Define reproductive effort (RE)

Answer 8

All energy spent + risks taken for brood at cost of future broods

• minimal in r-strategists
• maximal in K-strategists
• iteroparity = RE spread over many broods
• semelparity = all RE concentrated in 1 huge brood

Question 9

Three allocation of parental investment

Answer 9

1. Life history
   
   • e.g. long lived spp. might invest less in current offspring
2. Confidence in paternity
3. Physiology
   
   • e.g. homeotherms must keep young warm