Mating systems

Question 1

Describe monogamy + examples

Answer 1

• 1 male 1 female
• Can be long bonds or short term
• Typical system in birds, few mammals and fish
• Often see size asymmetry
• Males smaller (little competition between males)

Question 2

Describe Polygyny + examples

Answer 2

• 1 male associated with multiple females
• Few birds, most mammals

Examples:
Simultaneous polygyny in Red-Winged blackbird
Successive/sequential polygyny e,.g Orangutan

Question 3

Describe Polyandry + example

Answer 3

• One female associated with multiple males
• Generally rare: few birds, fish, mammals

Examples:
Successive/sequential polyandry in the Spotted Sandpiper
Simultaneous polyandry in the Painted Snipe

Question 4

Describe Promiscuity (polygynandry)

Answer 4

• > 1 female and >1 male
• Not common in birds, mammals but does occur frequently in fish, reptiles and amphibians

Question 5

Describe the difference in reproductive potential of males and females

Answer 5

• Males are limited primarily by access to females
• Females are limited primarily by access to resources
• So, males have a higher reproductive potential than females

Question 6

In their comparative study of mammalian mating systems, what did Clutton-Brock (1989) find mating systems rely on?

Answer 6

Female monopolisation by males depends on:
- Female group size
- Female range size

Question 7

If females are solitary and their range is defendable what mating system arises when:
- Female range is small
- Female range is large

Answer 7

• Small range = Polygyny e.g Voles, Otters
• Large range = Monogamy e.g Gibbon

Question 8

If females are solitary and their range is NOT defendable what mating system arises?

Answer 8

Scramble competition polygyny
- e.g Organutan females wander large unpredictable ranges to find food
- So, one male cannot defend one female

Question 9

If females are social and their range is defendable, what mating system arises when:
- Small group
- Large group

Answer 9

• Small group = Uni-male polygyny e.g Colobus
• Large group = Multi-male polygyny e.g lion

Question 10

If females are social and their range is NOT defendable, what mating system arises?

Answer 10

• Large unstable group = lek polygyny
• Males may aggregate in leks when competition for females is intense