Mate Choice Flashcards
1
Q
What is anisogamy?
A
- root of the problem
- scarcity of females (due to time it takes to have and recover from having children) means they’re more valued to males leading to increased competition
2
Q
Definition of monogamy?
A
- each sex has one partner
- favoured when: there’s input from both parents needed to raise offspring, male has to guard mate, low chance of meeting many females
3
Q
Example of monogamy?
A
- house sparrows
- when given supplementary food the male spent more time with the female, 10% of chicks were from extra pediments
- when not given extra food, 35% of chicks were sired by other male birds that flew in while the male was out collecting food
4
Q
Definition of polygyny?
A
- males have more than 1 partner while females only have 1
- promotes conflict between males and choosiness by females
- favoured when one sex is operationally rare
5
Q
Why do males fight?
A
- to establish dominance and access females
- for control of resources that females require
- for direct control over groups of females
6
Q
Definition of polyandry?
A
- females have more than 1 partner while males have 1 partner
- favoured when: females can escape parental care duties, females require resources provided by more than 1 male, males have biased sex ratio
7
Q
Example of polyandry?
A
- spotted sandpipers
- females behave like males: larger, arrive at breeding grounds first, fight for territory, attract several males, skewed reproductive success
8
Q
Example of ecological factors favouring polyandry?
A
- sandpipers
- live in very cold climate
- females need to insulate and incubate eggs thoroughly, can lay many eggs but only 4 fit in nest
- so she has male lay on eggs and incubate them
- chicks are altricial so can fend for themselves so little cost to the male
9
Q
Definition of polygynandry?
A
- females have more than 1 partner and males also have more than 1 partner
- favoured when males can’t monopolise females and females gain from multiple matings
10
Q
Example of costs in energy of choosing?
A
- satin bowerbirds
- females move around large hilly, mountainous and jungly landscape that allows wide selection of males
- costly due to having to fly between them and remember where each one is
11
Q
Example of costs in time of choosing?
A
- sage grouse
- since they lek the female has to spend nearly 50 times the amount of energy just standing there and watching
12
Q
What are the benefits of choosing?
A
- direct benefits: territory, nuptial food, paternal food, paternal care, reduced harassment, sperm
- indirect benefits (females offspring gain benefits and lives longer/produces more offspring)
13
Q
What should choosy females do?
A
- pay attention to signals of available benefits
- prefer males with exaggerated signals
- prefer signals that can’t fake
- maximise their benefits
14
Q
What are signals for direct benefits?
A
- repertoire size is equal to parental care (e.g. warbler song is indicator of care it will provide later in life)
- may indicate an absence of predator
15
Q
What are signals for indirect benefits?
A
- area of fathers eyespots relate to chick survival in peacocks
- attractive fathers produce ‘sexy sons’
