Female Mate Choice Flashcards
What is intra sexual selection?
(Mate competition) e.g- tactics that males use to ensure their mating success
1) holding territory
What are the roles of females vs males?
Females- parental care, a lot of investment and are often in demand
Males- protection, not much care for offspring and are often in excess
What are some material resources?
1) A defended territory containing resources important in development of offspring.
2) An ability to provide food, making a contribution to females reproduction and offspring success.
Give 2 example of males using material resources to increase reproductive success.
- Female hanging flies will only allow a male to mate with her if he provides a large insect for her to eat during copulation.
- Male penguins will present females with stones to make their nest with (a nuptial gift).
What does the success of nuptial gift “cheats” depend on?
1) Male body condition (how well fed they are).
2) Female status (if virgin, more naive and will allow mating. If already mated before, they will reject).
What is the criteria for mate selection for the side blotched lizard?
- Territory quality (females preferred a smaller male on high quality territories than a larger male on poorer territories).
What does an indirect benefit model suggest?
- They predict that a females choice of male provides her with no obvious or immediate benefit to herself.
- The females fitness increases as a consequence of better offspring fitness (short-term sacrifice).
What is the “good genes” hypothesis?
- Female will select mates that have better genes than others.
- This is to ensure the success of her offspring surviving & reproducing.
Give 2 examples of the good genes hypothesis.
1) Male gray tree frogs produce calls that differ in length and pulse rate (females choose those with longer calls).
2) Wolf spiders will drum on leaves to attract females (females prefer high drumming rates).
What is the ‘sexy son effect’?
- Relating to sexual selection as a result of displays and badges.
- Females sometimes find a particular characteristic attractive (e.g- colourful plumage).
- If the trait is heritable, her sons will inherit this and consequently increase their reproductive success.
Give an example of the ‘sexy son effect’.
- Inca terns (monogamous seabirds).
- Males and females have a long white moustache.
- Moustache length is a mutual signal of body condition that indicates peak body mass and immunocompetence of chicks.
Sometimes, displays and badges may be a disadvantage to the bearer. What are the 2 hypotheses that may explain why they still evolve?
1) Fishers (1930) hypothesis- suggests selection of traits is a result of female preference, advantageous as females will select them (genes for reproduction).
2) The handicap hypothesis (Xahavi, 1975). predicts that secondary sexual traits are reliable indicators of quality because they are costly & reduce survival (genes for survival & reproduction) .
Give an example of the handicap hypothesis.
- Peacocks tail.
- Requires a lot of energy for growth & maintenance.
- Reduces birds agility & ability to avoid predators.
- It still continues to evolve, indicating that despite its apparent disadvantages, must have some benefit.
Explain the relationship between male mating success and female preference using an example.
- Female preference is largely associated with elaborate displays by males or those by which have better traits.
E.g- Anderson (1982) studied long tailed widow birds in Kenya. They looked at whether females preferred males with longer or shorter tails.
Females preferred males with longer tails & this trait presumably evolved through female preference.
Parents who had longer tails also proved to have offspring with fewer mite loads- indicating the degree of parasite resistance.
Females with this preference would mate with those males & offspring would inherit both the long tail and preference.
