Courtship

Question 1

Operational Sex Ratio defined

Answer 1

ratio of receptive breefing males to receptive breeding females
often skewed to more males than females

Question 2

Four Mating Systems defined (animal examples)

Answer 2

monogamy: one male, one female
e.g. bald eagle, wolf

polygyny: one male, multiple females
e.g. elephant seals, gorillas

polyandry: one female, multiple males
e.g. bees, naked mole rats?

promiscuity: many males many females all mate with each other
e.g.chimps, dolphins

Question 3

Bateman’s Principle defined

Answer 3

overall higher variability in reproductive success of males than in females. Males can have more offspring than females

Question 4

Sexual Selection defined (link to sexual dimorphism)

Answer 4

one sex selects the other sex based on a set of traits deemed attractive
this is why sexes become dimorphic (look different)

Question 5

Sexual Selection’s Impact on Natural Selection

Answer 5

Sectual selection can promote characteristics not vital for survival, and can select for traits that make survival more difficult

Question 6

Courtship (Visual) (animal examples)

Answer 6

Visual cues:
males with certain physical traits are more healthy
they can afford traits that make survival harder
e.g. widowbird tails, cardinal color, peacock feathers

Question 7

Courtship (Auditory) (animal examples)

Answer 7

Auditory cues:
when females can’t see males, so they listen
certain noises indicate large, meathy males
e.g toads croaks, deer roars

Question 8

Courtship (Olfactory) (animal examples)

Answer 8

Olfactory cues:
chemical pheromones - indicate attractiveness and relatedness
e.g. mice, moths, butterflies, fish

Question 9

Bright Bird Hypothesis

Answer 9

birds eat food that gives them their color (cartenoids)
when they have infections, the cartenoids go to fighting infection, not coloration
dull colors = infected

Question 10

Fisher’s Runaway Selection Hypothesis defined

Answer 10

Trait initially helps with survival
gene for female choosiness arises
the trait is exaggerated, past its usefulness

Question 11

Zahavi’s Handicap Hypothesis defined

Answer 11

a trait may be a burden, therefore it’s costly to the bearer and only a superior individual can afford to carry the trait

Question 12

The Role of Symmetry in Pricking Mate

Answer 12

symmetry as good indicator of good genes

Question 13

Scorpion Fly Conditional Male Courtship-3 Strategies

Answer 13

Quality male: insect gift
ok male: dried saliva gift
poor male: jumps female

Question 14

Sunfish Nonconditional Male Courtship-Male Types

Answer 14

Small sneaker male
sexually mature at 2 years
releases sperm as large male and female mate
large territorial male
sexually mature at 7 years
defends female and eggs

Question 15

Nuptial Gifts defined (animal examples)

Answer 15

item given to female from male before mating, invitation to mate
e.g. scorpionflies, fireflies?, butterflies?
- can contain sperm (spermatophore)
- e.g. spiders, scorpions

Question 16

Dishonest Signals in Courtship (fireflies)

Answer 16

Females do dishonest flash pattern of other species
eats male of other species
Males do dishonest flash patterns of other species
females of same species try to eat them, see that they’re same species, mate