lecture 24

Question 1

When is hawk favored?

Answer 1

When W>D, meaning that the resource provides a greater benefit that exceeds the costs of conflict, D

Question 2

When is dove favored?

Answer 2

When W

Question 3

what proportion of hawks and doves gives a stable balance?

Answer 3

p=proportion of hawks
1-p=proportion of doves
at equilibrium, the mean payoff to hawk is equal to mean payoff to dove (mixed strategy)

Question 4

Speckled wood butterflies

Answer 4

behavior can be described as half dove, half hawk

Question 5

Communication

Answer 5

sender intentionally produces signal to send info to receiver; subset of recognition systems

Question 6

4 forms of communication

Answer 6

honesty (both sender and receiver benefit), deceit (only sender benefits), eavesdropping (cost to sender, benefit to receiver), and spite (harms both sender and receiver)

Question 7

Black winged damselfly

Answer 7

vision is used for communication; white marks on wings communicate gender info

Question 8

Audition example

Answer 8

frogs; singing transmits info on parasite load

Question 9

Chemical senses example

Answer 9

Naked mole rats; queens leave pheromones in toilet chamber to prevent development of other workers’ ovaries

Question 10

Substrate vibrations example

Answer 10

male spiders try to modify behavior of female to get her to mate with him rather than eat him

Question 11

Functions for communication

Answer 11

recognition of species, mate attraction, courtship, alarm, warning of predators, agonistic encounters, and recruitment

Question 12

Recognition of species example-Cowbirds

Answer 12

cowbirds lay eggs in host of other species, needs to be able to differentiate between the host species that are more successful; also if the host could recognize the difference, maybe they wouldn’t accept the parasitic egg

Question 13

Optimal Acceptance Threshold Model

Answer 13

By reducing overlap between cues of conspecific (same species) and heterospecific, could reduce acceptance and rejection errors

Question 14

Electric fields

Answer 14

certain types of fish can generate and detect electric fields, which can be used to communicate; weakly electric fish are located closer together, while strongly electric fish are also located together

Question 15

Mountain dusky salamander

Answer 15

male bites females and injects a love potion that causes females to be reproductively receptive; this communication allows males and females to coordinate reproductive behavior

Question 16

Male red deer-progression of communication to determine dominance

Answer 16

Start off with roar contest to see who has greater endurance; then do a parallel walk to assess each other’s size; if still a stalemate, then will fight to assess physical strength

Question 17

Recruitment in ants

Answer 17

ants leave behind chemical trails to tell other ants where to go, but other times they will just pick up other ants and drag them to the food (tandem running)

Question 18

Eavesdropping: frogs and bats

Answer 18

females prefer male frogs that give whining calls with chucks, but this call also attracts bats, which will eat the frogs

Question 19

Great tits: avoiding signal exploitation

Answer 19

great tit gives off “seet” call, which is high frequency and can’t be heard by sparrow hawks; this seet call has evolved in multiple species

Question 20

Origin of honeybee dance

Answer 20

bumblebees use scent to mark location of food sources, but this may allow other bees to eavesdrop on marked food sources; honeybees use waggle dance, which other species don’t understand

Question 21

Co-option of ancestral call in bowerbirds

Answer 21

the skrraa call, which has been used by past generations of bowerbirds as an aggressive call has evolved in a cluster of species to also serve as a courtship call

Question 22

Sensory exploitation- Courtship by male water mites

Answer 22

when a signal giver taps into a pre-existing mechanism; when female is in prey-catching position, male approaches and waves a trembling foreleg, setting up vibrations like a prey would make; female grabs male and male deposits spermatophores in front of her

Question 23

Pre-existing sensory biases-experiment with bird “hats”

Answer 23

experimentally added a feather cap that was either white, green, or red to male; females strongly preferred males with a white feather cap, and preferred no cap at all to red or green caps; maybe they prefer white capped males because females line nest with white feathers