lecture 24 Flashcards
When is hawk favored?
When W>D, meaning that the resource provides a greater benefit that exceeds the costs of conflict, D
When is dove favored?
When W
what proportion of hawks and doves gives a stable balance?
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)
Speckled wood butterflies
behavior can be described as half dove, half hawk
Communication
sender intentionally produces signal to send info to receiver; subset of recognition systems
4 forms of communication
honesty (both sender and receiver benefit), deceit (only sender benefits), eavesdropping (cost to sender, benefit to receiver), and spite (harms both sender and receiver)
Black winged damselfly
vision is used for communication; white marks on wings communicate gender info
Audition example
frogs; singing transmits info on parasite load
Chemical senses example
Naked mole rats; queens leave pheromones in toilet chamber to prevent development of other workers’ ovaries
Substrate vibrations example
male spiders try to modify behavior of female to get her to mate with him rather than eat him
Functions for communication
recognition of species, mate attraction, courtship, alarm, warning of predators, agonistic encounters, and recruitment
Recognition of species example-Cowbirds
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
Optimal Acceptance Threshold Model
By reducing overlap between cues of conspecific (same species) and heterospecific, could reduce acceptance and rejection errors
Electric fields
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
Mountain dusky salamander
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
Male red deer-progression of communication to determine dominance
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
Recruitment in ants
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)
Eavesdropping: frogs and bats
females prefer male frogs that give whining calls with chucks, but this call also attracts bats, which will eat the frogs
Great tits: avoiding signal exploitation
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
Origin of honeybee dance
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
Co-option of ancestral call in bowerbirds
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
Sensory exploitation- Courtship by male water mites
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
Pre-existing sensory biases-experiment with bird “hats”
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
