communication

Question 1

where can communication occur

Answer 1

-alarm clocks
-parent offspring interactions
-competition for mates
-courtship

Question 2

what does communication require

Answer 2

-a sender and a receiver
-one or both of these must gain a benefit from the communication (normally both)

Question 3

benefit to signaller, cost to receiver

Answer 3

-femme fatale fireflies lure in males from other species and eats them
-they do this by mimicking a flashing signal

Question 4

cost to signaller, benefit to receiver

Answer 4

-female ormia flies receive and respond to calls of crickets
-many predators eavesdrop on the signals and use them to detect ca[tures

Question 5

benefit to signaller and receiver

Answer 5

-in male 3-spined stickleback
-bright males benefit because they get larger females laying larger eggs in their nests
-females edenfit as bright males are healthier and so tend to lay eggs in nest better
-only his quality males can make the big display signals
-orange bright colour in males caused by carotenoids and this can’t be inherited, its from the environment- this is a really good trait to have as it attracts a lot of females

Question 6

types of signals

Answer 6

-vocal
-visual
-chemical/olfactory
-tactile
-electric

Question 7

tactile signals with chimps

Answer 7

-one or both of the animals need to touch- important in complex social groups of grooming
-in chimps, those who often groom others benefit more- more food e.g.

Question 8

female- spotted hyenas

Answer 8

-spotted hyenas have meeting ceremonies where they present their penis
-female hyenas have a clitoris resembling a penis

Question 9

how did the female hyenas clitoris become pseudopenis

Answer 9

-in males mammals a penis develops if embryonic tissue is exposed to androgens (male sex hormones)
-female spotted hyena foetuses are exposed to high levels of androgens
-pseudopenis in hyenas likely due to exposure of male hormones- biochemical effects
-cumulative selection- small changes over time of the pseudopenis

Question 10

costs and benefits of a ‘penis’ in female hyenas

Answer 10

-costs: offspring are born through clitoris, 10-20% of females die while giving birth (very narrow)
-benefits: siblicide is common due to high males hormone levels which is useful for continued survival or that offspring are more likely to get fed and survive
-todays pseudopenis is used for signalling as female dominance is linked with reproductive success

Question 11

function of chick begging

Answer 11

-potentially very costly
-higher frequency begging calls don’t travel as far therefore more likely to get picked up by predators

Question 12

what’s the function of a chick begging

Answer 12

-begging may be an honest signal of hunger or a signal that they’re worth investing in
-chicks need to compete with their siblings for food
-the parents respond and work harder to get more food due to increased loudness of begging calls
-more food= easier to shut up the birds

Question 13

Japanese great tit

Answer 13

-because the signal size is a compromise between the costs and the benefit this bird produces a really little call which is quiet, yet it is packed with very sophisticated and complex information
-they have two main predators, snakes and crows, which the snakes go through the nest entrance and invade the nest cavity, and the crow snatch the nestlings from the entrance
-due to having 2 predators, this means that they have 2 different callings to tell the birds in the nest to flee differently depending on which predator is there
-chicka call for crows
-jar call for snakes