BIOL3046 Lecture Notes - Lecture 18: Infrasound, Supernormal Stimulus, Brood Parasite
5 Jul 2018
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Department
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Animal Behaviour BIOL3046 460381099
Lecture 18: Honest signals.
• May try to lie, in order to manipulate the receiver for its own benefit. Some organisms
may bluff willingness to escalate or a male competing for a females attention may
exaggerate his qualities.
• However, both parties must benefit from the exchange, otherwise signalling system
would not be stable.
• Where we expect to see honest signals:
o 1. Overlapping goals: When two animals have the same foals, communication is
honest. Example: Bee waggle dance; Begging in chicks (this may cause conflict as
the parents fitness depends on the offspring survival).
o 2. Signal cannot be faked: If a signal is directly related to the signaller’s quality, it
can’t be faked. Example: Male deer vocalise during courtship, but the length of
vocal tract is proportional to body size, so the roar gives the female honest
information. Status signals: Visible signal that cannot be manipulated. Example:
Many birds have ‘badges’ relating to their level of dominance. This related to age
and hormones of the individuals; Blue footed boobies have brightly coloured
feet, displaying them to the female. Fitter males can afford to have bright blue
feet.
o 3. Costly signals: May prevent a male from exaggerating his qualities. This is
known as the Handicap Principle, where signals that are costly to sender are
favoured by the receiver, and only the best individuals can produce such signals.
Example: Long tail feathers of male peacocks serve as sexual ornaments, and are
only carried by the fittest individuals.
o 4. Dishonest signal can be identified: A stable social unit favours honest
communication, where repeated interactions and individual recognition
discourage cheating. Example: Vervet monkeys occasionally try to cheat. Males
may sometimes try to entice females by making a ‘food’ call, then try to mate
with them. But, those individuals will then be filtered for being dishonest.
• However, dishonest signals do exist. Example: Asian corn moth has learned to copy the
echolocation signals of bats. This bat call makes the moths freeze. Thus, the male moth
mimics the sound, female freezes, and he has the ability to mate with her.
Document Summary
Lecture 18: honest signals: may try to lie, in order to manipulate the receiver for its own benefit. Overlapping goals: when two animals have the same foals, communication is honest. Example: bee waggle dance; begging in chicks (this may cause conflict as the parents fitness depends on the offspring survival): 2. Sig(cid:374)al (cid:272)a(cid:374)(cid:374)ot (cid:271)e faked: if a sig(cid:374)al is di(cid:396)e(cid:272)tly (cid:396)elated to the sig(cid:374)alle(cid:396)(cid:859)s (cid:395)uality, it (cid:272)a(cid:374)(cid:859)t (cid:271)e faked. Example: male deer vocalise during courtship, but the length of vocal tract is proportional to body size, so the roar gives the female honest information. Status signals: visible signal that cannot be manipulated. Ma(cid:374)y (cid:271)i(cid:396)ds have (cid:858)(cid:271)adges(cid:859) (cid:396)elati(cid:374)g to thei(cid:396) level of do(cid:373)i(cid:374)a(cid:374)(cid:272)e. this related to age and hormones of the individuals; blue footed boobies have brightly coloured feet, displaying them to the female. Fitter males can afford to have bright blue feet: 3. Costly signals: may prevent a male from exaggerating his qualities.
