Second, when the food-finding species hears the alarm call, it responds by
looking up and fleeing. Thus, the alarm call reliably elicits a response from
the target receiver. Finally, the antshrike and tanager have the flexibility to
produce the alarm in the absence of a predator. Thus, our conditions for a
lie of commission have been met.
False alarm calls by antshrikes and tanagers are relatively common. Thus,
there is no support for the prediction that lies of commission must be rare.
One explanation for this high rate of deception comes from an economic
analysis of the interaction. For both species, the benefit comes from capturing an insect. For the food-finding species, the potential cost comes from
ignoring the alarm call. Looking at the trade-offs, it never pays the foodfinding species to ignore the alarm call because the benefit of eating an
insect is greatly outweighed by the costs of being eaten by a predatory bird.
Because of this imbalance, the antshrike and tanager can give false alarm
calls at high rates. Within this snapshot of an evolutionary arms race, the
antshrikes and tanagers have the upper hand.
Several questions emerge from Munn’s studies for which we have no
answers. For example, how often do antshrikes and tanagers make mistakes
in terms of detecting a predator? Establishing the error rate is important
because it sets up a more accurate measure of the rate of deceptive alarm
calls. When a false alarm call is sounded, how often do tanagers and
antshrikes manage to capture the insect? How do other antshrikes and tanagers respond when they hear a deceptive as opposed to an honest alarm
call? Can they detect a difference? Or do they go along with the prank in
order to preserve the trick on a subsequent occasion when it is their turn?
How often do antshrikes and tanagers produce deceptive alarm calls to the
same individuals? Although the overall rate of deceptive alarm calls is quite
high, one might expect that a sufficiently high rate with one individual, over
a short period of time, would cause the receiver to begin ignoring the call.
Finally, how do antshrikes and tanagers acquire the ability to deceive by
producing deceptive alarm calls? Do young birds make mistakes, giving
deceptive alarm calls to other members of their species? Do they give
deceptive alarm calls in contexts outside of food competition? Answers to
these questions are certainly attainable by manipulating the contexts
in which each species encounters the other, by exploring the acoustics of
deceptive and honest alarm calls in greater detail, and by selectively playing
back deceptive alarm calls under controlled conditions. For example, one
could play back deceptive alarm calls at higher rates than what is given
naturally in order to determine when members of the food-finding species
habituate. Given the level of description already provided by Munn, the
mixed-species flocks in Peru provide an ideal situation for looking at the
dynamics of interspecific deception.
The dynamics of inter- and intra-specific interactions may be quite different with respect to the necessary and sufficient conditions for evolving
the capacity to generate lies of commission. Most studies of intraspecific
3. Unpacking “Honesty”
109
looking up and fleeing. Thus, the alarm call reliably elicits a response from
the target receiver. Finally, the antshrike and tanager have the flexibility to
produce the alarm in the absence of a predator. Thus, our conditions for a
lie of commission have been met.
False alarm calls by antshrikes and tanagers are relatively common. Thus,
there is no support for the prediction that lies of commission must be rare.
One explanation for this high rate of deception comes from an economic
analysis of the interaction. For both species, the benefit comes from capturing an insect. For the food-finding species, the potential cost comes from
ignoring the alarm call. Looking at the trade-offs, it never pays the foodfinding species to ignore the alarm call because the benefit of eating an
insect is greatly outweighed by the costs of being eaten by a predatory bird.
Because of this imbalance, the antshrike and tanager can give false alarm
calls at high rates. Within this snapshot of an evolutionary arms race, the
antshrikes and tanagers have the upper hand.
Several questions emerge from Munn’s studies for which we have no
answers. For example, how often do antshrikes and tanagers make mistakes
in terms of detecting a predator? Establishing the error rate is important
because it sets up a more accurate measure of the rate of deceptive alarm
calls. When a false alarm call is sounded, how often do tanagers and
antshrikes manage to capture the insect? How do other antshrikes and tanagers respond when they hear a deceptive as opposed to an honest alarm
call? Can they detect a difference? Or do they go along with the prank in
order to preserve the trick on a subsequent occasion when it is their turn?
How often do antshrikes and tanagers produce deceptive alarm calls to the
same individuals? Although the overall rate of deceptive alarm calls is quite
high, one might expect that a sufficiently high rate with one individual, over
a short period of time, would cause the receiver to begin ignoring the call.
Finally, how do antshrikes and tanagers acquire the ability to deceive by
producing deceptive alarm calls? Do young birds make mistakes, giving
deceptive alarm calls to other members of their species? Do they give
deceptive alarm calls in contexts outside of food competition? Answers to
these questions are certainly attainable by manipulating the contexts
in which each species encounters the other, by exploring the acoustics of
deceptive and honest alarm calls in greater detail, and by selectively playing
back deceptive alarm calls under controlled conditions. For example, one
could play back deceptive alarm calls at higher rates than what is given
naturally in order to determine when members of the food-finding species
habituate. Given the level of description already provided by Munn, the
mixed-species flocks in Peru provide an ideal situation for looking at the
dynamics of interspecific deception.
The dynamics of inter- and intra-specific interactions may be quite different with respect to the necessary and sufficient conditions for evolving
the capacity to generate lies of commission. Most studies of intraspecific
3. Unpacking “Honesty”
109