Question

Cheney and Seyfarth recorded one vervet monkey making a
call that indicates danger from another group of vervets
(wrrr)
• They played the wrrr call to the group, and group
began to ignore it
• They then played another call from the same monkey
which means more or less the same thing (chutter)
• The group immediately ignored that, suggesting that
they implicitly treated the particular calling monkey to
be unreliable at calling about approaching groups of
other monkeys

What control condition would need to be run to make sure that the vervets who ignored the wrrr and chutter calls treated the two calls as referring to the same situation, vs. just treating the particular monkey whose calls were being played as generally unreliable?

would it be another group of monkey but under what setting since it's a control condition? Please help

Answer 1

There can be two reasons for the given outcome:

1.The vervet monkeys does not take wrrr and chutter call as a warning signal.

2. the particular group of monkeys do not trust the monkey making the calls.

To find out which one is true, we need three control set ups.

CONTROL 1

The same group of monkeys are subjected to wrrr call from a different source (another monkey- preferentially a monkey that is reliable in the group. It can be found out after observing the group for a while. The social structure of monkey groups are complex and there are usually alpha males and sometimes females) If a high ranking monkey gives the call( wrrr) and no one responds then the call must be for something else and it is not a warning signal. If they are responding then the source was unreliable before.

CONTROL 2

The same experiment as in control 1 but with chutter call. If the same group of monkey respond to wrr and not to chutter that means wrr is the warning signal and chutter means something else.

If they respond to the chutter but not wrrr that means chutter is the warning signal.

if they respond to both(separately) , both the calls are used as warning and the source was unreliable before.

when both the calls are able to evoke escape response separately but not simultaneously that means that the monkeys are habitual of the situation and that’s why they are not responding.

CONTROL 3

To test whether wrrr and chutter are actually warning calls, a new group of vervet monkeys can be subjected to these two calls and response noted.

if a new group responds to the calls then it is indeed the warning signal and the monkey in question was an unreliable source that’s why the group was not responding to the calls.