Living with her family high above the ground
in the northern tropical forests of Colombia,
you will find Shakira,
a cotton-top tamarin with a penchant for conversation.
Say, “Hola!”
Though you may not realize it,
this one pound monkey communicates
in a highly sophisticated language
of 38 distinct calls
based on variations of chirps and whistles.
The response she just gave is
known as a “B chirp”,
a call often directed at humans.
To appreciate the complexities of Shakira’s language,
let’s learn a few chirps and whistles,
then examine how their combinations
form grammatically structured sequences.
The chirp Shakira used to greet us
comes from a class of calls known as
single frequency modulated syllables.
This class is made up of short duration calls, or chirps,
and long duration calls, like screams and squeals.
Researchers have determined that there are eight
different types of chirps categorized by
stem upsweep, duration, peak frequency, and frequency change.
In addition, each chirp has its own unique meaning.
For example, Shakira’s “C chirp” is used
when she is approaching food,
where as her “D chirp” is only used
when she has the food in hand.
Single whistles also exhibit a unique intention with each call
and just as there are eight different chirps,
there are five different whistles.
Based on frequency modulation,
single whistles are subdivided into four categories:
squeaks, initially modulated whistles,
terminally modulated whistles, and flat whistles.
The language’s quality of unique intention
is wonderfully exemplified by the category
of initially modulated whistles.
These whistles change based on the proximity
of Shakira to other members of her family.
If Shakira is greater than .6 meters from her family,
she’ll sound a large initally modulated whistle.
But if she’s less than .6 meters from her family,
she’ll sound a small initially modulated whistle.
Now that we’ve learned a few chirps and whistles,
Shakira wants to show off by taking you
through a quick day in her life with these calls.
While heading towards a feeding tree for her first meal of the day,
she says, (monkey noise),
a call most often used in relaxed investigations.
However, suddenly she spots the shadow of a hawk.
“E chirp” for alarm.
This call alerts her family to the presence of this predator,
and Shakira jumps to the safety of an inner branch.
The coast seems clear,
so Shakira makes her way towards her dad.
Wait, wait. Who is that?
Ah, it’s her younger brother, Carlos.
Cotton-top tamarins often squeal during play wrestling.
Uh-oh. He’s playing a little too roughly, and Shakira screams,
alerting her parents to help her.
Her dad makes his way towards the ball of rolling fur
and her brother stops.
Shakira shakes herself
and scratches herself to get the hair on her head
back in place.
Then Shakira spots another group of unfamiliar tamarins
and hears their normal long call.
She turns to her family. (Monkey noise)
Did you catch that? First there was a chirp, then a whistle.
This is what’s known as a combination vocalization,
a phrase that contains both a chirp and a whistle.
These are two calls strung together to convey a message.
The combination of these two elements
alerts her family to the presence of another group,
the “F chirp”, and the distance they are away,
the normal long call whistle.
In other words, Shakira just said a sentence.
Her simple demonstration is just the tip of the iceberg.
She’s got trills, chatters, multiple whistle calls,
more combination vocalizations, even twitters.
Yet sadly enough, we may not get to hear
everything she has to say.
Mixed in with chirping sonatas from high above
is the constant thud of a machete chopping trees.
Shakira’s habitat in Colombia is being cut down,
piece by piece,
and if we don’t work to protect
the critically endangered cotton-top tamarin,
it will become extinct in our lifetime.
If the chirp from one tamarin to the next
has proven to be more than just idle chit chat,
imagine what else we have left to discover.
Imagine what else Shakira can tell us.
