University of Missouri students strap on some polainas, or snake guards, early one morning in Santa Rosa National Park located on the western side of Costa Rica.
While there are plenty of snakes these students could encounter, they will follow field biologist Elizabeth Sargeant looking for something else: white-faced capuchin monkeys.
“They will come down really low, but don’t worry too much about that. They may even come down to the ground; maybe within a couple of meters.”
Sargeant is in Santa Rosa studying the allo nursing phenomenon within the Capuchin community in Costa Rica. Allo nursing means having a baby breast feed from multiple mothers as opposed to one. Sargeant is trying to figure out why.
“There is a very interesting behavior called allo nursing, where the babies will nurse off of mothers that are not their own. So, the infants really interact a lot with those that are not their mothers and that’s what I’m looking into.”
Sargeant works with her team of two other researchers to track the monkeys and detail their behavior on a day to day basis. Sargeant says she works as long as the monkeys are active.
“Typically we follow them all day, from sun up to sun down. So, we’re up by four and we’re back around 6:30 or sometimes seven o’clock. So I’ve been up since four o’clock this morning.”
Those twittering sounds are the young Capuchins calling out to their mothers or others in the group. Regardless of who it is, Sargeant says each monkey recognizes each call.
“We know that they can tell individuals apart when they are calling. Something in their brain clicks that says ‘you know that call, so make a call’”
Each of the monkey groups are named by the location they come from as well as their own chosen category. One group is named after Disney characters, like Rafiki and Belle, while another one is named after Harry Potter characters. Sargeant says that each monkey has its own look and personality, so it is easy to distinguish them after being in the field.
Sargeant is now on her second research tour which started at the beginning of January. Even in such a sort time, Sargeant feels attached to each monkey.
“You get really invested with these guys after you’ve been around them for so long. Even to this day some people ask older researchers if “so and so” is here and they say “no, they’re gone. They’re dead.” It could have been a baby that they named or something like that.”
The group of researchers has a rule that if they are the first to see a baby, they get to name it. Sargeant named her first baby Ollivander, after the character in Harry Potter.
“The way it works here is that if you find a baby you get to name it. And you have to follow the guidelines for each group. So last year I found two babies, one named Ollivander and the other one isn’t named because we haven’t sexed it yet.“
Sargeant will stay until June to continue watching the monkeys and developing her thesis on allo nursing. Until then, she will keep following the groups from sun up to sun down.
Kyle Cardine. Reporting from Santa Rosa National Park, Costa Rica
Video by Aaron Braverman