Conservation & Research
On the quest for musmuquis: the elusive black-headed night monkey

What it takes to study night monkeys in the jungle – from poop samples to carrying a large mic on a stick – by student Sheridan Plummer, from the School for Field Studies.


Six American students, one wacky professor, lots of beans and rice, endless jungle and a winding river. We're wading silently in the darkness through knee deep puddles in the search for the elusive musmuqui – aka the black-headed night monkey, aka aotus nigriceps. This is what one week of visiting research looks like at the Manu Learning Centre (MLC) run by Crees.


We are students at the School for Field Studies (SFS), an American study abroad program focusing on ecological field research with locations all over the world, ranging from Turks and Caicos to Cambodia and Peru.


After completing five field courses, including Tropical Ecology, Conservation Science, and Political Ecology, we split up into three groups to conduct field research projects on various topics. Our group of nine – including our energetic professor, a photographer extraordinaire, and a crucially vital snack-providing intern – set off for the Amazon jungle to study aotus nigriceps.


The wacky professor himself, Will Helenbrook | Image © Sheridan Plummer


Our typical day at the MLC was a bit erratic. Most mornings we were up at 4:45am, groggily throwing on field pants and headlamps while stumbling to put on boots and meeting the group at the start of the trail.


We then made our way through the reserve as quietly as possible, listening intently for a rustle of tree branches or the characteristic “ch-ch” call of the musmuqui. After a few hours, and hopefully a few sightings, we made our way back to camp for hot coffee, breakfast, and a much needed nap in the hammocks overlooking the river.


The days were filled with analysing research... or on less productive days – a game or two of poker and a pleasure book in the shade of the comedor. Then out we went each night at dusk, again attempting silence while trudging through mud and brambles with ears and eyes alert.


Tackling the terrains of the MLC on a quest for the elusive musmuqui | Image © Sheridan Plummer


With four different projects between the six of us students, there was a lot of work to be done. The rainforest of the MLC, with its incredible diversity and wildlife, presented itself both a place of an extraordinary abundance of data and an extraordinary abundance of distractions.


We had sightings of a tapir, toucans, a puma, a troop of pale-winged trumpeters, Gavina the resident sloth, a jaguar caught inspecting our camera trap, five different species of monkey, and a pair of juguarondies. We found ourselves completely in awe of the wilderness surrounding us. Our focus morning and night, however, always returned to our musmuquis.



Distractions at the MLC are aplenty, whether its sightings of rare species or the attention grabbing views | Image © Sheridan Plummer


Our project covered the spectrum from collecting fecal samples (yes, poop) to walking through the forest with a boom and expensive headphones on. Here is a quick look at what it takes to survey musmuquis with SFS:


Project 1: Aotus nigriceps parasitology


Researchers: Caroline R., known as “La Rubia”, enjoys warm go-gurt and flexing her killer calves.

Kaitlin G., known as “Crookshanks”, lover of angsty alt-rock from the 2000s and anything with fur or a tail.


Objectives: To determine the effects of anthropogenic disturbance on parasitism of A. nigriceps. Studying parasitism helps to predict vitality and group dynamics of musmuquis.


Project 2: Vocalization patterns


Researcher: Leigh P., known as “Leaky Lunch”, watches The Departed once a week, star of her marathon canoe racing team.


Objectives: To determine whether individuals within a group have characteristically different calls from one another, to determine whether groups have their own characteristic calls, and to determine whether Aotus calls differ over a wider geographic region, and across species. This information could clue us into group dynamics of this elusive species, and could also help create a more complete evolutionary history of A. nigriceps.


Project 3: Diet and germination


Researcher: Isabelle B., known as “Foobar”. Superpowers include: speed reading, travelling the world, and smelling musmuqui poop from miles away.


Objectives: To catalog A. nigriceps’ diet and test for increased germination rates among digested seeds to determine which plant species are being dispersed. A. nigriceps may play a vital role as seed dispersers, contributing to secondary succession and forest regeneration.


Project 4: Ecological niche modelling and conservation


Researchers: Ben S., known as “Herb”, somehow resembles everyone’s dad, buys peanuts in bulk, is secretly a sucker for a good love story.

Sheridan P., known as “Sonny”, most likely to eat her weight in bread and inadvertently give someone a black eye on the futbol field.


Objectives: To find and predict the distributions and habitat of aotus nigriceps using QGIS, a geographic information systems software technology used for environmental problem solving and mapping. The information gathered will be used to assess threats to the species and to develop a conservation plan for continued survival.


Poo samples can tell you a lot, whether it’s about important information on parasites or about diet and germination | Image © Sheridan Plummer


As we prepare to leave the MLC and all of our musmuqui friends (humans included), looking back on our time here is both overwhelming and dreamlike. From the wildlife sightings and hiking to the futbol tournament and ceviche making, this week has been more than we could have ever imagined. Crees holds a special place in our hearts. This once-in-a-lifetime experience studying night monkeys in the jungles of Peru will not soon be forgotten.


Team Musmuqui... “ch-ch”



From all of us at Crees, we’d like to say a big thanks to the School for Field Studies for joining us on as part of your project, to Will and Jess for leading an incredible team, and to all of Team Musmuqui for being such a fantastic addition to camp and for teaching us about night monkeys. It was a pleasure having you at the MLC and your presence will be sorely missed! ch ch!