Primate Conservation Limelight

Dr. Karen Strier

Photo credit: © Joao Marcos Rosa. Photo Courtesy of K.B. Strier

Dr. Karen B. Strier is Vilas Research Professor and Irven DeVore Professor of Anthropology at the University of Wisconsin-Madison, where she has been since 1989. She earned her BA from Swarthmore College and her M.A. and Ph.D. from Harvard University. Dr. Strier served as the President of the International Primatological Society (2016–2022). She was elected to the U.S. National Academy of Sciences (2005) and as a fellow of the American Academy of Arts and Sciences (2009) and of the American Association for the Advancement of Sciences (2003). She is the recipient of Distinguished Primatologist awards from the American Society of Primatology (2010) and the Midwestern Primate Interest Group (2011), and holds honorary lifetime memberships in the Sociedade Brasliera de Primatologia and the Sociedade Latin Americana de Primatologia. She received an honorary Doctorate of Science from the University of Chicago (2006). In 2020 she was awarded the “Prêmio Muriqui” from the Conselho Nacional da Reserva Biosfera da Mata Atlantica, considered to be one of the highest conservation honors in Brazil. In 2021 she received the Margot Marsh Biodiversity Foundation Award for Excellence in Primate Conservation. She is the author of many scientific and popular articles, in addition to two single-authored books, including Primate Behavioral Ecology, which was originally published in 2000 and is, as of 2021, in its 6th edition.

An international authority on the critically endangered northern muriqui monkey, which she has been studying in the Brazilian Atlantic Forest since 1982, her pioneering, long-term field research has been critical to conservation efforts on behalf of this species and has been influential in broadening comparative perspectives on primate behavioral and ecological diversity. 

Recently, Dr. Strier sat down with the New England Primate Conservancy (NEPC) to answer questions and discuss her work.

Northern muriqui mother and baby. Photo credit: ©Pablo Fernicola. Photo Courtesy of K.B. Strier

It’s such a privilege to be able to study the muriquis and to have learned so much about them. The more that people understand them and care about them and know about them, then that’s how you can also build interest in muriquis and promote their conservation.

What was the first primate you ever saw in the wild? When and where did this occur?

Yellow baboons, in Amboseli National Park, Kenya, in January 1979, when I was a research assistant on the Amboseli Baboon Project for six months.

Did it change you?

There was a moment in the field, when I was watching the baboons, and I felt like everything I enjoyed—science, animals, and nature—came into perfect alignment. That was a memorable moment that made me realize there was a way to do what I loved.

Karen Strier with Amboseli yellow baboons, 1979. Photo Courtesy of K.B. Strier
Can you share with us a little bit about how you found yourself in the field of conservation? Why primates?    

I always liked science, animals, and nature, and once I had been in Amboseli I knew I wanted to do something with animals outdoors. I wasn’t fully committed to primates per se, though. But when a project I had hoped to join working with bears fell through, I went to graduate school in Anthropology at Harvard University instead. Once I made that decision, I knew I would study primates, at least for my PhD research. 

Primates are special animals because of their long lives and social complexity. From an anthropological perspective, they are the taxonomic group to which we humans belong, and therefore they offer us comparative perspectives. I was interested—and am still interested—in these comparisons. Early in graduate school, I was lucky to find my way to the muriquis in Brazil. The muriquis are critically endangered, which automatically meant that everything I learned about them had relevance, not only for science but for their conservation as well. I love that my scientific research has conservation applications.

Northern muriqui in motion. Photo credit: ©Carla B. Possamai. Photo Courtesy of K.B. Strier
What’s a typical day—assuming there is one—look like in that role?  

I lead at least two lives. One is my university professor life. A typical day might involve some combination of teaching and/or meeting with students both at University of Wisconsin-Madison and over Zoom or WhatsApp with my students and colleagues in Brazil about data. I read as much as possible. 

My other life is when I am in the forest in Brazil. Then it is spending as much time as possible with the muriquis. That means getting to them in the morning and staying with them as they travel for as long as I can, walking up and down trails in the forest with them overhead. Now I also have to keep up with other responsibilities, so full days in the forest are rare, but I try to see the muriquis at least for a few hours every day I am there.

Do you have any amusing or fascinating anecdotes about your time in the field you wish to share?

In terms of studying the monkeys, there were lots of crazy times where it was just amazing. As in: “I can’t believe this is happening.” I had that experience quite often during that first year of my research, when it was just me out there. In my book, Faces in the Forest, I talk a lot about those early milestone moments getting to know the muriquis and habituating them.

Once, the females tried to defend me against a male muriqui from another group. The females were hugging one another overhead and screaming at him. He finally got scared and ran away. Then the females came toward me and reached their arms down as if they were inviting me to hug them. 

Being with the muriquis is also a very sensory experience. For instance, their smell, and how graceful they are—and how beautiful!

These days, I don’t spend as much time in the forest—I have students that do that. I’ve trained about 80 students—Brazilian students. They all have great experiences. Even though I may have seen something already, for them it’s the first time they see it. So, they come back all excited: “I just saw this happen…” “Wow… yeah! They do that sometimes!” The sense of wonder, being able to see wild animals up-close—to see their interactions and study them—is such a privilege.

Most of my funny things, though, actually have had more to do with my interactions with people—mainly from the time before I could speak Portuguese. I was very awkward and clumsy in my language abilities. Anyone who travels to another country will know what I’m talking about. But you realize in those moments how nice most people are—so tolerant and understanding. As long as they know you’re sincere and making an effort, people are usually really nice and appreciative.

Dr. Karen Strier. Photo credit: ©Joao Marcos Rosa. Photo Courtesy of K.B. Strier
You said muriquis have a particular smell?

This is something that I described a long time ago, and I still notice it. They smell like cinnamon. It’s maybe not a big deal for everyone, but for me it was huge. I think they smell like cinnamon because a lot of the leaves they eat happen to be from the cinnamon family.

I don’t know if everyone smells it. But maybe the reason it was such a precious sensory experience for me was because, in the beginning of my research, even if I couldn’t see them, I would know they had been somewhere recently because I could still smell them. That always made me happy because I knew I could find them from their smell.

So now when someone’s baking an apple pie, you’re transported back to the Atlantic Forest?

[Laughter] Not exactly! It’s more of a wild cinnamon. And there are other smells in the forest mixed in with it as well. So, it’s not quite the same.

The converse of all that, of course, is that one of the scariest times in the field was in January 2017, during my first trip back to Brazil in the middle of a yellow fever outbreak. At first, we couldn’t find the muriquis anywhere. Then, it turned out we lost about 10% of them over a 6-month period. That was the greatest loss the population had ever experienced in such a short time. Decades and decades of conservation, and population growth, and efforts to save these animals—publications, research, public awareness, and educational campaigns. Then in just a few months… It is possible for primate populations to be decimated if they are small. Fortunately, the muriqui population had grown enough that this loss could be tolerated. But unfortunately, this was also at a time when many people weren’t vaccinated against yellow fever, so humans were also getting sick and dying.

It was really poignant, and a huge realization of how important everything that we had done was. Having done the monitoring we were able to know what had been going on prior to this outbreak. That was significant. Lots of times in these sorts of situations, when you see lots of animals disappearing, you think you might know what’s going on. But you don’t necessarily have any way to quantify it. We were able to quantify it because we knew exactly who was there before the outbreak.

Now, we’re not actually even 100% sure in the case of the muriquis that it was yellow fever per se, because we have never been able to collect a sick animal and do the immunological studies on them. But the coincidence in time can make us almost certain that it was related to the outbreak.

It was really scary how quickly you could have so much loss, not just in my population of muriquis, but all over the place. And the howler monkeys were such a big part of that forest and the ecosystem, mostly because of their vocalizations. So, losing so many of them—even when I was in Brazil the last two times in January and again in March (2022), I maybe only once or twice saw some howler monkeys or heard them. But it used to be that they were all over the place. One of my former students, now a post-doc, Dr. Carla Possamai, is following the recovery of the howler monkeys and other sympatric primates, while we are continuing to monitor the muriquis.

It’s really sad. It’s not even like you can point to some company and say “these are evil people…” It was a disease. It spread. Most of the people there have been vaccinated now, but there’s nothing to protect these primates in the future.

We’ve all just lived through the COVID-19 pandemic, and we all know a bit about how scary these disease outbreaks can be now.

What sort of precautions did you and your students take during the coronavirus pandemic? Was it dangerous for the muriquis for you to be in such close contact with them?

The field station visitation was closed. The students who were there at the time the pandemic hit Brazil were probably safer being at the field station in such a rural and unpopulated area than it would have been to travel back to their families. Fortunately, no one got sick. Then, when things started relaxing a bit, we always got everyone coming out to the field site tested beforehand. We wore masks in the forest and around each other—practicing all the protocols to ensure everyone was safe.

With the muriquis, because they are mostly arboreal, and because they are more distantly related to us, there isn’t as much of a risk for them to contract respiratory diseases from humans. At least, there’s less of a concern than with more closely related species like apes or baboons or macaques, which are more vulnerable to these human respiratory diseases. Those projects really had to use serious precautions. But we used all the local protocols and kept increased distance. The owners of the reserve closed it down to tourists until we would be more sure that things were safe. I was really pleased that people took such great care and that we could regulate it. We took every precaution possible. Hopefully, we won’t have to go through that again!

Karen Strier (back) and former student/current collaborator Carla Possamai. Photo Courtesy of K.B. Strier
What do you appreciate most about your current job?

I appreciate that my job is all about learning, whether through my own research or my students’ and colleagues’ research, and about sharing knowledge. I appreciate that sharing knowledge is a positive thing, that can challenge and change the way others see the world. I appreciate that my work gives me a chance to contribute to science and conservation. I also appreciate that I have a lot of autonomy about how I spend my time. Maybe because of this, I work long hours and rarely take time off. There is never enough time to do everything. That is occasionally stressful, but more often it is stimulating.

I feel like it’s such a privilege to be able to study the muriquis and to have learned so much about them. The whole purpose of learning all that is to help other people who don’t have the opportunity to study them in the wild to understand that information and put it into perspective so that the muriquis get included in comparisons. Of course, the more that people understand them and care about them and know about them, then that’s how you can also build interest in muriquis and, in turn, promote their conservation.

In addition to them being really unusual and fascinating animals that play an important role in their ecosystem and have a long and unique evolutionary history, they’re also emblematic—symbolic—of what extinction will be for the loss of just general biodiversity. A world where we lose our ability to see or understand or simply let a peaceful species like muriquis live in peace—in their forests—seems like we will have lost something for humanity.

Do you feel like it’s fair that the muriquis get called the “hippy” monkey? Do you feel that accurately represents them?

I like that name. It’s a good description of them. Muriquis are really laissez-faire, peaceful, tolerant, and liberated; I think it characterizes their lifestyle much better than a lot of other terms would.

Can you speak a little about muriquis peacefulness? What makes them different from other notably “affectionate” species like titi monkeys?

If you rank primates along a continuum of the most aggressive and the most peaceful, the muriquis are among the very most peaceful. On that continuum, there’s a lot of variation by species, by habitat, by social structures. If you put primates in an ecologically stressful situation, you can induce aggression almost every time. But in a natural setting that’s relatively stable, then you get to see more of the nature of the animals.

The muriquis’ peacefulness has been something that we’ve seen not only in my long-term study over time (meaning: under very different demographic conditions when the population density was low and high), but also we still see the fundamental basis of this peacefulness and the lack of this agonistic-based dominance hierarchy that you see in almost all other primates under almost all circumstances. With muriquis, we’ve seen this not only in my own long-term study, but we’ve also seen this with all other northern muriqui populations that have also been studied in the wild.

Titi monkeys are quite different because they are living in a family group. So, the males and females are mates, and they’re both mutually invested in their offspring, which are likely to be fully related to both parents. Those are slightly different conditions than the muriquis, which are living in these big multi-male/multi-female groups.

One of the things that contributes to muriquis’ peacefulness, I think—and it would also apply to the titi monkeys—is that males and females are sexually monomorphic or nearly so. This affects the dynamics of physical power between the sexes, so you don’t have males being able to physically intimidate or threaten females. If they’re the same body size and canine size, then females have a lot more autonomy, and then males have to figure out other ways of interacting besides throwing their weight around and threatening others with aggression.

Northern muriqui from Projeto Muriqui de Caratinga. Photo © Pablo Fernicola. Photo Courtesy of K.B. Strier
When you think about your career to date, can you think of a time that you might consider your proudest moment/proudest accomplishment?

There were different moments at different times in my life. It was an amazing feeling to be able to follow the muriquis for days at a time, by myself, after I had earned their trust and could keep up with them.  It was amazing to receive some of the honors and recognition I’ve gotten for my work. I’ve been so lucky in this regard. Maybe the 20th and then 30th anniversary celebrations for my long-term study (with the 40th one coming up in June 2023)—these were proud moments because they included all of the students and colleagues who have helped make this long-term continuing study, and all we have learned and been able to do for conservation, possible. I really can’t name just one thing, though. So many accomplishments represent collaborative efforts and I love it when everyone can celebrate together.

When you think about the state of primate conservation today, what brings you the most concern?

I worry about running out of time. There are a lot of problems in the world and we need to ramp up our efforts to deal with climate change and habitat loss and hunting pressures.  

An important reserve dedicated to the northern muriqui is the Reserva Particular do Patrimônio Natural-Feliciano Miguel Abdala, located in the state of Minas Gerais. The reserve is named for its founder, Feliciano Miguel Abdala (1908–2000), a private landowner and passionate conservationist, who established the reserve as the Caratinga Biological Station in 1982.
Karen Strier with Senhor Feliciano in 1988. Photo Courtesy of K.B. Strier
What might you say to someone struggling to understand why northern muriqui conservation is important?

This is one I get a lot, even from friends and family. In addition to them being really unusual and fascinating animals that play an important role in their ecosystem and have a long and unique evolutionary history, they’re also emblematic—symbolic—of what extinction will be for the loss of just general biodiversity. A world where we lose our ability to see or understand or simply let a peaceful species like muriquis live in peace—in their forests—seems like we will have lost something for humanity. Apart from all the insights of what we might learn about behavior from ourselves, and behavior alternatives to aggression, and dominance hierarchies, and competitive behavior—we lose biodiversity. Biodiversity is important for human well-being and the whole world’s. There is so much we don’t know yet about muriquis and the role they play in their ecosystem—and still so much we don’t know about how different parts of the environment are important for human well-being. I think it’s our job as humans to protect as much as we can. I don’t think we have any right to take away the future of other species.

What brings you the most hope? 

There are a lot of amazing people dedicated to working to save primates, and in most cases we have the knowledge and technology and personnel that are needed. For example, on my project we have used non-invasive methods—based on analyses of dung collected from individual muriquis—to learn about fertility and stress, and about genetics. One of my former post-docs and colleagues, Dr. Fabiano de Melo, has pioneered the application of remote sensing and especially drone technology for locating muriquis and other endangered wildlife in places where more traditional survey methods are not effective. Arboreal cameras are also being used now with great success by other muriqui researchers, and I am interested in merging these remote methods of monitoring the monkeys with others that include vegetation and acoustic analyses.   

We know what we need to do to save muriquis and their habitats, and there are many people eager to implement these plans using the most advanced and least invasive methods possible. These are the things that give me hope. Now it is just a race against time.  

Northern muriquis from Projeto Muriqui de Caratinga. Photo: ©Pablo Fernicola. Photo Courtesy of K.B. Strier


To donate to Karen Strier’s research project to protect northern muriquis visit:

Textbook: Primate Behavioral Ecology by Karen B. Strier

Other publications by Karen Strier:

By Zachary Lussier, June 2022