- Conservationist Yap Jo Leen launched the Langur Project Penang after witnessing dusky langurs, an endangered monkey she was studying for her Ph.D. research, getting struck by vehicles on Malaysia’s Penang Island.
- Since 2019, her group has built three canopy bridges made from repurposed fire hoses to help langurs and other tree-dwelling wildlife safely cross busy roads, with no recorded langur roadkill deaths at the first bridge site since its installation.
- The project combines wildlife conservation with citizen science and environmental education, training volunteers to track langur movements, collect ecological and social data, and work with local communities to reduce human-wildlife conflict.
- Yap says the long-term goal is not simply to build more wildlife bridges, but to foster a broader culture of coexistence and community stewardship for urban wildlife across Malaysia.
TANJUNG BUNGAH, Malaysia — When Yap Jo Leen was tracking dusky langurs in the forests of Penang for her master’s degree in 2016, she watched a langur they called Towkay Soh — Hokkien for “lady boss” — get hit by a car while trying to cross a busy coastal road. Dazed, the langur managed to get back on its feet and retreat into a tree while Yap and her colleagues blocked traffic.
As Towkay Soh recuperated over the next few days, the langur group’s empathy for each other was on full display, Yap says.
“Female individuals, they would approach her and groom her and even try to make her feel better,” Yap says. “I always believe that the primates, humans and monkeys, we all share a similarity, which is connection.”
Other langurs weren’t so lucky. From 2016 to 2018, Yap recorded eight langur roadkill deaths in the same area.
So, in 2019, Yap and her collaborators built an artificial canopy bridge over the road, made from old fire hoses. Since then, they’ve recorded zero langur roadkill deaths in the area, Yap says.
Since 2023, the group has built two more canopy bridges on Penang Island. Besides reducing roadkill and mitigating human-wildlife conflict, the bridges serve as a tool for environmental education on an island where rapid urbanization and habitat loss is driving people and primates into contact.
To study the langurs and help people learn to share an environment with them, Yap deploys a team of volunteer citizen scientists who track langur movements, collect data, and record GPS coordinates, under the banner of an organization she founded, the Langur Project Penang (LPP).
LPP also conducts outreach into local communities to teach people how to coexist with wildlife. A former citizen scientist now leads LPP’s environmental education program, which involves conducting training for schools and companies. They have a partnership with a local international school, for example, to teach kids how to develop a system of codes for studying Penang’s exotic squirrel species on their campus and log their behavior. Revenue from the program feeds back into LPP’s conservation work.
“Primate observation is more than just scientists’ work — it can be everyone’s hobby, like bird-watching,” Yap says.
Yap spoke with Mongabay’s Philip Jacobson and AFP’s Isabelle Leong in Tanjung Bungah, the site of one of LPP’s canopy bridges, about her work in Penang. The following interview has been lightly edited for length and clarity.
AFP and Mongabay: What is the Langur Project Penang and how did it start?
Yap Jo Leen: LPP is a primate conservation enterprise that’s focused on fostering coexistence among humans and urban wildlife, especially nonhuman primates, a.k.a. monkeys. We work on three pillars: First is citizen science; second, environmental education; and third would be scientific conservation projects such as the installation of canopy bridges.
AFP and Mongabay: What prompted you to launch LPP, and what gap in conservation are you trying to address?
Yap Jo Leen: I started Langur Project Penang from a simple Facebook page back in 2016, when I was just starting as a postgrad student working on my master’s and Ph.D. I just worked on it as a journal online to share my experience working in the secondary forest of Penang, and also to talk about the individual langurs that I knew from my observation. And eventually it just grew, and I had very huge support from my supervisor and co-supervisor from that time, Dr. Nadine Ruppert and Dr. Nik Fadzly. They encouraged me to do my own thing. So I feel that the opportunity and freedoms that I gained helped me to develop LPP into a primate conservation enterprise, which we came a long, long way.
I feel like for the youth nowadays, they are not given a lot of opportunities in terms of gaining hands-on skills in on-the-ground grassroots conservation efforts. So for Langur Project Penang, we have shifted from just pure research more towards community engagement and citizen science initiatives, which I would like to provide more opportunity in terms of capacity building as well as career chances for the youth and also the existing generation around us.
AFP and Mongabay: Can you tell us more about these dusky langurs?
Yap Jo Leen: Dusky langurs, they are indeed my favorite species of primate, better than human primates [laughs]. We can actually find them not only in Peninsular Malaysia but also Myanmar and Thailand. We address them as “arboreal” primates because they rely on canopy and treetops for survival. So they need certain food plants, which are high up in the canopy: fresh leaves, fresh fruits, fresh flowers and seed pods. We can find all these plant varieties not only in the virgin forest but also in secondary forests, even green spaces around our residential area.
Dusky langurs, they have white spectacles. This gives them many nicknames: Some people call them the dusky leaf monkey or even spectacled leaf monkey; some people call them the white spec monkey; some people call them the black-and-white panda monkey. So I think this uniqueness of the white marking among the black-grayish fur, it leaves a very good impression in people so that people can see them as an adorable species, and at the same time as something to remember from Peninsular Malaysia.
In Penang, we are very lucky to find dusky langurs as the ambassador species, where a lot of tourists from all around the world will drop by Penang just to do monkey observation or nature appreciation as a whole. Even though it’s the second-smallest state in Malaysia, Penang is such a rich-biodiversity landscape that I think as Penangites, we really need to educate further for more Penangites to truly appreciate the value of coexisting with our nature.
AFP and Mongabay: Are there misconceptions that people have toward dusky langurs?
Yap Jo Leen: I think we have to explore this from two different perspectives. If we are living in a place where nature and urban coexist really well, when we see nonhuman primates such as dusky langurs coming into our residential area, if we still have sufficient connectivity around our residential area, people may value them as a natural heritage. But if we are talking about the landscape being divided, or “habitat fragmentation” to be precise, then more people will see our urban wildlife as a kind of nuisance, or even as intruders entering their residential area, their comfort zone. So there will be lots of misunderstandings occurring on the ground. So there’s a lot of work to be done, especially in informing the residents regarding why do the urban wildlife and dusky langurs come to your area, and what are the human strategies that we can develop together as a community that’s co-sharing spaces with our urban wildlife.
AFP and Mongabay: How did the idea of these canopy bridges come about, and why was it chosen as a solution?
Yap Jo Leen: I think it has to be traced back to 2016, when I was just starting as a postgrad student, following a group of dusky langurs. We call them the Ah Lai family. Lai is actually a native dialect of Hokkien, it means “welcome,” “come.” So Ah Lai is my first love, the first dusky langur that I studied in the secondary forest of Penang, located in Teluk Bahang.
As I was following them throughout their home range, which consists of the hills and the sea, and also through the ecotourism sites around the area, I realized they don’t just stay in the forest; they also come out to cross the road to the coastal region to look for food as well as to cover the beach site as part of their home range. So throughout the observation, especially 2016 to 2017, we recorded lots of road-crossing activities, as well as people living around the area reporting to us, mentioning about the road-crossing behaviors of the dusky langurs, and the macaques as well.
An idea struck: Why don’t we do more than just behavior observation? We can actually intervene to try to make people more aware of the risk of roadkill to animals. And secondly, maybe we can try to build bridges. Back in 2017, this idea was wow, because no one in Malaysia had actually done it before, especially in urban areas. I started to contact my former supervisor, Dr. Nadine, and talked to some mentors. And eventually I met APE Malaysia [who] introduced me [to] this fire hose thing, and I was very, very new to such materials as well. And after them sharing regarding the zoos in America that use fire hoses as hammocks or even as some enrichment materials for the animals in the zoo, we decided that maybe we can try this approach, as [the materials are] free, it’s donated by fire departments. So this is how the whole idea started. It’s all experimenting, trying, beginning with curiosity.
AFP and Mongabay: I understand one of the langurs from the first family you followed actually got hit by a car. Was that part of what led to the bridge idea?
Yap Jo Leen: Yes, it is. One of the female individuals that we study in Ah Lai’s family, we call her Towkay Soh. Towkay soh [in] Hokkien means “lady boss.” She’s actually the eldest female adult individual in Ah Lai’s group.
When I started following Ah Lai’s family, he has a group of 17 to 18 individuals, I remember vividly there was one evening, because I was doing the 12-hour shift of sampling, fieldwork, and Towkay Soh and her infant accidentally got hit by a car. Thank God it was just a mild momentum crash. And Towkay Soh managed to get up from the road, and we were trying to block the traffic so that Towkay Soh could retreat up to one of her resting trees nearby.
We observed Towkay Soh continuously for a few days after that and realized that she has been coping, resting up on the tree. And it’s quite amazing because we also saw female individuals approach her and groom her and even try to make her feel better. So some people would say we are actually projecting emotion towards the animals, and it caused us to think in a very empathetic way. But I always believe that the primates, humans and monkeys, we all share a similarity, which is connection. We have the connection among each other, which is something that we all have to learn from animals.
AFP and Mongabay: Can you walk us through how these bridges work and how the langurs have responded to them?
Yap Jo Leen: So far we have installed three bridges. The first bridge, Ah Lai’s Crossing, is located in Teluk Bahang. Since we installed Ah Lai’s Crossing back in 28th February, 2019, it was a very simple design, just a long fire hose twisted to mimic tree branches and then hung in the air with a pole on one side and three on the other end.
It actually took only three days for the first long-tailed macaque to cross the first prototype of Ah Lai’s Crossing. So it was amazing. And then the plantain squirrel followed after that. But guess what? Dusky langurs, it actually took them nine months to make the first crossing on Ah Lai’s Crossing. Can you imagine, for the first nine months you’re anticipating the dusky langur, the target species, to cross, but it never crossed. But in the end, right now, Ah Lai’s Crossing has multiple crossings per week. And I have been checking the [camera-trap] footage once every two months, and langurs and macaques, they are coexisting, sharing the highway together. Even plantain squirrels, even civet cats, and also Sunda slow lorises, and even paradise tree snakes — presently, we have nine species of wildlife using Ah Lai’s Crossing.
The second bridge, Numi’s Crossing, we installed back in 6th February, 2024. Numi’s Crossing is considered the first artificial road canopy bridge to be installed in a high-density residential area [in Malaysia]. This residential area is unique because it’s close to the hills and not too far from the sea as well. But even though the hills look near, it’s actually quite far away for the animals, their habitat being fragmented.
So in the Numi’s Crossing planning, we actually considered lots of different elements during the designing. One of the elements would be Ah Tan. Ah Tan has a stump tail due to the fact that he broke his tail during one of the overlapping group fights. Due to his short tail, he’s unable to balance himself on a vertical design like Ah Lai’s Crossing. So we created this bridge in a horizontal design just to help him cross a little bit better. But surprisingly, after we installed Numi’s Crossing, Ah Tan and his family crossed on the sixth day, the whole family just taking turns crossing over, and they crossed very comfortably. So it brought a sense of release because it’s a new design and we weren’t sure.
At the same time, we have also observed that Ah Tan and his family are spending significantly less time in the neighborhood that they used to be trapped in. Not to emphasize the word “trapped” — it’s like being fragmented and divided. And so right now they have more opportunity to venture out from the road, to venture closer to the hills where maybe this is where they belong.
We just installed the third bridge, the Obscura. The Obscura is like an extended version of the first two bridges. The first bridge, Ah Lai’s Crossing, is to help the dusky langurs and the treetop animals cross the road safely. The second bridge, Numi’s Crossing, is to help the langurs cross the road safely, but also to foster coexistence among the people that live in this residential area with the langurs around them. And the Obscura is also to try to encourage Penangites and Malaysians to have a more respectful approach towards nature, to practice sustainable ecotourism as well as ethical human-wildlife interaction.
Batu Ferringhi [the location of the third bridge] is actually one of the major tourism sites in Penang. There’s such a high density of tourists coming in, from all around the world, and you also have a small group of local communities still staying in that area. So you have a mix of different people of all walks of life. And when there’s people, you have issues happening on the ground, like the environmental issues of waste management and interaction with wildlife. So the third bridge is more about cultivating responsible human-wildlife interaction, because there are lots of issues of inadequate waste management, and also people feeding wildlife. Not only monkeys, but also pigeons, and also all sorts of wild animals that we can find starting to appear in nearby urban areas.
AFP and Mongabay: Do you have any figures you can share in terms of a reduction in roadkill or of langurs going to neighborhood areas?
Yap Jo Leen: First of all, I would like to emphasize again, this area is full of residential areas: There’s Residential Area A, B and C. Ah Tan and his family used to be observed almost on a daily basis at one of the residential areas, Taman Concord [Residential Area A]. So complaints were arising from the ground, and we worked with the state government agency as well as the local community over there trying to figure out why Ah Tan and his family always spent their time in this Residential Area A. That was the question, right.
So we gathered data for almost a year — data on their activities, their diet, their movement and road crossing counts and how they utilize different sleeping sites and different routes as part of their home range in Taman Concord. Throughout the one year of observation, alongside our citizen science initiative on the ground, we were able to see that Ah Tan and his family were actually trying to cross over to the other side of [where] Numi’s Crossing [is now]. But they found it very difficult to cross. We saw individuals attempting to cross, but they would make a U-turn halfway or even go under the road itself. There’s a stream under the road where they were willing to risk their lives to cross [due to the presence of dogs and, during the rainy season, fast waters] along the stream rather than walk on the road itself.
We also did ethnography work, interviewing people in Residential Areas A, B and C, the neighboring communities next to Taman Concord, because the location of Numi’s Crossing is actually in the center of different community spaces. We interviewed around 130 random residents. We realized that different types of communities living around this road, they all have different perceptions. Some of them may see langurs more, some of them may see langurs less. So from their description and storytelling, we were able to work with anthropologists as well as citizen scientists to measure, OK, where do Ah Tan and his family usually like to go? And who are the residents that have the loudest voices to express regarding the negative interaction between their experience and the dusky langurs? And who are the individuals that we can actually work together with long-term in cultivating and fostering a better relationship to help people and monkey coexist together?
So [for] all this we have data in the form of codes representing different types of perceptions. And we also have data, like a thousand different data points that represent the GPS coordinates of the monkeys, as well as activity data and dietary data. So the social science aspect of the data is integrated with the ecology behavior part of the data, and these two elements are combined to produce stakeholder reports. And the stakeholder reports allow us to simplify it further into layman’s data and share it with the different stakeholders. And only from there we’re able to convince the stakeholders and get the bridge up. So it’s a long process. I would say one bridge takes one to two years.
AFP and Mongabay: How urgent is the situation for dusky langurs in Malaysia considering they are endangered?
Yap Jo Leen: Most primate species all around the world, and in Malaysia as well, they are near threatened and endangered. So I’m not going to be biased towards dusky langurs — I’m going to say that all urban wildlife needs immediate attention. Immediate attention doesn’t mean that we have to save them from the endangered or even a near threatened status. To me, the urgency is on the awareness part. And for us, people see us like the accountable party to actually do all this education work on the ground. But to me, I want to motivate more people to be stewards of nature and wildlife in Malaysia. Because through education, even though some people find “education” a very subjective term, something that should be done in school, something that should be done in the family, why don’t we all work together instead of saying, “Oh, you are scientists, you can save the species.” No, regular people can be citizen scientists, regular people can speak a word for our squirrels in our backyard. Because everyone can definitely change someone’s mind as long as we try. And for LPP, building bridges is what we choose to do. And we really hope that more people will get inspired by our action. It’s a collective action.
AFP and Mongabay: What exactly is a citizen scientist?
Yap Jo Leen: Citizen science means that everyone, not just professional scientists — it could be a 12-year-old kid, it could be a 50-year-old man, it could be a 64-year-old senior citizen — everyone can contribute towards science and conservation by helping professional scientists in terms of on-the-ground conservation or even science data collection. There are already many, many successful citizen science projects. For example, in Singapore, the Raffles banded langur project, Dr. Andie Ang, she works with Singaporeans that sign up as her citizen scientists to follow the Raffles banded langur in Singapore in order to get more information regarding their well-being. So I really wanted to cultivate that scene in Penang, even though we should motivate this scene throughout Malaysia, but of course we need to start somewhere localized. And for me, labeling the platform as citizen science gives acknowledgement to individuals, so that they know that what they are doing serves an impact. And the impact is sustainable, long-term, and most importantly is transferable. This is really important. Most of the time, science is very difficult to transfer because it requires very technical skill and very precise outcomes of the research. But citizen science makes science less complicated, more enjoyable. I think we need to reframe conservation as conversation so that we start from conversation to bring more attention towards conservation.
AFP and Mongabay: You call your citizen scientists, your team, the Duskies. How many Duskies do you have?
Yap Jo Leen: Even though I started to have my friends and family join me as assistants back in 2016, I wasn’t aware of the term citizen scientist until I think the beginning of COVID. So I think we’ve already had nearly 150 individuals sign up as Duskies. But if you talk about current active Duskies, which means the long-term citizen scientists, it would be 15 to 18, who are very active in fieldwork.
Citizen scientists, we categorize them as two types. The first type would be the on-site citizen scientists that we equip with skills for data collection, and also social science, ethnography-related work as well. It requires long-term training: They need to commit to at least three months, and also they need to commit to at least once-a-week involvement in citizen science fieldwork. They need to learn how to use a pair of binoculars, and some of them find this very challenging because of dizziness or even neck ache looking up at the trees, the buildings, etc. But once they realize that, wow, the individuals that they are following, the dusky langurs and long-tailed macaques, they have their own traits and personality, every citizen scientist will gain their new favorite monkey of the month or even monkey of the year or even favorite monkey forever. So I think this is the personal connection that develops between the monkeys and the citizen scientists. And it’s also taught us something: If you love something, it doesn’t mean you have to occupy it, you don’t have to touch it, you don’t have to feed it; most important is to appreciate them from a safe distance and also respect them through ethical ways. So by being a long-term citizen scientist with Langur Project Penang, you’ll learn about the importance of community outreach, the importance of ethical animal observation, and be able to be a trainer for the younger generation or new batches of trainees as well.
And second, citizen scientists can remotely share data with us regarding monkey sightings in towns, cities, recreational forests, anywhere they go, because we still need to understand where can we find what kind of monkeys are in different areas of Malaysia, right? And for us, we can’t travel all around Malaysia in a short time in order to understand the population distribution. So by working with the people who are generally interested to share regarding their monkey photos, sightings, videos, all kinds of valuable data, we also take this opportunity to reach out wider so that those people living in Selangor, for example, they also can be the ambassador of the species of their own. It doesn’t mean you have to be a member of LPP to do that. Like I mentioned before, everyone should be stewards for nature and also wildlife.
AFP and Mongabay: What sort of data does the first type of citizen scientist collect?
Yap Jo Leen: For our long-term citizen scientists, we teach them how to recognize individuals. When they’re able to recognize individuals at least to the sex/age classes, for example male, female, juvenile, infant, or at least to be able to tell the individuals apart, then we’re able to collect data on their activity patterns, and we also observe what they are eating. For example, the food plant leaves in the forest can be very different than the food plant leaves in urban areas. So all this plant information is very valuable because we share with the different stakeholders if some of them would like to do a reforestation project, or we share with researcher friends from different parts of Southeast Asia to compare what are the langur species in general, their feeding, are they similar or different.
At the same time, the citizen scientists also track the langur movement. We don’t have radio tracking on animals; we track them by observation, so that we’re able to understand how they utilize their whole home range per day, or even per morning or afternoon. And most importantly, we engage with local people to observe the interaction between the monkeys and the people at that particular site so that we’re able to get different types of perception sharing from those who are observing monkeys and use that opportunity to raise awareness and educate further.
AFP and Mongabay: Do you and the citizen scientists have an app or software that you use to record your data?
Yap Jo Leen: For the data collection, like for a description of their diets or their interaction with other animals and people, we use simple Excel sheets. Our citizen scientists, they range from age 17 to 65, so we wanted a platform that is accessible for everyone. So an Excel sheet with an observer and a data collector works really well.
In order to mark the location of the dusky langurs, where they go in the morning or throughout the day, we use a hiking app known as Wikiloc so that we’re able to pin down their location coordinates precisely every 15 minutes. As well as using the iNaturalist app, our favorite app, so that we can learn more about the local bird species, butterflies and, most importantly, to identify the food plant species that the monkey is feeding on. That is the learning stage for the citizen scientists to use the iNaturalist app for identification, but of course, we still do accurate identification of the plants afterwards.
AFP and Mongabay: What would success look like for LPP in the next five to 10 years? Do you plan to build more canopy bridges?
Yap Jo Leen: This is a very tough question. But to me, I would like LPP to be a platform where youth can shine. I’m nurturing lots of youth individuals like [LPP project executive] Hui Yi [Long, a former volunteer citizen scientist]. She’s my mentee; I really hope that individuals like her, role models like her, can continue to inspire more in the younger generation to come.
For me personally, the goals of LPP will be very people-centered. I want to work with more community types and create more capacity-building opportunities to guide people. I don’t want to use the word help; I want to use the word guiding them, and even motivate them. Because if I can do it, everyone can do it. I started from just being confused, but it’s all about the passion and hard work. Even though passion is one thing, hard work is another thing, but I’m sure there’s a balance between it.
So more bridges or no more bridges, it depends. I wouldn’t set myself a KPI of how many bridges I want to build in Malaysia. For me, it’s all about trying to influence more people to be a better Malaysian, kinder Malaysian. That is my goal. It sounds very simple, but it’s a very difficult task, especially when you’re working on people-centered conservation work.
For LPP, we would like to get more involved with local academic institutions so that we’re able to publish our data. But I’d also really like to expand LPP into a foundation so that we’re able to get more support in terms of grants, or even enhance our own environmental services revenue so that we’re able to assist and motivate more youth to get engaged in wildlife conservation work in Malaysia.
Banner image: Langur Project Penang founder Yap Jo Leen teaches children about canopy bridges during an environmental education session. Image by Wong Hui Yi/Langur Project Penang.
This article is part of a reporting project between Mongabay and Agence France-Presse (AFP).
In Malaysia, a bridge helps endangered langurs and humans coexist
Credits
This story first appeared on Mongabay
This article is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.
You may republish this article, so long as you credit the authors and Mongabay, and do not change the text. Please include a link back to the original article.
