Updated: Aug 8, 2021
Primate Wonder had the pleasure to sit down with Jenna Lawson to chat about her conservation work in Costa Rica and why she thinks primates are such an important species to study.
Jenna is in her final year of her PhD studying Landscape Ecology at Imperial College London. She has been studying the Geoffroy’s spider monkey (Ateles geoffroyi), an endangered species extending over much of central America. Jenna’s PhD aims to encapsulate the protection and restoration of Geoffroys’s spider monkey in their home range through connecting suitable habitats within the Osa Peninsula, Costa Rica. As well as working on her PhD, Jenna works alongside a long-standing conservation organisation in Costa Rica as an advisor. Here she has put her many skills to use through assisting with their redevelopment and contributes to their conservation programmes.
Q: Why did you decide to study primates? Were they your first choice to study? A: No actually, primates were never the intention with my PhD. It just so happened that primates were the best study species for my topic. The main intention for my PhD was originally to understand why there was so much biodiversity in and around Corcovado National Park in Costa Rica and not in some of our other study sites. We always knew that the Geoffroy’s spider monkey (Ateles geoffroyi) was a key species that was only present in and around the park, and it is well known that these primates can engineer healthier forests and increase biodiversity. I believe primates were the most important species to study in this case, due to their status as keystone and umbrella species. So, it was obvious that if we protected the spider monkey and their habitat in the region, you will in turn protect other species. The spider monkey is one of the most forest sensitive species, being completely reliant on the forests for survival and not crossing even small open spaces. Other species such as jaguars can pass through plantations and other human environments such as pineapple farms, whereas a spider monkey simply can’t, and won't. If we consider an arboreal species such as the spider monkey, the literature states that it’s the first species to disappear with disturbance and once you restore an area it’s one of the last species to come back. So, for us it was obvious that Geoffroy's spider monkey was what we needed to study to fully understand the difference between our study sites.
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WHAT IS A KEYSTONE SPECIES? A keystone species is an organism that has an excessively large effect on its natural environment relative to its abundance. This species places a key role in maintaining the structure of an ecosystem.
WHAT IS AN UMBRELLA SPECIES? An umbrella species is an organism that is typically chosen to be protected for conservation purposes. This is mostly due to this species indirectly protecting many other species within the ecosystem.
Q: Tell us a bit about your PhD? A: My PhD has focused mostly on the bioacoustics of Geoffroy's spider monkey’s along with a variety of different components. One of our study sites Corcovado National Park, which contains most of the Geoffroy's spider monkeys in Osa Peninsula, Costa Rica generally has a high rate of biodiversity. In the middle, there is a matrix of towns, villages, plantations and grasslands. Here, we are aware of hunting and illegal logging occurring to make way for palm and other plantations. But throughout this matrix of human activity there are also pockets of fragmented forests. Further north of our study area there are two national parks, Terraba-sierpe wetlands and Piedras Blancas National Park. Oddly, spider monkeys are just not found in these regions. So, it seems our focal animal, the Geoffroy's spider monkey, is stuck in this one national park which it is cut off from other surrounding habitats. As the spider monkeys can only be found in these and a few other locations in Costa Rica, this poses risks for this species and other biodiversity in the area as, for example if there was ever a natural disaster, we would face losing a large chunk of the wildlife populations in this region.
Osa Peninsula, Costa Rica - Jenna sampled three study site through her PhD to understand the ecology of Geoffroy’s spider monkey (Ateles geoffroyi).
A: So, the aim of my PhD became two-fold, to understand why Corcovado National Park is so rich with biodiversity compared to other sites, and to understand why the spider monkey could not disperse across the area to these other national parks. Once it is understood why spider monkeys are not dispersing to other areas, then the final goal is to produce a habitat suitability map, a biological corridor and management plan for the area. With this we can help advise local governments and NGOs about how best we can connect the study areas to produce further habitat for wildlife. To do this, a large chunk of my PhD is trying to find out where the spider monkey occupies where they do not and to identify different components that may be preventing them from dispersing, such as human presence, road construction, hunting, illegal logging, land use for plantations, grasslands etc. as well as such variables as elevation. We use all these different components to determine what the problems may be by comparing the presence of the spider monkeys in each area.
WHAT IS A HABITAT SUITABILITY MAP? A Habitat suitability map is a map of the probability of suitable habitat for an at-risk species (NatureServe.org).
Q: You are still in the process of completing your PhD. But why do you think spider monkeys may not be present in these other patches of forest? A: From our initial results we can see that there is a restriction in the area between these national parks. The spider monkeys will not use the grasslands, palm and teak plantations or urban areas, they also do not go close to paved roads in the region, and it is a mix of these factors that seem to be preventing them from dispersing past certain points. I also suspect it might be related to food sources as they only feed on mature fruit and perhaps there just isn’t enough mature fruiting trees in these areas, however we cannot calculate this and can only make suggestions from other studies. It could also be hunting, with the region that they do not seem to pass being a higher risk area.
Geoffroy’s spider monkey (Ateles geoffroyi) | Photo Credit: Jenna Lawson
Q: What methods were used to determine species richness of your study areas? A: To determine general biodiversity in an area we are using a form of soundscape analysis which uses sound to determine the general health of an area. You can take a recording and say, ‘OK, there are 50 sounds on this recording from 20 different sources.’ From this data you can compare with other habitats such as palm plantations that may find only 10 recordings from 1 source. We don’t know what is making the sounds we just know there is more or less sounds in different areas. So, from this method you can describe the richness of the area you’re interested in.
Jenna used a piece of equipment called AudioMoth to gather audio data from the spider monkeys | Photo Credit: Jenna Lawson.
Q: Why was sound your chosen method? A: Bioacoustics was the main method used in this project. I produced a pilot study on which method could be most effective for this study. We tried drones to identify the spider monkeys in the canopy, and tested line transects. We found that the landscape we are working with just wasn’t suitable for many of the traditional methods usually used in this kind of project. For example, with the line transect method; firstly, we were unable to cut the transects into the landscape as in some national parks it is not permitted, and a large part of our study area is just a matrix of land owned by hundreds of different people. Second, the landscape is so elevated that even if we had the permission to do transects there would be areas where we just wouldn’t be able to get through. So, bioacoustics won us over.
WHAT IS A LINE TRANSECT? A line transect is a scientific method used to measure the distribution of organisms. The method consists of a tape or string laid along the ground in a straight line between two poles. This provides a guide for researchers, who will then walk the length of the transect several times to collect data.
Q: Why is bioacoustics the most appropriate for studying specifically the spider monkey? A: Spider monkeys are extremely vocal, so this was perfect. The equipment is recording constantly, so we can gather 24 hours of surveys; even better. This is a huge amount of data compared to methods where we would be recording the spider monkeys ourselves for an hour or so per day for example. But, with a large amount of data comes a large amount of analysis. With collaborations, from very talented data scientists in Imperial College London we have now developed a specialist AI (Artificial Intelligence).
An Audio recording of Geoffroy’s spider monkey (Ateles geoffroyi) | Audio Credit: Jenna Lawson | Video: Canva
Q: How does the AI model work? A: It’s basically us training a machine to do what our ears can do. For instance, we could sit for hours picking apart a recording and making a note of every time we hear a spider monkey call. This is extremely labour intensive and not particularly an accurate method. We have about 60,000 hours’ worth of data, I think it would probably take about 30 years to listen to the full data set. Which is where the AI comes in. We are training an algorithm to do this for us. You generally need 500-1000 good examples of the noise you aim to teach to the AI algorithm and then you are training this algorithm to recognise this sound. Also, the more that the AI hears of the data set, the better accuracy it will have to pick up this sound. Q: What do you hope to achieve in the future with this new developed AI model? A: With the data we have collected throughout my PhD and the development of AI we hope to roll this out throughout the whole of Latin America so other researchers can use acoustics to study the spider monkey, in what we believe is a non-invasive method to cover a large region and study this species at a landscape scale. Providing this AI software to others studying spider monkeys will save a huge amount of time as they won’t have to spend long periods of time compiling the data like we did. It took us 2 years to produce the machine learning model (the AI) for the spider monkeys, which hopefully wouldn’t be necessary in future studies.
Q: What do you think needs to be addressed in the future to encourage the spider monkeys into new territories? A: We are still to complete some final pieces of analysis. However, we believe that forest needs to be protected and/or restored in the region between these national parks and corridors built across major roads. As hunting and illegal logging takes place in the region, it will also be important to work on ways to reduce these threats. I think we (biologists) also need to collaborate with social scientists who are working on the ground with communities, and we need to come together to achieve these goals. If the community and the economy is not healthy then it doesn’t matter what we do to try and prevent primates going extinct, if people do not have sustainable opportunities, then it is becomes difficult to protect forests and prevent hunting and logging.
Left to right: Jenna and the team she worked with for fieldwork; Jenna educating students in Costa Rica on her work in acoustics, snippet of the vegetation of one of the field sites; Jenna Lawson | Photo Credit: Jenna Lawson.
For the next generation of conservationists, conservation must stem from collaboration, innovation and implementation. Through working with experts and people on the ground, conservationists can design new methods to practice and apply long-term plans to conserve wildlife facing extinction. As Jenna Lawson's PhD shows, research is of pinnacle importance for the survival of all species, and the more we discover species specific preference to pristine habitats and human disturbed habitats the better chance we have to secure the future of primates, and other wildlife.
We would like to say a huge thank you to Jenna for taking part in this series and collaborating with us.
If you are a part of an incredible NGO helping with primate conservation, or are currently studying primates and would like to share your work (or know of someone else's awesome work), Please don't hesitate to get in touch to be featured. If you are interested email us at firstname.lastname@example.org