Flir thermal cameras are supporting ground-breaking stress research in great apes by scientists at the University of Sussex, UK.
These advanced thermal cameras help ecologists see fluctuations in nose temperature, a known indicator of stress levels. It is hoped that the study will help researchers in a variety of ways, including identifying which chimpanzees and gorillas in sanctuaries are best suited for release into the wild.
Among the people central to turning these ambitions into reality is lead researcher Gillian Forrester (PhD, SFHEA), professor of comparative cognition in the university’s School of Psychology.
“Through the process of evolution, we look at how we became the intelligent, walking, talking, tool-wielding great apes that we are today,” she explains. “It’s effectively a proxy for looking at what we do and don’t share with our common ancestors.”
One factor common to ancestral species is stress, particularly the way individuals respond to biological stress.
“When we feel stressed, overwhelmed, or fearful, changes occur in blood flow to the face. Our nervous system reroutes blood in the face to other sensory organs, such as the eyes and ears. This helps individuals look for and hear danger. The resulting side effect is that your nose gets a little colder as the blood moves away. We call this “nasal soaking,” and it’s been an interesting avenue to explore in stress response and recovery. ”
Assessing nasal depression using the translational capabilities of Flir thermal technology allows ecologists to overcome current scientific limitations. Currently, assessing stress typically requires connecting subjects to heart monitors, blood pressure monitors, pulse monitors, etc., which not only induces stress in itself, but is clearly inappropriate for chimpanzees and gorillas.
Field survey
The research team is working with wildlife parks in the UK and chimpanzee and gorilla sanctuaries in Africa. Most people in these shelters have experienced some level of trauma in their past.
“Assessing their stress levels could allow us to better manage their rehabilitation, identify suitable candidates for release, and consider new types of interventions by targeting those who are not released,” she explains. “For example, it could also help identify good adoptive mothers for incoming baby monkeys.”
This research, facilitated by Flir T1020 uncooled camera technology and A6301 cooled camera technology, will help the team understand the healthy and unhealthy ranges of nasal droop. It also helps discover how quickly individuals recover after a stressful event, providing an indicator of resilience and self-regulation.
beyond what the eye sees
From the outset, Flir thermal cameras have proven to be the technology that facilitates this important research. The University of Sussex team initially used a portable and easy-to-use infrared scientific camera, the Flir T450sc. But in early 2025, ecologists moved to Flir T1020 (T1K) primarily for HD-quality thermal images, packing more detail into each image than ever before.
This research combines Flir’s uncooled TK1 camera with the highly sensitive cooled A6301 camera, each selected for a variety of environments, from field observation to research in managed reserves.
“We intend to use two different types of sensor technology, uncooled and cooled, depending on the specific data collection activity,” Professor Forrester reveals. “Both sensors have their benefits, but we use the high-sensitivity cooled MWIR sensor in the Flir A6301 to achieve an additional level of image detail in static studies.”
At the sanctuary, a screen next to the enclosure plays a video that elicits a negative (stress) or positive response. The researchers set up a static Flir A6301 cooled camera to study nasal depression as individual apes spontaneously walk forward to watch the video.
area of interest
In particular, the Flir cooled thermal camera will allow Professor Forrester and his team to create regions of interest on the face and collect data. To ensure suitability, ecologists require a threshold of at least 50 pixels per region of interest. In this case, the high resolution of the Flir A6301 proves to be important. Additionally, the high sensitivity (3-5 μm) of these cooled cameras allows researchers to detect respiration/breathing as thermal images, allowing another interesting biological measurement.
In addition to static studies using cooled thermal cameras, Sierra Leone ecologists will undertake “focal tracking” studies that will observe the normal behavior of individual apes as they move around the reserve throughout the day.
“Here we use an uncooled Flir T1K thermal camera, because we can walk around with it, reach different sides of the enclosure, and climb onto observation decks,” Professor Forrester says. “It has a very effective zoom feature and will definitely prove useful when we travel to Uganda in 2026 to work with the first group of habituated wild chimpanzees. We will use Flir T1K to follow them through their natural habitat and take samples of their stress levels.”
thermal ecology kit
To bring further benefits to this type of research, UK-based Thermal Vision Ecology (sister company of Flir distributor Thermal Vision Research) recently began developing the Thermal Ecology Kit, a mobile thermography system specifically designed for ecological surveys. This kit includes a Flir cooled or uncooled camera with multiple lens options connected to a tripod and a battery pack that provides 6 hours of power. The entire system connects to a Windows tablet preinstalled with Flir Research Studio, an advanced thermal analysis software suite that provides a simplified workflow for viewing, recording, and evaluating data.
The kit proved successful in bat research and was formally recommended to Professor Forrester and his team for great ape research. Not only does wildlife documentation become easier, post-survey reporting times are reduced, field safety is improved, and the need to hold a camera for hours at a time is eliminated. With backpack design and plug-and-play functionality, this system is convenient to carry and use.
“Using the Thermal Ecology Kit allowed us to replace the bulkier and less flexible kit we had used during our previous fieldwork in Gabon,” says Professor Forrester. “We use an additional GoPro camera in this kit because we need synchronized natural light RGB video in addition to thermal images to identify individuals. We mount the GoPro on top to ensure the same perspective and provide synchronized data whether we use a cooled or uncooled camera from Flir.”
Next up, the University of Sussex’s ecological research team wants to collaborate again with experts at Flir to develop specific software tools for data sampling. This work will provide further benefits as ecologists continue to seek further understanding of the role of biological determinants in stress monitoring.
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