It’s a Monkey, It’s a Margay! No, Just Ernest Again.


The T.A.C.T. (Terrestrial and Arboreal Camera Trapping) project started when Ernest was wondering why there is hardly any information on the stratification of communities of medium to large mammal throughout the rainforest.

Ernest Minnema has been traversing the world for the past 10 years as a naturalist at various field stations. Being a new-age explorer has led him throughout Australia, Brazil, Guyana, Panama, and now Costa Rica.

Originally from the Netherlands, Ernest has grown into a exemplary force on the UGACR naturalist team. For the past 14 months, he has illustrated the most pristine night hikes, carbon offset work, sustainability tours, and of course, mammal talks.

He now looks into the composition of mammal communities through different layers of the forest. His main focus is what species are present, what are their behaviors, and their spatial and temporal distribution. This starts to draw patterns of when and where we find some of the most elusive animals in the world, with a central reference point in the pre-montane wet forest.

“Any time I had an issue as a kid, I would walk into the forest, climb up into a tree and find a seat… that was my way of escaping the world below when I wasn’t happy. It’s because most people don’t look up too often.” – Ernest Minnema


Ernest has committed to mentorships and personal practice to acquire the skills necessary to quicken his efficiency. Now he spends two and a half days climbing twenty trees to collect data every three weeks.

It is relatively common to see camera trapping on the forest floors, even in our surrounding reserve areas. What is incredibly unique about Ernest’s work is that it includes mammals in all four layers of the rainforest: the forest floor, understory, canopy, and the emergent layer of the canopy. Some mammals are rarely found on the ground, so it’s a new look into the entire animal kingdom.

This particular practice is something new to all rainforests, not only Costa Rica. He breaks the mold by conducting one of the only arboreal camera trapping projects in Central America.

The goal to close out the year of data will not only show differences in stratification but the change of diversity and migration between the two seasons.

“Seeing a large mammal is one of the hidden gems in the forest.” They are some of the most elusive animals who demand space to exist, travel, migrate, and hunt.


Ernest also has a deep love for arachnids and reptiles, but figured that his climbing and camera skills could combine to fit a greater need in science.  It’s not about what he could do, but what was valued in the scientific community.

Because there isn’t much scientific precedence or peer-reviewed literature concerning mammal distribution in the area, it will create baseline knowledge to test more theories in the future. He’s formulating a recipe to blaze a new trail in mammal research.

Even having 20 camera traps can only inform us to that specific, localized area. One of Ernest’s main struggles is finding methods for statistical analysis to calculate commonly used ecological indices from what he captures on his cameras. These indices are needed to extrapolate the generated knowledge to the vast areas that these mammal communities inhabit.

The academic soundness of his research is the most puzzling part of his process.“So as good research should do, it always raises more questions.”

“You have information, so that is the data set, but creating knowledge from that information – that is the academic challenge, how to go from information to knowledge.”


This margay video wiggles into a special place in our hearts. It’s one that we could hear Ernest yelling about from across campus. Ernest usually positions the trap for a horizontal stretch of the tree, which in this frame is to the top-right edge off screen. Lucky camera number 13 was repositioned by a curious capuchin monkey just days before this video, making it possible to see this margay grooming itself.

Before the generation of camera traps, mammal researchers had a different experience gathering data through short-term direct observations. These methods require long sampling transects and frequently result in a low number of encounters, because they are highly dependent on visibility. The real die-hards will travel with a troop of monkeys for a week to a month perhaps, pitching a hammock and hoping they can catch the monkeys to hang with them the next day.

Camera trapping is a proven method to overcome these limitations. They can detect previously undocumented presence of elusive and rare species, previously undocumented behavior for a variety of animals, and even discover new species.


Now we start to ask more specific questions:

“We take this strategy from the forest floor, but it could very well be different… If we take out that [emergent canopy] layer, what does the animal actually do?… If I can show that in the rainy season we have a lot of Mexican Hairy Porcupines, then someone else can say, but why?”

“Do we only find these patterns in the secondary forest, or do the animals act the same in the primary forest?”

A great example is the spider monkey, known for relying heavily on primary forest. It was reported last year in 2016 during the same part of the season as Ernest trapped it this year – something we wouldn’t have known if not for his cameras.

The spider monkey is now the 21st target species of mammal Ernest has found on campus. Outputs like these are fairly hard to come by for someone who doesn’t use any bait for their traps. All of the sightings have happened in a non-biased fashion.

Ernest’s ability to wander with the general public is what makes him so approachable. That’s why he’s decided to share his project with staff and friends.


“I like to tell people that I never really started climbing – I just never stopped; it’s only changed forms.”

It’s unlikely that Ernest will ever stop climbing. There are always new opportunities on his plate, whether it be academics, or his experience in the formal education spectrum, or being able to mentor others to facilitate their research. He teases the idea of organizing data into a PhD project to continue in academia.

One of his current pleasures is taking our local workers and community up for tree-climing tours. It’s growing into a favored bonding activity of the staff, interns, and locals in San Luis.

Because his project is completely self-funded, he is now reaching out to the community in order to maintain his equipment and his project. You can support his GoFundMe page here.


This story features a collaboration of Molly Bond’s photos from the community climbing workshop, a profile of Ernest setting the trap by previous intern Rachel Eubanks, and photos taken by current Photojournalism Intern Charles Austin Boll.

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