New short film captures rare spider monkey feeding behavior (commentary)

Reaching the forest floor — far from the safety of the canopy — is a perilous voyage for any monkey, not to mention an inexperienced juvenile. Nonetheless, an integral feeding ritual means that canopy-dwelling spider monkeys must at times venture to the ground, and encourage their young to do so too.

“A Rainforest Reborn” is a new short film revealing the rarely-seen feeding behavior of a group of endangered Peruvian spider monkeys (Ateles chamek) at a mammal clay lick. It follows a family of monkeys who must teach their young daughter how to access and eat this clay alone for the first time, even if it will be one of the most dangerous lessons of the young monkey’s life.

“A Rainforest Reborn” was filmed at the Crees Reserve in the heart of the Manu Biosphere Reserve, a UNESCO world heritage site in Peru. Incredibly, this 650-hectare rainforest reserve is a regenerating, secondary forest; it was cleared for farming and selectively logged just 30 years ago. However, 87 percent of all biodiversity has returned, including endangered species like the spider monkey. Even species new to science have been discovered here.

The seemingly bizarre behavior of eating clay is not particular to monkeys, nor mammals in general. In fact, macaw clay licks are somewhat emblematic of the Manu region, drawing thousands of birding tourists every year. While this is an incredibly interesting and at times extremely colorful display of animal behavior, the reason for it has remained a mystery. It may be that animals eat clay to neutralize their stomach and remove toxins from an otherwise acidic diet. Other studies have suggested that by eating clay, animals like spider monkeys are supplementing a sodium-poor diet, as the western Amazon basin is lacking in salt.

Witnessing and filming this behavior by spider monkeys is rare. Due to hunting and habitat loss by deforestation, the species is under serious threat. The monkeys spend the majority of their lives in the top levels of the canopy, and by coming down to the forest floor they are exposing themselves to predators more adept at hunting on the ground. Capturing footage of this dangerous but essential feeding ritual is therefore incredible, and the fact it was captured in a regenerating rainforest makes it all the more inspiring and hopeful. However, it was also extremely challenging.

For a start, the species lives 100 feet up in the tops of trees within a large area of rainforest. Add to that the uneasy partnership between tropical forest humidity and camera equipment, and things can get tricky.

After spending an unsuccessful 40 hours in a hide, I took to looking through Crees Foundation’s data for incidental spider monkey sightings in order to find their nesting sites and the routes they commonly use for travelling through trees. For five weeks I then solo-trekked through the rainforest, walking slowly, listening carefully, and carrying 15 kilograms of equipment in dry bags to protect them from the humidity.

To increase my chances, I also camped in an area where the monkeys were often spotted. Miraculously, this also turned out to be a nesting site for one family who I could film settling down for the night. However, the ground I filmed on was a steep slope in the thick of the forest undergrowth, with vines that wrap and strangle trees until they eventually fall, allowing light into the canopy and new species to grow. It was not ideal; I could barely see through the trees and my tripod legs were in a maze of vines and roots. What happened next should not be a surprise: a slip, a fall, and a snapped tripod leg.

Now my daily solo-treks were coupled with the challenge of filming a level lower on my tripod. Thankfully, these efforts soon paid off when I met our family of monkeys using teamwork to guard and enter the clay lick.

To capture the activity, in a sheltered area, I set up my equipment as quickly as possible, so as to not miss the action or disturb the group. The monkeys were calling to one another, entering and leaving the clay lick, and the young monkey was communicating with her family. You can therefore imagine my horror when, despite the dry bags, I could not see a thing through the lens: it had been completely attacked by humidity! Thankfully, after a frantic five minutes of cleaning, the lens cleared up and I could finally film. With camera traps inside the clay lick itself, from three different angles, I could also capture the feeding without disturbing the monkeys or changing their natural behavior.

Needless to say, the rainforest certainly doesn’t give away its secrets easily — and nor should it.

The Manú Biosphere Reserve is one of the most biodiverse places on the planet, however it is also under serious threat from illegal logging, hunting, mining, agriculture, and the illegal construction of a new road. Striking a balance between development, improved health, and better opportunities for local people with conservation has always been difficult. However, it is crucial if endangered species like these spider monkeys are going to survive.

Eilidh Munro has spent the last year working as a filmmaker and photographer in the remote Peruvian Amazon, capturing rare animal behavior and footage of a species new to science. She co-created and ran the Crees Foundation’s first Multimedia Internship, an educational training program teaching courses in photography, filming, writing, and conservation communications. Eilidh’s next adventure will be a filming expedition to the Manu Biosphere Reserve, where her team seek perspectives on a controversial road being illegally built through the region. You can follow their expedition plans at voicesontheroadfilm.com, view Eilidh’s previous work at munrorambling.com or follow her on Instagram @eilidhmmunro.

FEEDBACK: Use this form to send a message to the author of this post. If you want to post a public comment, you can do that at the bottom of the page.