Forest Elephants Are the Ultimate Climate Warriors, According to Science
Ambling through the thick of the West African rainforest, a forest elephant pauses to get a closer look at the tree in front of her. Her tusks and long trunk help strip the bark away so she can grab her next morsel of food. For a few minutes, she munches away, swallows it down with a gulp and then returns to her herd to seek out her next snack.
This same scene plays out on repeat — forest elephants spend close to 18 hours each day just feeding on a wide variety of leaves, grass, branches, stems, wood and fruits. As the megaherbivores of the forest, these creatures typically consume between 200 and 400 pounds of vegetation every single day.
Yet there’s more going on here than just a simple snack. New research suggests that the way forest elephants eat — specifically which trees they feed on — can play a critical role in climate mitigation.
All trees capture carbon – they suck it out of the air during the cycle of photosynthesis, releasing it again slowly when they decompose. This process takes years, sometimes even centuries. During that time, trees act as essential carbon reserves that naturally offset greenhouse gas emissions. In the U.S. alone, forests are able to sequester over 800 million metric tons of carbon per year, or around 12 percent of our emissions.
There’s a caveat though — some trees are better at storing carbon than others. Larger, sprawling trees with higher wood density — greater in girth and height — are just plain better and more efficient at capturing carbon. Studies have shown that on average, 50 percent of live tree biomass carbon is stored in the largest 1 percent of trees — defined as any tree with greater than 23.6 inches diameter at breast height.
Here’s where the elephants come in. It turns out that elephants prefer to feed on smaller, faster-growing trees with a lower wood density. As a result, they end up not mostly avoiding the larger trees, the same ones that are better at storing carbon.
Elephants tend to avoid the higher wood density trees because they contain phenols and tannins. Scientists suspect it’s because these compounds can have a bitter taste, yet it’s these very compounds that end up boosting the trees’ natural defenses against structural and chemical challenges in their environment.
Even when these magnificent creatures do forage from the larger trees, they often end up choosing the largest of the fruits from them, then spreading the seeds around through their poop, which in turn ends up reseeding the vital carbon-storing tree varieties.
This kind of natural carbon capture and storage is one of the best tools we have to mitigate the effects of climate change. Studies show that just one forest elephant in the central African rainforest can capture 9500 metric tons of CO2 per sq kilometer — the same annual emissions of more than two thousand cars on the road.
There’s a great cost savings here too. Estimates suggest that the total value of carbon capture services provided by an African forest elephant today — calculated based on their current population — is a whopping $1.75 million. That’s why it’s so important to make sure these animals stick around. If forest elephants were driven to extinction — and right now they are critically endangered — we would lose out on storing over 3 billion metric tons of carbon, the equivalent in emissions of 2 billion gasoline-driven cars in one year.
Elephants Might Be Nature’s Best Gardeners Too
Better yet, elephants aren’t just great climate warriors. They’re also excellent natural gardeners — forest elephants consume and disperse more seeds of more species than any other animal on the planet.
The reason why is pretty simple — as the largest frugivores in tropical forests, elephants are able to ingest the kinds of larger seeds that other creatures can’t eat. Not only that, forest elephants cover longer distances than any other terrestrial seed dispersers — these creatures have annual home ranges of 75 square miles and travel distances of 4.5 miles daily. Usually, they disperse the seeds when they poop, but sometimes they spread them when they brush up against plants and shrubs as they make their way through the forests in search of food. For some plants such as the Irvingia species, which includes trees that produce the fleshy African Mango, elephants are the sole seed dispersers.
According to this latest research, the elephant’s dietary preference to source from high wood density trees both allows these trees to thrive and, even better, boosts the forest’s overall ability to function as a carbon reserve. And since these high wood density plants also have higher resistance to decay, higher structural strength and low mortality — when elephants consume fruit from these trees and plant them near and far all over the forest, they also help the entire ecosystem develop longevity and resilience.
So, Help Save the Elephants, Ok?
It’s not all good news, unfortunately. These powerful and vital creatures are disappearing at an alarming rate. Just as recently as the 1970s, there were close to 1.2 million of these animals living in Africa. Now, according to the most recent estimates, only 100,000 African forest elephants remain. Between 2002 and 2013, scientists believe that at least 60 elephants disappeared each day.
One of the main culprits is habitat loss caused by deforestation — nearly 4 million hectares of African forests are cut down each year, mostly to expand farm operations. The greatest expansion of crops across Africa include corn and soy, most of which goes to feed cows, pigs and chickens raised for meat.
One of the most powerful forms of individual climate action then — dietary change to plant-rich diets — might just help preserve the habitats of our climate-fighting elephant friends too. Simply put, rising global demand for meat has an impact in Africa — deforestation there is occurring almost twice as fast as the rest of the world. But one powerful way to halt what the World Resources Institute calls the “global land squeeze” is a dietary shift in favor of plant-rich foods. It’s not the only solution — policies that limit farmland expansion and deforestation are also needed — but experts agree that a shift towards eat more plants is essential, both for the elephants and the planet.
Author: Devatha P. Nair
Devatha Nair, Ph.D. is a science writer who uses her doctoral training to research and write about global food systems and their impact on human and non-human animals. Her writings have covered topics that range from the use of antibiotics and pesticides in farms to the role played by language in enabling bias against non-human animals. As a biomaterials scientist, she is also the author of multiple peer-reviewed journal articles and book chapters. She has Ph.D. in mechanical engineering from the University of Colorado.
Credits: This article by Devatha P. Nair, https://sentientmedia.org, is published here as part of the global journalism collaboration Covering Climate Now.