December 6, 2023

As much as we could, most of us don’t want to eat the same food every meal. Now researchers have found that the same is true for African elephants, whose diverse and individual food choices suggest they are incredibly discerning at the dinner table.

While the basic diet of the giant herbivores is staple food (also different from ours), they eat a wide variety of plants, and one animal’s fecal sample even showed more than 100 different species.

A global team of scientists, including conservation biologists at Brown University, used DNA metabarcoding for the first time to gain new insights into social foraging and food choice in two elephant families in Kenya. Because elephants are tricky to track in observational studies, little is known about social foraging among the world’s largest land herbivores.

“When I talk to non-ecologists, they’re amazed that we’ve never really had a clear picture of what all these charismatic, large mammals actually eat in nature,” said the study’s author, Environmental Research and Environmental Research. Assistant Professor Tyler Kartzinel said. Ecology, Evolution, and Organismal Biology from Brown University. “The reason is that it is difficult and dangerous to observe these animals up close, they travel long distances, they feed at night and in dense bushes, and many of the plants they eat are very small.”

DNA metabarcoding is the latest advance in genetic detective work, in which DNA fragments are extracted from biological samples (in this case, elephant dung) and then matched to a database of plant DNA “barcodes”.

In addition, the team analyzed stable isotopes of carbon in feces and elephant hair, used GPS tracking and remote sensing data, and hired Paul Musili, curator of the East African herbarium at the National Museum of Kenya, to precisely identify the plant. matter.

They found that diets were much more diverse and varied between individual animals, providing new insights into how elephants eat.

They eat a variety of plant forms (herbs, trees, succulents) and plant parts (leaves, fruit, bark, twigs), but also give priority to high-quality foods such as fruit and even feed from garbage dumps (if there provide more food) and have higher nutritional value than foraging in the wild.

The researchers also found that there is selection based on biological needs, such as pregnant or lactating elephants eating a different diet than other elephants, which may even indicate a “craving.”

This broad, sustainable diet is also critical to survival in environments where resources are often limited, with each adult elephant eating about 330 pounds (150 kilograms) of plant matter per day.

“It’s important for conservationists to remember this: When animals don’t get enough to eat, they may survive, but they may not thrive,” Kaziner said. “By better understanding what each individual eats, we can better manage iconic species such as elephants, rhinos and bison, ensuring their populations grow in a sustainable way.”

It is hoped that these insights gained through new genetic analysis methods will inform conservationists and landowners about the diversity that herbivorous species need, and how to better provide enrichment in captivity alongside quality and quantity.

“Every elephant needs variety, a little bit of spice — not in the food, but in the eating habits,” Kaziner said.

The study was published in the journal Royal Society Open Science.

source: brown university