Eli5: How are elephants able to consume enough calories when all they eat is leaves and vegetables and those have very few calories?
In: 60
Like any herbivores, they eat a *lot*. You can get by with low calorie food sources with high volume. Their digestive systems are built to handle huge volumes of high-fiber low-calorie plant matter.
Herbivores often have microorganisms in their digestive tract that gradually break down the otherwise indigestible cellulose in plants into usable sugars. It takes a lot of chewing and a long time in the herbivore’s gut, so a lot of them chew their food more than once and a lot of them have multiple stomachs
They eat a lot of leaves, they have huge stomachs compared to carnivores and eat about 150kg per day or over 300 pounds of food.
Bacteria and protozoa in the herbivores guts will ferment their plant diet into more usable, higher quality nutrients, basically volatile fatty acids that they can use as energy source
Elephants specifically have a simple stomach, like horses, so they have a very long intestine with a well developed cecum in their large intestines, where this fermentation process will take place. Cows, goats, sheep, llamas, camels, giraffes for example are ruminants, they have a multi chambered stomach, fermentation by bacteria and protozoa occurs in this special organ
Adult elephants eat 100 to 200 lbs of plant material per day and have a symbiotic relationship with gut bacteria that allows them to digest cellulose (and therefore extract more calories and proteins than humans can) in a process called hindgut fermentation.
You could probably live on the energy from leaves too if you spend 18 hours a day eating (assuming your stomach could handle the volume and actually digest leaves and twigs)
Latest Answers