How are some of the largest land animals like Rhinos, Elephants and Giraffes are herbivores? How do they get so big from eating grass, don’t they ever get hungry?

Question

I don’t get how something so big just eats grass like a cow. If we eat vegetables all day we won’t get fat or super big so how are they able to do it? I feel like eating grass all day is not very filling.

In: Biology

Answer 1

They have very efficient digestive systems that have specialized to extract energy from plant material. The tradeoff is that they need to eat a lot of plants to meet their energy needs, which means they spend a lot of their lives eating. They have the advantage of ready access to food for which they have to do very little work.

Carnivores are the opposite extreme. They don’t have to eat as frequently, but they have to expend a lot of energy in order to hunt, kill, and consume their prey.

Omnivores like us can reap the benefits of both. We can obtain most, but not all, of our essential nutrients from a plant-based diet and we can consume animal meat/fat in order to obtain energy and protein for our metabolism, as well as obtain the critical nutrients that we can’t get from plants.