The orangutan diet is composed of over 400 types of food, according to the Smithsonian National Zoological Park website. However, their main source of sustenance is fruit. Their diet consists of 65 to 90 percent fruit. They eat lychees, mangoes and jackfruits. However, their primary fruit is ficus (figs) due to the availability and digestibility. Though they eat many types, they are drawn to fatty and sugary fruits.
Orangutans will also eat leaves and shoots from trees. When fruit is not readily available, they will even eat tree bark and soils rich in minerals. Seeds are a part of their diet if other more favored food items are not in supply.
Though these great apes primarily eat vegetation, they do eat items from other food groups. Arkive.org reports that these animals also consume honey, insects, bird eggs and small animals. They have also been observed eating fish.
The Smithsonian National Zoological Park reports that Bornean orangutans in captivity are given commercial biscuits, fruits such as apples, bananas and oranges, and vegetables including green beans and carrots. They are given meat in the form of boiled beef or baked fish once a week. Seeds, popcorn and peanuts are scattered around their enclosures in order to allow foraging.
Orangutans are the largest arboreal (tree dwelling) mammal in the world. Unfortunately, the Bornean orangutan is an endangered species. They are listed on International Union for Conservation of Nature (IUCN) Red List of Threatened Species; their population has shrunk by 50 percent in the last 60 years to between 45,000 and 69,000 as of 2005.
