When I asked Ibu Maryanti what her main goal for enriching the orangutans is, she responded, “I want them in their hearts to feel like they are in the forest.” Ibu Maryanti is the coordinator of environmental enrichment for the 330 orphan orangutans living at OFI’s Orangutan Care Center and Quarantine. Giving the orangutans the opportunity to express natural behaviors is always on our minds as we do enrichment at the Care Center. I’ve been at the Care Center, volunteering as the Environmental Enrichment Fellow since August. Over the past few months, we’ve been doing some really neat things to enrich the lives of our red haired friends.
In the wild, orangutans dedicate a great deal of their time to making nests in which to rest and sleep. Here at the Care Center, we have a staff member named Mr. Gatot who dedicates most of his time to collecting and bringing truckloads of branches to the Care Center. Ibu Maryanti and I then distribute these branches to all of the orangutans in their sleeping enclosures. Each orangutan uses the branches in his/her own way. Many orangutans take the time to make a proper nest and carefully and deliberately lay each branch in a particular position, with stems pointing outward. Other orangutans seem only interested in some of the branches they are given, particularly those with the tastiest young leaves, fruit, or flowers. Still other orangutans use their branches as tools to gain access to things around them that they want – reaching the branches out between the slats of their enclosure and pulling objects such as fruit, other branches, or stones, within reach.
Orangutans working for food at their “termite” feeder board
Mr.Gatot bringing fresh branches to the Care Center
The forest at the Care Center isn’t big enough to provide food for our 330 orphan orangutans, so we do our best to provide them with enrichment that necessitates the approximation of natural feeding behaviors. In the wild orangutans travel great distances and work hard to find and gain access to their food. Thus, a great deal of the enrichment we give to the orangutans involves working for their food. One simple thing we do is scatter and hide treats, so that the orangutans must work to find them.
Furthermore, we have just built our own version of an enrichment device used around the world for apes called a “puzzle feeder.” Ours is a box with 3 levels, and many small holes on each level for the orangutans to stick their fingers inside and push the food along its path. At the end of each level is a hole in the floor that allows the food to drop down to the next level. When the orangutan gets the food to the corner of the bottom level, they can remove it through a bigger hole. It may not be the same as foraging for their food in the wild but it does actively engage the orangutans in obtaining their food.
Two of our finished puzzel feeders from the side that the orangutans see.
The three levels of the puzzle feeder are visible before the back of the box is attached
In the wild, orangutans use their fingers and lips to remove the nutritious inhabitants of termite and ant nests. Whenever we find termite nests in the forest or around the Care Center, we give them to the orangutans. However this is a rare delicacy, and so normally we approximate the insect removal behaviors by putting special treats such as jam, peanuts, honey, peanut butter, or raisins, inside the holes of a feeder board or a tube. This way, the orangutans need to pick at the feeder board/tube, in a very similar way to how they would pick at an ant or termite nest, in order to get the prize.
Montana eating from a termite nest
Ibu Maryanti filling a “termite” feeder board with pineapple jam and peanuts
Ibu Maryanti holding a “termite feeder tube” that is strong enough to stand up to the large males. This one is filled with peanut butter and ready to be closed so that the males must access the peanut butter with a stick through the smaller hole.
Mamat using a stick to get honey out of his “termite” feeder tube