Enrichment, Fun for All the Animals
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Blue enrichment bags containing honey and seed laden tops of pineapples to be given out as enrichment

Blue enrichment bags containing honey and seed laden tops of pineapples to be given out as enrichment

At the Orangutan Foundation International’s (OFI) Care Center in Indonesian Borneo where approximately 300 wild born ex-captive orangutans reside, it is a familiar sight to see Ibu Mariyanti and her enrichment team, going to and from facility to facility. With bright blue bags brimming with various items slung over their shoulders, the team members bring the handmade enrichment materials they have meticulously crafted that morning to the orangutans. “I am always thinking of ways we can provide enrichment, I never stop, it’s never finished,” Ibu Mariyanti says.

Typical examples of enrichment materials include small parcels filled with rambutan fruit nestled among small leaves, and then wrapped up with blades of grass. Orangutans enjoy unwrapping the parcels to get the prize inside. The process provides valuable experience offering both physical and mental stimulation for the orangutans. “I always like to give natural enrichment; I try to stay away from toys or plastic as these are human inventions. At the zoo it’s okay if the animals are there for life, but at a sanctuary we want them to be released back to the wild; we don’t want them to get used to plastic toys,” Ibu Mariyanti explains. Some forms of enrichment are there to interact with; others are to be tasted while others provide visual pleasure! Colorful fruit freshly picked from the forest, cut up into small pieces and frozen, serves to stimulate both the eyes and taste buds. Days fly by as the team fills hundreds of ice cube trays with bits of fruit. These frozen treats are offered on especially hot days, helping the animals in OFI’s care to hydrate and chill.

The enrichment office contains smorgasbord of materials

The enrichment office contains smorgasbord of materials

The enrichment storeroom is filled with tools and items to prepare materials for enrichment. It is a creative laboratory filled with padlocks, keys, nails, screws, drill heads, and hand and electric saws, to oversized balls of string and yards upon yards of rope. The enrichment area has recently been expanded, with a newly cemented area providing more space for the team to prepare materials. Here, mornings usually see the team either wrapping parcels, or cutting and sawing items.

Whenever a new Pondok* (In the Indonesian language, “pondok” means hut.) is constructed, the enrichment team steps in to ensure that the new indoor enclosures in the facility provide adequate stimulation for the orangutans by putting in permanent installations that will encourage play and natural behavior. The team also makes repairs to existing structures. When the orangutans head out to forest school, the team swoops in to make their construction improvements. “It’s always easier when the orangutans aren’t inside the enclosure. If they are, they always want to take, take, take, destroy, destroy, destroy,” laughs Ibu Mariyanti. The team installs such things as log ladders and hanging bridges for the younger orangutans to sit or swing on. Blue barrels with the tops cut off provide hiding and napping spots. Rope-threaded logs simulate branches which orangutans can climb.

Enrichment member Pak Hendri testing out the strength of the rope bridge in the indoor orangutan enclosure

Enrichment member Pak Hendri testing out the strength of the rope bridge in the indoor orangutan enclosure

Enrichment is especially important for larger orangutans who, for logistical and safety reasons, cannot be let out daily to forest school. The enrichment team even makes it to the quarantine facility, as enrichment is also critical for newly arrived orangutans. Many have been kept illegally as pets and in small, confined cages for their entire lives. OFI doesn’t waste any time in nurturing the natural behaviors of these deprived infants. Ropes and tires are hung in the enclosures, and poles and platforms erected for the orangutans to sleep, play, and rest on. Enrichment team member Pak Hendri is the first to test the new fixtures, exhibiting his inner orangutan as he hangs from ropes and sits atop rope bridges.

Variety is the spice of life, and “pondoks” are not alike in the enrichment they contain. For example, some pondoks offer treasures like wicker balls filled with peanuts. The orangutans really have to work out how to get into these brainteasing balls! Some orangutans use a strong grip to rip apart the balls, or bang them on the floor. Other individuals delicately pry open the wicker vines making up the ball piece by piece.

When the enrichment staff distributes materials, juvenile orangutans are often not in a very sharing mood, and simply grab as many items as they can. But the enrichment team is always prepared for this eventuality and brings along enough items and materials to ensure that every single orangutan gets something.

Large cut up branches threaded on rope to simulate natural branches

Large cut up branches threaded on rope to simulate natural branches

Borneo is home to 288 species of terrestrial mammals. OFI’s Orangutan Care Center inevitably ends up looking after other species, such as gibbons and sun bears, in addition to orangutans. Gibbons rarely come down to ground, preferring to be as high up as they can and spend much time climbing and brachiating when they are not resting. Enrichment for the gibbons in OFI’s care can be as simple as a few hanging poles and thick ropes from the roof to create a more tri-dimensional space. These small additions can go a long way in stimulating the gibbons, who show their appreciation as they use the materials to glide around their enclosure with their long arms.

Enrichment is also vital for the sun bears in OFI’s care, as it helps keep them psychologically occupied, staving off boredom and preventing stereotypic behaviour. Bigger bears cannot safely be released into the forest, though large enclosed forested areas up to one hectare in size will allow bears to mimic a life in the wild as much as possible. Tire hammocks help fulfil the sun bears’ natural inclination to nest in trees. Log enrichment is used to provide new and interesting scents to sniff at and dig their claws into as they search for insects. The logs are procured from the forest surrounding the Care Center, but sometimes come from more distant camps. Fallen logs and branches are most easily found following a big rain storm.

A favorite treat for sun bears or “honey bears” are hollowed out bamboo stems which are filled with honey and water, frozen solid for three days, and then delivered individually to each bear. This exciting treat can keep a bear busy for hours and sometimes causes a bit of frustration as bears use their sickle-like claws to rip at the bamboo and get to the honey. But some sun bears are content to hold the bamboo between their paws, sucking patiently as the ice slowly melts. All of the bears enjoy peanut butter, so this too makes a good bamboo filler, or the filling for a peanut butter banana sandwich (the banana acting as the bread). Not one of the sun bears turns their nose up at this treat!

At the end of the day, green branches are delivered to all the orangutans and sun bears alike. The greens are chewed on, made into nests, or generally thrashed about. As Ibu Mariyanti says, enrichment is something that is constantly evolving and required daily. New ideas for species-specific enrichment are constantly being proposed and tested. The growing number of animals with unique needs presents a multitude of challenges. But with the dedication and energy of OFI staff and volunteers, the challenges are always met.

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  • Allison Leach
    2018-07-14 at 5:57 PM

    Thank you, Philip! What a wonderful story on the vital role enrichment plays in captivity. Ibu Maryanti and her team do an amazing job providing healthy and creative enrichment on a daily basis. Ibu Maryanti develops and delivers some of the best enrichment I have ever seen (and I have worked with great apes on multiple continents)! I look forward to learning more and more from her in the coming years. She is an absolute treasure of OFI! Bless her!!!!!

  • Fiona Stubley
    2018-08-04 at 2:51 PM

    Great story yet again Philip.

  • Maryanti
    2018-08-12 at 9:19 AM

    terima kasih banyak untuk kerja samanya philip.

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