Happy International Orangutan Day! | Cincinnati Zoo Blog

Today we celebrate the most endangered apes in the world: orangutans! The Jungle Trails team cares for one special Sumatran orangutan here at the Cincinnati Zoo & Botanical Garden, Henry! Orangutans are considered semi-solitary apes so they spend more time alone than with others. While Henry has had female orangutan companions in the past, he has shown a preference to a bachelor lifestyle which we respect. Henry can often be found “hanging” around with his gibbon friends Lance and Hosen.

Classified as critically endangered, Sumatran orangutans are one of 2 subspecies of orangutan (the other being Bornean). Orangutans are the only non-human great apes found outside of Africa and live in Indonesian and Malaysian rainforests. These apes are the largest tree-dwelling animal and the only true arboreal ape. In fact, the name “orangutan” translates to “man of the forest” in Malay, the official language of Malaysia. Unlike other great apes, which are terrestrial and use a form of locomotion called “knuckle walking”, orangutans are considered modified brachiators. This means while their gibbon friends (true brachiators) may swing from branch to branch, orangutans use their long arms to move carefully from branch to branch. Since they spend a majority of their lives in tree canopies, some of their largest threats are habitat loss and fragmentation, and deforestation.

Some male orangutans develop fatty cheek pads called flange on both sides of their face, which is what gives them a distinct face shape. You can make your own orangutan mask by following the instructions below!

Close Enough to Care:

The zoo has a mission of getting guests “close enough to care” which is important for not only our guest experience but also our conservation efforts. For our staff and animals, however, this goal takes on a whole different meaning. Jungle Trails keeper Stephanie talks about how we use close relationships, and positive reinforcement, to take care of Henry:

Monitoring heart health is an important component of caring for the apes at the Cincinnati Zoo & Botanical Garden. We began conditioning Henry, along with the bonobos and gorillas, to receive an awake echocardiogram, an ultrasound of the heart, in 2011. In doing this, we would have the ability to look at how the heart is functioning without having to have the animal under anesthesia.

There are many steps that lead up to this – building a relationship with Henry through positive rewards, finding what foods motivate him the most, and introducing all of the equipment needed to perform the ultrasound. We began with a fake ultrasound probe made with a PVC pipe with an end cap on it, just so he would get familiar with the sensation of it pressing on his chest. When he was comfortable with that we started to add a little bit of ultrasound gel, which is necessary for the images to come through. Henry has never been a fan of the gel, but will endure it for some grapes and yogurt! After this step, we introduced a small ultrasound machine, just strong enough to see the heart to know where the correct spot was on Henry to get the images of his heart. The final step was to bring in the large ultrasound machine and also get Henry used to seeing our volunteer technician, Jenny Schaaf, who would run the machine and communicate to me which way to turn the probe to get all the images she needed. Henry thankfully was not phased by the machine at all and did very well with seeing a new face!

As well as Henry did, male orangutans are extremely difficult to get great images on. They have a large air sac that drapes over their chest and also a prominent rib cage. Since Henry’s heart was healthy at that time, he only received an ultrasound during his regular checkups while under anesthesia. During his last checkup though, it was found that he had the start of some cardiovascular disease. With this diagnosis, we decided to start up the awake echocardiograms and make some modifications to help with the issues we had in the past. Our maintenance team has built a “heart box” that fits over the port we use for Henry’s blood pressure sleeve. It will allow Henry to stand in a position where his air sac can lay on top of this steel mesh box and his chest can be closer and more accessible for the ultrasound probe to capture the images needed. Henry is doing great with his conditioning, he picked right back up where we left off like a pro!

Along with echocardiograms, blood pressure is another important factor of heart health that can tell us a lot about how our bodies are functioning. Henry’s blood pressure training started in 2018. Like the ultrasounds, there were a great many steps that led up to achieving this behavior. Designing the steel mesh sleeve that Henry would place his arm into, finding the right size cuff, getting Henry used to all of the moving parts and also used to the sensation of the cuff squeezing his arm. His primary trainers worked diligently to make this process a success and Henry’s first readings were recorded in March of 2019! Some modifications needed to be made to make sure the readings were accurate, and now Henry voluntarily has his blood pressure monitored several times a month, as long as there is pineapple involved!”

The Cincinnati Zoo & Botanical Garden, and the Association of Zoos & Aquariums, are both taking action to help orangutans, and you can too! Here’s how you can help:

Handsome Henry

Henry and Lance the Mueller gibbon

Henry and Hosen