Monday, May 8 started out as a quiet day at the Gorilla Doctors regional headquarters in Musanze, Rwanda. Drs. Gaspard and Adrien worked at their desks catching up on field reports and Dr. Julius was off-site at a meeting. Then the call came in…

When the Call Comes

Umwari, an adult female mountain gorilla in Susa group, wasn’t feeding or taking care of her infant. She had been under observation for some time, as she was exhibiting clinical signs of heavy infestation with gastrointestinal parasites – hair loss along her back, weight loss and reduced activity. In fact, Gorilla Doctors had analyzed fecal samples from Umwari in order to confirm the presence of parasites and her epg (eggs per gram of feces) count was very high.

Umwari, an adult female mountain gorilla showing clinical signs of heavy gastrointestinal parasites – weight & hair loss. May 8, 2023. © Gorilla Doctors

Dr. Julius rushed back to the office and at around 11:30AM and Drs. Julius, Gaspard and Adrien headed toward Volcanoes National Park with all their field gear and medical supplies in case Umwari would require treatment. Susa group was ranging along the slopes of Mt. Karasimbi, so they first drove west along the main road toward Gisenyi, the border town between Rwanda and DR Congo. But they soon turned off onto dirt roads paved in volcanic stones and started climbing – the truck groaning and the passengers jolting over each and every bump.

“It’s Not Far”

After about 40 minutes the truck arrived at the embarkation point and the Gorilla Doctors team met up with additional park trackers who would help form the intervention team. Walking single file through farms and fields they reached the park entrance – marked by the stone ‘buffalo wall’ – intended to keep some of the wildlife in the park and out of local farmer’s crops.

“It’s not far” does not translate to “it’s not steep” – 50 minutes and 1,100 vertical feet later, the team arrived to find Susa group resting among the bamboo and feasting on young bamboo shoots, one of their favorite seasonal foods.

Assessing Umwari

While most of the team waited back away from the gorilla group, Drs. Gaspard and Adrien went to conduct a visual assessment of Umwari’s condition. She was feeding but still not caring for her infant, Mugangamwiza, who was being looked after by other sub-adult females in the group. And her body condition was poor – splotchy hair loss along her back and clear evidence of weight loss.

Following their initial visual assessment, Drs. Gaspard and Adrien discussed their findings with Dr. Julius and a decision was made to provide Umwari with supportive treatment via remote darting. The team proceeded to prepare darts filled with deworming medication and vitamins and loaded the dart guns.

Our Hospital is the Forest

Fortunately, the group was calm – Dr. Gaspard knew that the lead silverback, Impuzamahanga, was a gentle silverback. Nonetheless it is important for the veterinarians to keep the dart guns hidden behind their backs and to wait for the perfect moment when neither the silverback nor the intended gorilla patient is looking in the direction of the veterinarians holding the dart guns. The element of surprise can help keep the group from reacting aggressively. If the gorillas cannot associate the darting as coming from the humans surrounding them, then they find the action more confusing than alarming.

Drs. Gaspard and Adrien flanked Umwari, keeping a safe distance, waited for their moment and timed their shots to discharge at the exact same time. As you can see in this video, Umwari never saw the darts coming and had a mild behavioral reaction – simply getting a bit startled and then moving away.

The silverback remained calm, and only got up to investigate but found no evidence of an alarming situation as Drs. Gaspard and Adrien had already hidden the darting guns behind their backs! Umwari walked away with one of the darts still lodged in her left shoulder. The other dart was collected from the ground where it had fallen out, and then the team waited for the other dart to fall out of Umwari. In this video, Dr. Gaspard gives a real-time post intervention report, keeping a close eye on the silverback in the background.

“The Forest Will Always Surprise You”

After a successful intervention, the team packed up their ‘forest hospital’ and started back down the mountain. Just when they thought they could relax and have a casual downhill ‘stroll’, Susa group decided to start moving in the exact same direction as the team. In order to avoid crossing paths, the intervention team moved as quickly as possible, cutting a new trail through dense vegetation, mud and uneven terrain. During one section of the “trail”, that eventually required crawling on hands and knees Dr. Julius remarked, “the forest will always surprise you.”

Follow-up Visit #1

Two days later on May 10, Dr. Gaspard conducted a follow-up veterinary visit to assess our patient. He found the group alternatively resting and feeding. Umwari was grooming her infant and actively feeding. It was too soon to see any improvement in her overall body condition but her increased activity and the care she was giving to her infant were all positive signs that she was responding well to the medication. Close monitoring and observation of Umwari will continue.

Umwari showing increased activity post-intervention, May 10, 2023. © Gorilla Doctors

Follow-up Visits: #2 and #3

On Thursday, May 18 and again on Monday, May 29, Dr. Gaspard conducted follow-up evaluations of Umwari’s condition. She continued to show improvement in her activities, body condition and overall health. During his May 29 visit, Dr. Gaspard observed that the patches of hair loss around her left and right flank were still evident but some hair was already growing back.

Umwari on May 29 already showing the regrowth of hair along her flank. © Gorilla Doctors