7 mountain gorillas die of natural causes.

10/12/2008 14:23:17 By Dr Lucy Spelman - One of the Gorilla Doctors

December 2008. Unbelievably, after all the trauma of the war raging around them, 7 mountain gorillas have died in the last few weeks of natural causes.

The first two deaths were newborns, twins had been born in Pablo Group! The babies looked healthy and strong (only one set of twins has survived since monitoring of the mountain gorillas began years ago). Unfortunately the twins' mother had only recently rejoined the group, and, although no one saw it happen, it is almost certain that Cantsby, the lead silverback, killed them both shortly afterwards.

Silverback dies
The day the twins were born and killed ended on an even more negative note. The Karisoke trackers couldn't find Shinda, the silverback in charge of the group bearing his name. We'd been monitoring Shinda for lethargy and decreased appetite. Magda (one of the Gorilla doctors) had just visited him the day before. He was alert and eating, though slowly, and appeared to be experiencing pain in his back or hips. We'd made a plan to check him again if he didn't improve. When he disappeared, we assumed the worst, though it was true that he'd rebounded from similar episodes of lethargy before. Perhaps he'd rejoin his family the next day. Four days later, the trackers found Shinda dead. Extensive tests were carried out and we are waiting to confirm the cause of death.

Infant killed by other gorillas
A few days later, we heard that an infant gorilla in Amahoro Group had been found dead. This was Umurage, a little female I'd seen playing and looking healthy just two weeks earlier. Since the trackers reported that there'd been an interaction with a wild group earlier in the week, we think this infant was killed during a fight between gorilla groups. The results of Umurage's post mortem were clear: she'd been killed by a blow to her abdomen that ruptured her stomach and one kidney and bruised her intestines. She also had bruising of one ankle, as if she'd been grabbed by her feet and thrown. Unfortunately, such incidents are among the realities of life for the mountain gorillas.

Pneumonia
The next was Umurava, a young silverback from Pablo Group (One of the gorilla families) who disappeared for ten days. The trackers found him gasping for air with an infected abscess draining from his neck. He had a pneumonia and air sac infection that had ruptured through to the outside. We knew he was dying. Even so, he was aware of our presence and still capable of fighting back. I anesthetized him and Elisabeth helped me administer emergency treatments. Although he woke up from the anaesthesia, he died late the next day. His body had run out of white blood cells to fight the infection.

Cancer
Not long after Umurava's death, Jean Felix, Elisabeth (Gorillas doctors) and I were called to check on another urgent patient from Pablo Group, an old adult female named Puck. She'd been showing mild signs of indigestion on and off for a few months and then went missing for a day. The trackers found her slumped over and unresponsive, her body pressed against the trunk of a Hygenia tree. She, too, was still very aware of our presence and I didn't want to stress her. Despite our lightest dose of anaesthetic, she died during the intervention. The cause was a combination of cancer and infection. She had a very aggressive form of lymphoma and an abscess that had encircled her entire heart and filled much of her chest cavity.

I was shocked when Elisabeth, the vet tech for ORTPN, called to say that Umugisha (ooh-moo-gee-sha), an adult female in Amahoro Group, had been found near death. This was the mother of Umurage (ooh-moo-ra-gee), the infant on whom we'd just done a post mortem.

Umugisha sounded like a similar case to Umurava. I rushed to the field with my colleagues Magda, Jean Felix and Elisabeth with our medical kit. We found the gorilla alive, but barely. Unlike Puck and Umurava who could still respond to human presence with purposeful movement, Umugisha was lying on her back, able only to open her eyes and weakly move a foot or hand. Her condition was so bad that we were able to do an exam, collect samples, and administer treatments without anaesthetic.

We examined Umugisha and immediately found the problem: a huge mass in her abdomen. When we palpated below her ribs, we felt the equivalent of three large, hard rocks in the area where we should feel the edge of the liver, spleen, and intestines. The mass could be a chronic infection, but Magda and I suspected cancer. None of us, the trackers included, believed the gorilla would live through the night. Sadly, we were right.

Dilemma
Umugisha's is the third case where the patient was so ill that no medicine in the world could save her. These situations set up a struggle between our hearts and minds. Humane treatment of animals is a basic commitment for vets. In private practice or a zoo setting, we would euthanize such a patient, with the consent of owners or zoo staff, and our instinct was to put the gorilla out of her misery. On the other hand, we manage the mountain gorillas as a wild population, meaning that our mission is to intervene in life-threatening situations only when we believe we can save the animal. So we did what we could for Umugisha, but chose not to put her through any painful procedures, and left her to die rather than administering a drug to euthanize her. Though we always review such decisions with all concerned, on the whole most of the park rangers and guides and other officials prefer that we leave animals to die as they would naturally.

Tumour
Umugisha was indeed found dead the next morning. On post mortem, we found a huge malignant tumour that involved her diaphragm and stomach. The mass accounted for a whopping 3.5 of her 57 kilogram body weight. Once the final results are in, hers will be the third case of cancer found among free-living mountain gorillas. So far, all have been older females. The first was a female in DR Congo (before I started working for MGVP), the second was Puck, and Umugisha is the third. Now we need to review each case to see if they bear any similarity to one another. Maybe we'll find a new rule of threes. Meanwhile, we can only hope that our next few patients will be relatively healthy.

Pablo presumed dead
It helps to know that for as long as records have been kept, mountain gorillas have been disappearing from their groups to die on their own. For example, Pablo, the long-reigning leader of Pablo Group, hasn't been seen for months, and is presumed dead. Like many animals, mountain gorillas seem to know when their time is up; they curl up at the base of a tree or under a clump of vegetation to die. There's no chance for humans to intervene. This is part of the natural process of life and death. When habituated animals disappear, the only difference is that we know about it.

Not all doom and gloom - Baby gorillas
To end on a positive note, several babies have been born recently in both the research and tourist groups in Rwanda-including one just the other day-and all are perfectly fine. The news from DR Congo is also encouraging (see gorilla.cd blog.) The ICCN provincial director, Emmanuel de Merode, met with rebel leaders in the Mikeno sector of the Virunga Park and reached an agreement. The ICCN rangers have moved back to their main station at Rumangabo and so far they've been able to check on two gorilla groups. There are five infants!