On a warm spring day, 30-year-old McCullough chows down on specially chosen leafy greens at Cleveland Metro Park Zoo, seemingly undisturbed by a crowd of kids and adults who eagerly watch him, snapping pictures wide-eyed in awe at his size and his laid-back personality. He's one of four Western lowland gorillas, a species native to Western Africa, at the Cleveland Metro Park Zoo, and he's the only male. I think the exciting thing for people is seeing him. Our group interact with each other. If you stand here and watch them long enough, you can kind of tell who's in charge and who's not, and you can really understand their relationships with each other.
Tad Schaffner works as an animal curator at the zoo and has a special interest in the group's interaction. He facilitated the introduction of Nanika, the zoo's third female gorilla, from San Francisco just last month. We had a very quick integration and quarantine and got her into our group of four now, and so she joined.
our male, McColo, and our females, Frederica and KB Moya. I've been here for quite a while and I've been mostly used to our Bachelor Guerrilla group that we have for 27 years. And getting females back was really exciting.
The Cleveland troop's makeup changed in early 2017 following the death of McColo's longtime partner, B-Back, a 32-year-old male who suffered from heart disease. He had lived alongside McColo since the younger guerrilla's birth. The duo arriving in Cleveland together, in 1994. A color-coded chart arrayed with dots and squares occupies the largest part of one wall in Kristen Lucas's office.
We're inside the zoo's Sarah Allison Steffi Center for Zoological Medicine, and the old-school chart is critical to the breeding and transfer recommendations for 350 gorillas housed at zoos across North America. In addition to her role as the Director of Conservation and Science at Cleveland Metroparks Zoo, Lucas leads the gorilla species survival plan for the Association of Zoos and Aquariums, a consortium of more than 230 wildlife preserves in America and around the world. Each year we look at the entire population and try to make the best decisions for the longevity of the population so that it's sustainable. We're looking out a hundred years in the future to make sure that we have a genetically fit population. and one that will carry on for many years.
And then also looking out for individual animal welfare. Lucas and her team have been on a discovery mission over the past decade, culling data to determine why heart disease is so prevalent among captive gorillas, especially compared to their wild counterparts. More than 45% of gorillas in captivity are known to have heart disease, and it's the leading cause of death among males. Across the AZA population, we have this knowledge that adult males tend to get heart disease.
And because oftentimes we would find that out when we would anesthetize an adult male, the animal might have trouble under anesthesia or may die under anesthesia. So while we were trying to investigate heart disease we ran into this challenge of nobody wants to do exams on their animals, nobody wants to anesthetize an adult male. So it took a huge push of a lot of people saying we really need to figure this out.
Pam Dennis, a veterinary epidemiologist, works just down the hall from Kristen Lucas. She studies the health of populations. McCullough hadn't had an exam for many years.
You know, we looked at him, we did physical exams, but we didn't have him under anesthesia until there was this big invigoration of people to say, let's look at this. But when they did, Dennis, Lucas, and the rest of the staff in Cleveland received a dreaded confirmation, McCullough, too, has heart disease. Once we knew he had heart disease, then we could manage it.
We needed the information not only to get the diagnosis on him, but to define heart disease in a living animal versus on pathology. It can be a little scary because we're asking questions that involve the health of individual animals that we know, and we don't always know whether we're asking the right questions. But we have to actually be able to study it and measure it.
to demonstrate whether the changes that we make actually make a difference. Since McCullough's diagnosis nearly 10 years ago, staffers in Cleveland have trained the 400-pound animal to stand still for voluntary awake cardiac ultrasounds, which give far more accurate readings. It's really amazing to think that you could ask a gorilla to put his chest up against the mesh and keep his hands at a safe distance and then to be able to put a probe onto his heart and get an awake ultrasound so that you can actually see what's happening with his heart. But that's exactly the kind of work that we do here at Cleveland Metro Park Zoo through operant conditioning or positive ...as a reinforcement training.
What have we learned by doing that thing, being able to do really a physical exam on the animal anytime you want? What do we learn? We are able to monitor their health on an ongoing basis in a way that is not in any way stressful for them or intrusive.
So, for example, once we knew that our gorilla had heart disease, we were able to identify what the baseline heart rate was for that animal. We were able to identify what the heart is supposed to look like for this individual animal. And then we're able to monitor that over time in the same way that a human might take their blood pressure on a regular basis. That data is then shared with other institutions by way of the Great Ape Heart Project, a national collaboration investigating cardiovascular disease. You can only imagine if you went to your doctor with a problem with your heart and they just didn't know what was normal or how to diagnose a problem or even once you identify the problem, how to treat it.
And even more importantly, how to prevent it. So there are a number of different groups working alongside with the Grade 8 Heart Project trying to understand things from all of those different perspectives. And Cleveland Metro Park Zoo has focused a lot on diet and nutrition in addition to really trying to understand what are some of the ways that we can not only prevent the escalation of heart disease in a gorilla that's already been diagnosed, but also perhaps even prevent it for gorillas in the future.
In their journey to better understand heart disease, staff in Cleveland led by Alaina Less, a Case Western Reserve University Ph.D. student at the time, started with the gut, looking at the influence of a captive gorilla diet on overall health. The gorilla diet. previously was based primarily on a biscuit. And if you imagine what dog food is like, it's formulated so that it provides the animal with all of its essential vitamins, nutrients. But we've learned both in human nutrition as well as in wildlife management in zoos that oftentimes processed diets are not in the best interest of all the animals.
And so this was a question we had and we were curious both to know if we replaced that biscuit with other food items that might provide the same nutrients but feed a gorilla more like a gorilla should be fed both internally and also behaviorally. We worked with veterinarians. veterinarians and nutritionists from all over the country for well over a year to formulate a diet that we felt would work and that could be acceptable to the animals here at Cleveland Metro Park Zoo.
The gorillas'new diet included leafy greens high in fiber. The team noticed changes almost immediately. Changes resulting in longer feeding times, allowing for more natural gorilla behavior comparable to the amount of time they would spend eating were they still in the wild.
Gorillas at many zoos regurgitate their food after they're finished and they re-eat it and that behavior has always stumped me. Why are they doing this? What was amazing was that as soon as we transition to this new diet, that behavior completely stopped in our gorillas.
We knew we were on to something. Something is fundamentally changing that now that we have extended the feeding time and we think we are feeding their hindgut, they're actually hindgut fermenters, we think something has fundamentally changed. changed that has altered their behavior. So we saw that right away. It was an absolutely an aha moment.
We learned how to completely eliminate this behavior that had had been an issue for many zoos for for many years. One of the things that we were able to do with the change in diet was we were able to feed them a lot quantity wise a lot more lower calorie concentration but they actually have to move around more. to get their food.
With regurgitation eliminated, Dennis hopes that by studying gorillas'digestive tracts, scientists might be able to gather more clues, clues which could aid in prevention and treatment. That's done by looking at microbiomes, an ecological community of sorts found in the animals'feces. So we think of feces, poo, as, you know, a waste product. But really what it reflects is what's going on in the GI tract and in human health and... in veterinary medicine, we're really just starting to get a handle on this.
What we were hoping was that we could look at the heart disease versus non-heart disease and the standard diet versus the new diet, low-starch, high-fiber diet. And we hoped to see that the low-starch, high-fiber diet microbiome would better reflect that of the healthy gorillas. But what we found was, and this is why I'm particularly excited about it, is that if you look at the low-starch, high-fiber diet compared to the standard zoo diet, that roughly mimics the gut microbiome from humans, healthy versus diabetic.
And one of the questions that I have is insulin resistance, which is essentially the body is not responding to insulin that's being produced. It's sort of a pre-diabetic state. Could be an underlying cause. of heart disease and gorillas.
And so this this is a tiny little grain of information that gets us one tiny little baby step closer to figuring out how all of this interacts. Zoo executive director Chris Kuhar says because of the work here an increasing number of zoos are coming to Cleveland for answers and ideas. Other AZA facilities are now implementing the diet that we started here, implementing a lot of the training and husbandry techniques that we've used here, using cardiac ultrasound training to be able to do that on an awake gorilla.
Those are new procedures, new processes, new techniques that we're ground-truthing here and a lot of the research that we're implementing here, folks are watching. They're looking to see what the success is and they're taking those ideas and holding Cleveland as a model for how they can manage their gorillas moving forward. I think given the challenges of the questions we're trying to ask, we are making great strides and it's really energy generating to work with such a passionate group of people who are not only passionate about making a difference for the animals but really excited about the science and being able to use that to inform how we take care of these animals. We want to make a difference for the individual animal and, you know, indirectly for the entire population. We want there to be future generations of gorillas.
We want them to be healthy. They're in our care. For us to know they have heart disease and not figure it out, we can't do that. The zoo recently introduced a new outdoor gorilla habitat, adding climbing structures and exponentially increasing the square footage allowing more room for activity.
Considerations about conservation and the health of the animals were included in each update to exhibits like this one and others throughout the zoo. the zoo. A lot of people still have that vision of what zoos are in their head when you think of the word zoo and quite honestly it's changed drastically.
We've gone from being a consumer of wildlife, extracting wildlife from the wild, to Organizations that strive for sustainable animal populations and are actually doing a lot of work in situ, we're actually putting resources back into the communities that we were once withdrawing them from. We've become conservation organizations and we're just in the process now of really telling that story in a better way to our visiting public. A public that is also on a learning curve, not just regarding the critically endangered mountain gorilla but about other species, and with that education spurred by places like members of the Association of Zoos and Aquariums.
programs comes hope. Conservation isn't a long-term strategy. Conservation is an emergency strategy at this point. We've got to get in and protect. When you're talking about gorillas where there's, you know, animals in the numbers in the hundreds in terms of mountain gorillas, that's not something that we can plan for 20, 30, 40 years.
We've got to do something right now. And what we want to do is empower people, help people understand what they can do, give them a reason to participate and inspire them to participate. And part of that is changing out exhibits. Changing exhibits. Exhibits is one measure.
Changing minds is another. But the shift is coming, albeit slowly. Latest census findings indicate the mountain gorilla population increasing, with Cleveland intimately involved in the effort through a long-standing relationship with the Dian Fossey Fund, which operates in Rwanda and the Democratic Republic of Congo. Dr. Lucas makes regular trips to Rwanda, helping train university students there to become the next generation of conservationists.
While here at home, We watch and hope for the next generation of Kristen Lucas's. So my dream is that as the gorillas grow up and we are able to provide the most healthy food environment, physical environment, social environment. for them, then they will continue to inspire our kids, my own kids and others, to understand what gorillas are and why they are so special and significant. Special, significant, and revered for what our ape relatives can teach us while we do what we can to save them.
Makolo, Freddie, Kebby, Nanika, and hopefully thousands more.