In the context of the Covid-19 pandemic, the great importance of protecting mountain gorillas from infection transmission by tourists became clear, researchers report: The tightened protective measures in the Volcanoes National Park in Rwanda have not only protected the animals from infections with Sars-CoV-2, but apparently led to an overall decline in threatening respiratory diseases. The scientists therefore advocate maintaining the stricter rules and wearing face masks when visiting the gorillas in the future.
“Gorillas in the Mist” – the film about the story of the behavioral scientist Dian Fossey made our animal relatives famous in East Africa. The mountain gorillas (Gorilla beringei beringei) are a subspecies of the great apes that, in contrast to the lowland gorillas, only inhabit a small distribution area in the border area of Congo, Rwanda and Uganda. Despite intensive protection efforts, they are still threatened with extinction – their population is estimated at around 1000 individuals. Some of the mountain gorillas live in the Volcanoes National Park in Rwanda. There you can experience the peaceful great apes “almost up close” – visitors are led to their groups. The animals, which are hardly shy of humans, tolerate being approached to within a few meters.
Gorilla tourism: both a blessing and a curse
Tourism is a double-edged sword for the mountain gorillas: the lucrative source of income promotes their protection and the appreciation of the local population. But the small population is also exposed to a great danger due to the proximity of humans: Since gorillas are closely related to us, we can infect them with many of our infectious diseases. Some pathogens can have significantly worse consequences in animals than in humans. For this reason, protective regulations have long been in place: Tourists should keep their distance from the animals to avoid droplet infections.
The animal rights activists were now particularly concerned about the corona pandemic: there was a risk that tourists or carers would transmit Sars-CoV-2 to the gorillas and that a pandemic would then occur in the population. Because it is generally known from cases in zoos that gorillas can contract Covid-19. For example, protective measures in Volcanoes National Park have been tightened over the past two years: After tourism was initially suspended, masks had to be worn on all visits by the gorillas and the minimum distance was increased to ten meters.
Kirsten Gilardi from the University of California at Davis and Prosper Uwingeli from Volcanoes National Park now report how the health of the gorillas has developed since the pandemic began. The fundamentally good news is that Sars-CoV-2 has apparently not been transmitted to the animals so far: all examinations of gorillas with signs of respiratory disease were negative. But not only that. There was a positive trend in the health of the animals – there were fewer infections overall.
Fewer respiratory disease outbreaks
As reported by the University of California in Davis, the data from previous years showed that respiratory diseases are very problematic for the animals: the infections are the second leading cause of death in mountain gorillas. In the five years before March 2020, there were in the population of the Volcanoes National Parks average 5.4 respiratory disease outbreaks in gorilla family groups per year. As has now been shown, this changed noticeably from March 2020 to December 2021: There were only an average of 1.6 outbreaks of respiratory diseases per year in the population.
According to the researchers, the decline correlates with the overall smaller number of people getting close to the gorillas and the additional health protection measures put in place to further limit the risk of transmission. The findings are thus an indication of the effectiveness of early and decisive action by the park authorities to protect the mountain gorillas. “The results highlight the need for best practice measures that minimize transmission of disease from humans to great apes. Especially in view of the spread of the omicron variant and the return of gorilla tourism, the “Gorilla Doctors” and the Rwanda Development Board recommend that the more intensive measures be continued permanently,” writes the University of California at Davis.