NOV 05, 2020 1:10 PM PST

Violence in Overcrowded in Gorilla Groups Slows Population Growth

WRITTEN BY: Tiffany Dazet

Since the late 1960s, conservationists and researchers have worked to save gorillas from extinction. A new study by the Dian Fossey Gorilla Fund and the University of California Davis demonstrates how habitat loss and fragmentation impacts mountain gorilla social interactions and populations. According to an article from the Fossey Fund, about 600 of an estimated 1,063 mountain gorillas live in the Virunga massif, which covers small areas of Rwanda, Uganda, and the Democratic Republic of the Congo. As stated by Dr. Damien Caillaud—a lead author and associate professor of anthropology at UC Davis—while the Virunga gorilla population grew, their habitat did not.

The study estimated that this population's average gorilla group size was between 25 and 65, astonishing numbers beyond the typical average of 10 individuals per group. Additionally, each group had up to eight silverbacks, which, according to the Fossey Fund, causes social instability as young silverbacks challenge their older group leaders.

The Fossey Fund reports that these groups' habitat area was limited by agricultural fields and other gorilla social units in the region. Higher group density combined with the overlap in home ranges led to more violent encounters between social units, primarily infant mortality. According to the study, infant mortality increased by 57%, dropping the annual population growth rate from 5.05% to 2.37%.

The study also reports that the remaining 43% decline is likely attributed to feeding competition, male-male aggression, stress, and infectious diseases. According to the study, seven lethal fights among mature males were recorded. Dr. Winnie Eckardt—a lead author and research manager at the Fossey Fund—stated, "Before 2007, we would talk about intergroup encounters for months because they were so rare. After that, they began to happen with such frequency that we could hardly keep up with documenting them." The video below from the Fossey Fund demonstrates one such intergroup interaction.

The study states that this research's implications play a considerable role in gorilla conservation efforts as it suggests that mountain gorilla social groups require varying amounts of habitat space. Additionally, the researchers expect the Virunga gorilla population to continue to grow, albeit more slowly, and group density to continue increasing. This, of course, means that aggressive encounters will also rise in frequency, and the researchers suggest that conservationists and policymakers in the region should prepare accordingly.

Sources: Fossey Fund, Science Advances

About the Author
BS Biology
Tiffany grew up in Southern California, where she attended San Diego State University. She graduated with a degree in Biology with a marine emphasis, thanks to her love of the ocean and wildlife. With 13 years of science writing under her belt, she now works as a freelance writer in the Pacific Northwest.
You May Also Like
MAY 13, 2022
Cannabis Sciences
Is cannabis good or bad for the environment?
MAY 13, 2022
Is cannabis good or bad for the environment?
Is cannabis good or bad for the environment? There's debate as to which way the industry leans, and where it's headed.
MAY 12, 2022
Plants & Animals
Coffee's Impact on Cholesterol Depends on Drinker Sex, Brewing Method
MAY 12, 2022
Coffee's Impact on Cholesterol Depends on Drinker Sex, Brewing Method
Coffee is one of the most popular beverages on the planet. Produced from the seeds of the Coffea plant, coffee beans are ...
MAY 16, 2022
Cancer
"Pawsitive" Effects of Pet Therapy
MAY 16, 2022
"Pawsitive" Effects of Pet Therapy
  Over the past couple of months, we have explored art and music therapies, two types of alternative therapeutic ap ...
MAY 20, 2022
Health & Medicine
Taboo Bird Flu Vaccines Considered in Europe Amid Poultry Outbreak
MAY 20, 2022
Taboo Bird Flu Vaccines Considered in Europe Amid Poultry Outbreak
Vaccines are yet again a subject of controversy, but this time it's got nothing to do with COVID. An outbreak of avi ...
JUL 28, 2022
Earth & The Environment
Meet Nun Cho Ga, The Latest Frozen Mammoth Discovered in Canada!
JUL 28, 2022
Meet Nun Cho Ga, The Latest Frozen Mammoth Discovered in Canada!
Gold miners working in the freezing Klondike gold mines in Canada's Yukon territory have made a discovery while excavati ...
AUG 04, 2022
Cancer
Fiber in Green Bananas Protects from Some Cancers
AUG 04, 2022
Fiber in Green Bananas Protects from Some Cancers
Starch, a natural, sugar-containing component in many green plants, is present in high concentrations in foods such as p ...
Loading Comments...