In 1974, an infant mountain gorilla was born in Volcanoes National Park in Rwanda. Researchers named him Titus.
As is typical for young gorillas in the wild, Titus spent the first years of his life surrounded by his mother, father and siblings, as well as more distant relatives and unrelated gorillas that made up his social group.In 1978, however, tragedy struck. Poachers killed Titus’ father and brother. In the chaos that followed, his younger sister was killed by another gorilla, and his mother and older sister fled the group.
Juvenile Titus, who was at a developmental stage similar to that of an 8- or 9-year-old human, experienced more tragedy in his first four years of life than many animals do in a lifetime.In people, a rough start in life is often associated with significant problems later on. Early life adversity can take a wide variety of forms, including malnutrition, war and abuse.People who experience these kinds of traumas, assuming they survive the initial event, are more likely to suffer health problems and social dysfunction in adulthood and to have shorter life spans.
Often, these outcomes trace back at least in part to what public health researchers call health risk behaviours – things like smoking, poor eating habits and a sedentary lifestyle.But researchers have documented the same kinds of problems in adulthood in nonhuman animals that experienced early life adversity.
For example, female baboons who have the hardest childhoods have life spans that are on average only half as long as their peers that have the easiest.Activities like smoking and unhealthy food choices can’t be the whole story, then, since animals don’t engage in typical human health risk behaviours.Given the connection between adverse events while young and poor health later in life, one might expect that Titus’ unlucky early years would predict a short, unhealthy adulthood for him.However, there are interesting hints that things might work differently in mountain gorillas, which are one of humans’ closest living relatives.
Decades of gorilla observations
Studying wild gorillas over a long period, we explored the impact of early life experiences on their adult health. Unlike other primates, mountain gorillas seemed resilient to losing their mothers if they reached an age where nursing had ceased. We sought to understand if this resilience extended to other adverse events and how early experiences shape long-term outcomes. With detailed data from the Dian Fossey Gorilla Fund spanning over 55 years, we analyzed information on 250 gorillas from birth to departure or death. We identified six adverse events for gorillas under age 6, such as maternal and paternal loss, violence, isolation, instability, and competition. Many young gorillas did not survive these challenges, indicating their adverse nature. This research sheds light on the long-lasting effects of early life experiences in gorillas, resembling similar effects observed in humans and other animals.
