Over a decade of observation of chimpanzees as well as gorillas in Central Africa’s wilds has shown that long-lasting and cooperative social relationships can be formed between these two species.
Within the Goualougo Triangle – a conservation stronghold in the Republic of Congo – the two endangered animals often cross paths.
Even though these interactions can occasionally become aggressive, particularly at the edges of an interaction, Nouabale Ndoki National ParkWestern lowland gorillas are more common than western ones ().Gorilla gorilla gorilla) and chimpanzees (Pan troglodytes) in the 250-square-kilometer slice of forest (100-square-miles) peacefully coexist.
They seem to be able to get along well.
They will usually only interact for around an hour. Rarely, the two species can interact for up to eight hours, eating, playing, wrestling and chasing each other.
One day, a researcher caught a juvenile male chimpanzee mounting and thrusting onto an immature female.
Although studies on gorillas and chimpanzees in Africa have shown that they interact, this is the first documented documentation of the interaction over a prolonged period of time.
“There are very few studies on interactions between primate species that can account for the identity and behavior of individuals.” SaysCrickette Sanz is a biological anthropologist at Washington University in St. Louis.
“It is well-known that these apes are able to recognize individuals of their species and form long-term relationships. But, we didn’t know that this was possible for other species.”
Sanz and his associates also did their own research and reviewed published reports about chimps, gorillas, and other animals between 1966 and 2020. They found 33 interspecific interactions at eight African sites.
The observations of the team were limited to the Goualougo triangle. They counted 206 interactions between local gorillas and chimps from 1999 to 2020.
These results disprove a common belief that great apes may gather together to lower the chance of predation.
The study found that both gorillas and chimpanzees responded to each others’ alarm calls. However, larger chimpanzee populations were more likely than smaller groups to spend time with gorillas. These groups are more susceptible to predators such as leopards, snakes or raptors.
A chimp may even leave his group to search for a gorilla in another part of the world.
The silverback protected by their group was removed by gorillas, and they were observed gathering with chimps.
The risks must be outweighed by the benefits. Researchers think that the perks may have to do with sharing information and foraging, as the two species were observed co-feeding in the same trees in approximately a third of their observations.
Scientists have observed that fig trees account for more than half the interspecies interactions.Ficus speciesThese trees are very rare in the conservation area. These trees offer their fruit only for three to four days.
According to researchers, chimpanzees broadcast their knowledge loudly when they find a fruiting tree fig.
These calls were surprisingly heard by gorillas, who sometimes changed their direction of travel to follow the sound.
According to the authors, “Chimpanzees were not attracted to gorilla food sources in any way similar to other species,” Note.
“While more research is necessary to understand the temporal patterning interspecific associations at food resources, we believe that gorillas could exploit the chimpanzee’s knowledge of where ripe fig is located.”
Sometimes this meant that gorillas would climb in the fig tree with the chimpanzees. Sometimes they would stay on the ground to eat fallen fruit.
These co-feeding events were a time when young gorillas or chimpanzees would seek each other out.
It is unclear why chimpanzees do not get upset by gorillas eating their leftovers. This is especially true for rare trees. Maybe there are social benefits like interspecific grooming and childcare that outweigh any competitive costs associated with sharing meals.
“We can no longer assume that an individual ape is completely occupied by other members of their species’ social landscape,” SaysJake Funkhouser, biological anthropologist
“The persistence and strength of social relationships observed between apes suggests a deep social awareness and multiple social transmission pathways that were not previously imagined.” These are important insights, as these interspecies relationships can be used to transmit both harmful and beneficial socially-learnt cultural behaviors.
It is possible that early hominins may have had interactions with great apes, as evidenced by their discovery.
For instance, fossil records in South Africa indicate that there were at most three hominin types 2 million years ago in a region no bigger than the Goualougo Triangle.
Although it’s impossible for us to know how many territories these early humans may have shared, the fact that our ancestors have close relatives who regularly play and send information to one another suggests that they might have done so once upon a time.
“In short, it is impossible to assume that these interactions did occur,” stated the authors. write.
It’s definitely worth chewing on.
The study was published by iScience.
