Primatologist Answers Ape Questions From Twitter | Tech Support | WIRED

Ape Support (00:00:00)

• Tera Swinsky, Chief Scientist for the Dian Fossey Gorilla Fund, answers questions about apes from the internet.

Chest Beat (00:00:11)

• Gorillas pound their chests to show off their size and strength.
• Males have air sacks under their chests that amplify the sound of their chest beats.
• The lower the frequency of a chest beat, the larger the male gorilla.
• Chest beats can be heard up to a kilometer away.
• Females use chest beats to assess potential mates.

Bonobos (00:01:11)

• Bonobos settle social conflicts through sex.
• Male-male, male-female, and female-female sex are all common forms of conflict resolution.
• Bonobos may share food after having sex.

Primates (00:01:43)

• Primates are an order of mammals that appeared on Earth about 60 million years ago.
• Primates are characterized by high levels of social complexity, relatively large brains, and forward-facing eyes.
• There are three main categories of primates: prosimians, monkeys, and apes.
• Prosimians include bush babies, tarsiers, lorises, and lemurs.
• Monkeys include new world monkeys (found in Central and South America) and old world monkeys (found in Asia and Africa).
• Apes include gibbons, siamangs, orangutans, bonobos, gorillas, chimpanzees, and humans.

Communication (00:02:38)

• Apes communicate through vocalizations, gestures, and facial expressions.
• One common vocalization is the pig grunt, which is a mild warning to leave the gorilla alone.
• Another vocalization is the belch vocalization, which is used to let others know the gorilla's location.
• Gorillas also use the belch vocalization when approaching humans to indicate that they are not a threat.

Planet of the Apes (00:03:25)

• The new Planet of the Apes movies are accurate in their portrayal of Caesar's leadership and dominance, which is typical of chimpanzees.
• The movies are inaccurate in their portrayal of bonobos as aggressive and evil. Bonobos are actually one of the most peaceful of the great apes.
• The apes in the movies were genetically modified, so they do not necessarily represent how apes in the wild behave.

Smiling (00:04:17)

• Non-human primates' smiles are often signs of submission, not aggression.
• Teeth are often used in displays of aggression, combined with other facial expressions.

Two Foreheads (00:05:19)

• Male gorillas have a heavy brow ridge and a sagittal crest, which gives them amazing jaw strength for fighting and attracting females.

Attacks (00:06:02)

• Gorillas have a healthy fear of humans and would likely avoid confrontation.
• Chimpanzees are more likely to attack humans, especially if they feel threatened or their territory is invaded.

Chimpanzee Wars (00:06:57)

• Chimpanzees live in complex societies and are very territorial.
• Chimpanzee males patrol their territories and may kill individuals from neighboring communities.
• Sometimes, when a community splits, they may try to eliminate members from their former community.

King Kong (00:07:34)

• Andy Serkis' motion capture performance as Kong is considered one of the most accurate and soulful depictions of the character.
• Serkis visited Rwanda to learn about gorilla behavior and observed two gorilla brothers playing and laughing, which he incorporated into Kong's character.

New World vs Old World (00:08:19)

• New World monkeys live in Central and South America.
• Old World monkeys live in Asia and Africa.
• Japanese Macaques live in the mountains and enjoy hot pools.
• Bonobos are found only in the Democratic Republic of the Congo.
• Gorillas live in Rwanda, Congo, Uganda, Cameroon, Nigeria, Equatorial Guinea, and the Republic of Congo.
• Chimpanzees have the largest distribution of any African great ape, found from Tanzania to Senegal.
• Humans are found on every continent.

Orangutans (00:09:46)

• Male orangutans have cheek pads or flanges on their faces, which are secondary sexual characteristics.
• Cheek pads may help broadcast messages and attract females.
• Some male orangutans can choose not to develop these characteristics and stay in a form that looks more like a female.
• Orangutans are the most arboreal of the great apes, spending lots of time in trees.
• Their long arms and large hands with thumbs placed far back help them grab onto tree branches.

Monogamy (00:11:03)

• Some primates in Central and South America, like marmosets and tamarinds, are often monogamous.
• Most primates are not monogamous.
• Polygyny is a reproductive strategy where one male mates with multiple females, commonly seen in Silverback gorillas.
• Promiscuous mating is where both males and females mate with multiple members of the opposite sex, seen in chimpanzees and baboons.
• Mating with multiple males confuses paternity, ensuring all males help protect the offspring.

Gibbons (00:11:49)

• Gibbons are one of the few monogamous primate species.
• Male and female gibbons spend long periods living together.
• They perform a duet, a beautiful sound made by both partners singing together, which can be heard over long distances in the forest.

Ripped Gorillas (00:12:22)

• Gorillas are the largest primates, with males weighing around 400 lbs and having 100% muscle mass.
• Despite only eating plants, gorillas have an extra advantage in their digestive system.
• Their larger intestines and hind gut fermentation help them break down fibrous plant material and extract more nutrients.
• Gorillas are roughly 10 times stronger than humans.

Social Hierarchies (00:13:27)

• Primate social groups usually have hierarchies, with larger males often becoming dominant.
• Dominant males use secondary sexual characteristics like canine teeth and size to fight for dominance.
• Dominance provides opportunities for breeding.
• In gorillas, the Silverback is the dominant male responsible for protection and decision-making.
• Some primate groups, like bonobos and baboons, have female dominance.
• Baboon females stay in their birth group and organize in matrilines, with dominant mothers providing support to their offspring.

Primate Culture (00:14:25)

• Primates do indeed have culture, defined as behaviors or traits passed down through learning rather than genetics.
• Leaf clipping in chimpanzees varies in meaning between populations, serving as an invitation to play or for sex.
• Grooming behavior in chimpanzees involves a unique arm-raising and clasping motion specific to a particular population.

Slow Loris (00:15:14)

• Slow lorises are nocturnal primates found in Asia, characterized by their large eyes adapted for low-light conditions.

Farts (00:15:35)

• Gorillas produce a lot of gas due to their diet of 60 pounds of vegetation daily.
• Despite the frequent farting, gorillas generally ignore it as a normal part of their daily routine.

Prehensile Tail (00:15:56)

• Prehensile tail is an adaptation that acts as an appendage, allowing primates to hold onto branches and move.
• Found only in New World monkeys like howler monkeys and spider monkeys.
• Apes do not have prehensile tails, they have a balanced upright center of gravity and walk upright.

Numerical Order (00:16:37)

• Chimpanzees have been studied for their understanding of numerical order.
• They can put numbers presented on a screen in order from 1 to 18 or 20.
• It's unclear if they understand the concept of numerical order or just learn the sequence.
• Chimps can choose between numbers to get treats, showing an understanding of which number will give them the most rewards.

Spear Hunting (00:17:37)

• A viral video showed an orangutan using a stick as a tool to manipulate its environment, possibly imitating fishermen.
• Orangutans have been observed copying specific behaviors from humans, such as cleaning routines and wearing hats.
• Tool use is not new to primates and has been observed in chimpanzees, elephants, dolphins, and certain birds.

Life Span (00:18:58)

• Great apes generally live to be in their 30s or 40s, with gorillas having the longest lifespan among them.
• Great apes have shorter lifespans in the wild compared to captivity.

Sadness (00:19:14)

• Gorillas display sadness when they lose a family member.
• They make hooting vocalizations to find other group members.
• Gorillas show empathy by consoling and hugging each other, especially the young.
• Gorillas go through a mourning period when a member dies, staying with the body and grooming it.

Endangered Species (00:19:52)

• Great apes are endangered, with four out of six critically endangered.
• 2/3 of the 500 primate species are endangered.
• Chimpanzees and gorillas have populations of a few hundred thousand.
• Mountain gorillas have only a thousand left.
• Sumatran orangutans have 13,000 left.
• Bonobos have an estimated population of 15,000 to 20,000.
• Nigerian-Cameroon chimpanzees have less than 10,000 left.
• Deforestation, climate change, and hunting are causing ape populations to decline.
• Half of the remaining apes could be lost in the next 20 years.

Dian Fossey (00:20:49)

• Dian Fossey founded the organization the speaker works for.
• Fossey went to Rwanda in 1967 to study mountain gorillas.
• She lacked a scientific background but had a love for animals.
• Fossey gained acceptance into gorilla society and shared their story.
• She changed the perception of gorillas from ferocious beasts to gentle giants.
• Fossey identified gorillas by their individual nose prints.
• She studied gorillas like Shaza, who was born in 1982.
• Fossey started active conservation efforts to protect gorillas.
• She removed snares to prevent gorillas and other wildlife from being caught.
• Fossey's work helped prevent the extinction of mountain gorillas.
• Mountain gorillas are the only great ape increasing in number.