Not all orangutan mothers raise their infants the same way

June: Hey there, and welcome to Kindred Minds. I'm June — primatologist, storyteller, and someone who has spent way too many happy hours watching orangutans figure things out in the rainforest. This show is about the true, scientifically grounded stories of our closest relatives — the primates — and what those stories reveal about all of us. Today's episode is brought to you by Ada, who helps clients integrate A I into their workflows; Ago Consulting — pronounced "Ahh-Go" — silicon development consulting from A I to SoC; and Zen Semiconductor, an umbrella company with a portfolio of companies across the silicon industry. We are so grateful for their support. Today we've got orangutan moms who each parent in their own distinct way, a fascinating natural experiment that the pandemic accidentally ran on primates in zoos, some sobering news about one of the rarest great apes on Earth, and a deep dive into ancient fossils that remind us how long the primate story has been unfolding. So settle in — because today is all about how much of ourselves we see when we look into those eyes that are so much like our own. June: Okay, let's start with something that I find genuinely moving — and I think once you hear it, you will too. There's a new study out on Sumatran orangutan mothers, and what it found is this: not all orangutan moms raise their babies the same way. Now, that might sound obvious — of course they don't, you might say — but here's why it matters scientifically. For a long time, animal behavior research tended to treat members of a species as interchangeable. You'd average out behaviors across individuals and call that "what the animal does." But what this research shows is that individual Sumatran orangutan mothers have their own consistent, characteristic ways of mothering. Some are more attentive, some give their infants more independence earlier, some are more physically protective — and crucially, each mother tends to behave in that same characteristic way across different infants, across different pregnancies. It's not random. It's not just a response to that particular baby's personality. It's something the mother brings to the relationship herself. June: And researchers are using a word for this that I think is really significant: maternal personality. Now, personality in animals is a well-established concept in behavioral ecology — it refers to consistent individual differences in behavior that are stable across time and context. We see it in birds, in fish, in dogs, in chimpanzees. But documenting it specifically in maternal behavior, in a great ape that is already so cognitively sophisticated, adds a really rich new layer. Because what it implies is that infant orangutans aren't just being shaped by "orangutan mothering" as a generic category — they're being shaped by their specific mother's approach. Her tendencies. Her style. Just like human children are shaped not just by "parenting" in the abstract, but by who their particular parent is. June: Sumatran orangutans are semi-solitary — mothers and their dependent offspring are really the core social unit. There's no troop, no village. Just mom and her infant, navigating the forest together, sometimes for seven or eight years, which is one of the longest periods of infant dependency in the animal kingdom outside of humans. So the relationship between a Sumatran orangutan mother and her infant is one of the most sustained, intimate, one-on-one developmental relationships in nature. The mother is, in a very real sense, the infant's entire social world for years. She is the source of food, warmth, safety, and learning. So the fact that mothers differ in how they handle that — and that those differences are consistent enough to suggest something like a maternal personality — that tells us the developmental environment for each infant orangutan is genuinely individual. It's personal. And that has potential downstream effects on how those infants develop, how they learn, how they eventually parent their own offspring one day. June: What I keep coming back to is this: when we talk about maternal personality in orangutans, we're not projecting human experience onto animals. We're recognizing something that the data is showing us — that individuality in caregiving is not a human invention. It's a feature of primate life. And maybe that's not so surprising, when you consider what we share biologically with these animals. Which brings me perfectly to our next thread. June: So — here's a number I want you to sit with for a moment. Humans and orangutans share roughly 96 to 97 percent of their D N A. Now, I know percentages can feel abstract, but let me try to make that feel real. Your D N A is essentially a set of instructions — a recipe — written in a chemical alphabet of four letters: A, T, C, and G. The human genome contains about three billion of those letters. And when you line up the human recipe next to the orangutan recipe, about 96 to 97 out of every hundred letters are identical. The same instruction. The same biological word. June: The genes that build an orangutan's brain, that regulate her stress hormones, that guide the development of her hands, that shape her immune system — those are largely the same genes doing the same jobs in us. We share the same basic developmental toolkit. The same ancient evolutionary machinery that builds a primate. And here's what I find so beautiful and so humbling about that: the differences we do see between us and orangutans — in cognition, in social complexity, in language — those emerge from a relatively small fraction of genetic difference. Small tweaks in gene expression, in timing of development, in the dosage of certain proteins. Evolution is a tinkerer, not an inventor from scratch. It doesn't build new organisms from new materials. It modifies, adjusts, repurposes. June: And that's why studying orangutan maternal personality isn't just an orangutan story. When researchers find that individual orangutan mothers have consistent behavioral styles that shape their infants' development — they're looking at a system that runs on biological hardware very similar to ours. The hormones involved in primate bonding — oxytocin, cortisol, prolactin — these are the same molecules operating in orangutans and in human mothers. The neural circuits that support maternal attunement, that make a mother sensitive to her infant's cues — those evolved long before the orangutan and human lineages diverged, roughly 13 to 14 million years ago. We didn't invent mother love. We inherited it. June: And there's something else worth mentioning here — something the pandemic actually helped scientists see more clearly. When zoos closed to the public during COVID-19, researchers noticed something: primate behavior changed. And not in a uniform way. Different species responded differently to the sudden absence of human visitors. Some animals seemed calmer. Some showed changes in their activity patterns. Some — and this is the part that gets me — seemed to miss the stimulation. The social interest. The presence of people watching them, engaging with them. Now, the findings varied by species and by individual, and researchers are careful about interpreting exactly what those behavioral shifts mean. But what the natural experiment of zoo closures gave us is a window into something we often underestimate: how much the social environment matters to primate wellbeing. For animals built on the same social, emotionally sensitive biological platform that we are — presence and absence, attention and its withdrawal, these things register. They matter. And that's a shared recipe showing itself again. June: Now I want to bring us to a story that is both harder and more urgent — and I think it's one that belongs in any honest conversation about primates and people. June: There's a species of orangutan called the Tapanuli orangutan — Pongo tapanuliensis — and if you haven't heard of them, I understand, because they were only formally recognized as a distinct species in 2017. That made them the first new great ape species to be described in nearly a century. And the moment scientists celebrated that discovery, they also had to confront a devastating reality: the Tapanuli orangutan is already the most endangered great ape on the planet. Fewer than 800 individuals remain, all of them in a single fragmented forest landscape in North Sumatra, Indonesia, in an area called the Batang Toru ecosystem. June: Now, you might assume that the biggest threats to an animal like this come from large-scale industrial projects — the kind of megaprojects that make headlines. And there have been serious concerns about those. But new reporting from Mongabay reveals something that's both more complex and in some ways more difficult to address. The primary drivers of habitat loss for the Tapanuli orangutan right now are small-scale farming and logging. Smallholders clearing land for agriculture. Local timber extraction. The quiet, incremental conversion of forest into fields and gardens, happening across hundreds of small decisions by individual families and communities trying to make a living. June: And that framing matters, because it changes what solutions look like. You can campaign against a dam or a mine — you can have a policy win, a project halted. But when the threat is distributed across thousands of small land-use decisions by people living in poverty, the path forward requires something more nuanced. It requires working with communities. Supporting sustainable livelihoods. Making it economically viable for local people to be the forest's guardians rather than its clearers. It requires recognizing that the people living alongside the Tapanuli orangutan are not the villains of this story — they're people navigating hard circumstances, just like people anywhere. June: What strikes me about this story, and why I wanted to bring it into our thread about primate and people connections, is that it illustrates how deeply entangled the fate of great apes is with the lives of the humans who share their landscape. These aren't separate stories. The wellbeing of Tapanuli orangutan communities and the wellbeing of human communities in Batang Toru are bound together by the same forest. The same watershed. The same ecosystem services — the clean water, the stable soils, the biodiversity that keeps the whole system resilient. When we protect that forest for the orangutans, we protect it for the people too. And when economic pressure forces people to clear it, everyone loses. June: There's something else worth holding in mind here: the Tapanuli orangutan's genetic distinctiveness — the fact that they are a separate species — means they carry evolutionary lineages and D N A variants that exist nowhere else on Earth. Losing them wouldn't just be a tragedy of numbers. It would be the permanent erasure of a unique biological story, a unique branch of the primate family tree, millions of years in the making. And we know from fossil evidence — including some remarkable new discoveries of six previously unknown fossil primate species that are giving researchers a snapshot of what primate communities looked like during an ancient period of climate stress — we know that climate change and habitat disruption have driven primate extinctions before. This is not a new story. But we are, for the first time in that long history, the species with the awareness and the tools to write a different ending. June: I want to close today's episode by coming back to where we started — with an orangutan mother in the Sumatran rainforest, doing what mothers do. Watching her infant. Reading cues. Responding in her own particular way, shaped by who she is, not just what she is. And I think that image holds something true and important about all of this. June: Intelligence is not ours alone. Personality is not ours alone. The bonds of care, the weight of loss, the pull of curiosity — these are primate inheritances, written into our shared D N A, playing out in orangutan families and chimpanzee communities and in us, every day. We are not the crown of creation, separate and above. We are one branch — an extraordinary one, with extraordinary responsibilities — of a very old, very beautiful family. June: And that family needs us to pay attention. Not out of guilt, but out of recognition. Because when you really see how alike we are — how the same recipe builds us all — it becomes very hard to look away. June: Kindred Minds, brought to you by Ada, Ago Consulting, and Zen Semiconductor. Thank you so much for spending this time with me today. If this episode moved you or made you curious, please subscribe, leave a review, and share it with someone you think would love it — because the best thing we can do for these stories is keep telling them. You'll find links to the research and reporting we discussed today in the link in show notes. Until next time — stay curious, stay kind, and remember: these are your relatives. Take care of them.