Radiolab
Radiolab

Bonus: Wild Animal Dads from Terrestrials

June 18, 2026

AI Summary

5 min read

In the forests of Argentina, a male owl monkey reaches out to touch the umbilical cord of his newborn as the infant emerges from the mother, an act observed for the first time in the wild by Eduardo Fernandez Duque and his team.

Owl Monkey Observation

Eduardo Fernandez Duque, a biological anthropologist, has tracked owl monkeys for decades in South American forests. These nocturnal primates, roughly the size of a chihuahua with large orange eyes, show fathers who remain close during birth and immediately take over primary care once nursing ends. The infant climbs onto the father’s back within the first week and stays there for roughly three months, traveling through the canopy while the father grooms it, teaches it to curl into a camouflaged ball for daytime sleep, and later demonstrates which fruits to eat and how to catch insects. Eduardo’s data indicate the growing infant eventually forms a stronger bond with the father than with the mother. This pattern directly contradicts earlier assumptions drawn from chimpanzee studies that positioned primate fathers as either aggressive or largely absent.

Diverse Examples Across Species

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What you'll learn

  • 1 (01:55) **Introduction: Fatherhood in the Animal World** - Host Lulu Miller introduces a special Father’s Day episode from *Terrestrials*, aiming to expand the understanding of what fatherhood can look like.
  • 2 (04:47) **Meet the Guides: Two Human Dads** - Michael, a new father, and Dr. Eduardo Fernandez-Duque, a biological anthropologist who studies owl monkeys in Argentina.
  • 3 (05:36) **The Owl Monkey Dad: A First-Time Observation** - Eduardo’s team witnesses the first-ever birth of an owl monkey in the wild, revealing the father’s immediate involvement.
  • 4 (09:46) **Michael’s Struggle: The "Natural" Dad Myth** - Michael describes feeling awkward as a new father, influenced by the idea that chimp dads are aggressive or absent, which he thought was the "natural" human role.
  • 5 (11:21) **The Play Date: A New Perspective** - Michael meets Eduardo, who shares the owl monkey dad’s nurturing behavior, prompting Michael to ask: “Why did they pick chimpanzees to compare us to?”
  • 6 (16:11) **Dad Venture: Seahorses** - Michael introduces the seahorse, where the male gets pregnant and gives birth, shattering the hard lines between mom and dad roles.
  • 7 (17:53) **Dad Venture: Poison Dart Frogs** - The male poison dart frog guards eggs and individually carries each tadpole on its back to separate water pools, returning to feed them by luring the mother.

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Show Notes

In honor of Father's Day, here is a family friendly bonus episode from our kids' podcast Terrestrials. 

What does it really mean to be a dad? In the animal world, fathers have long been painted as aggressive or absent. At best providers and protectors, but certainly not caregivers. And yet for every tale of a lion or chimp dad eating its own young (yikes!), there’s another creature who tells a sweeter story. 

Two HUMAN dads bring us on this DADventure: Dr. Eduardo Fernandez-Duque, who has spent decades studying owl monkey dads in the forests of Argentina, and Michael Feigelson, who once worried he wasn't cut out for the softer side of parenting. 

They introduce us to seahorse dads who get pregnant, poison dart frog dads who give piggyback rides to their tadpoles, Darwin frogs who swallow their eggs to keep them safe, burying beetles who build "corpse cribs," jacana birds who do all the egg-sitting, and stickleback fish who construct intricate underwater nests for their young. Along the way, we learn that nature doesn’t offer just one model of fatherhood. Alongside Mother Nature... there just might be a Father Nature, too.

Special thanks to the Van Leer Foundation for the support of this episode. 

Resources on Animal fatherhood

Human fatherhood