NATIONAL MUSEUM OF NATURAL HISTORY

Get To Know the Natural World’s Most Devoted Dads

Celebrate Father’s Day with pudgy penguins, karate-kicking frogs and other dependable animal dads


Several grey, white and orange king penguins perch on top of their eggs, which are snuggly sheltered under a flap of their flabby skin between their feet.
Thanks to their blubbery dad bods, male penguins can keep their eggs warm for weeks on end without food. David Cook Wildlife Photography via Creative Commons

Whether you’re breaking out of a crocodile egg or bursting from a seahorse’s belly, many newborn animals need a strong father figure. In a world where some animal parents are liable to make a snack of their offspring, males of species ranging from giant waterbugs to ostrich-like rhea birds go the extra mile—and then some—to ensure their young ones stay safe. These dependable animal dads protect, nurture, and even carry fertilized eggs in their own stomach. 

As we celebrate all the dads and father-figures in our own lives this Father’s Day, let's give some well-deserved due to several of the best animal dads.

Expecting Seahorses

None
In a shocking reversal of biologic reproductive norms, a female seahorse “impregnates” the male by inserting her eggs into his brood pouch, where they are then fertilized. Saspotato via Creative Commons

Thanks to a willingness to reverse gender roles, the seahorse may be the gold standard for paternal care in the animal world. After a male successfully woos a female, the two seahorses intertwine their tails. The action is more than just a romantic gesture. As the seahorses mingle, the female inserts a tube called an ovipositor into the male seahorse’s brood pouch and pumps up to 300 eggs into his stomach. Essentially, she’s impregnating him with her clutch of eggs. The male seahorse then fertilizes these eggs and carries them for several weeks inside his inflated stomach until it's time to birth the young seahorses out. As if taking on child-birthing once wasn’t enough, male seahorses will return to the same mates to go through the process again.

Seahorses are not the only male creatures to tote their developing young. Male hardhead catfish can store nearly 50 eggs in their mouth, starving themselves for up to two month until the baby catfish hatch and swim away. A giant African bullfrog male can gulp up nearly 6,000 eggs to store in his vocal sac. The developing eggs sit snugly inside his throat for around six weeks before the male regurgitates the wriggling brood of tadpoles into a nearby pond.

Watchful rheas

None
While the ostrich-like rhea looks intimidating, these large South American birds are actually caring papas who always have an eye out for the kids. Smithsonian Institution

At up to 5 feet tall, male greater rheas may look intimidating. But when it comes to child care, these large, flightless South American birds are devoted. Male rheas build nests for their mates (unlike monogamous seahorses, polygamous rheas prefer to spread their love to up 12 females at a time) to lay their eggs in. 

Then, he plops down on top of the gold-colored eggs for six weeks until they hatch. The male rhea cares for his chicks alone like a doting dad. If any female rhea or predator gets too close to his chicks, the rhea will charge at them to ensure his young stay safe. This protective father will watch over his chicks for the first two years of their lives.

Guiding gharials

None
An endangered male gharial defends gharial hatchlings in India’s Chambal River. Smithsonian Institution

When it comes to parental care, reptiles often get a bad rep. But several species prove that being cold-blooded doesn’t mean you’re a bad parent. One such compassionate reptile is the gharial, a slender-snouted group of endangered crocodiles found in India and other parts of south Asia. 

After a complex mating ritual involving head slaps and hisses, female gharials will deposit their eggs into burrows along the muddy river bank. Once the mini-crocodilians emerge from their nest, they’ll scurry over to the nearest adult, male or female. Unlike other predators who snack on unrelated offspring, male gharials protect their newborn brethren no matter which nest they came from. Oftentimes this protection also includes free ferry service as young gharials often hitch a ride on an adult’s back. 

Piggybacking water bugs

None
Thanks to their sturdy shells, giant water bugs are capable of carrying a clutch of up to 150 eggs on their back at once. Smithsonian Institution

Gharials are not the only animal dads who are happy to give the kids a lift. While male giant water bugs, also known as alligator ticks and toe biters, may look a little frightening, they are a busy mom’s dream because they are on perpetual carpool duty. After the aquatic bugs mate, the female sticks her fertilized eggs onto the male’s back. Some male waterbugs shoulder as many as 150 eggs at once. 

As he goes about his day-to-day life, the waterbug will sporadically venture to the surface to ensure their eggs don’t become waterlogged. They’ll also repeatedly squat down to keep the eggs aerated and even use their legs to comb through the eggs to ensure no parasites or fungi have hitched a ride. Just before his growing eggs hatch after several weeks, the male fasts to ensure he does not consume one of his offspring by mistake. Once he drops the kids off in a pond or stream, this dependable dad is ready to mate again so he can care for the next clutch.

Grappling glass frogs

None
While glass frogs look like most other frogs from above, their translucent underbelly gives an in-depth glimpse of their internal anatomy.  Mauricio Rivera Correa via Wikimedia

Like reptiles and insects, amphibians are rarely mentioned when it comes to caring animal parents. But that overlooks one of the most remarkable fathers on our list — the karate-kicking glass frog. Found in the rainforests of Central and South America, glass frogs are widely known for their translucent skin. While the tops of their bodies are lime green, their underside is as clear as glass, making internal organs like hearts, livers and stomachs visible from the outside. 

These tiny frogs are also notable for their dedication to their offspring. After a female glass frog deposits her eggs on the underside of a damp leaf, the male frog stands watch over the vulnerable eggs. The backs of some glass frogs are even patterned to resemble the egg clusters, which comes in handy when hungry predators like wasps come around. But any insect keen on eating his eggs has a surprise coming — a swift frog foot to the face. While a hornet sting can be lethal, these frog dads are devoted to protecting their eggs at any cost.  

Protective (and pudgy) penguins

None
An emperor penguin egg deposited in the National Museum of Natural History’s ornithology collection. Smithsonian Institution

No list of best animal dads would be complete without mentioning male penguins, who have mastered the dad bod. For weeks, male penguins perch on top of the eggs as the females are out at sea hunting. When it comes to keeping the eggs warm in harsh Antarctic conditions, it helps to be pudgy. Studies have found that female penguins actually seek out paunchier partners who can sit on their eggs longer without food. Females are so keen on plump penguins that they can get a sense of a partner’s girth from his breeding calls alone.

When it comes to being a successful penguin dad, it pays to let yourself go. Although the males are fasting, if an egg hatches early, penguin dads are capable of regurgitating weeks-old food to ensure the newborn gets the nutrients it needs before mom comes home. So if you’re grilling out with your dad this Sunday, throw a couple squid on the barbecue in appreciation of these hungry, pot-bellied penguin dads.

Related Stories:
Meet Some of the Animal World’s Marvelous Moms
Eight of Nature’s Wildest Mating Rituals
Study Finds Polygamy Helps Male Acorn Woodpeckers Thrive
Meet Seven Species Named After Musicians