Big birds: The 1964 guide to the giant extinct penguins of Aotearoa

Most of us think well of penguins. There’s something joyous about their awkward waddling, something heart-warming about their tiny flipper wings, a reminder that these earthbound creatures once knew how to fly. 

They’ve featured in everything from an Oscar-winning documentary (March of the Penguins, in which Morgan Freeman chronicles the harrowing breeding-and-feeding cycle of Antarctica’s Emperor penguins), to a hit children’s film (Happy Feet, about a tone-deaf tap-dancing penguin in search of a mate), to the “penguin trips” meme, which is hugely popular either because it evokes the struggles of day-to-day life or just because it’s hilarious. Splat!

But penguins are more nuanced than that. And more awful. Their “inappropriate mating” so unnerved the scientist George Murray Levick, who studied the Adélie colony at Cape Adare as part of the Scott Antarctic Expedition, he wrote his notes in Greek so they couldn’t be widely read. Behaviours he witnessed included infidelity, prostitution and necrophilia, as well offspring-less birds kidnapping their neighbours’ chicks.

Furthermore, the inside of a penguin’s mouth is like something out of the prop department from Ridley Scott’s Alien, complete with dripping rows of serrated ridges. They’re called papillae and they are, apparently, optimised for gathering shrimps and algae. A Google image search also confirms they are terrifying when viewed head on.

Turns out, penguins are not the sweet cuddlesome critters both Hollywood and nature photography have led us to believe they are. Which makes it slightly alarming to find out that Aotearoa used to be home to several species of penguins that were as tall as your average 12-year-old.

How these megafaunal birds came to be is classic Darwin. About 66 million years ago, the asteroid-instigated mass extinction that wiped out the dinosaurs also put an end to giant marine predators like the plesiosaurs. With nothing hunting them or competing with them, the oldest genus of penguin, the Waimanu, thrived in the then-warm waters around the subcontinent of Zealandia. In time, penguins started to get larger – sort of like how shrew-sized protomammals evolved into housecats and bears and blue whales once the dinosaurs were gone.

Waimanu, whose fossils were found near Canterbury’s Waipara River in 1980, wasn’t that big. It was about the size of a modern hoiho (yellow-eyed penguin). But Waimanu had some chonky descendants. We’ve been digging up the remains of enormous native penguins since the Victorian era, and boy have we had some whoppers.

Pachydyptes ponderosus

Pachydyptes is the OG of New Zealand’s giant aquatic birds. In fact, it is also known as “the New Zealand giant penguin”, possibly because it didn’t initially occur to scientists that such a small place could have had more than one version.

Pachy was identified after a 175.8mm-long humerus bone was found by a Mr Charles Traill at Fortification Hill near Oamaru, sometime around 1870. It stood at least 1.3 metres tall and weighed as much as 80 kilograms, which is, according to a very informative website called Weight of Stuff, about the same as a baby elephant. This is a bit worrying in light of the “inappropriate mating” thing. Fun fact: Pachydyptes means “stout diver”, while ponderosus means weighty.

Skeleton of the Kairuku at the University of Otago.
PHOTO: Laura Williamson

Two Kairuku

A huge humerus is cool, but under a glass case in a dark hallway next to the Geology Museum at the University of Otago, there is a sizeable skeleton. It belongs to Kairuku, which wandered Otago during the Oligocene period, about 26 million years ago. Kairuku looked a little different from the chubby waddlers we are used to, boasting skinny wings and a long spear-shaped bill – all the better to poke your eyes out.

Which it could have done. This mega-penguin could stretch out to 1.5 metres long when swimming and weighed up to 60 kilograms. The university’s skeleton is actually a composite of two slightly different species (Kairuku grebneffi and Kairuku Waitaki) and was reconstructed from three specimens found at sites near Waimate in Canterbury and Duntroon in North Otago. The first bones were discovered nearly 50 years ago, but Kairuku only got its name, which means “diver who returns with food” in te reo Māori, when the skeleton was assembled in 2012.

Kumimanu fordycei

Things started to get crowded in 2016 and 2017, when the fossils of two new species of giant penguins were found preserved in boulders on the North Otago coast: Kumimanu fordycei and Petradyptes stonehousei. One was a monster. The largest living penguin today is the Emperor penguin, which weighs up to 40 kilograms. Kumimanu fordycei’s weight was nearly quadruple this. It would have tipped the scales at 155 kilograms, which, speaking of the weight of things, is the same as a panda and more than NBA superstar Steven Adams. Its humerus bone alone was the size of a human arm.

Petradyptes stonehousei

Petradyptes stonehousei co-existed with Kumimanu fordycei during the Palaeocene Epoch, about 55 to 60 million years ago. Size-wise, it was a bit of an Arnold Schwarzenegger and Danny DeVito in Twins situation, with Petradyptes topping out at a mere 55 kilograms. Still, that’s larger than any penguin walking the Earth today.

Model of a Pachydyptes ponderosus. Auckland Museum – Collections Online. Auckland Museum Page 163.3 Object LB6382.

Crossvallia waiparensis

In 2018, the bones of yet another big bird emerged. Discovered by an amateur palaeontologist called Leigh Love at the Waipara Greensand site, Crossvallia waiparensis was a contemporary of K. fordycei and P. stonehousei. It was a 1.6-metre, 80-kilogram “monster penguin”, and all I am saying is I am glad I didn’t live during the Palaeocene, because I am 1.6 metres tall, which would put me eyeball to eyeball with the thing, and well within reach of its papillae.

Not to worry, fossil records indicate that the giant penguins of Aotearoa started disappearing about 15 million years ago. This was possibly due to the proliferation of sea lions and elephant seals, which either competed with them for food, or ate them. Now that’s a Happy Meal.

Honourable mention: Squawkzilla

When it comes to prehistory, penguins weren’t the only big birds about town. Fossils discovered in 2008 indicate that, about 19 million years ago, a colossal parrot stalked our land. Heracles inexpectatus, or “Squawkzilla” as researchers like to call it, was one-metre tall and had, according to Professor Michael Archer of the UNSW Sydney Palaeontology, Geobiology and Earth Archives (PANGEA) Research Centre, “a massive parrot beak that could crack wide open anything it fancied … perhaps even other parrots.”

It makes you think. Even the biggest things don’t last forever, or, in the context of geologic time, very long at all.

LAURA WILLIAMSON

Header image: Hey shorty! A modern-day penguin at Curio Bay, Southland, New Zealand. PHOTO: Great South