Darwin’s Dinner Plate

At first the animal pen seems empty. A strip of grass, a few shady trees and a small pool with a large boulder in the center offer no clues as to what animal makes the enclosure its home. It isn’t until a zookeeper steps onto the grass that the “boulder” lifts her head from the water. With deliberate steps, what appeared to be a large rock instead slowly reveals herself as a giant tortoise.

Meet Harriet, a Galapagos Land Tortoise (Geochelone elephantus porteri). At first glance, the casual observer might not think there’s anything too exciting about this particular reptile. Sure she’s big, weighing in around 150 kilograms with a shell that measures about a square meter. But with her sluggish steps and tendency to spend the days snoozing in her pond, Harriet isn’t the most visually exciting attraction at this small zoo on Australia’s east coast. Visitors who dig a little deeper however, will find there’s far more to this particular tortoise than meets the eye.

At 175 years of age, Harriet was the oldest known living creature on earth.

“It’s amazing, the second you tell people Harriet’s age they just fall in love with her. Everyone wants to give her a pat,” says keeper Kelly Jackson.

Ms. Jackson is an education officer at the Australia Zoo just outside of Brisbane in Queensland, where Harriet has lived for the past fifteen years. She says it’s unsurprising so many people want to make contact with Harriet.

“When you look at Harriet, you’re looking at history.”

Famous Beginnings

Harriet’s story begins more than 165 years ago on one of the larger islands in the Galapagos chain, off the coast of Ecuador. Likely born in 1830 on Isla Santa Cruz, Harriet was around five years old and about the size of a dinner plate when she attracted the attention of a certain naturalist of note. Sir Charles Darwin landed in the Galapagos in 1835 and took Harriet and two other tortoises back to England for scientific studies. In 1842 John Wickham, one of Darwin’s colleagues, brought Harriet to Australia aboard a whaling ship and the land down under has been her home ever since.

Ms. Jackson says the secret to Harriet’s longevity is simple.

“I always tell people it’s because Harriet has never been with a man.” With a grin, Ms. Jackson explains that while Harriet still lays eggs each year, she has never mated and therefore none of the eggs ever hatch.

There appear to be several reasons Harriet has never produced offspring. Not the least of which is for more than 100 years Harriet was known as “Harry.”

Brought to the Brisbane Botanical and Zoological Gardens in 1842, “Harry” was also the only tortoise of “his” kind in Australia. Over the next century, “Harry” became a favorite of Gardens’ visitors. Children used to be given rides on his back and even today there are still many residents of Brisbane that remember “Harry” from the Gardens.

When the zoological part of the Gardens closed in 1952, “Harry” was moved to a wildlife sanctuary on Australia’s Gold Coast. It wasn’t until the 1960’s that it was discovered “Harry” was in fact, Harriet, explaining why previous attempts to mate her had been unsuccessful.

In 1988 Harriet was moved to her current home at the Australia Zoo. The zoo has gained fame as the home base of Crocodile Hunter Steve Irwin. And while the crocodile feedings a few hundred meters away can be a bit boisterous, for the most part Harriet is enjoying a quiet retirement.

“She’s certainly earned some down time and we recently expanded her enclosure,” says Richard Jackson, Kelly’s husband, and head reptile keeper at the zoo.

Mr. Jackson says after her many years in the Botanical Gardens, Harriet has earned a chance to relax.

“When she was in the Gardens, she had to put up with people riding her.. You can still see the scars on her shell where people used to engrave their names on her back. I think she was even painted a couple of times by soldiers returning home from various wars.”

Harriet does have feeling in her shell. The top part or carapace and bottom part or plastron are actually an extension of her ribs. Unusually affectionate for a reptile, Harriet enjoys a good scratch along her shell and under her legs. These days, the scratching is done by keepers and volunteers, rather than untrained visitors to the zoo. By offering Harriet a relatively undisturbed environment, Mr. Jackson says zoo officials expect Harriet will still be going strong for at least another couple of decades.

“We figure she should probably reach at least 200 years old… there’s really not much of a precedent for such long-living reptiles. We’re basing our estimate on the fact that she really shows no signs of slowing down.”

Headed for the record books

While Harriet is currently the oldest living being on the planet, she isn’t the oldest living animal ever recorded. According to the Guiness Book of World Records, that honor belongs to a Madagascar radiated tortoise (Astrochelys radiata) named Tui Malila. Presented to the Tongan royal family by Captain James Cook in the late 1700’s, the tortoise was either 188 or 192 years old at its death in 1965.

However, Mr. Jackson is confident Harriet will easily surpass that record.

“We feed her a diet of eggplant, zucchini, squash, beans and parsley. It’s much more varied than anything she could get in the wild… We’re taking good care of her. We even built her a special cave with a heating pad inside so she could stay warm on cooler days.” Mr. Jackson pauses to smile. “Of course, she never uses the cave. She just decided to sleep outside. That’s our Harriet.”

Harriet eats only plants: leaves, flowers, fruit — the whole thing.

Munching thoughtfully on a hibiscus flower, which Mr. Jackson says is one of Harriet’s favorite foods, the tortoise seems unconcerned with her age. However her claim to fame is one that others would like to share.

“There are some zoos out there, especially in America, that claim they have or have had tortoises that are older than Harriet. But they don’t have records like we do.”

While flooding in Brisbane destroyed a number of city records – including those involving Harriet from 1842 to 1893, Mr. Jackson says it’s clear that this tortoise is the same one brought to Australia by Whickham.

“Back 165 years ago there just weren’t any tortoises like Harriet in Australia. There are no other animals she can get mixed up with. Charles Darwin himself recorded taking tortoises back to England with him.”

Harriet’s varied diet should help her live long into the future.

Even today, Mr. Jackson says there’s only one other tortoise of Harriet’s subspecies in the entire country. Her lack of company is a sad reflection of the threat facing her species. Like so many other animals, the numbers of porteri and other tortoise subspecies in the wild are declining at a frightening rate. During the 19th and 20th centuries, hundreds of thousands of tortoises were killed by fishermen who used the reptiles’ ability to go long periods of time without food and to store large quantities of water in their bladder as a “maintenance free” source of food and water. Today the tortoise is threatened both by fishing and by encroaching human populations into its natural habitat. The introduction of non-indigenous species, such as goats and rats, to the Galapagos has proved disastrous for tortoises. Goats eat the vegetation tortoises rely on for food and rats eat their soft eggs. Several subspecies are already extinct and Harriet is thought to be one of only about a dozen porteri left in the world.

While the zoo has no plans to attempt to breed Harriet, Mr. Jackson hopes the continuing public education campaign at the zoo will inspire visitors to become more involved in conservation in the Galapagos.

“I think it’s just the coolest thing,” he says of Harriet’s presence at the zoo. “You have to think about it, I mean 165 years ago she was on a boat traveling back to England, way before cars or T.V. or telephones. The stuff she must have seen. She just leaves human beings in the dust.”

What you have in your mind?