Credit: Peter Halasz (Wikipedia user Pengo)
The Lord Howe Island Stick Insect (Dryococelus australis) was one of the strangest animals ever to walk the earth.
It lived only on Lord Howe Island, a tiny island of 300 people about halfway between Australia and New Zealand. It was eight inches (20 cm) long. It looked like a weird cross between a cockroach and a lobster, and so it was nicknamed the Tree Lobster. It had no natural predators. It was completely harmless, living in and munching on trees.
In 1918, the SS Makambo ran aground on Lord Howe Island, and thousands of rats escaped like, uh, rats from a sinking ship. The rats ate and bred, and the tree lobster never stood a chance. Within two years, the Lord Howe Island stick insect was extinct.
Except it wasn’t.
The Discovery
Thirteen miles (20 km) southwest of Lord Howe Island is Ball’s Pyramid, an extinct volcano that juts 1,800 feet (560 meters) up from the remote Pacific Ocean. It’s one of the world’s truly beautiful places, and one that very few people ever get to see. But you can see it in this photo:
Image Credit: Jon Clark (CC BY 2.0 license)
…and you can go there yourself with on Google Earth, embedded below. Be sure to zoom out until you can see Lord Howe Island, and then a looooooooong way farther until you can see the coast of Australia.
Scientists guessed – hoped, really – that some tree lobsters might have floated the 13 miles from Lord Howe Island to Ball’s Pyramid and established a sustainable population there. There are no trees on Ball’s Pyramid, but there are enough small bushes to provide a food and shelter for some stick insects. And so, two of them (scientists, not stick insects) decided to have a look for themselves.
In February 2001, David Priddel and Nicholas Carlile traveled to Ball’s Pyramid to search. They climbed the rock, hundreds of feet above shark-infested waters, to search. And after a few searches, they found some sign of tree lobsters. And by “sign,” I mean “poop.”
But of course a few piles of poop isn’t enough evidence to conclude that a species has apparently risen from the dead. And the stick insect is nocturnal, so to find live animals, they knew they had to go back at night.
And so on the night of February 26, 2001, Priddel and Carlile went back to look again. “Went back” meaning “climbed up a sheer rock face above shark-infested waters in complete darkness.” Yes, they had safety equipment, but it must have still been terrifying.
And they found it: under a single tea tree plant (Melaleuca howeana) was the world’s entire population of Lord Howe Island Stick Insects. Twenty-four of them. The scientific paper Priddel and Carlile wrote uses detached academic prose, which completely fails to hide their excitement:
Two members of the survey team (N.C. and D.H.) ascended the Pyramid at night to conduct a nocturnal search of the area surrounding the shrub… Reaching this site at approximately [10 PM], they found, observed and photographed two adult female D. australis on the outer edges of the shrub (Figure 2).
These specimens, the first to be seen alive in more than 70 years, were highly conspicuous, their glossy bodies strongly reflecting the [flashlight]…
(Priddle, Carlile, Humphrey, Fellenberg, & Hiscox, 2003)
The Current Situation
Two years later in 2003, scientists returned to Ball’s Pyramid to collect specimens. They returned with two males and two females, which they sent to the Melbourne Zoo to start a captive breeding program.
Seventeen years and fifteen tree lobster generations later, a healthy population of 14,000 tree lobsters lives in captivity – mostly in Melbourne, with some pairs in zoos all over the world. Once rats are eliminated from Lord Howe Island (which they’re also working on), the plan is to reintroduce the tree lobster to its original habitat.
It’s a rare success story in a world full of creatures we are driving to extinction. But let’s take our success stories when we can. There’s hope.
More information
If you’d like to learn more about this fascinating story, check out these resources:
- The Wikipedia article on the tree lobster (Dryococelus australis)
- This excellent NPR story by Radiolab co-host Robert Krulwich
- The paper announcing the discovery (Priddle, Carlile, Humphrey, Fellenberg, & Hiscox, 2003). The abstract is public but the article is paywalled. If you’d like to read it in full, let me know, I might have a friend that can find it.
- This absolutely brilliant Australian animated short film about the tree lobster, linked there and embedded below
How you can help
The captive breeding program is expensive, so if this story is calling to you through a world full of need, the Melbourne Zoo is accepting donations to continue their work. Here is a two-page fundraising brochure explaining the program. If you feel called to donate to conservation biology more generally, a good place to start is the World Wildlife Fund. Obviously no pressure to donate during these trying times. I have no affiliation with either entity, so no conflict of interest.
Postscript
This has been super-fun, I hope you’ve enjoyed reading as much as I’ve enjoyed writing it. Here’s that animated film, embedded via Vimeo.
Be sure to check out the rest of my series on Things That Are Not What They Seem, Except They Weren’t.
