The Parasite and the Parrot: A Love Story
Two bizarre New Zealand species are on the brink of extinction. Can they save each other?
When it comes to parasites, few are as diabolically elegant as the Hades flower. The rootless, leafless plant lurks beneath the thick undergrowth of New Zealand forests, attaching itself to trees and pilfering nutrients. As it drains its host, the Hades leaves beautiful scars—fluted burls that remain in the wood. It’s these so-called flowers that give the plant its nickname, the wood rose.
Collectors used to bag the once ubiquitous bark roses, varnishing them for home decoration. But environmental threats such as deforestation and invasive species have landed the Hades flower on the endangered-species list. By the end of the last decade, the plant’s span had shrunk to four percent of its original range. Scientists guessed that just a few thousand plants remained, but they couldn’t be sure. And while the flowers do sprout shoots and bloom for two months a year, possums and pigs make such quick snacks of the buds that the underground Hades plant is impossible to track.
Unsure of how many Hades flowers are left, the New Zealand Department of Conservation has been desperate to protect the species. As part of a recovery plan in the 1990s, it considered transplanting populations of the plant but couldn’t find an area with enough bats or other creatures to pollinate it. Of course, protecting the Hades flower isn’t the only conservation issue on the island.
New Zealand is a hotbed of endangered species. Because the archipelago’s flora and fauna were isolated for so much of human history, its native species were ill equipped to protect themselves when settlers arrived. In the last few years, conservationists have been stumped about how to save the Hades flower. Then, in a lucky coincidence, they hit upon a possible solution. What if they recruited another endangered species—the hapless kakapo bird—to help?
The kakapo is unquestionably cute—the bird looks like a parakeet crossed with an owl crossed with a Muppet—but it’s impossible to underscore how useless it is. Also, it has some of the world’s worst evolutionary luck. Kakapos can’t fly, so they build their nests on the ground. Instead of hiding their homes, they settle down in big open spaces. They’re nocturnal, feeling their way through forests with the whiskerlike feathers on their faces. Perhaps most self-defeating, kakapos emit a strong musky scent that’s impossible to ignore. And it’s this combination—their preference for slow nighttime strolls combined with the body odor of dinner—that made the bird easy pickings for humans, dogs, cats, and every other predator. It was once one of the country’s most prevalent birds; today there are only 124 kakapos left.
For scientists who study endangered species, one of the major challenges is figuring out how historical animal populations behaved in long-gone ecosystems. How did they interact with one another? Who ate what? Which species were enemies and which were friends? It’s akin to watching a movie with the major plot points edited out. That’s where fossilized feces can come in handy. Rock-hard mineralized animal droppings—known as coprolite—function as thousand-year-old clues to animal diet, behavior, and relationships and are often key to reconstructing these ecological “deleted scenes.”
In 2010, New Zealand paleoecologist Jamie Wood and a team of researchers trekked to Honeycomb Hill Caves in the northwestern corner of New Zealand’s South Island to collect coprolite as part of a project to reconstruct the diets of extinct birds. Among the bits of organic matter, Wood and his fellow researchers noticed something distinctive: round grains of pollen, each full of large holes with raised borders, almost like the suckers on an octopus’s tentacles. The moment Wood peered at them under the microscope, he knew he was looking at a Hades flower.
“I knew the plant didn’t occur on the South Island anymore,” he says. “But it wasn’t until we started to research the ecology that we worked out the full significance of the finding.” Radiocarbon dating revealed that the coprolite was 900 years old. Its source? A kakapo.
Scientists hadn’t known that the parrot and the plant were acquainted. But as he learned about the Hades flower’s life cycle and the problems it faced, Wood realized that the pollen in the coprolite hinted at an untold story. Before they were each driven out of their shared territory by human settlement and encroaching predators, kakapos fed on the Hades flower and carried its pollen on their whiskery feathers, helping the plant reproduce.
If the two species were reunited, would the parrots resume their ancient role and help the plants pollinate? The chance to find out came when the Department of Conservation’s Kakapo Recovery relocated eight kakapos to one of the last remaining refuges of the Hades flower, Little Barrier Island off the coast of North Island. In the early morning hours one day in April 2012, wranglers captured the birds by hand and placed them in pet carriers. The crates were packed with damp towels, along with apples and carrots for the kakapos to snack on. When the birds arrived a day later, it marked the first time in years that the two strange species shared a home.
Setting the kakapos loose on the island, outside of heavy human handling, is an important step in the parrot’s repopulation process. “We need to see if they can survive and flourish without outside help,” conservation minister Kate Wilkinson told a New Zealand newspaper. “This initiative could play a major role in securing the long-term survival of the species.”
As for the bird’s role in helping the Hades flower spread, it’s still too early to tell whether the endangered species matchmaking will work. So far, there’s little evidence that the kakapos have taken notice of the flowers. But scientists are optimistic, holding out hope that somewhere in the dark forest—as these strange little birds feel their way toward the pale flowers barely poking out of the ground—old ties still bind.