CLOSE
Dieter Braun
Dieter Braun

The Parasite and the Parrot: A Love Story

Dieter Braun
Dieter Braun

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.

This story originally appeared in mental_floss magazine. You can get a free issue here or check out our iPad edition.

nextArticle.image_alt|e
Ted Cranford
arrow
science
Scientists Use a CT Scanner to Give Whales a Hearing Test
Ted Cranford
Ted Cranford

It's hard to study how whales hear. You can't just give the largest animals in the world a standard hearing test. But it's important to know, because noise pollution is a huge problem underwater. Loud sounds generated by human activity like shipping and drilling now permeate the ocean, subjecting animals like whales and dolphins to an unnatural din that interferes with their ability to sense and communicate.

New research presented at the 2018 Experimental Biology meeting in San Diego, California suggests that the answer lies in a CT scanner designed to image rockets. Scientists in San Diego recently used a CT scanner to scan an entire minke whale, allowing them to model how it and other whales hear.

Many whales rely on their hearing more than any other sense. Whales use sonar to detect the environment around them. Sound travels fast underwater and can carry across long distances, and it allows whales to sense both predators and potential prey over the vast territories these animals inhabit. It’s key to communicating with other whales, too.

A CT scan of two halves of a dead whale
Ted Cranford, San Diego State University

Human technology, meanwhile, has made the ocean a noisy place. The propellers and engines of commercial ships create chronic, low-frequency noise that’s within the hearing range of many marine species, including baleen whales like the minke. The oil and gas industry is a major contributor, not only because of offshore drilling, but due to seismic testing for potential drilling sites, which involves blasting air at the ocean floor and measuring the (loud) sound that comes back. Military sonar operations can also have a profound impact; so much so that several years ago, environmental groups filed lawsuits against the U.S. Navy over its sonar testing off the coasts of California and Hawaii. (The environmentalists won, but the new rules may not be much better.)

Using the CT scans and computer modeling, San Diego State University biologist Ted Cranford predicted the ranges of audible sounds for the fin whale and the minke. To do so, he and his team scanned the body of an 11-foot-long minke whale calf (euthanized after being stranded on a Maryland beach in 2012 and preserved) with a CT scanner built to detect flaws in solid-fuel rocket engines. Cranford and his colleague Peter Krysl had previously used the same technique to scan the heads of a Cuvier’s beaked whale and a sperm whale to generate computer simulations of their auditory systems [PDF].

To save time scanning the minke calf, Cranford and the team ended up cutting the whale in half and scanning both parts. Then they digitally reconstructed it for the purposes of the model.

The scans, which assessed tissue density and elasticity, helped them visualize how sound waves vibrate through the skull and soft tissue of a whale’s head. According to models created with that data, minke whales’ hearing is sensitive to a larger range of sound frequencies than previously thought. The whales are sensitive to higher frequencies beyond those of each other’s vocalizations, leading the researchers to believe that they may be trying to hear the higher-frequency sounds of orcas, one of their main predators. (Toothed whales and dolphins communicate at higher frequencies than baleen whales do.)

Knowing the exact frequencies whales can hear is an important part of figuring out just how much human-created noise pollution affects them. By some estimates, according to Cranford, the low-frequency noise underwater created by human activity has doubled every 10 years for the past half-century. "Understanding how various marine vertebrates receive and process low-frequency sound is crucial for assessing the potential impacts" of that noise, he said in a press statement.

nextArticle.image_alt|e
Scientific Reports, Fernando Ramirez Rozzi
arrow
Stones, Bones, and Wrecks
Humans Might Have Practiced Brain Surgery on Cows 5000 Years Ago
Scientific Reports, Fernando Ramirez Rozzi
Scientific Reports, Fernando Ramirez Rozzi

In the 1970s, archaeologists discovered a site in France containing hundreds of cow skeletons dating back 5000 to 5400 years. The sheer number wasn't surprising—human agriculture in that part of the world was booming by 3000 BCE. What perplexed scientists was something uncovered there a few decades later: a cow skull bearing a thoughtfully drilled hole. Now, a team of researchers has released evidence that suggests the hole is an early example of animal brain surgery.

Fernando Ramírez Rozzi, a paleontologist with the French National Center for Scientific Research, and Alain Froment, an anthropologist at the Museum of Mankind in Paris, published their findings in the journal Nature Scientific Reports. After comparing the opening to the holes chiseled into the skulls of humans from the same era, they found the bones bore some striking similarities. They didn't show any signs of fracturing from blunt force trauma; rather, the hole in the cow skull, like those in the human skulls, seemed to have been carved out carefully using a tool made for exactly that purpose. That suggests that the hole is evidence of the earliest known veterinary surgery performed by humans.

Trepanation, or the practice of boring holes into human skulls, is one of the oldest forms of surgery. Experts are still unsure why ancient humans did this, but the level of care that went into the procedures suggests that the surgery was likely used to treat sick patients while they were still alive. Why a person would perform this same surgery on a cow, however, is harder to explain.

The authors present a few theories, the first being that these ancient brain surgeons were treating a sick cow the same way they might treat a sick human. If a cow was suffering from a neural disease like epilepsy, perhaps they though that cutting a hole in its head would relieve whatever was agitating the brain. The cow would have needed to be pretty special to warrant such an effort when there were hundreds of healthy cows living on the same plot of land, as evidenced by the skeletons it was found with.

Another possible explanation was that whoever operated on the cow did so as practice to prepare them for drilling into the heads of live humans one day. "Cranial surgery requires great manual dexterity and a complete knowledge of the anatomy of the brain and vessel distribution," the authors write in the study. "It is possible that the mastery of techniques in cranial surgery shown in the Mesolithic and Neolithic periods was acquired through experimentation on animals."

Either way, the bovine patient didn't live to see the results of the procedure: The bone around the hole hadn't healed at all, which suggests the cow either died during surgery or wasn't alive to begin with.

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios