Dinosaur extinction, wolf restoration, gorillas in decline: a few great reads

REUTERS/Philippe Wojazer
What caused the fifth great extinction?

Let’s take a drive in the Indian countryside outside Hyderabad with the writer Bianca Bosker and her fascinating profile subject, the renegade scientist and disaster-prone wanderer Gerta Keller:

Where I looked out our van’s window at a landscape of skeletal cows and chartreuse rice paddies, Keller saw a prehistoric crime scene. She was searching for fresh evidence that would help prove her hypothesis about what killed the dinosaurs — and invalidate the asteroid-impact theory that many of us learned in school as uncontested fact.

According to this well-established fire-and-brimstone scenario, the dinosaurs were exterminated when a six-mile-wide asteroid, larger than Mount Everest is tall, slammed into our planet with the force of 10 billion atomic bombs. The impact unleashed giant fireballs, crushing tsunamis, continent-shaking earthquakes, and suffocating darkness that transformed the Earth into what one poetic scientist described as “an Old Testament version of hell.”…

Keller doesn’t buy any of it. “It’s like a fairy tale: ‘Big rock from sky hits the dinosaurs, and boom they go.’ And it has all the aspects of a really nice story,” she said. “It’s just not true.”

Honestly, I can’t decide what’s more impressive about Bosker’s recent Atlantic piece, “The Nastiest Feud in Science,” which leads my list of recommended long reads for the holiday weekend.

The mere existence of this feud, between the “impacters” who support the asteroid theory and the challengers they’ve largely muffled, was quite the eye-opener. On the other hand, its bitterness is a stomach-turner as you meet respected scientists defaming rivals to the point of termination and nervous breakdown. And then there is weird, engrossing life story of Gerta Keller:

[A]ppropriately for someone who studies mass extinctions, she has a tendency to attract disaster. Long before our 90-minute flight touched down, she’d told me about having narrowly escaped death four times — once while attempting suicide, once from hepatitis contracted during an Algerian coup, once from getting shot in a robbery gone wrong, and once from food poisoning in India — and this was by no means an exhaustive list. She has crisscrossed dozens of countries doing field research and can claim near-death experiences in many of them: with a jaguar in Belize, a boa in Madagascar, a mob in Haiti, an uprising in Mexico.

The asteroid theory is relatively youthful. It dates to a 1980 paper, and didn’t fully gain traction until the 1991 discovery of the underwater Chicxulub crater off the Yucatan. Still, it is described (by supporters) as having “reached the level of the evolution hypothesis” and being “nearly as close to a certainty as one can get in science.”

Keller’s research on the fossil record of plankton-like foraminifera suggests a more gradual event, over a period of 300,000 years: A massive and extended flow of lava from the “Deccan traps” — fissures that filled the atmosphere with ash and gas until atmospheric heating reached the point of no return, and the planet’s fifth great extinction ensued.

She is hardly the only proponent of Deccan vulcanism (or other alternatives) as the dinosaur killer. Bosker reports on a 1997 blind test in which six researchers were asked to examine the same set of fossil samples and decide whether they pointed to a sudden extinction or a slow one; they split three to three. More recently, a scientific conference heard a debate between impacters and Deccans, and a majority was persuaded to the latter side.

However, Keller may be the most vilified of the impacters’ rivals:

“I’ve never come across anything that’s been so acrimonious,” [Cardiff University geochemist Andrew] Kerr says. “I’m almost speechless because of it.” Keller keeps a running list of insults that other scientists have hurled at her, either behind her back or to her face. She says she’s been called a “bitch” and “the most dangerous woman in the world,” who “should be stoned and burned at the stake.”

And she is not the only one who thinks determining the truth about this prehistoric event still matters:

“Without meaning to sound pessimistic,” the geophysicist Vincent Courtillot writes in his book Evolutionary Catastrophes, “I believe the ancient catastrophes whose traces geologists are now exhuming are worthy of our attention, not just for the sake of our culture or our understanding of the zigzaggy path that led to the emergence of our own species, but quite practically to understand how to keep from becoming extinct ourselves.”

***

Rob Wielgus is another scientific pariah, and on a subject somewhat closer to home: wolves and their reintroduction to landscapes where they’d been exterminated.

If not as widely loathed as Keller, Wielgus has made enemies and lost jobs, due partly to his opinions, partly to issues with his research methods and, you have to assume, partly to his persona. Here’s how Christopher Solomon introduces him to readers of The New York Times Magazine, in “Who’s Afraid of the Big Bad Wolf Scientist”:

You might not guess from looking at him that Rob Wielgus was until recently a tenured professor of wildlife ecology. Wielgus likes to spend time in the backwoods of the American West that lie off the edge of most tourist maps, and he dresses the part: motorcycle leathers, tattoos on both forearms, the stringy hairs of a goatee dangling like lichen from his lower lip. Atop his bald head he often wears a battered leather bush hat of the type seen at Waylon Jennings concerts. A Camel smolders in his face like a fuse. The first time I called him, he told me that he couldn’t chat because he was riding his Harley home from the Sturgis Motorcycle Rally in South Dakota.

Wielgus had a 35-year career in wildlife research and teaching, first in Canada and then for two decades at Washington State University’s Pullman campus, in the state’s agricultural eastern reaches. His conclusions are hardly unique or radical in wolf research: that killing wolves to prevent livestock losses is probably less effective than repelling them with nonlethal means, and may even be counterproductive.

But this is not a welcome message in eastern Washington or other parts of the northwest, where the ongoing hatred and illegal killing of wolves continues at a level that can make Minnesota’s enduring conflict seem sort of civil.

In the fall of 2014, Wielgus and a colleague published the lab’s first wolf study in the journal PLOS One. Crunching a quarter-century of data about wolf attacks on livestock in three other states, the authors found something unusual: Killing wolves one year was associated with more, not fewer, deaths of livestock the following year. The paper further suggested that killing wolves may cause the increased livestock deaths.

Just because two things are correlated doesn’t mean that one causes the other, but Wielgus posited a firm connection. As he explained to me, killing wolves fractures the highly regimented social order of the pack. “So, if you kill wolves, you get more breeding pairs, you get more livestock depredation.” This was of a piece with his previous work: When humans kill the apex predator, a chaotic reshuffling is set into motion, with unintended consequences….

The study made national headlines. It also fired up some lawmakers and ranching and agriculture groups. At the time, Wielgus’s university had been looking for money and support for a few major construction projects, including some tied to the College of Agriculture. W.S.U. also was gathering support to build a medical school in Spokane. As reported in The Seattle Times, when the study appeared, an outside lobbyist for W.S.U. wrote to the university’s director of state relations, Chris Mulick, “[H]ighly ranked Senators have said that the medical school and wolves are linked. If wolves continue to go poorly, there won’t be a new medical school.”

It’s to Solomon’s considerable credit that he reports significant challenges to Wielgus’ work, and also recognizes the man’s offputting tendencies to the dramatic, the profane, the incendiary and the insincere. Here is a complex story of a complicated figure at the new center of an old controversy so convoluted and bitter it has rewritten our national history of species protection.

***

If shifts in weather and climate were to put humans into competition with another species — even an admired, closely related species — for a critical resource, would we respond with cooperation, competition, or indifference?

Elements of each appear in Elham Shabahat’s examination for Mongabay of a shifting relationship on the volcanic slopes of  equatorial Africa, “Rwandan people and mountain gorillas face changing climate together.” Sounds optimistic, but in this instance “together” means concurrently more than cooperatively.

Shabahat’s setting is the Virunga Mountains of and around Volcanoes National Park, in the Albertine Rift area where Rwanda shares borders with Uganda and the Democratic Republic of the Congo. (Although she does not say so, this is of course the research territory made widely familiar by the murdered gorilla researcher Diane Fossey’s book, and subsequent film, “Gorillas in the Mist.” )

In general, the critically endangered eastern mountain gorilla continues to slide toward extinction under the familiar burdens of poaching and habitat loss that Fossey documented; fewer than 1,000 remain as of a 2018 count by the International Union for Conservation of Nature. But things have improved a bit in Rwanda, Shabahat writes, with the estimated population rising from 480 at the beginning of the decade to 604 by 2016.

But long-time observers say climate change is bringing new survival challenges to the area.  Longer and deeper droughts in recent years have caused serious water shortages, which impact both local farmers and the mountain gorillas. People now must often go deep into the park to find clean water, which increases the likelihood of contact with the great apes, which increases the likelihood for the transfer of human diseases to the animals.

Those would be primarily respiratory infections, which are more deadly than you might expect to a 450-pound wild animal in a moist, tropical environment. But the Rwandan government is loath to bar people whose streams and ponds disappear in the deepening, lengthening dry seasons from drawing on alternatives up the slope.

“There have been many changes to the dry season. Before the dry season used to come in July, and even in mid-July we would get rain for 2-3 days,” said Vestine Mukanoheri, a farmer from the Gahunga Sector. “Now, the dry season starts in May and goes up to October. This [negatively] affects the water we have access to.”

Another farmer told Shabahat, “We go every day to the park in August as a group. We sometimes see gorillas when we go into the park. Buying water is expensive and not everyone can afford it.”

But as climate change worsens, bringing longer droughts, easily-accessible water sources are drying up near the park’s edge. “I have worked in Volcanoes National Park for 22 years, both as a gorilla tracker and as park staff. I know exactly where the water was before, and today, those spots have dried up,” said Benjamin Mugabukomeye, Country Director at the International Gorilla Conservation Programme.

That group has provided some farmers with water tanks that capture and store rain, another solution many cannot afford. And water isn’t the only driver of unfortunate human encroachment. There is tourism — park visitors will pay $1,500 to spend an hour in close proximity to wild gorillas — and continued poaching, as well as the accidental killing of gorillas with snares set for other animals. Also, a high likelihood that continued climate shifts will accelerate farmers’ clearing of new, higher land.

 “For farmers near Volcanoes, the most tangible effect of climate change [so far] is the reduced number of Irish potatoes. Their crops are affected by the long dry season and the unpredictable weather,” said Mugabukomeye. “It’s a big issue for farmers to know when to plant crops for good production.” The United Nations Intergovernmental Panel on Climate Change has predicted very high risks of reduced crop productivity due to climate change in Africa.

Meanwhile, some of the gorillas’ favorite foods — including bamboo and eucalyptus — are in decline.

A vine called Galium is a favorite among the great apes, but the plant saw a 50 percent decline in biomass between 1989 and 2010. Other key plant species that gorillas eat have either shifted downslope or moved higher up the mountains over time, and some scientists agree that it is reasonable to assume that these altitudinal shifts were caused by changes in climatic patterns. 

Comments (1)

  1. Submitted by Ray Schoch on 08/30/2018 - 10:33 am.

    I’ve read the Atlantic piece, and was as surprised as anyone at the hostility involved in what is, for most people, a pretty arcane dispute. Not insignificant, but not exactly a mainstream topic of conversation in most workplaces, either. As for the others, and keeping in mind that my scientific background is pretty close to zero (I taught history, not biology), offhand, I can’t think of any instances where human needs or desires conflicted with those of another animal species, and humans resolved the conflict by making a conscious choice to coexist with the other species. More often, if we can’t domesticate an animal and/or use it for food or amusement, we generally see to it that the animal goes away. Permanently.

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