Earth’s ‘megafauna’ vanished as tribes spread. Now palaeontologists are asking if early humans were the cause
Humans might have played a role in the extinction of the woolly mammoth. Photograph: Andrew Nelmerm/Getty Images/Dorling Kindersley
They were some of the strangest animals to walk the Earth: wombats as big as hippos, sloths larger than bears, four-tusked elephants, and an armadillo that would have dwarfed a VW Beetle. They flourished for millions of years, then vanished from our planet just as humans emerged from their African homeland.
It is one of palaeontology’s most intriguing mysteries and formed the core of a conference at Oxford University las 20th of march when delegates debated whether climate change or human hunters killed off the planet’s lost megafauna, as these extinct giants are known.
“Creatures like megatherium, the giant sloth, and the glyptodon, a car-sized species of armadillo, disappeared in North and South America about 10,000 years ago, when there were major changes to climates – which some scientists believe triggered their extinctions,” said Yadvinder Malhi, professor of ecosystem science at Oxford, one of the organisers of the conference, Megafauna and Ecosystem Function.
“However, it is also the case that tribes of modern humans were moving into these creatures’ territories at these times – and many of us believe it is too much of a coincidence that this happened just as these animals vanished. These creatures had endured millions of years of climate change before then, after all. However, this was the first time they had encountered humans.”
Modern humans emerged from Africa around 70,000 years ago, travelled across Asia and reached Australia 50,000 years ago, a time that coincides with a wave of extinctions of creatures there, including the diprotodon, a species of wombat that grew to the size of a modern hippopotamus. By about 14,000 years ago, humans had reached North America by crossing the land bridge that then linked Siberia and Alaska. Then they headed south.
By 10,000 years ago, Homo sapiens had conquered North and South America at a time that coincided with major megafauna extinctions, including those of the giant sloth and the glyptodon.
“We think of Africa and south-east Asia – with their lions, elephants and rhinos – as the main home of large animals today, but until very recently in our planet’s history, huge creatures thrived in Australia, North America and South America as well,” said Professor Adrian Lister of the Natural History Museum in London. “The question is: why did they disappear in the new world but survive in the old world?
“Some believe it is because large animals in Africa and south-east Asia learned to become wary of human beings and decided to avoid them at all costs. However, I also think climate change may have been involved in the Americas and Australia and that humans only finished off these big animals when they were already weakened by loss of habitats and other climate-related problems.”
The idea that humans were involved in any way in eradicating dozens of species of giant animal when we were still hunter-gatherers has important implications in any case. It was thought, until relatively recently, that it was only when humans invented agriculture several thousand years ago that our species’ relationship with the natural world become unbalanced. Until then, humans had a close affinity with nature. But if ancient hunter-gatherers played a part in wiping out these species of huge animals as long as 50,000 years ago, humanity’s supposed innate harmony with the living world appears misplaced.
More to the point, humanity is still paying the price for the disappearance of the megafauna of the Americas and Australia, the Oxford conference will hear. “There is now a lot of evidence to suggest that large herbivores like gomphotheres, a family of elephant-like animals that went extinct in South America around 9,000 years, played a key role in spreading nutrition in areas like the Amazon. They would eat fruit in the forest, including avocados, and their excrement would then fertilise other areas. That no longer happens and places like the Amazon are today affected by low nutrition as a result,” Malhi said.
Another example is provided by the giant wombat, the diprotodon, which some scientists have argued browsed bush across Australia and kept biomass levels very low. When the diprotodon vanished, plants and shrubs across the outback grew unhindered. The result was major bush fires which, archaeologists have discovered, became a serious problem just after the giant wombat disappeared from Australia.
A massive crack discovered on Pine Island Glacier in Western Antarctica which scientists now say is headed toward irreversible disintegration. The crack, discovered by an overflight in 2011, will eventually release a massive iceberg. Photo by: NASA.
Two hundred years from now, the planet could look very different. This week two landmark studies revealed that West Antarctica’s ice sheet is in a state of seemingly inevitable collapse linked to climate change. The slow-motion collapse would by itself eventually lead to a rise in global levels of 3.6-4.5 meters (12-15 feet), overrunning many of the world’s islands, low-lying areas, and coastal cities. The only silver lining is that scientists conservatively estimate that the collapse could take 200-1,000 years.
“There’s been a lot of speculation about the stability of marine ice sheets, and many scientists suspected that this kind of behavior is under way,” said Ian Joughin, a glaciologist with the University of Wisconsin, who co-authored a study in Science focusing on a key glacier in the region, Thwaites Glacier.
The team found that Thwaites Glacier is in a state of rapid retreat, which likely cannot be halted. By itself, the Thwaites Glacier would raise global sea levels by almost 2 feet; however, the Thwaites Glacier is also the stop gap to the much larger West Antarctica ice sheet. Once the Thwaites Glacier is gone, nothing will prevent the full ice sheet from melting, according to researchers, adding another 10-13 feet.
A high-resolution map of Thwaites Glacier’s thinning ice shelf. Warm water, driven by stronger winds, is cutting into the bottom of the floating shelf on the glacier. Scientists now believe the glacier’s melt is inevitable. Map by: David Shean/University of Washington.
Moreover these estimates only account for Western Antarctica, and not other ice losses across the continent or in Greenland.
Joughin and his team used airborne lasers to better map the topography of the ground beneath Thwaites Glacier, giving them the most accurate view yet of how melting will occur.
But, Joughin told Climate Progress that their findings were “conservative” and “do not include all the feedbacks.” While they note that the likeliest timeline given current information is 200-500 years, the team also didn’t run a worst-case scenario, meaning the ice loss could occur even faster.
The Science study was complemented by other research from NASA on six glaciers in same region–including Thwaites–which came broadly to the same conclusion: the melting of the region’s glaciers has passed a tipping point. This team used satellite and airborne measurements to record the melting of the glaciers since the early 1990s and better map the topography.
“The collapse of this sector of West Antarctica appears to be unstoppable,” noted co-author Eric Rignot, with the University of California and NASA, whose study was published in Geophysical Research Letters. “At this point, the end appears to be inevitable.”
Unfortunately, the team found no hills or mountains that could slow the melt.
The findings also mean that the recent Intergovernmental Panel on Climate Change (IPCC) may already be out of date. The landmark report in September did not include melting from Antarctica in its estimates of sea level rise, which ranged from 0.28 meters to 1 meter (0.9-3.2 feet) by 2100.
While melting in the region is extremely complex, but both studies agree that stronger winds–possibly linked to climate change, the hole in the ozone layer or both–have pushed warmer waters underneath the glaciers, unhinging them.
“The fact that the retreat is happening simultaneously over a large sector suggests it was triggered by a common cause, such as an increase in the amount of ocean heat beneath the floating parts of the glaciers,” added Rignot.
While West Antarctica’s great melt may be inevitable, whether it takes a couple hundred years or a thousand may depend, at least partly, on how much fossil fuels are burned in the future, according to the researchers.
Iceberg in the Amundsen Sea off of Western Antarctica. As the glaciers melt, they often birth massive icebergs. Photo by: NASA.
Citations:
I. Joughin et al. Marine Ice Sheet Collapse Potentially Underway for the Thwaites Glacier Basin, West Antarctica. Science, 2014.
Rignot et al. Widespread, rapid grounding line retreat of Pine Island, Thwaites, Smith and Kohler glaciers, West Antarctica from 1992 to 2011. Geophysical Research Letters, 2014.
Thinking about knocking down a few trees in the backyard? Think again. Felling even a handful of trees can change the local climate, according to a new study.
Think twice before cutting…
It’s been known for some time that clearing forests can have regional-scale impacts on climate by reducing evapotranspiration (the emission of water vapor by plants, which cools the land) and changing albedo (how much solar radiation gets reflected away from the ground surface).
But now it appears these effects happen at surprisingly small scales. Especially in warmer parts of the world, clearing even a football field-sized area is enough to provoke significant heating of the immediate area.
So, spread the word: Cutting down trees doesn’t just have a global impact, by increasing carbon emissions; or a regional impact, by changing evapotranspiration and albedo.
Killing trees also has a sizable local impact, meaning it directly affects the quality of life of those living nearby.
The impacts of climate change are likely to be “severe, pervasive, and irreversible,” the chair of the Intergovernmental Panel on Climate Change said Sunday night in Yokohama, Japan, as the world’s leading climate experts released a new survey of how our planet is likely to change in the near future, and what we can do about it.
Here’s what you need to know:
We’re already feeling the impacts of climate change. Glaciers are already shrinking, changing the courses of rivers and altering water supplies downstream. Species from grizzly bears to flowers have shifted their ranges and behavior. Wheat and maize yields may have dropped. But as climate impacts become more common and tangible, they’re being matched by an increasing global effort to learn how to live with them: The number of scientific studies on climate change impacts, vulnerability, and adaptation more than doubled between 2005, before the previous IPCC report, and 2010. Scientists and policymakers are “learning through doing, and evaluating what you’ve done,” said report contributor Kirstin Dow, a climate policy researcher at the University of South Carolina. “That’s one of the most important lessons to come out of here.”
Heat waves and wildfires are major threats in North America. Europe faces freshwater shortages, and Asia can expect more severe flooding from extreme storms. In North America, major threats include heat waves and wildfires, which can cause death and damage to ecosystems and property. The report names athletes and outdoor workers as particularly at risk from heat-related illnesses. As the graphic below shows, coastal flooding is also a key concern.
Globally, food sources will become unpredictable, even as population booms.Especially in poor countries, diminished crop production will likely lead to increased malnutrition, which already affects nearly 900 million people worldwide. Some of the world’s most important staples—maize, wheat, and rice—are at risk. The ocean will also be a less reliable source of food, with important fish resources in the tropics either moving north or going extinct, while ocean acidification eats away at shelled critters (like oysters) and coral. Shrinking supplies and rising prices will cause food insecurity, which can exacerbate preexisting social tensions and lead to conflict.
Coastal communities will increasingly get hammered by flooding and erosion. Tides are already rising in the US and around the world. As polar ice continues to melt and warm water expands, sea level rise will expose major metropolitan areas, military installations, farming regions, small island nations, and other ocean-side places to increased damage from hurricanes and other extreme storms. Sea level rise brings with it risks of “death, injury, ill-health, or disrupted livelihoods,” the report says.
We’ll see an increase in climate refugees and, possibly, climate-related violence.The report warns that both extreme weather events and longer-term changes in climate can lead to the displacement of vulnerable populations, especially in developing parts of the world. Climate change might also “indirectly increase” the risks of civil wars and international conflicts by exacerbating poverty and competition for resources.
Climate change is expected to make people less healthy. According to the report, we can expect climate change to have a negative impact on health in many parts of the world, especially poorer countries. Why? Heat waves and fires will cause injury, disease and death. Decreased food production will mean more malnutrition. And food- and water-borne diseases will make more people sick.
We don’t know how much adaptation is going to cost. The damage we’re doing to the planet means that human beings are going to have to adapt to the changing climate. But that costs money. Unfortunately, studies that estimate the global cost of climate adaptation “are characterized by shortcomings in data, methods, and coverage,” according to the IPCC. But from the “limited evidence” available, the report warns that there’s a “gap” between “global adaptation needs and the funds available.”
There’s still time to reduce the impacts of global warming…if we cut our emissions.Here’s the good news: The IPCC says that the impacts of climate change—and the costs of adaptation—will be “reduced substantially” if we cut our emissions of greenhouse gases.
Old-growth Amazon tree canopy in Tapajós National Forest, Brazil. A new NASA study shows that the living trees in the undisturbed Amazon forest draw more carbon dioxide from the air than the forest’s dead trees emit. Image credit: NASA/JPL-Caltech
A new NASA-led study seven years in the making has confirmed that natural forests in the Amazon remove more carbon dioxide from the atmosphere than they emit, therefore reducing global warming. This finding resolves a long-standing debate about a key component of the overall carbon balance of the Amazon basin.
The Amazon’s carbon balance is a matter of life and death: living trees take carbon dioxide out of the air as they grow, and dead trees put the greenhouse gas back into the air as they decompose. The new study, published in Nature Communications on March 18, is the first to measure tree deaths caused by natural processes throughout the Amazon forest, even in remote areas where no data have been collected at ground level.
Fernando Espírito-Santo of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., lead author of the study, created new techniques to analyze satellite and other data. He found that each year, dead Amazonian trees emit an estimated 1.9 billion tons (1.7 billion metric tons) of carbon to the atmosphere. To compare this with Amazon carbon absorption, the researchers used censuses of forest growth and different modeling scenarios that accounted for uncertainties. In every scenario, carbon absorption by living trees outweighed emissions from the dead ones, indicating that the prevailing effect in natural forests of the Amazon is absorption.
Until now, scientists had only been able to estimate the Amazon’s carbon balance from limited observations in small forest areas called plots. On these plots, the forest removes more carbon than it emits, but the scientific community has been vigorously debating how well the plots represent all the natural processes in the huge Amazon region. That debate began with the discovery in the 1990s that large areas of the forest can be killed off by intense storms in events called blowdowns.
Espírito-Santo said that the idea for the study arose from a 2006 workshop where scientists from several nations came together to identify NASA satellite instruments that might help them better understand the carbon cycle of the Amazon. In the years since then, he worked with 21 coauthors in five nations to measure the carbon impacts of tree deaths in the Amazon from all natural causes — from large-area blowdowns to single trees that died of old age. He used airborne lidar data, satellite images, and a 10-year set of plot measurements collected by the University of Leeds, England, under the leadership of Emanuel Gloor and Oliver Phillips. He estimates that he himself spent a year-and-a-half doing fieldwork in the Amazon.
“It was a difficult and audacious study, and only Espírito-Santo’s dedication made it possible,” said Michael Keller, a research scientist at the U.S. Forest Service and co-author of the study.
Correlating satellite and airborne-instrument data with ground observations, Espírito-Santo and his colleagues devised methods to identify dead trees in different types of remotely sensed images. For example, fallen trees create a gap in the forest canopy that can be measured by lidar on research aircraft, and dead wood changes the colors in a satellite optical image. The researchers then scaled up their techniques so they could be applied to satellite and airborne data for parts of the Amazon with no corresponding ground data.
“We found that large natural disturbances — the sort not captured by plots — have only a tiny effect on carbon cycling throughout the Amazon,” said Sassan Saatchi of JPL, also a co-author. Each year, about two percent of the entire Amazon forest dies of natural causes. The researchers found that only about 0.1 percent of those deaths are caused by blowdowns.
This study looked only at natural processes in Amazonia, not at the results of human activities such as logging and deforestation, which vary widely and rapidly with changing political and social conditions.
The other institutions participating in the study are the University of New Hampshire, Durham; the Universities of Leeds and Nottingham, U.K.; Oxford University, U.K.; James Cook University, Cairns, Australia; U.S. Forest Service International Institute of Tropical Forestry, Puerto Rico; EMBRAPA Satellite Monitoring Center, Campinas, Brazil; National Institute for Research in Amazonia, Manaus, Brazil; EMBRAPA Eastern Amazonia, Santarém, Brazil; National Institute for Space Research (INPE), São José dos Campos, Brazil; the Missouri Botanical Garden, Oxapampa, Peru; and the Carnegie Institute for Science, Stanford, Calif.
NASA monitors Earth’s vital signs from land, air and space with a fleet of satellites and ambitious airborne and ground-based observation campaigns. NASA develops new ways to observe and study Earth’s interconnected natural systems with long-term data records and computer analysis tools to better see how our planet is changing. The agency shares this unique knowledge with the global community and works with institutions in the United States and around the world that contribute to understanding and protecting our home planet.
Rolf Peterson/Minneapolis Star Tribune/MCT/Newscom
Since 1958, ecologists have watched wolf and moose populations on Isle Royale in Lake Superior wax and wane in response to each other, disease and the weather. But for the longest predator–prey study in the world, the wolf is now at the door. Devastated by inbreeding, the wolf population has dropped from 30 individuals a decade ago to just 10 spotted in field counts so far this year, leading the US National Park Service to consider importing new animals for a ‘genetic rescue’.
Now, nature is intervening — and could either save the landmark project without the need for tranquillizer darts and wolf crates, or sound its death knell. As temperatures plummeted last month, Lake Superior froze for the first time in six years. The 24-kilometre ice bridge could let wolves from the Canadian mainland cross to the US island, bringing an influx of genes (see ‘Wolf island’). But project scientists say that the opposite is more likely: free to roam, the last wolves could leave the island in search of mates.
That would put an end to a study that has provided textbook ecology lessons for generations. It has shown how predation can structure populations of prey: when wolf numbers plummet, moose populations tend to soar (see ‘Ecosystem in flux’). And it has offered insights into wolf behaviour, moose physiology, the life cycle of moose ticks and how wolves might be driven to form packs to ward off scavengers such as ravens, rather than for any hunting advantage.
Through the decades, the search for cause and effect in the ecosystem has been rendered much easier by isolation from the mainland’s human and animal populations. Occasionally, however, Lake Superior freezes. The very first wolves came to Isle Royale over an ice bridge in the early 1940s, some 30 years after the first moose. The lake froze nearly every year at the beginning of the study, but that has changed. The most recent ice bridge was in 2008; before that, the last one was in 1997, when a wolf that biologists called ‘the old grey guy’ came to the island. He sired 34 pups and provided a rare boost of genes that doubled the population by the mid-2000s.
Whether any wolves have crossed this year’s ice bridge will not be clear immediately. The scientists are conducting their annual population survey, and are flying along the island shore in their Super Cub plane two or three times a week, but snow fills wolf tracks very quickly. If new wolves do arrive, their presence will probably be confirmed in the coming months, when DNA is extracted from faeces samples.
John Vucetich, co-leader of the project and an ecologist at Michigan Technological University in Houghton, says that the need for an influx of genes is becoming urgent. In the past two decades, wolf skeletons have displayed spinal deformities that can painfully pinch nerves and affect gait and generally reduce fitness. According to work led by Vucetich and Rolf Peterson, also an ecologist at Michigan Technological University, this might explain why the number of moose needed to support a given number of wolves has increased: the predators’ attacking efficiency may be compromised (J. Räikkönen et al. Biol. Conserv.142, 1025–1031; 2009).
For Vucetich, genetic rescue is required not so much to maintain the continuity of the study as to preserve the ecosystem. Moose eat balsam fir trees. When the moose population expands, unchecked by predation, fewer fir seedlings can grow large enough to ‘escape’ into the canopy above the reach of moose and reproduce. There is already a missing generation of trees from between about 1910, when the moose arrived on the island, and 1940, when the wolves came. Most of Isle Royale’s balsam firs are thus either older than 100 years and near the end of their lives, or young and short enough to be browsed to death. If the trees do not achieve escape in the next decade or so, says Vucetich, “large portions of Isle Royale are not going to generate balsam fir, which is a really basic component of a boreal forest ecosystem”.
Many scientists familiar with Isle Royale support genetic rescue, especially because human activity has contributed to the current population crash. Climate change has led to the decreasing frequency of ice bridges. Canine parvovirus, probably caught from a domestic dog, caused the wolf population to fall from around 50 to 14 in the early 1980s. And in 2012, three wolves were found dead in an abandoned mining pit. Given this history of human influence, the argument that leaving the wolves alone would be allowing nature to take its course does not sway most ecologists.
David Mech, a US Geological Survey wolf biologist based in St Paul, Minnesota, argues in favour of “watchful waiting”. He says that much can be learned from studying how inbreeding affects population persistence, and that the knowledge would be useful for conservation biologists, who often need to nurture small, inbred populations of endangered species. He is not convinced that the wolves will die out; they have hit low numbers before and bounced back, he notes. And even if they do disappear, new wolves can be brought in quickly.
But Vucetich says that it could be five years before the last wolf dies and scientists confirm its demise, and another five before federal bureaucracies approve a genetic rescue and a pack develops into a predation force. He fears that a decade without significant moose predation would leave the fir trees devastated.
Phyllis Green, superintendent of the Isle Royale National Park, is considering three alternatives: doing nothing; watchful waiting followed by reintroduction if the population hits zero; or genetic rescue. She has not initiated a formal decision-making process, and will not commit to a timeline, but says that she wants to make a decision in consultation with her regional and national directors “before we run out of options”.
She is proceeding cautiously, she says, in part because of the implications of her decision. The mandate of the National Parks Service, as enshrined in a 1916 Act of Congress, is to “conserve the scenery and the natural and historic objects and the wild life therein and to provide for the enjoyment of the same in such manner and by such means as will leave them unimpaired for the enjoyment of future generations”. Generally, this has meant a hands-off approach, but a genetic rescue could set a precedent for interventions to counteract the effects of climate change in other parks.
Green knows that many scientists are in favour of genetic rescue, but she also hears from “wilderness-oriented” advocates who urge her not to intervene. “It is one of the wicked problems,” she says.
Nature 506, 140–141 (13 February 2014) doi:10.1038/506140a
Healthy pups and frigid weather change the scientific debate on Isle Royale
In the upper left, the male and female alpha wolves of this pack on Isle Royale rebuke one of their new pups born last year on Isle Royale. Photo: JOHN VUCETICH,
It’s only February, and already it’s been an extraordinary winter for the wolves of Isle Royale.
At least two new healthy pups, and perhaps three, have survived their first perilous months of life — proof that the famous wolves, which number less than a dozen, may not be dwindling after all.
And twice this winter, the bitter cold that has halted shipping across Lake Superior has also created temporary ice bridges across the 20-mile channel between Isle Royale and the Minnesota-Ontario mainland, raising the tantalizing possibility that once again wolves could either leave the island or arrive on their own four feet.
Both developments are likely to only confound a precedent-setting decision that faces the National Park Service: whether to intervene in nature’s course and bring new wolves onto the island in an effort to preserve them and the critical balance between the predators and their primary prey, moose. Conservationists say the decision could establish new policy on managing critical species in national parks everywhere and even change the definition of wilderness as a place where only nature is allowed to rule.
The wolves, which once numbered as many as 50, are at their lowest ebb since researchers first began tracking them in the 1950s and are closely followed by naturalists all over the world. Scientists running the Isle Royale wolf study today, from Michigan Technological University say they fear that even with the new pups, they could die out, largely as a result of inbreeding.
At best, the new pups “might extend the amount of time the population can bump along,” said Rolf Peterson, who has been studying the wolves and moose along with John Vucetich for years.
In a series of e-mails sent from the island this week, Peterson said that even now the number of wolves is too small to keep the moose population in check and the forest ecosystem in balance. Since 2006, moose numbers have more than doubled to nearly 1,000. That’s far less than their peak of nearly 2,500 more than 30 years ago, but the rate of growth is dramatic.
The huge mammals depend on balsam firs, one of the primary species of trees on the island, as a major part of their diet. If they eat too many, then other trees would take over and, in the long run, neither wolves or moose would survive.
But other wolf experts disagree, including David Mech, a wolf expert with the U.S. Geological Survey in Minnesota. Mech said that the wolves’ population is perilously low, but that it has bounced back before, and that the pups are evidence that it can again. Many of the wolves, he said, are only now at the best age for breeding, and this year could see even more and larger litters, he said.
“Those wolves are not nonreproductive,” he said. “In another year or two they could produce some more.”
Precarious
In the meantime, scientists say they provide valuable information on reproduction, genetics and ecology. This week, the prestigious journal Nature weighed in with an editorial.
“A declining island wolf population underlines the influence that humans have on nature,” it read. It points out that the whole system is “highly artificial.” Wolves and moose have been on the island less than 100 years, and in the 1980s the wolf population was nearly wiped out by canine parvovirus, an infection likely brought to the island by someone’s pet. (Dogs are no longer allowed.)
Meanwhile, climate change — also caused by humans — is greatly reducing the chances for the ice bridges that brought wolves to the island in the first place, it said.
Once a near seasonal event, the bridges have become increasingly rare. The last one formed in 2008, when two wolves collared with tracking devices disappeared, perhaps to the mainland. The last bridge before that was in 1997, when a wolf named “Old Gray Guy” appeared on the island and went on to sire dozens of puppies, providing an infusion of new genes that researchers credit with saving the population from demise.
This year satellite images show that two bridges have formed and then been broken again by wind, the latest in early February, said Peterson.
Isabelle’s fate
Isabelle, a five-year-old female, is not attached to either of the two packs on Isle Royale. Photo: ROLF PETERSON
Meanwhile, as humans fret about the wolves’ survival and the meaning of wilderness, Isabelle waits. She is, literally, a lone wolf on Isle Royale and a prime candidate to mate with a new arrival, should one come, or take off across an ice bridge, researchers said.
Isabelle was born in 2008 to one of the two packs on the island, but, as wolves often do, left the pack in 2012 to find a mate. The pickings are few — and all the males are related to her. That inhibits mating in wolves as well as people, Peterson said.
In addition, lone wolves are vulnerable to attacks from breeding packs in the relentless competition for the right to reproduce.
Because she wears a tracking collar, the researchers have been able to follow her lonely and persecuted life. Last year they saw three other wolves chase her to the edge of the water and attack her with all the ferocity they use to bring down a 900-pound moose. They left her wounded and bleeding on the edge of the ice. When the researchers left last winter, they weren’t sure if they would see her again.
“But she has survived,” Vucetich announced on the research study’s blog in late January. “It would not be surprising if she’s learned to kill moose by herself. A wolf that can do so is better than most.”
Isabelle is now 5, a prime age to mate. About one in 10 wolves will strike off on their own and try to start new packs, and some will travel for hundreds of miles in their search. On Isle Royale, however, the wolves are trapped — unless there is an ice bridge.
No one knows what’s in the heart of a wolf, but Peterson said he thinks it’s quite possible, that given the chance, Isabelle will head out. Mech said that as long as there are potential mates on the island, she’s more likely to stay put.
The chances that a wolf would come from the mainland are also very small, researchers said. It’s known to have happened only three times in the island’s history. And today mainland wolves face a treacherous path across roads, yards and urban areas — never mind 20 miles of shifting ice.
Still, the survival of the three pups and the renewed possibility of ice bridges may have bought the National Park Service some time. Phyllis Green, park superintendent, is weighing three options: doing nothing, reintroducing wolves if their numbers hit zero or a “genetic rescue” by bringing a few new wolves to mate with those that are in residence.
Peterson and Vucetich said they favor genetic rescue. And Isabelle, if she had a vote, would likely agree.
Aerial image of the Western Arctic Caribou herd, 2011. Jim Dau / ADF&G
Caribou and reindeer—members of theRangifer genus—are hunted and herded by many Arctic and Subarctic societies, which is why it’s natural to imagine that reindeer would be tasked with pulling Santa’s sleigh to and from the North Pole. Rangifer populations have fluctuated in number historically, but currently many wild herds have unusually low numbers and their winter ranges in particular are smaller than they used to be.
The map shows the current status of 24 major migratory tundra reindeer and caribou herds. Green indicates increasing populations; red indicates decreasing numbers; black and yellow indicate populations have remained stable either on the high or low end of their historic numbers. Only a few herds are increasing or are stable at high numbers; the most recent population estimates indicate that most herds continue to decline or remain at low numbers after severe declines.
Just as scientists try to figure out the causes behind climate cycles, wildlife experts are trying to understand what is behind cycles in herd populations. Local and traditional knowledge indicates that caribou go through periods of abundance and scarcity every 40-60 years. The size of individual herds has varied greatly since 1970 when population estimates began. Since it is normal for herds to vary in size over time, scientists are still uncertain whether the current low numbers are natural or perhaps driven by some of the rapid changes in the Arctic environment. For some herds, their current ranges are approaching the low end of their historic extent.
In the United States, there are four distinct herds of caribou in Alaska—two that are decreasing in number and two that are increasing. The Western Arctic herd—the state’s largest—reached a population low of 75,000 in the mid-1970s, and then rebounded during the 1980s and 1990s to reach a peak of 490,000 in 2003. The herd then declined to 325,000 in 2011. While the herd is still very large, the Alaska Department of Fish and Game says it may become necessary to reduce harvests in the future if this decline continues.
Many countries are attempting to stabilize population numbers through harvest management. Beginning in 2000, Greenland began to allow hunting to reduce caribou populations. Despite this, surveys indicated that the largest herd, the Kangerlussuaq-Sisimiut, remained at around 98,000 animals. The second largest, Akia-Maniitsoq, decreased from an estimated 46,000 in 2001 to about 17,400 in 2010. One possible cause might be differences in topography: hunting access is easier in the Akia-Maniitsoq territory compared to the rough, mountainous terrain that the Kangerlussuaq-Sisimiut inhabits.
Between the 1950s and 1970s, Russia’s Taimyr Herd—one of the largest in the world—increased from 110,000 to 450,000 in 1975. Even after commercial hunting increased, the herd held to a size of about 600,000 animals. When subsidies to commercial hunters were removed, hunting declined and the herd grew rapidly by 2000 to 1 million animals. Currently the herd is assumed to have declined to about 700,000 animals.
More information about individual migratory Rangifer herds in the Arctic can be found in the Migratory Tundra Rangifer chapter of the Arctic Report Card: Update for 2013.
Map by NOAA Climate.gov, based on rangifer migratory range data provided by Don Russell.
The Western Arctic Caribou Herd has been declining at a rate of 4 to 6 percent a year since the population peaked in 2003 at 490,000 animals, said Jim Dau, a Kotzebue-based biologist with the Alaska Department of Fish and Game. “I don’t see any indication that that’s about to turn around,” Dau told the Western Arctic Caribou Herd Working Group at its annual meeting in Anchorage.
The last official population estimate, released in 2011, put the herd at 325,000 animals. An updated estimate is expected next spring, Dau said. Biologists are examining aerial photos and other data to come up with a number for the size of the herd, which roams over much of northwestern Alaska.
Population could slip to about half its 490,000 animal peak
So far, biologists have documented increased mortality for adult females and decreased survival for calves, a combination that bodes poorly for population numbers, Dau said.
“Maybe even this year, we could slip below 265,000 animals,” triggering more conservative management and more hunting restrictions, he said.
Such a drop would mean the herd had lost 60,000 animals, or almost 20 percent of its population, since the last count two years ago.
Some factors appear ruled out as causes for the decline, Dau said. The number of animals hunted has been stable over several years, so overharvesting should not be a big factor, he said. Still, even though the total harvest has not increased, hunters are now taking about 5 percent of the herd, compared to 3 percent in past years, he said.
The road and other facilities associated with the Red Dog Mine — the world’s largest zinc producer and the only industrial development in the caribou habitat — also seem blameless, as caribou have easily migrated across that area, he said. There is no sign of significant disease outbreaks or parasite infestations, he said.
Male caribou in Alaska (Photo credit: Wikipedia)
But some potential culprits have emerged — too little lichen and too much ice.
The Bureau of Land Management has documented an incremental shift from lichen — the caribou’s preferred food — to grasses and shrubs in the animals’ winter range, Dau said. But at the same time, starvation does not seem to be a major problem for the caribou. “We’re seeing fewer skinny caribou now than we used to see,” Dau said, but those animals that are malnourished seem to be much more vulnerable to wolf predation, he said.
Weather oddities, possibly resulting from climate change, could also be taking a toll on the caribou, Dau said. There is more freezing rain falling in the region, creating hazardous conditions for the animals. Just three weeks ago, Kotzebue endured four to six days of a rain-snow mix that coated the area with ice.
“Icing events seem to be more common now that fall weather is more mild,” Dau said. Effects can be seen on caribou bodies, with white patches of accumulated ice forming between the eyes and areas of shorn fur cut by sharp ice edges.
Movement across the land became difficult, and ice on the ground was a barrier to food sources.
Amid the extremely mild fall of 2013, the caribou migration south was late and unusually crowded, with “a very discrete leading edge,” Dau said. “If you were south of that leading edge, you wouldn’t know there was a caribou in northwestern Alaska,” he said. “If you were below that edge, you were surrounded by tens of thousands of caribou.”
The population information is sobering, said members of the Western Arctic Caribou Herd Working Group, an advisory group representing village residents, hunters, reindeer herders, environmentalists and guides.
Roy Ashenfelter, chairman of the working group, said members should let villagers and hunters elsewhere know about the declines “so that when changes come about, it’s not a surprise.” Though hunting did not cause the problem, hunters should prepare to be part of the solution, he said. “One of the things we’ve learned is to not wait until the last minute and tell the public, ‘Hey, here are some restrictions,’” he said.
Allan Savory’s livestock hypothesis hinges on what he calls “holistic management and planned grazing.”Photo by Vyacheslav Oseledko/AFP/Getty Images
When Allan Savory finished his TED talk early last month, foodies worldwide collectively salivated. In roughly 22 minutes, Savory, a biologist and former member of the Rhodesian Parliament, challenged the conventional wisdom blaming livestock for the degradation of global grasslands into hardpan deserts. It has long been a basic tenet of environmentalism that 10,000 years of overgrazing has caused this desertification. Environmentalists insist that to restore degraded landscapes, we must reduce the presence of cattle, eat less meat, and allow ecosystems to repair themselves. Savory, who admits that he’s suggesting “the unthinkable,” wants humans to do the exact opposite: Add cattle to the deserts, manage them with obsessive precision, and eat more meat. Most of the world’s land, he says (at about 18:40), “can only feed people with animals.”
Savory’s hypothesis hinges on what he calls “holistic management and planned grazing.” These methods are designed to re-enact the movements of the prehistoric herds that once nurtured global grasslands with their manure deposits and “hoof action” (gentle trampling that increases the soil’s ability to hold water). By mimicking the natural symbiosis between plants and animals, holistic grazing would, Savory argues, encourage the regrowth of carbon-sequestering grasslands. These grasses would absorb enough carbon to counteract the methane production that’s associated with cattle husbandry (thanks to cow burps and farts) and halt global warming. (To put that claim in perspective, note that the Earth’s oceans and plants currently absorb only half of the 7 billion metric tons of carbon that human activities release into the atmosphere each year.) In order for Savory’s plan to work, the stocking density of livestock—the number of animals grazing a given area of land—would need to increase, in some cases, by as much as 400 percent. And for ranchers to make a living, they would sell their beef.
Savory’s speech quickly attracted praise. Chris Anderson, the TED host, said to Savory after his show, “I’m sure everyone here … wants to hug you.” Michael Pollan, apassionate advocate of pastured beef, called Savory’s talk the “highlight of TED” in a tweet that provocatively asked, “Eat MORE meat?” The Organic Consumers Association published an article that used Savory’s presentation to assert that “what we need is MORE moving, grazing animals, not less,” and to argue that holistic grazing “would be beneficial for the environment, the health of the animals, and subsequently the health of humans consuming those animals.” The takeaway was clear: If you’re interested in saving the planet, sharpen your steak knives.
Well, not so fast. For all the intuitive appeal of “holistic management,” Savory’s hypothesis is beset with caveats. The most systematic research trial supporting Savory’s claims, the Charter Grazing Trials, was undertaken in Rhodesia (Zimbabwe today) between 1969 and 1975. Given the ecological vagaries of deserts worldwide, one could certainly question whether Savory’s research on a 6,200-acre spot of semiarid African land holds any relevance for the rest of the world’s 12 billion acres of desert. Extrapolation seems even more dubious when you consider that a comprehensive review of Savory’s trial and other similar trials, published in 2002, found that Savory’s signature high-stocking density and rapid-fire rotation plan did not lead to a perfectly choreographed symbiosis between grass and beast.
Instead, there were problems during the Charter Grazing Trials, ones not mentioned in Savory’s dramatic talk. Cattle that grazed according to Savory’s method needed expensive supplemental feed, became stressed and fatigued, and lost enough weight to compromise the profitability of their meat. And even though Savory’s Grazing Trials took place during a period of freakishly high rainfall, with rates exceeding the average by 24 percent overall, the authors contend that Savory’s method “failed to produce the marked improvement in grass cover claimed from its application.” The authors of the overview concluded exactly what mainstream ecologists have been concluding for 40 years: “No grazing system has yet shown the capacity to overcome the long-term effects of overstocking and/or drought on vegetation productivity.”
The extension of Savory’s grazing techniques to other regions of Africa and North America has produced even less encouraging results. Summarizing other African research on holistically managed grazing, the same report that evaluated the Charter Grazing Trials found “no clear cut advantage for any particular form of management,” holistic or otherwise. It noted that “more often than not” intensive systems marked by the constant rotation of densely packed herds of cattle led to a decline in animal productivity while doing nothing to notably improve botanical growth.
A 2000 evaluation of Savory’s methods in North America (mostly on prairie rangelands in Wyoming, Oklahoma, Texas, and New Mexico) contradicted Savory’s conclusions as well. Whereas Savory asserts that the concentrated pounding of cow hooves will increase the soil’s ability to absorb water, North American studies, according to the authors, “have been quite consistent in showing that hoof action from having a large number of animals on a small area for short time periods reduced rather than increased filtration.” Likewise, whereas Savory insists that his methods will revive grasses, “the most complete study in North America” on the impact of holistic management on prairie grass found “a definite decline” of plant growth on mixed prairie and rough fescue areas. It’s no wonder that one ecologist—who was otherwise sympathetic toward Savory—flatly stated after the TED talk, “Savory’s method won’t scale.”
Even if Savory’s plan could scale, foodies would still have to curb their carnivorous cravings. The entire premise of any scheme of rotational grazing, as Savory repeatedly notes, is the careful integration of plants and animals to achieve a “natural” balance. As Dr. Sylvia Fallon of the Natural Resources Defense Council has shown, symbiosis between grazing herds and grasses has historically worked best to sequester carbon when the animals lived the entirety of their lives within the ecosystem, their carcasses rotted and returned their accumulated nutrients into the soil, and human intervention was minimal to none. It is unclear, given that Savory has identified this type of arrangement as his ecological model, how marketing cattle for food would be consistent with these requirements. Cows live up to 20 years of age, but in most grass-fed systems, they are removed when they reach slaughter weight at 15 months. Cheating the nutrient cycle at the heart of land regeneration by removing the manure-makers and grass hedgers when only 10 percent of their ecological “value” has been exploited undermines the entire idea of efficiency that Savory spent his TED talk promoting.
Further weakening Savory’s argument for the wholesale application of holistic management to the world’s deserts is his distorted view of desert ecology. There are two basic kinds of deserts: genuinely degraded landscapes in need of revival and ecologically thriving ones best left alone. Proof that Savory fails to grasp this basic distinction comes when, during his talk, he calls desert algae crust (aka “cryptobiotic crust”) a “cancer of desertification” that represses grasses and precipitate runoff. The thing is desert algae crust, as desert ecologists will attest, is no cancer. Instead, it’s the lush hallmark of what Ralph Maughan, director of the Western Watersheds Project, calls “a complete and ancient ecosystem.” According to the U.S. Geological Survey, “Crusts generally cover all soil spaces not occupied by green plants. In many areas, they comprise over 70 percent of the living ground cover and are key in reducing erosion, increasing water retention, and increasing soil fertility.” Savory, whose idea of a healthy ecosystem is one with plenty of grass to feed cattle, neglects the less obvious flora—such as, in addition to algae crust, blackbrush, agaves, and creosote—that cattle tend to trample, thereby reducing the desert’s natural ability to sequester carbon on its own terms. “It is very important,” Maughan writes, “that this carbon storage not be squandered trying to produce livestock.”
Savory’s most compelling and controversial assumption—one that’s absolutely central to his method—is that humans can viably “mimic” (a word he uses about a dozen times in the TED talk) “all of nature’s complexity.” This is a stunning claim. The conceit of mimicry as a virtue of Savory’s technique is challenged in part by the fact that not all deserts rely on the presence of herd animals for their ecological health. In many desert ecosystems, desert grasses evolved not alongside large animals but in concert with desert tortoises, mice, rats, rabbits, and reptiles. It’s difficult to imagine how a human-managed ecosystem such as Savory’s—dependent on manipulating the genetics of livestock, building sturdy fences, manufacturing supplemental feed, and exterminating predators—is more representative of “nature’s complexity” than a healthy desert full of organisms that have co-evolved over millennia.
In 1990, Savory admitted that attempts to reproduce his methods had led to “15 years of frustrating and eratic [sic] results.” But he refused to accept the possibility that his hypothesis was flawed. Instead, Savory said those erratic results “were not attributable to the basic concept being wrong but were always due to management.” In a favorable interview with Range magazine in 2000, Savory seemed unconcerned with the failure of his method in scientific trials: “You’ll find the scientific method never discovers anything. Observant, creative people make discoveries.”
Understandably, given his adherence to scientifically questionable conclusions in the face of evidence to the contrary, scientific institutions have not gone out of their way to work with Allan Savory. As a result, Savory has built his own institutions. From theCenter for Holistic Management (later the Allan Savory Center for Holistic Management) to the Savory Center to Holistic Management Internationalto theAfrica Centre of Holistic Management, Savory has kept his ideas in motion. Today, Savory, nearing the end of his career, heads the for-profitSavory Institute. Whether desert landscapes or the foundation’s coffers become any greener remains to be seen. In the meantime, the evidence continues to suggest what we have long known: There’s no such thing as a beef-eating environmentalist.
“We were once just as certain that the world was flat. We were wrong then, and we are wrong again.” That’s what Allan Savory had to say at TED about science’s view of desertification, a form of land degredation in which land loses its vegetation and bodies of water1. For years, scientists have believed that overgrazing by livestock is a major cause of desertification, and Allan Savory shared this opinion as a young biologist. Now Savory argues that we can prevent desertification by grazing more animals, with their movement carefully planned to mimic nature.
TED curator Chris Anderson dubbed Savory’s talk the highlight of the year’s conference and the official TED Twitter feeds described the talk as “profound and important.” Predictably, the talk was cheered by pastured meat enthusiasts, with Michael Pollan appearing ready to recant his advice to eat “mostly plants”:
Savory’s talk was also well-received in typically level-headed corners of the Twittersphere, with Discover Magazine calling it “one of the most thought-provoking” talks of the year, and Michael Shermer declaring it “moral progress in climate change.”
As C.J. Hadley’s profile in the February 2000 issue of the journal Rangelands makes clear, Savory has led an interesting life. He was born and raised in Zimbabwe (then Rhodesia), and worked in biology, military, politics, and other fields. Once a staunch opponent of grazing, he came to believe that we need more cows rather than fewer. As he told Hadley, “Severe grazing is absolutely essential to maintain biodiversity.” Overgrazing, he argues, is not the cause of desertification, arguing that grasslands have historically evolved with grazing animals. He now believes that the problem is poorly-planned grazing, and he now advocates for “holistic management and planned grazing” in order to address “all of nature’s complexity and our social, environmental, economic complexity.” According to Savory, well-planned grazing promotes plant growth, and the action of animal hooves on the soil improves the soil’s absorption of water. These ideas support the view that well-planned animal grazing can prevent and reverse desertification, thereby helping to combat climate change.
Savory’s methods have found little support from mainstream science. The same issue of Rangelands that featured Hadley’s profile of Savory also included an article by Jerry L. Holechek and others, which attempted to review the evidence for a number of Savory’s claims. Their review of studies from 13 North American sites and additional data from Africa found little evidence for any of the environmental benefits which Savory claimed for his methods. Moreover, the research consistently indicated that “hoof action from having a large number of animals on a small area for short time periods reduced rather than increased infiltration,” seemingly contradicting a key assumption of Savory’s methods.
In a letter to the editor of Rangelands that June, Savory dismissed Holechek’s findings, pointing out that the cited studies considered “short duration grazing” schemes rather than the Holistic Management methods for which Savory advocated. He explained, “The work Holechek et al. describe is unlike any range management practice I have ever advocated…In fact I have consistently stated that all grazing systems and rotations, including short duration grazing, will fail.” 3 As Savory explained in 1983, a key difference between short duration grazing and Savory’s Holistic Resource Management is that the latter method is “time-controlled,” adjusting grazing periods in accordance with the rate of plant growth.
Savory went on to describe what he identified as the only research trial ever conducted on his methods, which took place in Zimbabwe in the 1960s. The experiment, known as the Charter Grazing Trials and undertaken with Savory’s involvement, tested the claim that “we could double the stocking rate on any land under conventional management, improve the land and make more profit” with Savory’s methods. Savory reports, “The only trial ever conducted proved what I have always advocated and continue to advocate when livestock are run on any land.”
In general, it is unlikely that a single study on a few plots of land will definitively prove a statement about “any land.” Moreover, while I haven’t seen the original papers (which were published in the Zimbabwe Agricultural Journal), Holechek summarized the published work in a later issue of Rangelands, finding relatively weak support for Savory’s methods.
A further complication with the Charter Grazing Trials is that, as Savory’s letter notes, it tested “the planned grazing process then called short duration grazing, but today called Holistic Planned Grazing.” Indeed, Savory wrote in his 1983 Rangelandspiece, “For those without a deep knowledge of Short Duration Grazing, I am extremely familiar with this grazing system as I developed it.”
The best I can do to make sense of all this is to put everything in the context of Savory’s explanation of his method. In his 1983 article in Rangelands, Savory explained that the best analogy for what was then called the “Savory Grazing Method” was a computer:
If you know what you want to do with the computer and you feed in the right information it will aid you in achieving the result rapidly and surely. If some factors change and you observe the changes and feed in the new information the computer will again aid you efficiently in getting to your goal.
Thus, it is not necessarily contradictory for Savory to claim to have developed short duration grazing, that short duration grazing doesn’t work, and that the methods for which he has always advocated have been proven to work. The key is that the method that would become short duration grazing was the output of Savory’s “computer” when he fed in the information that was relevant to that situation. 4
That said, this ought to serve as a warning against the folly of claiming a single study as proof of anything. If the Charter Grazing Trials are proof of something, why is it not short duration grazing which was validated by its results? It is, after all, the method that was employed in the study. For Savory to now say that short duration grazing is a failure, he has to concede that a single study doesn’t prove the effectiveness of a method on “any land.”
Holechek’s 2000 article also claims that Savory had “expressed doubt that holistic resource management could be validated experimentally.” While I was not able to find a precise reference for this claim, Savory did not deny it in his response, and elsewhere he has expressed some reservations about scientific testing. For instance, in Hadley’s (mostly favorable) profile, he made it clear that he saw little use for the scientific method:
You’ll find the scientific method never discovers anything. Observant, creative people make discoveries. But the scientific method protects us from cranks like me.
While the intended irony of this statement has not escaped me, it’s hard to read it without concluding that he sees the scientific method as an obstacle to progress, rather than a tool for achieving it.
That is problematic because the scientific method is what will tell us whether Holistic Management works. Savory would like us to graze more cattle to fight desertification and climate change, even as scientific evidence indicates that his “solution” will actually exacerbate these problems. If we were to employ Savory’s methods on a large scale and they were to succeed in stopping desertification, that would constitute excellent experimental validation of those methods. 5 If we can’t experimentally validate his methods, then we cannot know them to work in real life, either. It is thus perfectly reasonable to ask for evidence on a smaller scale before we try such a thing, particularly as existing evidence indicates that this would make the problems worse. As Chad Kruger writes, “Being ‘unconventional’ is not, in itself, a problem, but when what you are arguing for is unconventional, you’d better ‘bring data.’”
It is also important to note that for all Savory’s insistence that his methods work, it has been associated with a number of failures. For instance, Hadley mentions a test farm in Zimbabwe, which collapsed as soon as Savory fled that country. Whereas those on the farm blamed the collapse on drought, Savory blamed on their lack of proper planning in his absence.
This is typical of Savory’s response to failure. The fault never lies in his methods but in people’s implementations of them. For instance, in a 1990 paper in the journal Ecological Economics6, Savory explains away “15 years of frustrating and eratic [sic] results” with the admission that “we had confused the integrated approach with the holistic approach, thinking that the terms were synonymous,” emphasizing that “the breakdowns we were experiencing were not attributable to the basic concept being wrong but were always due to management–of the people and the finances.” 7 Even after Savory realized that “the integrated approach and the holistic approach were opposites,”8 he had to struggle with “understanding not only what ‘holistic’ meant, but even more difficult, how to apply such an approach in day-to-day management.” Even when his own implementation of his own ideas leads to failure, he believes that the problem isn’t that the methods were flawed but that he didn’t fully understand them.9 It is this kind of convoluted reasoning that allows him to claim that his methods work.
In a review of Savory’s 1988 book Holistic Resource Management, M.T. Hoffman wrote “The apparent inconsistencies and lack of definitions (eg. for concepts such as complexity, stability, resilience, diversity and production which have a number of different meanings in the ecological literature), render it frustratingly difficult to compare his [Holistic Resource Management] approach with the broader literature.” Imprecise language doesn’t just make it hard to compare Savory’s methods with the existing literature. It also makes it nearly impossible to evaluate his approach scientifically because it allows Savory to blame any failures on a misunderstanding of the method. So long as nobody can understand Savory’s ideas, those ideas can’t be tested or disproven. In this framework, problems are solved not by trying different methods but by developing a “better” understanding of the existing one. It is therefore little wonder that after members of the Department of Range and Forage Resources at the University of Natal – Pietermaritzburg–Savory’s alma mater–met with Savory, they reported that it would be “extremely difficult” to test Savory’s ideas because “it would be difficult to evaluate even a short-term research endeavour (of 5 to 10 years), as the approach taken by Holistic Management proponents would surely have changed by then, as it has in the past.”
Changing one’s mind in response to new evidence isn’t bad at all. Indeed, it’s the scientific thing to do. However, that is not the kind of change that one finds in Savory’s writings. Savory insists that he’s been correct all along and that his evolution flows naturally from an improved understanding of his own bulletproof ideas. Whereas the scientific method lends itself well to self-correction, Savory’s vague language and inconsistency will lead to trying many different things without reason to expect improvement.
Savory argued at TED that Holistic Management “offers more hope for our planet, for your children, and their children, and all of humanity.” What Savory does not tell us is that there is the distinct possibility that if we try to implement those ideas, we will fail. In this case, he will tell us that we misunderstood his ideas. How comforting it will be to know that his ideas were correct, as they always have been!
In December, TED responded to concerns that independent TEDx authorized events were “dragging the TED name through the mud” by sending a letter to “the TEDx community” warning that bad science could lead to revocation of the TEDx license. The letter also included some advice for identifying bad science. I can’t help but think that Savory’s work should have raised concerns for anybody familiar with that list. At the least, Savory’s work “has failed to convince many mainstream scientists of its truth,” much of it “is not based on experiments that can be reproduced by others,” it comes from an “overconfident fringe expert,” and it uses imprecise vocabulary to form untested theories.
Of course, TED has no contractual incentive to apply the standards it sets for TEDx organizers to its own talks. However, the letter emphasizes that “your audience’s trust is your top priority,” and I think it’s fair to ask what TED did to respect that trust in this case. Did they research the science behind Allan Savory’s ideas? Are they satisfied that his talk amounts to “good science”? If Savory’s talk had run at a TEDx event, would that event’s license have been revoked? Now that TED has reined in TEDx, perhaps its next move should be to look in the mirror.
Although the reason for Allan Savory’s departure from Holistic Management International is not clear to me, Butterfield has editedSavory’s Wikipedia page to remove references to Holistic Management International, which seems to hint at less friendly relations between the organizations.↩
Curiously, Savory’s 1978 article “A Holistic Approach to Ranch Management Using Short Duration Grazing,” published in the Proceedings of the First International Rangeland Congress devoted several paragraphs to explaining short duration grazing, not once mentioning that it would fail. Instead, the article stated, “An immediate doubling of production is not uncommon on ranches which were considered fully stocked before changing to short duration grazing.”↩
Savory has used a number of terms for his methods over the years, including short duration grazing, Savory grazing method, holistic resource management, holistic management and holistic planned grazing.↩
This would not necessarily confirm that Savory had identified the correct mechanisms by which Holistic Management worked. It would merely show that they worked.↩
An earlier version of this post included a link to the wrong article here. I corrected the link at 7:30PM on April 4, 2013.↩
I added the end of this sentence post-publication (March 12, 2013 around 2:00AM PDT), starting from “emphasizing” because I thought it improved clarity. ↩
Savory goes on to write, “Since then an Englishman (Goldsmith, 1988) came to the conclusion not that [holistic and integrated] are opposites but that the integrated approach is still disciplinary while the holistic approach is non-disciplinary. I prefer his description which I think is more accurate than my own.”↩
In the language of his analogy, Savory points out that early computers were capable of performing computations correctly, but it was hard to achieve accurate results because the machines were not user-friendly.↩
Old-growth Amazon tree canopy in Tapajós National Forest, Brazil. A new NASA study shows that the living trees in the undisturbed Amazon forest draw more carbon dioxide from the air than the forest’s dead trees emit. Image credit: NASA/JPL-Caltech
Between Thorn Bushes and Claws 