Blood does not buy goodwill

In the paper published Guillaume Chapron and Adrian treves in Proceedings B of the Royal Society (Blood does not buy goodwill: allowing culling increases poaching of a large carnivore), the authors looked at whether removing protection for large carnivores would decrease illegal hunting. This idea is supported by many governments. Does it work as expected? Find out by watching this video and by reading the paper available at http://rspb.royalsocietypublishing.org/content/283/1830/20152939.

Abstract of the paper:

Quantifying environmental crime and the effectiveness of policy interventions is difficult because perpetrators typically conceal evidence. To prevent illegal uses of natural resources, such as poaching endangered species, governments have advocated granting policy flexibility to local authorities by liberalizing culling or hunting of large carnivores. We present the first quantitative evaluation of the hypothesis that liberalizing culling will reduce poaching and improve population status of an endangered carnivore. We show that allowing wolf (Canis lupus) culling was substantially more likely to increase poaching than reduce it. Replicated, quasi-experimental changes in wolf policies in Wisconsin and Michigan, USA, revealed that a repeated policy signal to allow state culling triggered repeated slowdowns in wolf population growth, irrespective of the policy implementation measured as the number of wolves killed. The most likely explanation for these slowdowns was poaching and alternative explanations found no support. When the government kills a protected species, the perceived value of each individual of that species may decline; so liberalizing wolf culling may have sent a negative message about the value of wolves or acceptability of poaching. Our results suggest that granting management flexibility for endangered species to address illegal behaviour may instead promote such behaviour.

The Risk of Captive Carnivores

I would like to share with you a very interesting article written by the The Endangered Wildlife Trust (EWT) about the risk of keeping carnivores in captivity and the bussiness behind. Many so-called NGO`S, Charities, etc which argue to work for carnivore conservation are part of one of the most unethical bussiness. Not only they keep wild animals in captivity as pets but also translocated what they call “problem animals” to new areas without monitoring the translocation, without a scientific protocol and viability study and sometimes (most of the times) without even a permit.. Please read and share the article, it would help you to identify who are this so called NGO´s and Charities:

Picture above: Captive adult cheetah male showing submissive behavior

The Endangered Wildlife Trust (EWT) is growing increasingly concerned about the proliferation of captive facilities holding a range of carnivores in South Africa for the sole purpose of tourism and financial gain. We urge the public to consider a few facts when visiting any of a number of these facilities that hold lions, Cheetah, Leopards, Wild Dogs, hyena and even some exotic (non-native to South Africa) species such as tigers and panthers.

* No captive carnivore facility is breeding carnivores for release into the wild, despite what they may claim. Captive carnivores do not contribute to the conservation of free roaming populations; they are not releasable and they do not form part of any registered conservation or management plan for any carnivore in Africa.

* In many carnivore facilities, petting and bottle feeding of cubs is offered, for a fee. These cubs are often taken away from their mothers to stimulate faster reproduction and provide aconstant supply of petting carnivores. Visitors pay to pet the animal and have their photograph taken with it, as well as with their slightly older tame carnivore siblings.

* These carnivores become human imprinted, they do not grow up in a natural social group, and this makes it impossible to release them into a natural habitat for the long-term. This, coupled with the disease risk posed by captive bred animals, as well as their potentially dubious genetic lineage renders them a risk for release to not only themselves, but to other free roaming carnivores.

* Frequently the situation of a ‘paying volunteer’ is exploited for further financial gain, with volunteers being told that the carnivore mothers are not able to care for their offspring and that once they are old enough, hand-raised carnivores will be returned to the wild.

* “There are approximately 6 000 captive lions in South Africa bred for a variety of economic purposes”, as opposed to approximately 2 300 free roaming in reserves and parks. [Draft Biodiversity Management Plan (BMP) for Lions, 2015]. In fact the BMP defines Captive Lions as being “lions [that] are bred exclusively to generate money. Managers actively manipulate all vital rates and demographics.”

Picture above: Captive adult cheetah male showing both aggressive and defensive behavior

The EWT’s concern relates to the public’s understanding of the role and the purpose of captive carnivores and these facilities in carnivore conservation and we urge the public to better understand the role of these facilities as well as the risk that these animals may pose to the public:

* Captive bred carnivores are always more dangerous than their wild counterparts. They lose their fear of humans and tend to associate humans with food providers. Their social structures are heavily interfered with and their natural cycles are often manipulated. A wild carnivore will usually steer away from humans but a captive bred carnivore may not feel the need for such caution.

*  A facility breeding carnivores will usually have to sell their offspring; it stands to reason that they cannot always have cubs and youngsters if they do not sell ‘excess’ animals.

* The captive bred lion hunting industry in South Africa has increased rapidly in recent years and South Africa is increasingly supplying captive bred lion bones for export to Asian markets.

* The Department of Environmental Affairs released figures in December 2013 that stated that “South Africa officially issued permits for the export of nearly (if not more than) 1 300 dead lions from South Africa to China, Lao PDR and Viet Nam from 2011 to 2012 inclusive.” BMP, 2015.

* “The so-called ‘canned hunting’ industry for lions has also increased in recent years and the total value generated from hunting captive lions amounted to about R98 million in 2006/2007.” Lion BMP, 2015.

* This raises the question: where do all these lions come from or go to? In South Africa, a thriving canned hunting industry can, in many cases, be linked to an equally thriving industry based on cub petting and commercial captive breeding centres.

Some may argue that there is educational value in allowing people to handle wild animals. Howeverthis kind of education provides the incorrect message that wild animals exist for human entertainment, that they can be petted like domestic animals. They also do not learn much about the natural behaviour, social structure or role of free roaming carnivores.
It is important to note that captive breeding is not a conservation recommendation for any carnivore species in South Africa. Carnivores in fact breed extremely well in the right conditions and for almostall our threatened carnivore species, the conservation priorities include reducing human-wildlife conflict, securing suitable habitat, reducing illegal offtake and maintaining balanced, functioning ecosystems. Without these in place, captive breeding leads to an over-supply of non-releasable animals which often end up as trophies. We also question that any funding generated from captive carnivore breeding goes to support the conservation of free roaming carnivores.

The EWT does not allege that any specific facility is breeding carnivores for the lion bone trade or forthe practice of ‘canned hunting’ but we do urge the public that visit these facilities to ask at the very least these critical questions:
· What is the plan for the long-term future of the animals in this facility?
· Where are the cubs’ mothers?
· Why are cubs not being raised by their mothers?
· What happens to the facility’s cubs when they grow up?
· If they are released into larger wildlife areas, where are these and can the facility provide documentation to prove a viable, ethical and successful release process?
· If the facility is breeding, do they have a management plan that determines responsible husbandry and management of all stock?
· Do any of the ‘stock’ have the opportunity to live out their natural lives, or are they hunted or bred with again?
· What happens to the facility’s surplus animals?
· Can the public inspect the record books of the facility and follow the life cycle of an individual animal?
· If these animals become part of another breeding programme, for what purpose?

The EWT calls for a more active participation from the public in questioning the role of all captive carnivore facilities and the management of the animals in their care. We also call on the tourism sector to recognise the role that they may be playing in supporting some facilities that cannot account for the conservation claims that they make. Find a pdf of the article HERE

Contact: Kelly Marnewick
Carnivore Conservation Programme Manager
The Endangered Wildlife Trust
Tel: +27 11 372 3600
kellym@ewt.org.za

Yolan Friedmann
CEO
The Endangered Wildlife Trust
Tel: +27 11 372 3600
yolanf@ewt.org.za
Lillian Mlambo
Communications Manager
The Endangered Wildlife Trust
Tel: +27 11 372 3600
lillianm@ewt.org.za

To this words, I would like to add a few links:

http://www.nature.com/nature/journal/v425/n6957/full/425473a.html

Click to access Jule_et_al_2008_Effect_of_captive_experience_on_reintroduction_success_of_carnivores.pdf

License to kill: reforming federal wildlife control to restore biodiversity and ecosystem function

For more than 100 years, the US government has conducted lethal control of native wildlife, to benefit livestock producers and to enhance game populations, especially in the western states. Since 2000, Wildlife Services (WS), an agency of the US Department of Agriculture, has killed 2 million native mammals, predominantly 20 species of carnivores, beavers, and several species of ground-dwelling squirrels, but also many nontarget species. Many are important species in their native ecosystems (e.g., ecosystem engineers such as prairie dogs and beavers, and apex predators such as gray wolves). Reducing their populations, locally or globally, risks cascading negative consequences including impoverishment of biodiversity, loss of resilience to biotic invasions, destabilization of populations at lower trophic levels, and loss of many ecosystem services that benefit human society directly and indirectly.

 

 

Why is our wildlife in trouble? Because we’re ignoring science

by Emma Burns

Cattle drovers have won back the right to graze livestock in the Australian Alps – against scientists’ advice. AAP Image/Bob Richardson

From reef dredging, to shark culling, to opening old-growth forests to logging, environmental policies are leaving Australia’s wildlife exposed to threats. The reason, we propose, is that society and government are often ignoring science – particularly ecology.

In a recently published book, more than 80 Australian environment professionals looked at what we have learned from studying ecosystems.

This book is based on long-term field research in numerous ecosystems. From this research, there are examples of science both being used and ignored in management and policy.

There is some good news. Forest studies have led to more sustainable forestry in Tasmania, and potentially soon in Victoria. And new restoration techniques are being trialed to protect endangered woodlands in the Australian Capital Territory.

But there’s still a long way to go. Here are three examples where science is seemingly being ignored by current environmental policy.

Alpine grazing

Under a trial approved by the federal government, cattle are now once again grazing in the Alpine National Park.

There is no scientific case for the trial. Since the 1940s scientists have been monitoring the alpine ecosystems.

For instance we know that hard-hooved animals such as cattle, sheep, horses, deer and pigs have significant negative impacts. These include changes to species composition, ecosystem dynamics, and fewer herbs such as Billy Buttons and Snow-daisies.

These studies also clearly demonstrate that grazing by domestic livestock does not reduce the frequency or severity of fire in the Australian alps, and can actually increase the risk of fire, as grazing encourages growth of flammable shrubs.

As a consequence of these studies, grazing of sheep and cattle had been phased out of most alpine areas. It poses a clear threat to the alpine ecosystem and natural heritage values of Alpine National Park, and we know that when grazing stops, the alpine ecosystems recover — albeit slowly, and future recovery is unlikely to be as robust as past recovery because environmental conditions are changing.

Alpine Billy Button Photo by Henrik Wahren

Culling fruit bats

Queensland and New South Wales are currently culling fruit bats, despite evidence that culls do not reduce health risks or work.

The threatened spectacled flying fox (Pteropus conspicillatus), targeted as part of the culls, also falls under conservation regulations and provides free services for human society, such as dispersal of pollen and seeds. But many humans fear them because of Hendra virus, and dislike them because urban camps are smelly and noisy, and because they damage commercial fruit crops.

Spectacled Flying-foxes Photo by A. McKeown

Regular calls are made for their conservation status to be downgraded and for management interventions such as camp removal and culling to be adopted. But a ten-year study that we referred to of the habits of spectacled flying foxes demonstrates that apparently simple solutions like moving or destroying camps will ultimately fail because the species is nomadic — naive individuals are always arriving at camps meaning that camps easily re-establish at the site or nearby.

The often repeated claims that flying-fox populations are exploding are also not supported by the research.

Forest management

Recently Prime Minister Tony Abbott suggested that too much forest is locked away from logging and blames “green ideology” for this. We don’t need ideology driving decision making about forest management but more science would be good.

Research on the effects of the 2009 Black Saturday fires in Victoria shows that a decline in hollow bearing trees, which is leading to declines in some fauna, has been linked to these high severity fires and a long history of timber harvesting. On the basis of this research, as well as economic factors, there is a public campaign to change this area’s land tenure from State Forest to National Park.

Professor David Lindenmayer proposes a Giant Forest National Park

However this research is specific to forests in Victoria, and the story may be different in other forest systems. Each system in question needs independent research.

How do we get more science in policy?

Environmental scientists, researchers and policy-makers have a “social imperative” to increase scientific knowledge in policy. Alongside our work on ecosystems, we developed a policy handbook to guide policy makers. And we encourage more ecologists, and their institutions, to distill and communicate their science in similar ways.

It’s not too late, but scientist and policy-makers need to work together and act with the urgency, scale and intelligence needed to meet our environmental challenges.

The book and policy handbook referred to in this article were supported by the Terrestrial Ecosystem Research Network. TERN has catalysed collaborations between researchers dedicated to ecological research but who would have been unlikely to work together without support from TERN.

Source: http://theconversation.com/why-is-our-wildlife-in-trouble-because-were-ignoring-science-27226

Arctic Alaska’s Conservation Conundrum

By  Dr. Joel Berger

The Arctic wind blows hard on the snow-covered plains a few hundred miles southwest of Prudhoe Bay.  It’s eight degrees in the winter chill. Despite global warming, I am still quite cold.  I watch the tracks of the grizzly bear disappear upslope as they narrow toward a newborn calf. Out of my field of vision its mother, a muskoxen – the quintessential land animal of the Arctic – stands guard. But it is no match for the powerful predator looking for its next kill.

Grizzly bears circle in the foreground with musk ox and calf in the distance, Joel Berger © Wildlife Conservation Society

About 3,500 years ago, the last woolly mammoths died on a distant Arctic island in the Chukchi Sea. Muskoxen—mammoths’ shaggy-coated Pleistocene contemporaries—still roam the Alaskan Arctic today. Muskoxen are known to many for their distinctive huddling behavior evolved for defense against predators like grizzly bears and wolves.   Recently this prey-predator relationship has itself become the focus of a discussion on conservation tools and approaches.

Declines in large wildlife lead to increases in disease risk

Source:

University of California – Santa Barbara

Summary:

In the Middle Ages, fleas carried by rats were responsible for spreading the Black Plague. Today in East Africa, they remain important vectors of plague and many other diseases, including Bartonellosis, a potentially dangerous human pathogen. The researchers concluded that the “spike in disease risk results from explosions in the number of rodents that benefit from the removal of the larger animals.”

In the Middle Ages, fleas carried by rats were responsible for spreading the Black Plague. Today in East Africa, they remain important vectors of plague and many other diseases, including Bartonellosis, a potentially dangerous human pathogen.

Research by Hillary Young, assistant professor in UC Santa Barbara’s Department of Ecology, Evolution and Marine Biology, directly links large wildlife decline to an increased risk of human disease via changes in rodent populations. The findings appear today in theProceedings of the National Academy of SciencesEarly Online Edition.

With an East African savanna ecosystem as their research site, Young and her colleagues examined the relationship between the loss of large wildlife — defaunation — and the risk of human disease. In this case, they analyzed Bartonellosis, a group of bacterial pathogens which can cause endocarditis, spleen and liver damage and memory loss.

“We were able to demonstrate that declines in large wildlife can cause an increase in the risk for diseases that are spread between animals and humans,” said Young. “This spike in disease risk results from explosions in the number of rodents that benefit from the removal of the larger animals.”

The researchers discovered this effect by using powerful electric fences to experimentally exclude large species like elephants, giraffe and zebra from study plots in Kenya. Inside these plots, rodents doubled in number. More rodents meant more fleas, and genetic screens of these fleas revealed that they carried significantly numbers of disease-causing pathogens.

The study was concentrated in an area where rodent-borne disease is common and sometimes fatal. According to Young, these rodent outbreaks and associated increases in disease risk may be exacerbating health problems in parts of Africa where diminishing wildlife populations are rife.

“This same effect, however, can occur almost anywhere there are large wildlife declines,” Young said. “This phenomena that we call rodentation — the proliferation of rodents triggered by large wildlife loss — has been observed in sites around the world.”

Downturns in wildlife numbers can cause rodent increases in a variety of ways, including by providing more access to food and better shelter. “The result is that we expect that the loss of large animals may lead to a general increase in human risk of rodent borne disease in a wide range of landscapes,” Young said.

“In this study, we show the causal relationship between disturbance and disease is alarmingly straightforward,” she added. “We knock out the large members of ecosystems, and the small species, which generally interact more closely with humans, dramatically increase in number, ultimately brewing up more disease among their ranks.

The study provides ecosystem managers with yet another reason to protect large and at-risk wildlife species. “Elephants are an irreplaceable part of our global biodiversity portfolio,” Young said, “but they also appear to be circuitously protecting us from disease.”

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Story Source:

The above story is based on materials provided by University of California – Santa Barbara. The original article was written by Julie Cohen. Note: Materials may be edited for content and length.

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Journal Reference:

1. H. S. Young, R. Dirzo, K. M. Helgen, D. J. McCauley, S. A. Billeter, M. Y. Kosoy, L. M. Osikowicz, D. J. Salkeld, T. P. Young, K. Dittmar. Declines in large wildlife increase landscape-level prevalence of rodent-borne disease in Africa. Proceedings of the National Academy of Sciences, 2014; DOI:10.1073/pnas.1404958111

University of California – Santa Barbara. “Declines in large wildlife lead to increases in disease risk.” ScienceDaily. ScienceDaily, 29 April 2014 http://www.sciencedaily.com/releases/2014/04/140429142201.htm

Want Dingoes to leave people alone? Cut the junk food

By Thomas M Newsome 

A dingo in the wild.

Dingoes are back in the news, with Prime Minister Tony Abbott raising concerns on ABC radio last week about dingoes in drought-hit areas of Queensland and New South Wales:

I’d learnt some years ago on my Pollie Pedal bike ride that wild dogs were a difficulty in the high country of Victoria, but I now discover that this is a much more widespread problem.

The federal government is close to announcing a new assistance package to help drought-struck areas. Given the Prime Minister’s unprompted remarks, there’s a chance that extra measures to control dingoes will be part of that package.

               Where dingoes are found and are most abundant around Australia.

                                                                                          Queensland and NSW has been particularly hard-hit by rainfall shortages in the past 18 months.

It would be an understandable move, given that dingoes are synonymous with livestock predation and come into conflict with people around some tourist and mining activities.

But while culling to control dingo numbers is one management option, there are other ways to lessen the impacts of dingoes on humans.

Dingoes are opportunistic predators that hunt a wide variety of prey. Consequently, they are especially likely to consume abundant food items. While in many cases this food is likely to be fauna, it can equally be food waste provided by people.

Our research suggests that waste food can be a key resource for dingoes, that has dramatic impacts on the ecology and behaviour of dingo populations. Further, it seems this food subsidy can escalate conflicts between humans and dingoes in all kinds of settings, including on farms, at mines and at tourist attractions.

How do humans change dingoes’ behaviour?

In the Tanami Desert in northern Australia, we compared dingo populations in areas with and without human-provided food. The results demonstrated that access to this food, scavenged from unfenced rubbish tips, altered the diet, weight, movement and social behaviour of dingoes.

Like many people, dingoes readily opt for an easy take-away meal. Discarded food scraps comprised 60-70% of the diet of dingoes living close to a rubbish tip, whilst further away, reptiles, especially blue-tongues and goannas, were dingoes’ primary prey.

Dingoes scavenging at a rubbish tip.

Click to enlarge

Our most recent study, which has just been published in the Journal of Mammalogy, confirmed that the eating habits of dingoes around the tip were similar to free-roaming domestic dogs in a nearby township. This is akin to dingoes acting just like man’s best friend.

Eating human-provided food scraps also had consequences for dingoes’ weights. As with over-consumption of other “junk” foods, they got fat: animals living close to the tip were 20% larger than their desert-living counter-parts. Further, these labrador-like dingoes moved only about half as much as dingoes in other areas. One dingo that ate food scraps had a home range size of only two square kilometres. This is dramatically smaller than another dingo, well away from human-provided food, which ranged over 2000 square kilometres. With food provided daily at the tip, dingoes didn’t need to roam over large areas hunting prey.

Contrasting dingo movements: the lines represent movement paths and the circle represents the main area of occupancy. Thomas Newsome, CC BY-NC-ND  Click to enlarge

The reduced dingo movements were also associated with drastically altered social behaviour. Ordinarily, dingoes maintain small family groups and will actively defend their territories to ensure they have access to food and water. Every day at the tip, where there was regularly sufficient food for at least 225 dingoes, we observed 50 to 100 individuals. From the DNA samples we collected from some of the dingoes using the tip, it was apparent that a group of at least 55 closely related individuals were living close by; a five- to ten-fold increase on typical dingo family size. Despite this, little aggression was observed, even towards dingoes visiting from away.

As well as changing the size and behaviour of dingoes, people appear to have also compromised the genetic purity of this remote population. We observed higher rates of cross-breeding between dingoes and domestic dogs around the facility, suggesting it might have been easier for domestic dogs to infiltrate dingo society where food was abundant.

Cutting down on conflict

Our key point is that access to easily available food appeared to drastically alter the way dingoes live and behave. And that could alter how dingoes interact with other predators and prey.

That could have important knock-on effects, because dingoes can help the environment and humans by suppressing overabundant animals that they prey on, including emus and kangaroos and possibly goats and rabbits. In some situations, they may even suppress smaller predators in their area, such as foxes and cats.

Our research found that when humans make food too easily available, it appeared to have mostly negative consequences. That includes sustaining and increasing dingo populations to unnaturally high levels – potentially leading to more conflict with humans.

An example of a properly built predator-proof fence at a rubbish facility. Thomas Newsome,CC BY-NC-ND Click to enlarge

Our findings are important given that people are increasingly making it easier for dingoes to eat our food scraps. Rubbish tips at mine sites, townships, remote communities and tourist areas throughout Australia are often left unfenced, or so poorly fenced that dingoes can freely access food.

Fortunately, addressing this problem is remarkably simple. At large industrial facilities (like mine sites), predator proof fences can be erected around food resources, such as rubbish tips.

At tourist facilities, including campgrounds and picnic areas, predator-proof containers for the storage of food and rubbish will help.

A predator-proof storage container (with bear-proof doors) installed in Yosemite National Park in the US. People and bears co-exist at Yosemite without the need for fencing around the camp ground. Thomas Newsome, CC BY-NC-ND  Click to enlarge

Of course, it would be ideal – and cheaper – if people would simply remove the waste they generate. Doing so would reduce the need for intensive, costly and often controversial management, such as culling or excluding dingoes, to ensure human safety.

Dingoes around a cattle carcass in Ravenshoe QLD. Carcasses attract a plethora of wildlife including dingoes. Graham Wienert and Invasive Animals CRC  Click to enlarge

Although it is difficult to deal with carcasses in pastoral operations, it is worth highlighting that these provide easy, take-away meals for dingoes. Similarly, dumping homestead food waste and carcasses in poorly constructed tips is an open invitation to enterprising predators.

Better and more consistent management of food scraps would contribute to a reduction in human-dingo conflict. It may even decrease rates of cross-breeding between dingoes and domestic dogs, a process that may permanently change the characteristics of Australia’s dingo.

Importantly, removing human food would enable the dingo to fulfil its natural ecological roles, including keeping a check on other animals like kangaroos. In the long-run, that will create benefits for all of us – including farmers.

Source: http://theconversation.com/want-dingoes-to-leave-people-alone-cut-the-junk-food-23436?

Humans have always been the nemesis of the planet’s wildlife

By George Monbiot, published in the Guardian 25th March 2014

A dead elephant in the Hwange National Park, Zimbabwe, thought to have died after poachers poisoned a salt lick with cyanide. Photograph: Aaron Ufumeli/EPA

You want to know who we are? Really? You think you do, but you will regret it. This article, if you have any love for the world, will inject you with a venom – a soul-scraping sadness – without an obvious antidote.

The Anthropocene, now a popular term among scientists, is the epoch in which we live: one dominated by human impacts on the living world. Most date it from the beginning of the industrial revolution. But it might have begun much earlier, with a killing spree that commenced two million years ago. What rose onto its hindlegs on the African savannahs was, from the outset, death: the destroyer of worlds.

Before Homo erectus, perhaps our first recognisably-human ancestor, emerged in Africa, the continent abounded with monsters. There were several species of elephants. There were sabretooths and false sabretooths, giant hyaenas and creatures like those released in The Hunger Games: amphicyonids, or bear dogs, vast predators with an enormous bite.

Professor Blaire van Valkenburgh has developed a means by which we could roughly determine how many of these animals there were(1). When there are few predators and plenty of prey, the predators eat only the best parts of the carcass. When competition is intense, they eat everything, including the bones. The more bones a carnivore eats, the more likely its teeth are to be worn or broken. The breakages in carnivores’ teeth were massively greater in the pre-human era(2).

Not only were there more species of predators, including species much larger than any found on earth today, but they appear to have been much more abundant – and desperate. We evolved in a terrible, wonderful world – that was no match for us.

Homo erectus possessed several traits that appear to have made it invincible: intelligence, cooperation; an ability to switch to almost any food when times were tough; and a throwing arm that allowed it to do something no other species has ever managed – to fight from a distance. (The increasing distance from which we fight is both a benchmark and a determinant of human history). It could have driven giant predators off their prey and harried monstrous herbivores to exhaustion and death.

Artist’s rendition of a prehistoric mastodon. Photograph: Bettmann/Corbis

As the paleontologists Lars Werdelin and Margaret Lewis show, the disappearance of much of the African megafauna appears to have coincided with the switch towards meat eating by human ancestors(3). The great extent and strange pattern of extinction (concentrated among huge, specialist animals at the top of the food chain) is not easy to explain by other means.

At the Oxford megafauna conference last week, I listened as many of the world’s leading scientists in this field mapped out a new understanding of the human impact on the planet(4). Almost everywhere we went, humankind erased a world of wonders, changing the way the biosphere functions. For example, modern humans arrived in Europe and Australia at about the same time – between 40 and 50,000 years ago – with similar consequences. In Europe, where animals had learnt to fear previous versions of the bipedal ape, the extinctions happened slowly. Within some 10 or 15,000 years, the continent had lost its straight-tusked elephants, forest rhinos, hippos, hyaenas and monstrous scimitar cats.

In Australia, where no hominim had set foot before modern humans arrived, the collapse was  almost instant. The rhinoceros-sized wombat(5), the ten-foot kangaroo, the marsupial lion, the monitor lizard larger than a Nile crocodile(6), the giant marsupial tapir, the horned tortoise as big as a car(7) – all went, in ecological terms, overnight.

A few months ago, a well-publicised paper claimed that the great beasts of the Americas – mammoths and mastodons, giant ground sloths, lions and sabretooths, eight-foot beavers(8), a bird with a 26-foot wingspan(9) – could not have been exterminated by humans, because the fossil evidence for their extinction marginally pre-dates the evidence for human arrival(10).

Artist’s rendition of a pack of dire wolves and two mammoths. Photograph: Stocktrek Images/Alamy

I have never seen a paper demolished as elegantly and decisively as this was at last week’s conference. The archaeologist Todd Surovell demonstrated that the mismatch is just what you would expect if humans were responsible(11). Mass destruction is easy to detect in the fossil record: in one layer bones are everywhere, in the next they are nowhere. But people living at low densities with basic technologies leave almost no traces. With the human growth rates and kill rates you’d expect in the first pulse of settlement (about 14,000 years ago), the great beasts would have lasted only 1,000 years. His work suggests that the most reliable indicator of human arrival in the fossil record is a wave of large mammal extinctions.

These species were not just ornaments of the natural world. The new work presented at the conference suggests that they shaped the rest of the ecosystem. In Britain during the last interglacial period, elephants, rhinos and other great beasts maintained a mosaic of habitats: a mixture of closed canopy forest, open forest, glade and sward(12). In Australia, the sudden flush of vegetation that followed the loss of large herbivores caused stacks of leaf litter to build up, which became the rainforests’ pyre: fires (natural or manmade) soon transformed these lush places into dry forest and scrub(13).

In the Amazon and other regions, large herbivores moved nutrients from rich soils to poor ones, radically altering plant growth(14,15). One controversial paper suggests that the eradication of the monsters of the Americas caused such a sharp loss of atmospheric methane (generated in their guts) that it could have triggered the short ice age which began 12,800 years ago, called the Younger Dryas(16).

And still we have not stopped. Poaching has reduced the population of African forest elephants by 65% since 2002(17). The range of the Asian elephant – which once lived from Turkey to the coast of China – has contracted by 97%; the ranges of the Asian rhinos by over 99%(18). Elephants distribute the seeds of hundreds of rainforest tree species; without them these trees are functionally extinct(19,20).

Is this all we are? A diminutive monster that can leave no door closed, no hiding place intact, that is now doing to the great beasts of the sea what we did so long ago to the great beasts of the land? Or can we stop? Can we use our ingenuity, which for two million years has turned so inventively to destruction, to defy our evolutionary history?

http://www.monbiot.com

References:

1. eg Wendy J. Binder and Blaire Van Valkenburgh, 2010. A comparison of tooth wear and breakage in Rancho La Brea sabertooth cats and dire wolves across time. Journal of Vertebrate Paleontology. http://www.tandfonline.com/doi/abs/10.1080/02724630903413016#.UzBUcM40uQk

2. http://www.eci.ox.ac.uk/news/events/2014/megafauna/valkenburgh.pdf

3. Lars Werdelin, 2013. King of Beasts. Scientific American. http://www.scientificamerican.com/magazine/sa/2013/11-01/

4. http://oxfordmegafauna.weebly.com/

5. Diprotodon.

6. Megalania.

7. http://www.wired.com/wiredscience/2010/08/last-giant-land-turtle/

8. Castoroides ohioensis

9. The Argentine roc (Argentavis magnificens).

10. Matthew T. Boulanger and R. Lee Lyman, 2014. Northeastern North American Pleistocene megafauna chronologically overlapped minimally with Paleoindians. Quaternary Science Reviews 85, pp35-46. http://dx.doi.org/10.1016/j.quascirev.2013.11.024

11. http://www.eci.ox.ac.uk/news/events/2014/megafauna/surovell.pdf

12. Christopher J. Sandom et al, 2014. High herbivore density associated with vegetation diversity in interglacial ecosystems. Proceedings of the National Academy of Sciences, vol. 111, no. 11, pp4162–4167. http://www.pnas.org/cgi/doi/10.1073/pnas.1311014111

13. Susan Rule et al, 23rd March 2012. The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia. Science Vol. 335, pp 1483-1486. doi: 10.1126/science.1214261. https://www.sciencemag.org/content/335/6075/1483.full

14. Christopher E. Doughty, AdamWolf and Yadvinder Malhi, 11 August 2013. The legacy of the Pleistocene megafauna extinctions on nutrient availability in Amazonia. Nature Geoscience vol. 6, pp761–764. doi: 10.1038/ngeo1895. http://www.nature.com/ngeo/journal/v6/n9/full/ngeo1895.html

15. Adam Wolf, Christopher E. Doughty, Yadvinder Malhi, Lateral Diffusion of Nutrients by Mammalian Herbivores in Terrestrial Ecosystems. PLOS One, doi: 10.1371/journal.pone.0071352. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0071352

16. Felisa A. Smith, 2010. Methane emissions from extinct megafauna. Nature Geoscience 3, 374 – 375. doi:10.1038/ngeo877. http://www.nature.com/ngeo/journal/v3/n6/full/ngeo877.html

17. Fiona Maisels, pers comm. This is an update of the figures published here: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0059469

18. http://www.eci.ox.ac.uk/news/events/2014/megafauna/campos.pdf

19. http://www.eci.ox.ac.uk/news/events/2014/megafauna/campos.pdf

20. http://www.eci.ox.ac.uk/news/events/2014/megafauna/galetti.pdf

Sources: http://www.monbiot.com/2014/03/24/destroyer-of-worlds/

http://www.theguardian.com/commentisfree/2014/mar/24/humans-diminutive-monster-destruction?

British Columbia’s hunting quotas are not based on science

Ignacio Yufera/FLPA

Data on grizzly bears in British Columbia are not reliable enough to justify higher hunting quotas, researchers argue.

As the Canadian province of British Columbia prepares to open its annual grizzly-bear hunting season, conservation scientists are protesting the provincial government’s decision to expand the number of animals that can be killed.

British Columbia officials estimate that there are 15,000 grizzlies (Ursos arctos horribilis) in the province, making up roughly one-quarter of the North American population. Although some sub-populations are declining and the species is listed as of “special concern” by some environmental bodies, it is not listed under Canada’s Species at Risk Act, which would afford the bears government protection. Citing the recovery of some sub-populations, the government has opened up previously closed areas to hunting and increased the number of hunting tags for bear kills from about 1,700 to 1,800.

But some researchers say that the original limits for the bear hunt were set too high for sustainable management, and the revised quota could exacerbate that problem.

“Wildlife management wraps itself in science and presents itself as being scientific, but really, when you examine it, it isn’t true,” says Paul Paquet, a biologist at the Raincoast Conservation Foundation in Sidney and the University of Victoria, Canada, and a co-author of a letter in Science this week¹ making the complaint.

The allowance is much higher than the actual kill rate — about 300 grizzlies are taken by hunters each year in the province, mainly as trophies — but Paquet and other conservation scientists argue that it is still possible that grizzly bears are dying at a rate that is too high for sub-populations to support.

“They’re going in the wrong direction,” says Kyle Artelle, a conservation ecologist at Simon Fraser University in Burnaby, Canada, and a co-author of the letter.

Last year, Artelle and his colleagues reported that it is common for more bears to die than the government’s stated “maximum allowable mortality rate” of 6% of the population per year². In more than half of British Columbia’s 42 huntable regions the number of deaths from ‘unnatural causes’, such as road accidents and hunting, exceeded that target for at least one three-year period between 2001–2011. The researchers conclude that reducing the risk of such ‘overkills’ to a low level would require an 81% reduction in the target. “Because these are long-lived, slow-reproducing populations, they don’t necessarily recover from overkill,” says Paquet.

Garth Mowat a biologist with British Columbia’s ministry of forests, lands and natural-resource operations, counters that the 6% target was never meant to be a hard cap. “We choose a conservative number because we know we’re going to go over it occasionally,” he says. “I think [the quotas] are as good as we can do with the data we have, and based on all that, the hunt is sustainable.”

Artelle disagrees that a 6% allowable mortality figure is conservative. He points out that other studies have come up with estimates of 0–5% for British Columbia². And although a December 2013 study by Mowat and his colleagues concluded that there are about 13,000–14,000 grizzlies in the province³, Paquet says that the number could be as low as 8,000 or higher than 15,000. The data behind such estimates, which come from sources ranging from aerial surveys to traps that snag the hair of passing bears, are often sparse or outdated, he says. “In many cases [the population estimate] will be based on assumptions that are maybe 10 years old. None of this is easy, obviously. But we need to take account of the uncertainties,” he says.

The Convention on International Trade in Endangered Species of Wild Fauna and Flora has banned the import of products from grizzly hunts in British Columbia to Europe, citing the province’s failure to implement a grizzly bear strategy it proposed in 2003, which called for better population assessments, among other things.

“In the United States, there’s recourse to courts,” says Paquet, who notes that there are frequent legal battles over US hunting and the country’s Endangered Species Act. “In Canada there’s essentially no appeal.”

Nature doi:10.1038/nature.2014.14914

1. Artelle, K. A., Reynolds, J. D., Paquet, P. C. & Darimont, C. T. Science 343, 1311 (2014). Show context
2. Artelle, K. A. et al. PLoS ONE 8, e78041 (2013). Show context
3. Mowat, G., Heard, D. C. & Schwarz, C. J. PLoS ONE 8, e82757 (2013). Show context

Source: http://www.nature.com/news/canadian-grizzly-bears-face-expanded-hunt-1.14914

Reducing numbers of one carnivore species indirectly leads to extinction of others

Previous studies have shown that carnivores can have indirect positive effects on each other, which means that when one species is lost, others could soon follow. A team from the University of Exeter and the University of Bern has now found that reducing the numbers of one species of carnivore can lead to the extinction of others.

Published online February 28, 2013 in the journal Ecology Letters, the study shows that simply reducing the population size of one carnivore can indirectly cause another similar species to become extinct. The research shows that changes in population size, as well as extinction, can create ripple effects across sensitive food webs with far-reaching consequences for many other animals.

The research shows that species could suffer just as much from harm to another species as from being under direct threat themselves. This adds weight to growing evidence that a ‘single species’ approach to conservation, for example in fisheries management, is misguided. Instead the focus needs to be holistic, encompassing species across an entire ecosystem.

The researchers assembled experimental ecosystems with three species of parasitic wasps, along with the three types of aphids on which each wasp exclusively feeds. They set up four sets of tanks each containing the three aphid and three wasp species and allowed the populations to establish for eight weeks. Over the next 14 weeks (seven insect generations) the researchers removed a proportion of the wasps from three of the sets of tanks every day — one species from each set. The fourth set had no wasps removed.

The team found that the partial removal of one wasp species led indirectly to the extinction of other wasp species. In the absence of one wasp species, the aphid it preyed upon grew in numbers. All three species of aphid feed on the same plant so increased competition for food led to changes in sizes of the aphid populations. However no aphid species went extinct and so the indirect extinctions of the wasps were not the result of extinction of their prey. Rather, it is likely that the wasps that went extinct had difficulty searching for suitable prey among large numbers of unsuitable ones.

Lead researcher Dr Frank van Veen of the University of Exeter’s Centre for Ecology and Conservation said: “We have shown that the complex ripple effect of a change in population size across food webs is more sensitive than previously thought and that a reduction in the numbers of one carnivore can lead to the extinction of another carnivore species. We also found evidence that the initial indirect extinction can itself trigger further ones, potentially leading to a cascade of extinctions, like dominoes toppling over.”

“The insect system is handy for experimentation but the same principles apply to any ecosystem, from mammals in the Serengeti to the fish in our seas. It clearly shows that we should have an ecosystem-based approach to conservation and to the management of fish stocks and other natural resources.”

The research team has recently been awarded a £470K grant by the Natural Environment Research Council (NERC) to extend this research at a larger scale.

Journal Reference:

1. Dirk Sanders, Louis Sutter and F. J. Frank van Veen. The loss of indirect interactions leads to cascading extinctions of carnivores. Ecology Letters, 28 FEB 2013 DOI: 10.1111/ele.12096

University of Exeter. “Reducing numbers of one carnivore species indirectly leads to extinction of others.” ScienceDaily. ScienceDaily, 28 February 2013. <www.sciencedaily.com/releases/2013/02/130228124144.htm>