Hunting to Extinction

Katy Drake

Our planet is flirting dangerously with the sixth mass extinction of plants and animals. Humans the culprits; habitat destruction and direct exploitation of species the crimes. As the decline of terrestrial land mammals continues to accelerate, bushmeat hunting, in particular, has gained new attention.

An international study, led by Professor William Ripple of Oregon State University and published in the journal Royal Society Open Science, provides an analysis of 301 species – including 126 primates, 65 ungulates (hooved animals), and 26 bats – signifying that they could be on their way out if unsustainable hunting practices for meat and medicine are not regulated.

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Pangolin

Image Credit: One Green Planet

Most of the threatened species occur in developing countries. The primary reason for hunting these mammals is meat consumption, followed by medicinal use. Bushmeat has long been a source of sustenance for many rural populations. However, the line between necessity and luxury is being blurred as population growth explodes and the demand for bushmeat is pushed higher still by urban populations and more prosperous countries, particularly Asia.

Demand alone cannot explain the entirety. The success of large scale commercial hunting has followed on the heels of greater hunter efficiency. Technology has driven a move from bows to firearms and foot to motorised vehicles, increasing the effectiveness and spatial extent of hunting. Yet, bushmeat hunting is not always selective and several modern methods, including traps and snares, produce substantial bycatch, cause injury to animals and increase carcass loss to scavengers.

Of the 301 species identified in Professor Ripple’s research, large mammals, many of which impact the landscape through seed dispersal and foraging, are disproportionately at risk of extinction from hunting. Large carnivores, which also form part of this group, help control populations of herbivores who otherwise would overconsume grasslands. No other taxonomic group comprises of terrestrial animals in a similar size class. As such, the loss of ‘top-down’ control on ecosystems, provided by large-bodied mammals, cannot be compensated for and would result in permanent ecosystem changes.

The smaller of the 301 mammals are of equal importance, performing specific ecological roles. Pangolin’s have recently joined the list of ‘high-profile’ species threatened with extinction. Their scales are believed to treat many illnesses, including psoriasis and poor circulation. All eight species of pangolin, the most illegally traded mammal in the world, are now threatened with extinction. They are a crucial component in the maintenance of healthy ecosystems providing effective ‘pest control’ and improving soil quality as they burrow for shelter and excavate for food.

However, ecosystem collapse is not the only consequence warned by the scientists of Professor Ripple’s international study. Rural forest communities depend on wild animals such as bonobos and antelope for up to 80% of their protein intake and while urban populations drive much of the new demand, as Nasi indicates in a new paper, ‘Empty forests, empty stomachs? Bushmeat and livelihoods in Congo and Amazon Basins’, bushmeat is not necessarily a luxury for all. It is one of the cheapest sources of protein available and therefore a necessity for much of the urban poor population.

An approximation indicates bushmeat consumption across the Congo basin and Amazon to be on average, 6 million tonnes a year. While some species are able to resist the pressures, only 2 percent of hunted mammal populations are stable or increasing. As the unsustainable practice pushes mammals closer to extinction, hunting returns continue to decrease, jeopardising the food security of the millions who rely on bushmeat as their main source of protein.

Awareness is certainly the first, crucial stepping stone to the solution but is by no means enough on its own. Increased legal protection of wild animals and efficient enforcement will be critical and has already had a proven effect on wildlife populations. The researchers also recommend empowering local communities to benefit from the protection of that wildlife, increasing education opportunities, improved family planning and providing food alternatives, such as plant-based proteins.

There are clear pressures today that threaten wildlife worldwide. Habitat destruction is undoubtedly one of the most dangerous. However, the enormous impact of bushmeat hunting on ecosystems and livelihoods cannot be overlooked. Is it really a victory to conserve a pristine habitat if it is hunted to the point of being ‘empty’?

 

We Might Be Able To Save Predators And Livestock At The Same Time.

Katy Drake

The debate is ongoing; should lethal or nonlethal predator control methods be used to protect livestock? According to logic, if predators are killing livestock, by removing those predators, livestock losses should decrease. However, as there are legal, ethical and ecological risks at stake, common sense may no longer pass as sound justification.

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Image credit: wallpapercave

Research, led by Associate Professor Adrian Treves of the University of Wisconsin, Madison, and published in the Frontiers of Ecology and the Environment, examined more than one hundred peer-reviewed studies of predator control methods and livestock in Europe and North America. Yet, of the over one hundred studies analysed, only twelve met the academic standards from which scientific inference could be drawn; with two reaching ‘gold standard’ and the other ten, a lesser ‘silver standard’.

The results from the twelve studies examined, suggest nonlethal methods of predator control are generally more effective and do not lead to counterproductive consequences.

A variety of predator control methods are used by livestock owners. Lethal methods include hunting, poisoning, kill traps and destroying the litters of young. Nonlethal methods include livestock-guarding animals, fladry (visual deterrents), other types of repellents, fences, diversionary feeding and sterilisation.

Of the one dozen studies analysed, seven examined lethal methods of predator control; two of which appeared to conclude a decrease in livestock loss but only to a minor degree and on a short term basis. In one particular case, it was found that less than one lamb was saved per lynx killed and had negligible practical benefits.

The remaining five lethal method studies concluded either no effect or, in two cases, an actual increase in predation. A study published in 2013 determined that killing cougars resulted in detrimental effects to livestock numbers. Older, male cougars would keep the younger, more aggressive males at bay. Consequently, the hunting of older males, resulted in the immigration of younger males and increased livestock loss.

By contrast, not one of the nonlethal method studies showed an increase in predation. Of the twelve studies examined by Treves and his colleagues, the only two that met ‘gold standards’ examined nonlethal methods which effectively decreased livestock losses through the use of livestock-guarding dogs and fladry, although fladry may be limited to deterring wolves.

One long term and in-depth study, conducted in France, concluded that a combination of mobile electric fences at night and at least five livestock-guarding dogs prevented almost all wolf predation on sheep.

Treves’ critics have suggested that his own study may not be living up to his standards as no independent experts were asked to review the validity of his research. They also suggest that Treves’ expectations of academic standards in predator control research may be impractical as complexities in the field of biology result in most ‘gold standard’ experiments being precluded.

So, what does this mean for the future?

Treves and colleagues have called for a suspension of predator control programs that do not have strong evidence to support their efficacy. They suggest that, like the EU Directive and many U.S. Federal policies, decision-making should be based on clear evidence and as such, until ‘gold standard’ tests have been completed, evidence-based policy should focus on nonlethal methods. However, a major culture shift will also be required amongst ranchers and livestock owners to turn from quick and easy lethal methods to nonlethal predator control.