Humans to Blame for 322 Animal Extinctions in 500 Years
August 7, 2014
Abigail Geer / Care2.com & Susan Bird / Care2
In an article published in the journal, Science, researchers took a closer look at animals that have disappeared at the hands of humans, and what this might mean for the future. One study showed that, as human population doubled in the last 35 years, the number of invertebrate animals such as beetles, butterflies and worms decreased by an alarming 45%. From the passenger pigeon to the Tasmanian tiger and the freshwater baiji dolphin, we are killing animals at an unsettling rate.
Humans to Blame for 322 Animal Extinctions in 500 Years
Abigail Geer / Care2.com
(August 4, 2014) -- In just 500 years, humans have been the cause of 322 animal extinctions, with two thirds of those occurring in the last century alone.
In a recent issue of the journal Science, researchers took a closer look at animals that have disappeared at the hands of humans, and what this might mean for the future.
One study showed that the human population has doubled in the last 35 years, and along with that increase, the number of invertebrate animals such as beetles, butterflies and worms has decreased by an alarming 45%.
The most famous mass extinction in Earth's history took place around 252 million years ago, wiping out 90% of marine life and 70% of terrestrial life, but history may be repeating itself and this time the apocalypse is us.
We Are Already In the
Midst of The 6th Mass Extinction
From the passenger pigeon to the Tasmanian tiger, and most recently the freshwater baiji dolphin, we are killing animals at an unsettling rate, and according to the International Union for the Conservation of Nature, another 20,000 or more animals are also on the verge of extinction.
Before we had even achieved civilization, we had already helped to hunt some of the world's biggest animals including wooly mammoths and giant sloths to extinction, and now with our destructive use of fossil fuels over the last several centuries, we have dangerously altered the climate for our fellow species.
Utilizing every inch of land we can for cities, logging and food, we exploit the habitats of our fellow animals and plants, forging unsustainable conditions for them to survive in.
With the current extinction rate being estimated at 1,000 times faster than ever before, we are in the midst of the fastest extinction event on record and it's the animals that are paying the biggest price.
As species start to disappear it is not just their presence that is lost, but also the loss of critical ecosystem functioning in which they play a central role.
Urgent Measures Must Be Taken to Protect the Earth's Inhabitants
Ecologists, zoologists and other scientists all agree that urgent steps must be taken if we are to stand a chance at protecting the precious life we have left.
We are facing a global tipping point and if we don't proceed with caution we may never be able to recover. Keeping animals alive and healthy isn't easy when they are surrounded by problems that threaten their ecosystem's stability.
Despite everything we are up against, there are steps that can be taken to help right the wrongs we have caused.
Nature-based tourism is a big business. Studies show that animals are worth more alive than dead, with activities like whale watching, shark watching and turtle spotting directly supporting hundreds of thousands of jobs, generating billions of dollars each year and accounting for a massive chunk of economic growth in nations the world over.
Conservation also plays a key role with the intentional movement of animals to restore populations and to protect them from disappearing forever, as well as working to curb our hazardous practices that are ravaging their natural habitats.
There is still hope, but the question is are we ready to make the necessary changes or will we blindly continue forward until it is too late to go back?
Did Humans, Not Climate Change,
Trigger Ice Age Animal Extinctions?
Susan Bird / Care2
(June 12, 2014) -- It's a debate that has raged for almost half a century. What exactly caused so many large mammals to die out right around the end of the last Ice Age? A prevailing theory holds that climate change caused massive loss of suitable habitat, leading to widespread extinctions.
A new study disagrees. Apparently, the evidence points not toward Mother Nature, but squarely at the human race, according to researchers from Denmark's Aarhus University.
For the first time, researchers undertook what they called a "global analysis and relatively fine-grained mapping of all the large mammals (with a body weight of at least [22 lbs.]) that existed during the period 132,000–1,000 years ago – the period during which the extinction in question took place."
They focused with more precision than any previous study on the percentages of large animals that became extinct in various geographic locales. What they found is striking.
That Last Ice Age:
For Animals, Different Than the Rest
More than one Ice Age has gripped the Earth over the millennia. Our planet has seen at least five major Ice Ages, in fact -- the Huronian, the Cryogenian, the Andean-Saharan, the Karoo, and the most recent, known as the Quaternary or Pleistocene glaciation. What's interesting is that only after the last one did we see significant extinction of large animals, according to this study.
The study results indicate only a minimal correlation between temperature and precipitation changes and the significant loss of so many great mammals.
"The significant loss of mega-fauna all over the world can therefore not be explained by climate change," said Christopher Sandom, Aarhus University Postdoctoral Fellow, "even though it has definitely played a role as a driving force in changing the distribution of some species of animals."
As it turns out, 177 different species of large mammals died out during the most recent Ice Age. The losses during this period spread out relatively evenly among continents, as follows:
Africa: 18 species
Europe: 19 species
Asia: 38 species
Australia and surrounding areas: 26 species
North America: 43 species
South America: 62 species
These extinctions occurred in almost all climate zones, affecting animals suited to cold, temperate and tropical climates alike. Australia lost creatures such as giant kangaroos, marsupial lions and giant wombats. Europe and Asia lost great elephants, rhinoceroses and giant deer. In North and South America, sabre-toothed cats, mastodons, giant sloths and giant armadillos went extinct.
Where Humans Go, Extinctions Follow
The fact that so many animals from such varied habitats all died out during roughly the same period correlates rather neatly with the footprint of ancient humankind as we spread out across the world.
The study's results show "a very strong correlation between the extinction and the history of human expansion," noted an Aarhus University press release.
"We consistently find very large rates of extinction in areas where there had been no contact between wildlife and primitive human races, and which were suddenly confronted by fully developed modern humans," said Professor Jens-Christian Svenning. "In general, at least 30 percent of the large species of animals disappeared from all such areas."
It's a scenario we know all too well. Humans show up to a new and untouched region and begin hunting. We take down the great mammals. We even hunt their prey. At some point, we go too far. It's a phenomenon known as "overkill." Sound familiar?
It seemed that way to the researchers, too. They note a definite similarity between what humans did 100,000 years ago and what we've done in the recent past to animals such as the American bison, the European bison, the quagga and the Eurasian wild horse.
We're still doing the same old thing today, as poachers busily decimate already rare species such as elephants, rhinoceroses and big cats, to name only a few. This is not the cycle of life, as it may have been once upon a time. Today, extinction is often caused by pure and simple greed.
Interesting, isn't it? Even ages ago, the influence of humankind profoundly affected animals. We can't really blame early man, of course -- he was just trying to survive. What's our excuse today?
Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.