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What Is An Endangered Species? | Earth Wise

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Biodiversity is declining rapidly throughout the world and people are mostly the reason.  Species are disappearing because of changes in land and sea use, the direct exploitation of organisms, climate change, pollution, and invasive alien species resulting from globalization.  The challenges of conserving the world’s species are many and difficult.  Among these challenges are determining which species are endangered and how and when to protect them.

What constitutes an endangered species is not necessarily obvious. 

Extinction risk increases as a species is driven to extinction from portions of its natural range.  Most mammal species have already been driven to extinction from half or more of their historic ranges because of human activities.

According to a recent survey of ordinary Americans, three-quarters of participants said that a species deserves special protections if it had been driven to extinction from any more than 30% of its historic range.  This compares with the language of the U.S. Endangered Species Act that defines an endangered species as one that is “in danger of extinction throughout all or a significant portion of its range.”

Experts and decision-makers are more accepting of risks and losses because they believe greater protection would be impossibly expensive.  Decision-makers tend to be influenced by special interest groups with a vested interest in not instituting protections.

Before human activities began elevating extinction risk, a typical vertebrate species would have experienced an extinction risk of 1% over a 10,000-year period.  Current policies consider a 5% risk over 100 years to be acceptable.  Policies consider whether we can afford to protect species.  Given the dangers of declining biodiversity, we should ask whether we can afford not to.

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What Is An Endangered Species?

Photo, posted July 29, 2018, courtesy of Sergio Boscaino via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Forest Regrowth In The Amazon | Earth Wise

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The Amazon is the largest tropical rainforest in the world.  It covers an area approximately equal in size to the lower 48 states, and is home to an estimated 10% of the world’s biodiversity and 15% of its freshwater.  These so-called “lungs of the planet” provide many important global ecological services, including carbon storage, and regulating air quality and climate.

Deforestation in the Amazon exploded in the 1970s and remains one of its biggest threats today.  Since the 1970s, more than 20% of the Amazon rainforest has been cleared.  Cattle ranching, soy and palm plantations, logging, and climate change are some of the biggest drivers of deforestation.  

Now, according to a new study recently published in the journal Ecology, the regrowth of Amazonian forests following deforestation may happen more slowly than previously thought.  These findings could have significant impacts on climate change predictions as the ability of forest regrowth in the Amazon – so-called secondary forests – may have been overestimated.  The research, which was conducted in Bragança, Brazil and includes two decades of forest monitoring, reveals that climate change and the wider loss of forests could be hampering regrowth.    

After 60 years of regrowth, the research team found that secondary forests only held 40% of the carbon when compared with forests undisturbed by humans.  Secondary forests also take less carbon from the atmosphere during periods of drought, and climate change is increasing the number of drought-years in the Amazon.  (During their 20 years of monitoring, the researchers also found biodiversity levels in secondary forests were only 56% of those seen in undisturbed forests). 

More long-term studies are needed to better understand the impacts of reforestation efforts.  

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Amazon forest regrowth much slower than previously thought

Photo, posted September 6, 2009, courtesy of Nao Lizuka via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Community Action And Coral Reefs

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Coral reef habitats are some of the densest and most varied ecosystems on earth.  While coral reefs cover just 0.2% of the ocean floor, scientists estimate that nearly one million different species of fish, invertebrates, and algae can be found in or around coral reefs. 

However, climate change is wreaking havoc on the health of coral reefs.  Warming and acidifying oceans are resulting in enormous coral losses.  Overfishing, development, and pollution are also threatening coral reef health.

According to new research, positive community action can help boost fish populations in coral reefs and safeguard future fish numbers.  The paper, which was recently published in the journal Proceedings of the National Academy of Sciences, details the social and ecological outcomes of work being done in Papua New Guinea since 2001. 

These communities have established a traditional system of rotational fishing closures in order to manage their fisheries resources.   They ban fishing on part of their reefs for a few years, and then open these closures when village elders believe fish behavior has changed and fish populations have recovered.  They then close a different part of their reefs, and repeat the process. 

The researchers found that these rotational practices resulted in more than twice as many fish on the closed reefs as compared to open ones, and the closures made fish less scared of people and easier to catch.  But the researchers did caution that this short term boost in fish numbers may not be enough to stop the overall impact of fishing.

Globally, more than 500 million people depend on coral reefs for food, income, and coastal protection.  Balancing community needs with environmental needs can be tricky business.  

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Positive community action can help coral reef health

Photo, posted October 11, 2011, courtesy of Paul Toogood via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Beavers And Biodiversity

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Beavers are large, semi-aquatic rodents known best for their ability to construct dams, canals, and lodges (their homes).  They are among the largest rodents in the world.  With powerful jaws and strong teeth, beavers fell trees to use as building materials, often changing their environment in ways few other animals can. But in a good way.  As it turns out, beavers are important for biodiversity. 

According to new research from the Faculty of Natural Sciences at the University of Stirling in Scotland, reintroducing beavers to their native habitats is an important step towards solving the freshwater biodiversity crisis. 

Researchers surveyed water plants and beetles in 20 wetlands in Sweden – 10 created by beavers and 10 that were not – in order to understand what impact beavers might have on the variety of plant and animal life around them. 

The research team’s findings build on previous work that has shown that beavers have an important impact on biodiversity.  This latest study discovered that the number of species found only in beaver-built ponds was 50% higher than in other non beaver-built wetlands in the same region. 

Beavers are known to be profound engineers of the environment. They use wood to build dams across rivers in order to form ponds behind them.  They do this to raise the water level in order to avoid predators, like bears and wolves. But it turns out many other plants and animals, like water plants and beetles, also benefit from their work.

According to the research team, reintroducing beavers to their native habitats should benefit the wider biodiversity and be seen as an important step towards solving the freshwater biodiversity crisis. 

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Beaver reintroduction key to solving freshwater biodiversity crisis

Photo, posted October 2, 2014, courtesy of USFWS Midwest Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Refugee Corals

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As climate change warms the ocean, subtropical environments are becoming more favorable for corals than the equatorial waters where they traditionally thrived.  As a result, drifting coral larvae are settling and growing in new regions.

According to new research in the journal Marine Ecology Progress Series, the number of young corals on tropical reefs has declined by 85% over the past 40 years.  At the same time, the numbers on subtropical reefs has doubled.

Only certain types of coral can reach these new subtropical locations.  That depends on how far the microscopic larvae can swim and drift on currents before they exhaust their limited fat stores.  Thus, the reef ecosystems that develop have new blends of species that have previously never coexisted.  It is not clear how long it will take for the new systems to reach equilibrium.

Coral reefs are complicated systems that depend on the interplay between species to enable their healthy functioning.  Apart from the corals themselves, there are the coraline algae that symbiotically coexist with them.  How all of this will play out in these evolving ecosystems is unknown.

In the meantime, the research has found that these refugee corals are settling at latitudes up to 35 degrees both north and south of the equator.  It is no longer so clear what constitute native species in the reefs.  It remains to be seen whether new reefs in subtropical oceans can support the incredible biodiversity seen in tropical reefs.  But ultimately, these changing ecosystems could potentially bring new resources and opportunities, such as fishing and tourism, to places where they never existed before.

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Coral Reefs Shifting Away from Equatorial Waters

Photo, posted March 22, 2011, courtesy of Simone Lovati via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Exotic Pets Can Become Problems

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Each year, millions of exotic animals are sold as pets around the world.  The term “exotic” lacks a set definition but is generally used to refer to an animal that’s wild or more unusual than standard pets, like cats and dogs. 

The exotic pet trade is a multi-billion dollar industry,  involving tens of millions of individual animals from thousands of species, including reptiles, amphibians, fish, birds, and mammals.

Some of the exotic pet trade is legal, but a lot of it isn’t.  Many animals are illegally captured from the wild to meet the global demand for exotic pets. 

People often purchase exotic animals without completely understanding the consequences.  Some exotic pets, for example, can live nearly twice as long as the average dog.  Caring for exotic pets can be both expensive and risky, since they are largely undomesticated (and therefore can have unpredictable behavior).

As a result, it’s not uncommon for owners to release exotic pets intentionally.  When this happens, the consequences can be catastrophic.  Sometimes the animal dies from starvation or predation, but in other instances, the animal proliferates and becomes an invasive species.

Invasive species are the second largest driver of biodiversity loss worldwide, and they cost the U.S. $120 billion a year. 

According to an academic review recently published in the journal Frontiers in Ecology and the Environment, the exotic pet trade is one of the primary causes of the spread of invasive species and has fueled the establishment of hundreds of them.  Tegus, Burmese pythons, and red lionfish are examples of pets-turned-pests. 

The best way to combat this trend is through education, detection, and rapid response. 

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Why you should never release exotic pets into the wild

Photo, posted September 19, 2010, courtesy of Mike Baird via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

One Million Extinctions

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A group of 145 expert authors from 50 countries has produced a report based upon a review of 15,000 scientific and government sources that is the first comprehensive look at the state of the planet’s biodiversity in 15 years.  The conclusions are alarming.

Thanks to human pressures, one million species may be pushed to extinction in the next few years, something with serious consequences for human beings as well as the rest of life on earth.

Based upon scientific studies as well as indigenous and local knowledge, the evidence is overwhelming that human activities are the primary cause of nature’s decline.  The report ranked the major drivers of species decline as land conversion, including deforestation; overfishing; bush meat hunting and poaching; climate change; pollution; and invasive alien species.

The tremendous variety of living species on our plant which number at least 8.7 million and perhaps many more – biodiversity – constitutes a life-supporting safety net that provides our food, clean water, air, energy, and more.

In parts of the ocean, little life remains but green slime.  Some remote tropical forests are nearly silent because insects have vanished.  Many grasslands are becoming deserts.  Human activity has severely altered more than 75% of Earth’s land areas and has impacted 66% of the oceans.  The world’s oceans increasingly are characterized by plastics, dead zones, overfishing, and acidification.

The main message of the 1,500-page report is that transformative change is urgently needed.  In order to safeguard a healthy planet, society needs to shift from a sole focus on chasing economic growth.  This won’t be easy, but we must come to the understanding that nature is the foundation for development before it is too late.

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One million species at risk of extinction, UN report warns

Photo, posted January 1, 2014, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Future Of Animals

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Researchers at the University of Southampton have forecast a global shift towards smaller birds and mammals over the next century.   

According to the research team, small, fast-lived, highly fertile, and insect-eating animals, which can thrive in all sorts of habitats, will predominate in the future.  Rodents and songbirds are examples of the so-called ‘winners.’  Less adaptable, slow-lived species, requiring specialist habitats, will be more likely to face extinction.  Among the so-called ‘losers’ are the black rhino and the tawny eagle. 

The researchers focused on more than 15,000 living mammals and birds and considered the following five characteristics: body mass, breadth of habitat, diet, litter or clutch size, and length of time between generations.  Using this data and data from the IUCN’s Red List of Threatened Species, the researchers used modern statistical tools to project and evaluate the loss of biodiversity.  

The study, which was recently published in the journal Nature Communications, predicts that the average body mass of mammals will collectively decline by 25% over just the next 100 years.  Over the past 130,000 years, the average body size of mammals only declined 14%.

This substantial downsizing of animals is forecasted to occur due to the effects of ecological change. But, according to the study’s lead author, the loss of these species, which perform unique functions within the global ecosystem, may ironically wind up being a driver of change as well.       

The researchers hope future studies will further explore the long-term effects of species extinction on habitats and ecosystems. 

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Study predicts shift to smaller animals over next century

Photo, posted April 6, 2013, courtesy of Nic Trott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Shipping And Invasive Species

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The increasing numbers of invasive species around the world are a major driver of biodiversity change and cause billions of dollars in economic damages annually.  Climate change is a major factor in the spread of invasive species, but a new study by McGill University suggests that global shipping growth will far outweigh climate change in the spread of non-indigenous pests to new environments in the coming decades.

One of the most significant ways in which the disparate regions of the world are interconnected is via transportation networks.   The global shipping network is the primary means by which materials and goods are moved worldwide, accounting for over 80% of world trade.  And for this reason, the global shipping network is responsible for much of the introduction of non-indigenous species across the planet.

Living organisms are often transported through ballast water, which is taken up to stabilize cargo vessels.  Other species are transported by biofouling, whereby they attach to the hulls of ships.  Taken together, these two pathways account for anywhere between 60 and 90% of marine bioinvasions.   (Terrestrial invaders are generally moved as a byproduct of shipping, for example by infesting wood packaging material).

The McGill study looked at trends in global shipping and how socioeconomic factors are driving change.  For example, China’s share of global container throughput has gone from 1.4% in 1990 to 20.1% in 2013.  So, the distribution and patterns of shipping have been changing dramatically and with it the spread of non-indigenous species.

Awareness of this issue is increasing.  For example, there have been policy initiatives such as the International Ballast Water Management Convention that is an effort to control bio-invasions through measures such as ballast exchange.  We need to take measures to limit the unintentional spread of species.

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Global forecasts of shipping traffic and biological invasions to 2050

Photo, posted December 3, 2009, courtesy of Roger W via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Climate Change And Infertility

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Many of us are all too familiar with the effects of climate change.  Our changing climate, as a result of our actions, is leading to rising global temperatures, biodiversity loss, ocean acidification, wildfires, more weather extremes like floods and droughts. But a lesser known effect of climate change could lead to frightening consequences: infertility.

According to researchers at the University of Liverpool, rising temperatures could make some species sterile and lead them to succumb to the effects of climate change far earlier than currently thought. Their work was recently published in the journal Trends in Ecology and Evolution, and it was produced in collaboration with scientists from the University of Leeds, University of Melbourne, and Stockholm University.

Biologists and conservationists are trying to predict where species will be lost due to climate change so that suitable reserves can be established in other locations.  But the problem is that most data on when temperature will make an area unlivable for a species is based on its ‘critical thermal limit’ or CTL.  This is the temperature at which a species would collapse, stop moving, or die. 

The authors of the article fear that the impact of climate change on species survival is being underestimated.  Because rather than zeroing in on lethal temperatures, the scientists argue the focus should be on the temperatures at which organisms can no longer breed.  Extensive plant and animal data suggest organisms lose fertility at a lower temperature than their CTL.

The scientists have proposed a new fertility-based metric to gauge how organisms function as temperatures climb: Thermal Fertility Limit or TFL.  Understanding when a species will cease to reproduce will certainly help conservation measures. 

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Climate change and infertility — a ticking time bomb?

Photo, posted August 11, 2013, courtesy of Mike Lewinski via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food Production And Climate Change

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According to a University of Oxford study recently published in the journal Science, food production is a major driver of climate change as it’s responsible for 26% of all greenhouse gas emissions.  But the research team found that the environmental impact of different foods varied greatly. 

Meat and other animal products are responsible for 58% of all food-related greenhouse gas emissions, despite only providing approximately one-fifth of the calories we consume.  The researchers found that beef and lamb in particular have the most damaging effect on the planet, responsible for half of all greenhouse gas emissions from animal agriculture. 

These findings echo recommendations from the Intergovernmental Panel on Climate Change about how individuals can reduce their carbon footprint through diet.  The IPCC suggests we consume less meat and dairy products, consume more locally-sourced seasonal foods, and throw less food in the trash.  

Avoiding meat and dairy products can reduce an individual’s carbon footprint from food by two-thirds.  The effects of doing so include everything from conserving water and preserving biodiversity to reducing pollution and deforestation. 

Interestingly, the same food can have major differences in terms of environmental impacts.  For example, beef raised on deforested land is responsible for 12 times as many greenhouse gas emissions as that raised on natural pastures.  But even the most climate-friendly meat options are still responsible for more greenhouse gas emissions than the highest-impact vegetable proteins, like beans and nuts. 

Big differences can also be made by avoiding chocolate and coffee produced from deforested lands.  

To learn more about the climate impact of your diet, follow the link to the ‘Climate Change Food Calculator’ on our website: Earth-Wise-Radio.org. 

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Reducing food’s environmental impacts through producers and consumers

Climate change food calculator

Photo, posted June 21, 2011, courtesy of USDA NRCS Montana via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Problem Of Urban Growth

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The rapid expansion of cities around the world has accelerated in recent decades.  If current trends continue, the equivalent of a city the size of London could be created every seven weeks by the year 2050, according to a study at Texas A&M University.

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Deforestation In The Amazon Rainforest

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The Amazon rainforest is the biggest in the world.  In fact, it’s larger than the next two rainforests combined.  The Amazon rainforest covers more than three million square miles, roughly the size of the lower 48 states.  It functions as a critical sink for carbon in the atmosphere, and is home to 10% of all known species in the world.  The region’s biodiversity is so rich that scientists are still discovering new plant and animal species today. 

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Bring The Wild Back Into Farmlands

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A recent study published in Science looks at the effects of maintaining at least a little bit of the wild on working lands including farmland, rangeland and forests.  The study concludes that doing so may be a key to preserving biodiversity in the face of climate change.

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Biomass: Renewable But Not Sustainable

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Biomass is often touted as a green energy source. Just recently, the US Environmental Protection Agency declared biomass energy to be carbon neutral – a policy already embraced by many European countries. However, burning forests for fuel has hard limitations and ecological consequences.

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Conflicts In Conservation

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In recent years there has been a great deal of discussion about animal intelligence and the idea of animal consciousness.   In the past, the notion that animals have feelings had been relegated to fringe status, but these days, a wealth of scientific findings has made it much more mainstream to entertain such ideas.

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The Value Of Biodiversity

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It is often said that biodiversity is crucial for staving off extinctions.  Ecosystems are complex and are essentially defined by the interdependencies among the various animals and plants.  It stands to reason that removing species from an ecosystem can have significant effects up and down the food chain.  Extinctions are much more likely when biodiversity diminishes.

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Deforestation-Free Palm Oil

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Few of us cook with palm oil or have ever even seen the stuff.  Nevertheless, 50% of all packaged grocery items – everything from ice cream and pizza to detergents and cosmetics – include it as an ingredient.  The global market for palm oil was $65 billion in 2015, and that number was projected to grow by more than 7% each year through 2021.

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