To Save Slow-Breeding Giants, Biologists Recommend New Method for Defining Endangered Species
Typically, conservationists use a methodology called population viability analysis (PVA), a species-specific risk assessment that considers when a particular population will go extinct given certain perimeters. A new study published in the Journal of Frontiers in Ecology and Evolution suggests that basing conservation decisions simply on low population counts in slow-breeding animals could cause irrevocable decline.
"Critical thresholds in so-called vital rates — such as mortality and fertility rates among males and females of various ages — can signal an approaching population collapse long before numbers drop below a point of no return," said lead author Dr. Shermin de Silva, adding that conservation efforts for megafauna should be aimed at maintaining their "demographic safe space." That is, a combination of key vital rates, such as offspring survival rate and habitat loss, that support population increases rather than short-term trends in population size and distribution
To come to this conclusion, de Silva and her team analyzed endangered Asian elephants as a case study, whose populations are thought to have been halved in less than a century. Today there are fewer than 50,000 wild Asian elephants, in part because they breed extremely slowly — oftentimes just one calf every six years or more. Mathematical modeling of near-optimal reproduction and high survival rates for calves determined that Asian elephant populations cannot tolerate losing more than 7.5 percent of females annually.
It leads to something de Silva calls a "demographic tipping point," the combination of vital rates that helps us understand how populations are impacted by a variety of environmental and human influences.
"Even large populations, if in decline, will eventually pass a point of no return that is difficult to predict in advance. Rather than wait for this eventuality, we suggest that demographic tipping points, and the corresponding safe spaces they define, can offer impetus to act early even when data are scarce," write the authors. Basing conservation approaches off of current trends in population and range is misleading for these types of animals because "short-term fluctuations may mask long-term trends" and even decisions made with the best of intentions may be ill-informed.
Their large body size makes the Asian elephant (Elephas maximus) an influential and vulnerable member of the ecosystem whose threats include overharvest, habitat loss and their time-consuming lifecycle. These megafauna need "proactive management" well before their numbers become critically low.
"But while the attention of the world has been focused on the ivory trade, for critically endangered Asian elephant populations the greatest threat is habitat loss — followed by illegal trade in live animals and parts," said de Silva, adding that habitat loss creates an "extinction debt" that slows down birth rates and increases mortalities. For these long-living species that are slow-to-breed, even small changes can make a profound difference.
This application of conservation could also be applied to other keystone species like giraffes, rhinos and eastern gorillas.
U.S. officials have announced that giraffes may qualify for protection under the Endangered Species Act following a lawsuit filed by conservation groups at the end of last year. https://t.co/iNWSKOcqAl#EndangeredSpeciesAct #Giraffes #ESA #Conservation— Faunawatch (@faunawatch) May 14, 2019
Correction: An earlier version of this story inaccurately referred to de Silva as a "him" instead of "her." The story has been corrected
This week marks the official start of fall, but longer nights and colder days can make it harder to spend time outdoors. Luckily, there are several inspiring environmental films that can be streamed at home.
1. Kiss the Ground<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="ccc5f0c92a5603e68aec39e56b0db02a"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/K3-V1j-zMZw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: Netflix</strong></p><p><strong>Premiere Date: Sept. 22</strong></p><p>Between <a href="https://www.ecowatch.com/wildfires-california-washington-oregon-photos-2647585008.html" target="_self">wildfires devastating the U.S. West Coast</a> and <a href="https://www.ecowatch.com/tropical-storm-beta-landfall-2647760268.html" target="_self">storms battering the Gulf</a>, the impacts of the <a href="https://www.ecowatch.com/climate-change/" target="_self">climate crisis</a> can feel overwhelming right now. <em><a href="https://kissthegroundmovie.com/" rel="noopener noreferrer" target="_blank">Kiss the Ground</a> </em>offers an alternative to all of the bad news by focusing on solutions.</p><p>The film, directed by Josh and Rebecca Tickell and narrated by Woody Harrelson, explains how we can heal the Earth through "regenerative agriculture," farming practices that draw carbon dioxide from the atmosphere and into soil as a way to restore soil health, which in turn boosts ecosystems and food supplies.</p><p>"<em>Kiss the Ground </em>shows how feasible it is to make these changes at a grassroots level immediately and make a truly substantive impact with low cost and easy to implement solutions," Executive Producer RJ Jain said in an email. "This is why I got involved."</p>
2. Public Trust: The Fight for America's Public Lands<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="5338f7a2931e356910026e5fd76fac56"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/jsKMTAaj_wQ?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: YouTube</strong></p><p><strong>Premiere Date: Sept. 25, 2 p.m. EDT </strong></p><p>This <a href="https://www.patagonia.com/films/public-trust/" target="_blank">award-winning documentary</a> tells the stories of Indigenous activists, journalists, whistleblowers and historians working to protect America's <a href="https://www.ecowatch.com/tag/public-lands" target="_self">public lands</a>. The film focuses on three political struggles: the shrinking of <a href="https://www.ecowatch.com/tag/bears-ears" target="_self">Bears Ears</a> National Monument in Utah, the mining of Boundary Waters Wilderness in Minnesota and the opening of the <a href="https://www.ecowatch.com/tag/Arctic-National-Wildlife-Refuge" target="_self">Arctic National Wildlife Refuge</a> to fossil fuel exploration.</p><p><em>Public Trust</em> was directed by David Garrett Byars and produced by Jeremy Rubingh. Patagonia Films, Patagonia founder Yvon Chouinard and actor Robert Redford are executive producers. It will be <a href="https://www.youtube.com/watch?v=OGjnIG7puzY" rel="noopener noreferrer" target="_blank">released</a> on YouTube in time for <a href="https://www.ecowatch.com/national-public-lands-day-2640656776.html" target="_self">National Public Lands Day</a>.</p><p>"Our country is fortunate to have millions of acres of public lands, including National Parks, Monuments, Wildlife Refuges and Wilderness set aside for future generations," Redford said. "Sadly, these lands that belong to you and me are under unprecedented threats from the greed of big corporations, eager to weaken restrictions in the pursuit of profits. Many of our current politicians are also to blame. <em>Public Trust</em> tells the story of citizens who are fighting back. It's a much-needed wake-up call for all of us who want to preserve our unique and wild cultural heritage."</p>
3. David Attenborough: A Life on Our Planet<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="156438a30836a765d7a92982545fc334"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/B_OFZvAd05Y?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: Netflix</strong></p><p><strong>Premiere Date: Oct. 4</strong></p><p>Beloved nature broadcaster <a href="https://www.ecowatch.com/tag/David-Attenborough" target="_self">David Attenborough</a> has spent his career introducing viewers to the wonders of our planet. In recent years, his footage of albatrosses swallowing <a href="https://www.ecowatch.com/tag/plastics" target="_self">plastic</a> in <em>Blue Planet II</em> has been credited with <a href="https://www.ecowatch.com/2018-fighting-plastic-waste-2624606566.html" target="_self">helping to ramp up</a> the global fight against plastic pollution. Now, in this <a href="https://www.wwf.org.uk/" rel="noopener noreferrer" target="_blank">World Wildlife Fund</a> (WWF)-produced <a href="https://www.attenborough.film/" rel="noopener noreferrer" target="_blank">documentary</a>, he reflects on the defining moments of his career and the devastating changes he has witnessed.</p><p><em>David Attenborough: A Life on Our Planet,</em> which was also produced by Silverback Films and directed by Alastair Fothergill, Jonnie Hughes and Keith Scholey, features an intimate conversation between Attenborough and Sir Michael Palin as the broadcaster reflects on his life and a career that took him to every continent on Earth. In addition to streaming on Netflix, the movie will be available in select theaters starting Sept. 28.</p><p>"For decades, David has brought the natural world to the homes of audiences worldwide, but there has never been a more significant moment for him to share his own story and reflections," WWF executive producer Colin Butfield said in a <a href="https://www.wwf.org.uk/updates/david-attenborough-life-our-planet" target="_blank">statement</a>. "This film coincides with a monumental year for environmental action as world leaders make critical decisions on nature and climate. It sends a powerful message from the most inspiring and celebrated naturalist of our time."</p>
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If all the glaciers and ice caps on the planet melted, global sea level would rise by about 230 feet. That amount of water would flood nearly every coastal city around the world [source: U.S. Geological Survey]. Rising temperatures, melting arctic ice, drought, desertification and other catastrophic effects of climate change are not examples of future troubles — they are reality today. Climate change isn't just about the environment; its effects touch every part of our lives, from the stability of our governments and economies to our health and where we live.
<p>Why environmental refugees flee their homes is a complicated mixture of environmental degradation and desperate socioeconomic conditions. People leave their homes when their livelihoods and safety are jeopardized. What effects of climate change put them in jeopardy? Climate change triggers, among other problems, desertification and drought, <a href="https://science.howstuffworks.com/environmental/green-science/deforestation.htm" target="_blank">deforestation</a>, land degradation, rising sea levels, <a href="https://science.howstuffworks.com/nature/natural-disasters/flood.htm" target="_blank">floods</a>, more frequent and more extreme storms, <a href="https://science.howstuffworks.com/nature/natural-disasters/earthquake.htm" target="_blank">earthquakes</a>, <a href="https://science.howstuffworks.com/nature/natural-disasters/volcano.htm" target="_blank">volcanoes</a>, food insecurity and famine.</p><p>The September <a href="http://visionofhumanity.org/app/uploads/2020/09/ETR_2020_web-1.pdf" target="_blank">2020 Ecological Threat Register Report</a>, by the Institute for Economics & Peace, predicts the hardest hit populations will be:</p><ul><li>Sub-Saharan Africa, South Asia, the Middle East and North Africa</li><li>Afghanistan, Syria, Iraq, Chad, India and Pakistan (which are among the world's least peaceful countries)</li><li>Pakistan, Ethiopia and Iran are most at risk for mass displacements</li><li>Haiti faces the highest risk of all countries in Central America and the Caribbean</li><li>India and China will be among countries experiencing high or extreme water stress</li></ul>
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