WBEZ | biodiversity http://www.wbez.org/tags/biodiversity Latest from WBEZ Chicago Public Radio en Keeping an aromatic invader at bay http://www.wbez.org/blogs/chris-bentley/2013-05/keeping-aromatic-invader-bay-107163 <p><div class="image-insert-image "><img alt="" class="image-original_image" src="http://llnw.wbez.org/styles/original_image/llo/insert-images/beaver-fell-610px.jpg" title="Linda Ruxton, left, and John Pastirik peer over a sea of Mayapples towards evidence of beaver activity in Eggers Grove. (WBEZ/Chris Bentley)" /></div><p>Each spring the &quot;<a href="http://niipp.net/?page_id=1534" target="_blank">Garlic Mustard Challenge</a>,&quot; <a href="http://www.youtube.com/watch?v=-Of5BdKZD5o" target="_blank">which sounds more like</a> competitive eating than conservation, enlists volunteers around the country for a blitz on <a href="http://www.wbez.org/episode-segments/incredible-edible-weed" target="_blank">an invasive plant that has edged out native species from Maine to Oregon</a>.</p><p>In the&nbsp;<a href="http://www.wbez.org/series/curious-city/question-answered-what-part-chicago-has-most-biodiversity-103725" target="_blank">relative hotbed of biodiversity</a>&nbsp;that is the northern Illinois-Indiana border, however, it only takes a couple faithful stewards to keep the aromatic invader at bay.</p><p>John Pastirik and Linda Ruxton live just blocks from Eggers Woods, the Forest Preserve site where they have led <a href="http://www.calumetstewardship.org/events/list/garlic-mustard-mondays-eggers-grove-forest-preserve-1#.UZHGTCuG3Os" target="_blank">weekly garlic mustard pulls</a> every spring for six years.</p><p>Pulling the white-flowered weed up from the roots, Ruxton explains how the plants quickly colonize new territory.</p><p>&ldquo;Every single one matters,&rdquo; she said. &ldquo;Because they each make thousands of seeds.&rdquo;</p><p>Like most successful invaders, garlic mustard can weather many environmental conditions. It springs up sooner than other understory plants and grows quickly, gaining an edge for sunlight and space on the forest floor.</p><p><img alt="Alliaria petiolata: Garlic Mustard" class="image-original_image" src="http://www.wbez.org/system/files/styles/original_image/llo/insert-images/garlic-mustard.jpg" style="height: 187px; width: 305px; float: left;" title="Garlic Mustard — Alliaria petiolata (Chris Bentley/WBEZ)" />But they only flower every other year, which gives conservationists a window to cut back the population.</p><p>Where Pastirik, Ruxton and other volunteers have cleared the garlic mustard, native plants and wildflowers flourish. Solomon&rsquo;s Seal, Jack in the Pulpit, and Wild Geranium dot an expanse of Mayapples spanning the forest floor between white, red and burr oaks.</p><p>Pastirik, 55, grew up and still lives in the East Side neighborhood where Eggers Grove sits. Pastirik said his five older brothers teased him for taking a census of the preserve&rsquo;s tree species while he was a Cub Scout, but it hasn&rsquo;t kept him out of the woods.</p><p>Eggers Grove is a series of lowland marshes and slightly raised ridges &mdash; remnants of Lake Michigan&rsquo;s shorelines in its ancient iterations. Severe flooding in recent years has drowned many of the oaks lower along the sloping gradients between ridges. But the high ground is also risky.</p><p>Gnawed oak trunks and stumps reveal the recent arrival of beavers. Pastirik says it might be possible to lure them away by planting Aspens or other desirable species nearby, but trapping may be the only way to keep them from chewing through the keystone species of this former oak savanna.</p><p>Human use also takes it toll on the preserve. ATVs and dirt bikes, although they are forbidden, have dug tread marks into the trail. Invasive species like garlic mustard latch onto that upturned soil.</p><p>&ldquo;The ruts act like furrows in a farm field,&rdquo; Pastirik said.</p><p>Farther along the trail, where volunteers have not visited lately, the weeds grow almost waist-high. Hoisting an empty fertilizer bag full of uprooted garlic mustard, Ruxton signals to Pastirik where he should bring the crew next week.</p><p><object height="458" width="610"><param name="flashvars" value="offsite=true&amp;lang=en-us&amp;page_show_url=%2Fphotos%2F34610267%40N05%2Fsets%2F72157633497847418%2Fshow%2F&amp;page_show_back_url=%2Fphotos%2F34610267%40N05%2Fsets%2F72157633497847418%2F&amp;set_id=72157633497847418&amp;jump_to=" /><param name="movie" value="http://www.flickr.com/apps/slideshow/show.swf?v=124984" /><param name="allowFullScreen" value="true" /><embed allowfullscreen="true" flashvars="offsite=true&amp;lang=en-us&amp;page_show_url=%2Fphotos%2F34610267%40N05%2Fsets%2F72157633497847418%2Fshow%2F&amp;page_show_back_url=%2Fphotos%2F34610267%40N05%2Fsets%2F72157633497847418%2F&amp;set_id=72157633497847418&amp;jump_to=" height="458" src="http://www.flickr.com/apps/slideshow/show.swf?v=124984" type="application/x-shockwave-flash" width="610"></embed></object></p><p><em>Chris Bentley writes about the environment. Follow him on Twitter at <a href="https://twitter.com/Cementley" target="_blank">@Cementley</a>.</em></p></p> Tue, 14 May 2013 15:12:00 -0500 http://www.wbez.org/blogs/chris-bentley/2013-05/keeping-aromatic-invader-bay-107163 Reuniting with nature in the nation's backyards http://www.wbez.org/blogs/chris-bentley/2013-02/reuniting-nature-nations-backyards-105473 <p><p><a href="http://www.flickr.com/photos/reallyboring/6055188964/" target="_blank"><img alt="" class="image-original_image" src="http://www.wbez.org/system/files/styles/original_image/llo/insert-images/exurban%20sprawl%20by%20Eric%20Allix%20Rogers%20via%20flickr.jpg" style="height: 406px; width: 610px;" title="Exurban sprawl meets cornfield in Woodstock, Ill. Agriculture and suburban development are leading factors in the homogenization of local landscapes. (Eric Allix Rogers via Flickr)" /></a></p><p>In 2011 Doug Tallamy and his wife drove from Pennsylvania to Oregon. Every time they stopped for gas, he would wade into a typical residential neighborhood and snap a few photos of the plant life and landscaping. Mix those photos up, he said, and it&rsquo;s impossible to tell which stop in the 2800-mile trip you&rsquo;re looking at.</p><p>&ldquo;Nobody is using the plants that are important to their biome &mdash; they all are the same from here to California,&rdquo; he said from his home in Pennsylvania, which sits on 10 acres of white pine, milkweed and other native species that the University of Delaware professor coaxed back into a landscape once choked with invasives. In just a few years, he tripled the number of bird species on his land.</p><p>Restoring native plants has a ripple effect, because so many insects are dependent on specific species for food, and 96 percent of birds rear their young on insects. It takes at least 4,800 caterpillars, Tallamy said, to feed one clutch (5-8 babies) of Carolina chickadees. But biodiversity isn&rsquo;t just for the birds.</p><p>&ldquo;Biodiversity losses are a clear sign that our own life-support systems are failing,&rdquo; he said.</p><p>Healthy ecosystems provide services like carbon sequestration, flood control and sustenance for the pollinating insects that nourish our agricultural system. And you don&rsquo;t need 10 acres to make a difference.</p><p>There are more than 45 million acres of lawn in the U.S.</p><p>While Tallamy does not want to abandon agriculture or manicured neighborhoods, he points out there is ample space to introduce a bit of wilderness into the nation&rsquo;s backyards.</p><p>Much of that land is in the suburbs, where urban sprawl has made the homogenous lawn a status symbol. But Chicago has plenty of land <a href="http://www.placemakingchicago.com/">to work with</a> &mdash; something to keep in mind as <a href="http://www.wbez.org/news/green-belt-envisioned-south-side-103970">the city targets thousands of empty lots</a> that could support community gardening and farming operations. <a href="http://chicagotonight.wttw.com/2011/08/18/native-plant-gardens">One Chicago condo-owner</a> introduced 175 native species of trees, shrubs and grasses to his 6,200 square feet 16 years ago, and has substantially cut back on landscape maintenance in the process.</p><p>In part that&rsquo;s because native plants are evolved to endure their local conditions. Tallamy&rsquo;s research found non-native ornamental species, common in many gardens, support 29 times less biodiversity than their native counterparts.</p><p>Take Illinois&rsquo; state tree, the white oak. Its genus, <em>Quercus</em>, is one the most productive known &mdash; just in the eastern U.S., more than 500 species of caterpillars develop on oaks. Illinois <a href="http://web.extension.illinois.edu/forestry/il_forest_facts.html">ranks 49th</a> among states in the amount of land left in its original vegetation.</p><p>&ldquo;If you have a chickadee that eats caterpillars, but you only have species of caterpillar in your yard, and that species crashes, your chickadees are out of luck,&rdquo; Tallamy said. But if you have 35 species, you have restored some resilience to the system.</p><p>Tallamy&rsquo;s focus on lawns has solicited skepticism from some landscapers. He recalled one nurseryman who left him nonplussed by asking, &ldquo;Are you trying to put us out of business?&rdquo; But with 29 million homes in the U.S., Tallamy said, restoring native species is a business opportunity for any landscaper willing to change his or her inventory. And the cost of not doing so could be even greater.</p><p>&ldquo;If there were dollar figures on the ecosystem services produced by the plants in our landscape,&rdquo; Tallamy said, &ldquo;everybody would be doing it.&rdquo;</p></p> Tue, 12 Feb 2013 07:30:00 -0600 http://www.wbez.org/blogs/chris-bentley/2013-02/reuniting-nature-nations-backyards-105473 Cats kill billions of birds each year, study says http://www.wbez.org/blogs/chris-bentley/2013-01/cats-kill-billions-birds-each-year-study-says-105233 <p><p><a href="http://www.flickr.com/photos/kmcmahon/6224268393/" target="_blank"><img alt="" class="image-original_image" src="http://www.wbez.org/system/files/styles/original_image/llo/insert-images/black%20cat%20by%20kirk%20mcmahon.jpg" style="height: 405px; width: 610px;" title="I can haz 2.4 billion birds? (Kirk McMahon via Flickr)" /></a></p><p><a href="http://mashable.com/2012/07/02/best-cat-memes-ever/">Meme this</a>: wild, outdoor cats could be killing far more birds and mammals than previously estimated &mdash; at least 1.4 billion birds and at least 6.9 billion mammals each year.</p><p>That&rsquo;s according to a <a href="http://www.nature.com/ncomms/journal/v4/n1/full/ncomms2380.html">new study in <em>Nature Communications</em></a> that says cat predation is the single greatest cause of bird deaths linked to human settlement &mdash; more than building collisions, pesticides or wind turbines. Previous assessments have <a href="http://www.nytimes.com/2011/03/21/science/21birds.html">called cats the no. 1 killer of birds</a>, but never by so wide a margin.</p><p>The study estimated that the median number of birds killed by cats annually is 2.4 billion and the median number of mammals killed is 12.3 billion. Most of that is from feral (stray) cats, so don&rsquo;t scold Snowball just yet.</p><p>There are more than <a href="http://www.examiner.com/article/what-is-a-feral-cat-colder-weather-shows-feral-cat-population">50 million feral cats</a> and <a href="http://www.humanesociety.org/issues/pet_overpopulation/facts/pet_ownership_statistics.html">some 86 million owned cats</a> in the U.S., according to the Humane Society of the United States. Chicago might have as many as <a href="http://articles.chicagotribune.com/2009-07-29/news/0907270294_1_neuter-and-return-trap-neuter-and-return-feral-cat/2">half a million stray cats</a> &mdash; an animal welfare crisis in and of itself. But the study also calls into question so-called Trap-Neuter-Return (TNR) policies for managing stray animals, which are supposed to rein in the population of feral cats without killing them.</p><p>The study&#39;s surprisingly high estimates of bird and mammal deaths, however, suggest cats could nonetheless represent an invasive presence in the U.S., with dire consequences for other animal populations. Proponents of TNR programs say they are successful in certain circumstances, and not yet widespread enough to have the impact they otherwise could.</p><p>By comparison, another <a href="http://www.nature.com/nature/journal/v447/n7141/full/447126a.html">study in <em>Nature</em></a> found each wind turbine kills an average of 4.27 birds per year, but other estimates have been higher &mdash; the American Bird Conservancy projects about 1 million total bird deaths due to wind turbines each year, if 20 percent of the country&rsquo;s electricity comes from wind power by 2030. Other estimates have put that figure lower.</p><p>(Wind turbines can also disrupt mating patterns and habitat for some bird species, as well as kill birds of prey larger than most cats would have the mettle to take on. There has been, however, some&nbsp;<a href="http://www.scientificamerican.com/article.cfm?id=wind-turbines-and-bird-conflicts">regulatory progress on minimizing these effects</a>. And fossil fuel-based energy production is no friend of the birds &mdash; <a href="http://reneweconomy.com.au/2012/want-to-save-70-million-birds-a-year-build-more-wind-farms-18274">by some estimates it is even worse</a>.)</p><p>Another <a href="http://www.wbez.org/episode-segments/chicago-bird-collision-monitors">1 billion birds die each year</a> following collisions with buildings, by some estimates, which makes skyscrapers a major cause of bird deaths.</p><p>It is worth noting that pinning down the number of dead birds and small mammals is <a href="http://www.voxfelina.com/2010/05/a-critical-assessment-of-critical-assessment-part-2/">an historically tricky proposition</a>. The new study is the most comprehensive yet, and was led by researchers from the Smithsonian Conservation Biology Institute and the U.S. Fish and Wildlife Service.</p></p> Thu, 31 Jan 2013 08:00:00 -0600 http://www.wbez.org/blogs/chris-bentley/2013-01/cats-kill-billions-birds-each-year-study-says-105233 Chicago's Hispanic neighborhoods farther from nature, study shows http://www.wbez.org/blogs/chris-bentley/2013-01/chicagos-hispanic-neighborhoods-farther-nature-study-shows-104838 <p><p><img alt="" class="image-original_image" src="http://www.wbez.org/system/files/styles/original_image/llo/insert-images/RS4344_P1030210-scr.JPG" style="height: 349px; width: 620px;" title="A man fishes in Humboldt Park lagoon in early fall. (WBEZ/Robin Amer)" /></p><p>Moving to the city shouldn&rsquo;t mean giving up nature. <a href="http://www.sciencedaily.com/releases/2010/07/100723161221.htm">Studies have shown</a> that people who spend more time in natural settings bounce back from stress faster and <a href="http://articles.cnn.com/2001-03-23/health/nature.health_1_nature-howard-frumkin-view?_s=PM:HEALTH">might even be healthier</a> than those without access to parks and open spaces. In Chicago, however, some communities are closer to nature than others.</p><p>According to recent research out of the University of Illinois at Chicago, residents of Chicago&rsquo;s Hispanic neighborhoods live farther from nature than residents of other neighborhoods.</p><p>What is unique about the study, titled &ldquo;<a href="http://www.esajournals.org/doi/pdf/10.1890/ES12-00126.1">Green infrastructure and bird diversity across an urban socioeconomic gradient</a>,&rdquo; is that it looked at multiple variables instead of just, say, average distance to greenspace. They measured proximity to open space and Lake Michigan, but also the presence of trees (canopy cover), and bird biodiversity in census tracts across the city.</p><div class="image-insert-image "><div class="image-insert-image "><img alt="" class="image-original_image" src="http://llnw.wbez.org/styles/original_image/llo/insert-images/Tree-canopy-cover,-bird-biodiversity-and-distance-to-the-lake.jpg" title="Left to right: tree canopy cover, distance to open space, and bird biodiversity. (Amélie Davis)" /></div></div><p>&ldquo;When you look at the patterns across all four variables,&rdquo; said <a href="https://sites.google.com/site/davisamelie/">Amélie Davis</a>, a postdoctoral research associate at UIC and lead author of the study, &ldquo;you can see the low- to mid-income Hispanic tracts are further from Lake Michigan, further from open space, they have lower bird biodiversity, and they have the lowest percent canopy cover.&rdquo;</p><p>That means they are also farther from the benefits those natural elements either indicate or provide directly &mdash; ecosystem services, to use the jargon. Canopy cover, for example, is more than aesthetic. Trees help regulate the local air quality, stormwater runoff and even noise pollution.</p><div class="image-insert-image "><img alt="" class="image-original_image" src="http://www.wbez.org/system/files/styles/original_image/llo/insert-images/streetview%20comparison.png" style="height: 266px; width: 620px;" title="A Google Streetview comparison of two neighborhoods with different amounts of canopy cover. (Google)" /></div><p>That socioeconomic disparities influence Chicagoans&rsquo; access to nature is not entirely surprising, given the city&rsquo;s legacy of <a href="http://www.suntimes.com/10333485-417/segregation-drops-sharply-in-chicago.html">segregation</a>. What was unexpected, Davis said, was that the statistical analysis found low-income, Hispanic neighborhoods fared significantly worse than low-income, African-American areas.</p><p>&ldquo;We thought if there was an environmental injustice,&rdquo; she said, &ldquo;it would be for all of the groups or none. Not the same group consistently underserved.&rdquo;</p><p>As <a href="http://featuresblogs.chicagotribune.com/theskyline/2011/10/cramped-chicago-half-of-the-citys-27-million-people-live-in-park-poor-areas-lakefronts-parkland-disg.html">the <em>Tribune</em>&rsquo;s Blair Kamin pointed out</a>, Chicago&rsquo;s massive lakeside parks give the impression that the whole city enjoys easy access to open space along the shoreline <a href="http://www.wbez.org/series/curious-city/question-answered-how-has-chicago%E2%80%99s-coastline-changed-over-decades-104328">(which is, after all, &ldquo;forever open, clear and free&rdquo;</a>). Inland it is a different story. Little Village, for example, has <a href="http://www.metroplanning.org/news-events/blog-post/6262">the least green space per capita</a> of any neighborhood in the city.</p><p>But Davis cautioned against assuming any ill-intent on the part of City Hall.</p><p><em>&ldquo;</em>It might be a concurrence of circumstance, and not pernicious,&rdquo; she said. Industry squeezed out most of the natural spaces in Pilsen and Little Village before those neighborhoods became an important Hispanic enclave. When their notorious coal-fired power plants shut down last year, however, <a href="http://www.archpaper.com/news/articles.asp?id=6258">residents of the southwest side left no doubt</a> about their aspirations for more green space.</p><p>And the study does not tell the whole story. Proximity to open space is not a perfect stand-in for access, to say nothing of the quality of that open space.</p><p>Davis&rsquo; research is funded by an Urban Long Term Research Area Exploratory grant from the National Science Foundation. &nbsp;The study was published in Ecosphere, a journal of the Ecological Society of America.</p><p><em>Follow Chris on Twitter <a href="https://twitter.com/Cementley">@cementley</a>.&nbsp;</em></p></p> Fri, 11 Jan 2013 07:30:00 -0600 http://www.wbez.org/blogs/chris-bentley/2013-01/chicagos-hispanic-neighborhoods-farther-nature-study-shows-104838 Clever Apes #22: Paper covers rock http://www.wbez.org/blog/clever-apes/2011-11-22/clever-apes-22-paper-covers-rock-94295 <img typeof="foaf:Image" src="http://llnw.wbez.org/blog/photo/2011-November/2011-11-22/IMG_3809 keeper.JPG" alt="" /><p><p><img alt="" class="caption" src="http://llnw.wbez.org/blog/insert-image/2011-November/2011-11-22/IMG_3809 keeper small.jpg" title="Rock paper scissors, and its variations, may lie hidden in the math that underlies natural systems. (WBEZ/Gabriel Spitzer)" width="600" height="450"></p><p>Charles Darwin ushered in modern biology with his explanation of how different species evolve. But his work leaves us with a paradox: Why should dozens or even thousands of species coexist in a single habitat? The theory suggests they ought to duke it out until just a few winners dominate. And yet we have such magnificent biodiversity all over. More than 2,000 species of trees share a single acre of rainforest in the Amazon. So what gives?</p><p><em><strong><span style="font-size: 8px;">Listen to the episode:</span></strong></em></p><p><audio class="mejs mediaelement-formatter-identified-1332483827-1" src="http://llnw.wbez.org/sites/default/files/Clever_Apes_22_Paper_covers_rock.mp3">&nbsp;</audio></p><p>The answer might lie in a game you probably mastered before you were 12: rock, paper, scissors. Any pairing of two species (say, “rock” tree and “paper” tree) will almost always lead to the weaker one going extinct (so long, “rock” tree). But introduce a third species – “scissors” tree – and you close up into a stable loop, where all three can coexist. This has been known for a while, and observed in natural settings among <a href="http://bio.research.ucsc.edu/%7Ebarrylab/lizardland/male_lizards.overview.html">side-blotched lizards in California</a> and <a href="http://www.nature.com/nature/journal/v428/n6981/full/nature02429.html">bacteria growing in a dish.</a></p><p>University of Chicago ecologist <a href="http://allesinalab.uchicago.edu/people/stefano-allesina.html">Stefano Allesina </a>scaled it up with a computer model, and showed it could indeed explain big, complicated systems like the Amazon jungle or underwater kelp forests. In fact, you can have as many species as you want coexisting, with one big caveat: Strangely, it has to be an odd number. That means no fourth throw in roshambo, though <a href="http://www.youtube.com/watch?v=iapcKVn7DdY">“rock, paper, scissors, lizard, Spock”</a> is safe.</p><p><img alt="" class="caption" src="http://llnw.wbez.org/blog/insert-image/2011-November/2011-11-22/ouroborous.GIF" style="width: 250px; height: 169px; float: left; border-width: 1px; border-style: solid; margin: 10px;" title="Side-blotched lizards form a loop in competing for mates. (Courtesy of Barry Sinervo)"></p><p>Dig even a little deeper, and it seems that rock, paper scissors describes a basic mathematical concept that appears in all kinds of systems, as shown in <a href="http://plato.stanford.edu/entries/game-theory/">game theory</a>. Whether it’s economics, political science or biology, any system where competitors have different advantages that can’t be ranked from best to worst probably has a little rock, paper, scissors tournament hiding in there somewhere.</p><p>Incidentally, actual rock paper scissors tournaments have been gaining steam, thanks largely to the efforts of the <a href="http://www.worldrps.com/">World Rock Paper Scissors Society. </a>If you want to learn how to crush the competition (and never change a diaper again! Oh wait, that’s probably just in my household), check out their <a href="http://www.worldrps.com/index.php?option=com_content&amp;task=view&amp;id=256&amp;Itemid=37">strategy tips. </a>You can also practice against a robot <a href="http://www.nytimes.com/interactive/science/rock-paper-scissors.html">here</a>.</p><p>Finally, we inaugurate our recurring series, Ask an Ape, in which we answer science-y questions posed by listeners. Please weigh in with your own question in the comment section below, <a href="http://twitter.com/#%21/cleverapes">tweet us</a>, post to our <a href="http://www.facebook.com/pages/Clever-Apes-on-WBEZ/118246851551412">Facebook wall</a>, or call our hotline: 312-893-2935.</p></p> Tue, 22 Nov 2011 22:19:00 -0600 http://www.wbez.org/blog/clever-apes/2011-11-22/clever-apes-22-paper-covers-rock-94295 Chicago researcher: Rock, Paper, Scissors helps explain biodiversity http://www.wbez.org/story/biodiversity/chicago-researcher-rock-paper-scissors-helps-explain-biodiversity <img typeof="foaf:Image" src="http://llnw.wbez.org/story/photo/2011-March/2011-03-14/P1000144.JPG" alt="" /><p><p>A Chicago researcher says he&rsquo;s found insight into how ecosystems work from what may be the world&rsquo;s most basic game: rock, paper, scissors. <br /><br />Stefano Allesina says there&rsquo;s long been a paradox in ecology. An ecosystem can teem with thousands of competing species, but the math can&rsquo;t quite explain that. Models suggest that more strong ones should push out more weak ones, leaving fewer species overall. <br /><br />Now Allesina says he&rsquo;s worked out a new model to account for the diversity. The key was finding a setting where multiple, equally powerful contestants can all survive: rock, paper, scissors. <br /><br />&ldquo;For any two species, you have one winner, and it&rsquo;s a very clear winner,&rdquo; says Allesina, an assistant professor of ecology and evolution at the University of Chicago. &ldquo;But through a third species, they can close this cycle, and then start this mechanism.&rdquo;<br /><br />Allesina scaled up the game to not just three variables, but hundreds or thousands. He says his model could account for almost unlimited biodiversity, and it also explains why why the loss of one seemingly minor species can topple a carefully balanced ecosystem. <br /><br />His findings are out in the Proceedings of the National Academy of Sciences. <br />&nbsp;</p></p> Mon, 14 Mar 2011 19:00:00 -0500 http://www.wbez.org/story/biodiversity/chicago-researcher-rock-paper-scissors-helps-explain-biodiversity Study finds huge portion of vertebrates at risk of extinction http://www.wbez.org/story/biodiversity/study-finds-huge-portion-vertebrates-risk-extinction <p></p> Tue, 26 Oct 2010 22:14:00 -0500 http://www.wbez.org/story/biodiversity/study-finds-huge-portion-vertebrates-risk-extinction