An '''endangered species''' is a population of an organism which is at risk of becoming extinct because it is either few in number, or threatened by changing environmental or predation parameters. Human beings are currently causing the greatest mass extinction of species since the extinction of the dinosaurs 65 million years ago. If present trends continue one half of all species of life on earth will be extinct in less than 100 years, as a result of habitat destruction, pollution, invasive species, and climate change. [http://www.well.com/~davidu/extinction.html] [http://en.wikipedia.org/wiki/Extinction#Modern_mass_extinction] ~~Examples -~~ http://z.about.com/d/animals/1/0/4/6/shutterstock_304343.jpg|right [http://news.nationalgeographic.com/news/2005/04/images/050419_aye-aye.jpg Aye aye] [http://www.sfondideldesktop.com/Images-Animals/Elephant/Afwld-African-Elephants-Mom-Nbabies-Walking-In-Lineup/Afwld-African-Elephants-Mom-Nbabies-Walking-In-Lineup.Jpg African Elephant] [http://www.shunya.net/Pictures/WesternIndia/Gujarat/LittleRannKutch/AsiaticWildAss02.jpg African Wild Ass] [http://www.wcs.org/media/image/webdog1.jpg African Wild Dog] [http://www.usgs.gov/125/articles/images/herp_alligator.jpg American Alligator] [http://hoglezoo.org/animal.photos/american.white.pelican2.jpg American White Pelican] [http://www.wcs.org/media/image/Asianele.jpg Asian Elephant] [http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/asian-lion.jpg Asian Lion] [http://www.streamlife.org.uk/images/gallery/copyrighted/l_Atlantic_Salmon.jpg Atlantic Salmon] [http://photos.igougo.com/images/p132253-Nosy_Be-Black_Lemur_-_Lokobe_Lookout.jpg Black Lemur] [http://www.smh.com.au/ffximage/2007/08/10/black_footedferret1_wideweb__470x314,0.jpg Black-footed Ferret] http://www.theage.com.au/ffximage/2007/11/26/MonarchButterfly_wideweb__470x345,0.jpg|right [http://www.nefsc.noaa.gov/faq/images/beached_blue_whalebb.jpg Blue Whale] [http://pictopia.com/perl/get_image?provider_id=318&size=550x550_mb&ptp_photo_id=1112913 Bowhead Whale] [http://www.mrnussbaum.com/cheetah.jpg Cheetah] [http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/chimp-peeking-through-leaves.jpg Chimpanzee] [http://www.thickets.net/toren/wp-content/uploads/2007/08/toast.jpg Coelacanth] [http://upload.wikimedia.org/wikipedia/commons/thumb/b/bb/Hawaii_turtle_2.JPG/300px-Hawaii_turtle_2.JPG Common Green Turtle] [http://www.brim.ac.cn/brime/bdinchn/photo/18.jpg Crested Ibis] [http://www.appalachianvoice.org/images/voicearchive/jan06/large/NatNotebook_Cougar.jpg Eastern Cougar] [http://www.birdingamerica.com/images/eskimocurlewbkmfullx.jpg Eskimo Curlew] [http://www.nefsc.noaa.gov/read/protspp/RightWhale/fin.JPG Fin Whale] [http://www.v-liz.com/galapagos/isabela/urvina~1/f-less1.jpg Flightless Cormorant] http://upload.wikimedia.org/wikipedia/en/thumb/e/e7/Loggerhead_close_up.jpg/240px-Loggerhead_close_up.jpg|right [http://www.indianjungles.com/images/gaur_goru.jpg Gaur] [http://www.herper.com/stockturtle/gavial.jpg Gavial] [http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t054/T054572A.jpg Giant Anteater] [http://armadillos-for-you.com/images/medium/p1060292.jpg Giant Armadillo] [http://www.danmex.org/Upload/Giant%20Panda.jpg Giant Panda] http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/humpback-whales-singing.jpg|right12 [http://williamcalvin.com/portraits/gorilla/WPZ%20gorilla%20020crop300x340.jpg Gorilla] [http://www.bookingcenter.com/images/packages/species_grey_whale.jpg Grey Whale] [http://www.firstpeople.us/pictures/bear/1600x1200/Feeling_Grizzly-1600x1200.jpg Grizzly] [http://upload.wikimedia.org/wikipedia/commons/thumb/6/61/Humpback_Whale_underwater_shot.jpg/800px-Humpback_Whale_underwater_shot.jpg Humpback Whale] [http://www.v-liz.com/india/images/python.jpg Indian Python] [http://news.bbc.co.uk/media/images/38196000/jpg/_38196675_rhino6.jpg Indian Rhinoceros] [http://library.thinkquest.org/5053/SouthAmerica/jaguar.jpg Jaguar] [http://www.rockjumper.co.za/images/ncal_kagu_p_morin.jpg Kagu] [http://www.australianstamp.com/Coin-web/feature/nature/kakapo2.gif Kakapo] http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Uncia_uncia.jpg/250px-Uncia_uncia.jpg|right [http://www.nmfs.noaa.gov/pr/images/turtles/kempsridley_noaa.jpg Kemp's Ridley Turtle] [http://homepage.mac.com/wildlifeweb/reptile/komodo_dragon/komodo_dragon_01tfk.jpg Komodo Dragon] [http://www.uoregon.edu/~shejohn/images/leatherbackturtle.jpg Leatherback Turtle] [http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/leopard-sleeping-in-tree.jpg Leopard] [http://www.southeasternoutdoors.com/wildlife/reptiles/images/loggerhead-returned-florida.jpg Loggerhead Turtle] [http://www.cdnn.info/news/eco/hawaiian_monk_seal_250358.jpg Mediterranean Monk Seal] [http://7art-screensavers.com/screenshots/wild-animals/deer.jpg Manipur Brow-Antlered Deer] [http://news.satimagingcorp.com/wp-content/uploads/2007/07/mountain-gorilla.jpg Mountain Gorilla] [http://www.gidgegannup.info/environmentimages/numbat.jpg Numbat] [http://z.about.com/d/healing/1/0/C/O/gtotem_orangutan.jpg Orangutan] [http://www.firstpeople.us/pictures/bear/Polar_Bears/1600x1200/Sleeping_Beauty_Polar_Bear-1600x1200.jpg Polar Bear] [http://www.lakbaypilipinas.com/images/philippine-eagle.jpg Philippine Eagle] [http://www.birdsasart.com/piping-Plover-on-wet-sand-winter-plum-_T9J1761--Little-Estero-Lagoon,-FL.jpg Piping Plover] http://www.messiah.edu/offices/publications/the_bridge/winter06/bbc_professor/images/copy%20of%20female%20zeteki%201.jpg|right [http://www.nwf.org/yellowstone/images/pronghorn.jpg Pronghorn] [http://esp.cr.usgs.gov/research/alaska/figures/figure33.jpg Przewalski's Horse] [http://www.newscientist.com/data/images/ns/cms/dn10962/dn10962-4_700.jpg Pygmy Hippopotamus] [http://themacandcheesechronicles.com/wp-content/uploads/2007/08/cimg2251.JPG Queen Alexandra Birdwing Butterfly] [http://upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Red_Wolf_and_pup.jpg/480px-Red_Wolf_and_pup.jpg Red Wolf] [http://www.saturdays.net/img/seaotter600.jpg Sea Otter] [http://www.oceanalliance.org/images/gallery/sperm_head_500.jpg Sei Whale] [http://www.dnr.state.md.us/wildlife/art/rteShortnoseSturgeon_adult.jpg Shortnose Sturgeon] [http://www.bergoiata.org/fe/felins/Calculation,%20Snow%20Leopard.jpg Snow Leopard] [http://www.terranature.org/takahe_inGrass.jpg Takahe] http://www.srcsd.com/gif/laguna-ext-owl.jpg|right [http://tapirblog.tapirdesign.com/wp-content/uploads/2007/04/l2451430.jpg Tapirs] [http://static.howstuffworks.com/gif/virtual-border-fence-3.jpg Texas Ocelot] [http://animals.nationalgeographic.com/staticfiles/NGS/Shared/StaticFiles/animals/images/primary/bengal-tigers-two-cubs.jpg Tiger] [http://www.fws.gov/northdakotafieldoffice/images/Trumpeter%20Swan%20Brood.jpg Trumpeter Swan] [http://www.islandnet.com/~marmot/jpegs/yrlng5.jpg Vancouver Island Marmot] [http://www.manateetoursusa.com/images/MTDpicsmisc/marinoman6.jpg West Indian Manatee] [http://www.therhinoguide.com/images/white-rhino-grazing.jpg White Rhinoceros] [http://www.sdgfp.info/Wildlife/Diversity/Digest%20Articles/whooping%20crane.jpg Whooping Crane] [http://www.project-himalaya.com/i-khumbu/s2-yak.jpg Yak]