Saturday, Aug. 17, 2019 | 2 a.m.
For better or worse, Homo sapiens have left their mark on the world. So much so that those in charge of our history are considering replacing Holocene—the label for our current geological period spanning the past 10,000 years—with Anthropocene, a term to describe a period where human activity has dominated the climate and environment on Earth.
Percentage of assessed species threatened with extinction
• Amphibians: 40%
• Mammals: 25%
• Conifers: 34%
• Birds: 14%
• Sharks and rays: 31%
• Reef corals: 33%
• Selected crustaceans: 27%
Why is the distinction significant? Scientists believe we are now in the middle of the sixth mass extinction, this one triggered primarily by human activity. The race is on to discover and catalog all the world’s living organisms before it’s too late. Here’s a look at just a few of the animals we’ve lost in recent history.
International Union for Conservation of Nature Red List
Formed in 1948, the International Union for Conservation of Nature is a network of organizations and experts devoted to good global stewardship. Part of its mission includes managing the Red List, a catalog of species threatened with extinction. Established in 1964, the list divides species into nine categories: not evaluated, data deficient, least concern, near threatened, vulnerable, endangered, critically endangered, extinct in the wild and extinct.
According to the Red List, scientists have assessed more than 96,900 species. Of these, more than 26,500 are considered potential candidates for extinction.
Nevada species spotlight
Dixie Valley toad (Bufo williamsi)
• Yuma clapper rail (Rallus longirostris yumanensis)
• Devils Hole pupfish (Cyprinodon diabolis)
• Southwestern willow flycatcher (Empidonax traillii extimus)
• Tricolored blackbird (Agelaius tricolor)
• Cui-ui fish (Chasmistes cujus)
• Carson wandering skipper (Pseudocopaeodes eunus obscurus)
In June, the Las Vegas Sun reported that U.S. wildlife officials agreed to consider protection for the Dixie Valley toad, a rare toad in Northern Nevada’s high desert. Featuring flecks of gold on its olive-colored skin, the 2-inch-long toad was discovered in 2007 in the thick underbrush of a spring-fed marsh in the Dixie Valley, where an ancient lake once covered 190,000 square miles.
One of the smallest “true toads,” the Dixie is found in an area covering fewer than 3 square miles in the marshy remnant of the lake bed east of Reno and is regularly threatened by development.
The Dixie Valley toad is also under threat from other factors including disease, predation from the non-native American bullfrog, habitat loss due to climate change and livestock grazing, etc.
Ways you can help
According to the National Wildlife Federation, up to one-third of U.S. species are at increased risk of extinction, and more than 1,300 U.S. plants and animals already have been federally listed as threatened or endangered and are protected under the Endangered Species Act. So how can you help?
Extinction is a problem we can’t simply fix by “saving the species” and keeping them in zoos. A captive population does not help maintain a fragile wild ecosystem. The hard truth is, once a species has made it high enough on the IUCN Red List, it will likely never recover.
So while it may be too late for some species, conservation is still a worthwhile effort to help others survive the delicate webs of a rapidly changing natural world.
1. Educate yourself, family and friends about endangered species in the area.
2. Donate to or volunteer with organizations such as the National Wildlife Federation or local agencies.
3. Make an effort to be zero waste by purchasing sustainable products, recycling, using less water and reducing your carbon footprint. Demand the same of corporations.
4. Put pressure on local politicians and organizations to defend natural spaces and support conservation policies.
5. Grow native plants to attract native species of insects, birds and other animals that bolster the ecosystem.
Extinct in the 21st century: World species spotlight
• Pyrenean ibex (Capra pyrenaica pyrenaica) 2000
• Baiji, Yangtze River dolphin (Lipotes vexillifer) 2007
• Spotted green pigeon (Caloenas maculata) 2008
• Eastern cougar (Puma concolor couguar) 2011
• Japanese river otter (Lutra lutra whiteleyi) 2012
• Formosan clouded leopard (Neofelis nebulosa brachyura) 2013
Pinta Island tortoise (Chelonoidis nigra abingdonii): 2012
Able to survive up to six months without food or water, Galápagos Islands tortoises were no match for humans. Settlers hunted the giant reptiles for meat and shell trophies, and grazing goats destroyed their habitat. The last of one subspecies was discovered in 1971, living all alone on Pinta Island. Scientists made efforts to mate the tortoise with other similar species, but to no avail. Lonesome George died June 24, 2012, at Galápagos National Park.
Spix’s macaw (Cyanopsitta spixii): 2000
Although not technically confirmed yet by the IUCN, the Spix’s macaw is considered possibly extinct in the wild because of habitat loss, capture, invasive threats, etc. According to the IUCN, although this species exists in several captive populations, the last known individual in the wild disappeared at the end of 2000. Any remaining population is likely to be too tiny to effectively repopulate. A native of Brazil, the species’ troubles were fictionalized in the film Rio, where Blu, the last captive male Spix’s macaw, must win over the heart of Jewel, the last wild female.
West African black rhinoceros (Diceros bicornis longipes): 2011
This black rhinoceros subspecies numbered fewer than 10 by 2001 and was located in the forests of war-ravaged northern Cameroon. Once all over central Africa, the population fell because of poaching for its horn. After it hadn't been seen in more than a decade, the IUCN listed the rhino as extinct in 2011. No West African black rhinos are known in captivity.
Extinct in the 20th century: World species spotlight
• California grizzly (Ursus arctos californicus) 1922
• Thylacine (Thylacinus cynocephalus) 1936
• Bali tiger (Panthera tigris balica) 1937
• Pig-footed bandicoot (Chaeropus ecaudatus) 1950s
• Caspian tiger (Panthera tigris tigris) 1950s
• Barbary lion (Panthera leo leo) 1960s
• Javan tiger (Panthera tigris sondaica) 1980s
Passenger pigeon (Ectopistes migratorius): 1914
Found throughout North America and once so numerous their flocks blocked out the sun, the passenger pigeon was driven to extinction in a short span of 100 years. Because of the destruction the voracious migratory birds wrought on crops and trees (the sheer weight of their number when perching could break branches) communities hosted mass pigeon shoots to cull themâ€”plus their feathers looked good in hats. Then, when their remaining numbers were at a critical threshold, a deadly virus hit. With too few animals left to reproduce, the bird disappeared.
Carolina parakeet (Conuropsis carolinenis): 1918
Similar is the story of the Carolina parakeet of the southeastern United States. Within the span of 100 years, the population of Carolina parakeets fell from several million to nothing, thanks in part to their eating things humans also like to eat, such as crops and orchard fruits. Highly social birds, they never left a fallen bird behind, which made them easy targets.
This story originally appeared in the Las Vegas Weekly.