The Holocene extinction is the first extinction event directly caused by another species -- us. It results from habitat destruction combined with hunting and the introduction of alien species to environments where they do not occur naturally. Scientists estimate that extinction rates are presently 1,000-10,000 times the historical background rate of about 1 species per million per year. They say that extinction rates will significantly increase in coming years.
86 percent of big animals in the Sahara Desert are extinct or endangered
(12/03/2013) Bigger than all of Brazil, among the harshest ecosystems on Earth, and largely undeveloped, one would expect that the Sahara desert would be a haven for desert wildlife. One would anticipate that big African animals—which are facing poaching and habitat loss in other parts of the world—would thrive in this vast wilderness. But a new landmark study in Diversity and Distributions finds that the megafauna of the Sahara desert are on the verge of total collapse.
Consumer report uncovers why people buy rhino horn
(11/26/2013) The rhinoceros is one of the largest and most iconic animals to roam the earth. However, poaching for their horn, erroneously believed to have medicinal value, has led the IUCN Red List to classify three of the world's five species as Critically Endangered. But, a new consumer report by the wildlife trade monitoring network, TRAFFIC, finds that rhino horn consumers in Vietnam buy the illegal product as much to raise their social status as to attempt to treat a fever or hangover.
Microhabitats could buffer some rainforest animals against climate change
(11/25/2013) As temperatures increase worldwide due to anthropogenic climate change, scientists are scrambling to figure out if species will be able to survive rapidly warming ecosystems. A new study in Global Change Biology offers a little hope. Studying reptiles and amphibians in the Philippines, scientists say some of these species may be able to seek refuge in cooler microhabitats, such as tree holes or under the soil, in order to stay alive during intensifying heatwaves. But, the scientists' stress, the shelter from microhabitats can only protect so far.
Strange mouth-brooding frog driven to extinction by disease
(11/21/2013) An unusual species of mouth-brooding frog was likely driven to extinction by the fungus Batrachochytrium dendrobatidis (Bd), making an unusual example of 'extinction by infection', argue scientists writing in the open-access journal PLOS ONE. Rhinoderma rufum has not been seen in the wild since 1980.
Nearly half a million seabirds die in gillnets every year, but solutions exist
(11/18/2013) A recent study from the Biological Conservation journal brings shocking news: every year across the globe, an estimated 400,000 seabirds are killed by gillnets. Gillnets, a common term for any net used to entangle and catch fish, are used all over the world, and at any depth. These nets, whether used in subsistence or commercial fishing, trap anything that swims through them. When unintended marine wildlife, or "bycatch," is caught in these nets, the results can be significant.
New bat species discovered in Brazil leaves another at risk
(11/15/2013) A team of researchers has discovered a new species of bat in Brazil, which has put a previously known species, Bokermann's nectar bat (Lonchophylla bokermanni), at risk of extinction. Long thought to comprise one species, the bat populations of the Atlantic Forest and the Cerrado – the tropical savannah of Brazil's interior - are in fact distinct from one another, according to a new study in Zootaxa. Scientists now say the Atlantic Forest's population represents a newly described species, which they have dubbed Peracchi's nectar bat (Lonchophylla peracchii).
Giant turtle-devouring duck-billed platypus discovered
(11/04/2013) Based on a single tooth from Australia, scientists believe they have discovered a giant, meter-long (3.3 feet) duck-billed platypus that likely fed on fish, frogs, and even turtles, according to a new study in Journal of Vertebrate Paleontology. At least twice the size of a modern duckbilled platypus, the scientists say the extinct giant likely lived between 15 and 5 million years ago.
Thought-to-be-extinct 'halloween' frog rediscovered in Costa Rica
(11/04/2013) A breeding population of a critically endangered harlequin toad thought to be extinct in Costa Rica has been discovered in a tract of highland forest in the Central American country, reports a paper published in Amphibia-Reptilia. Atelopus varius, an orange-and-black harlequin toad, was once relatively common from central Costa Rica to western Panama. But beginning in the 1980's the species experienced a rapid population collapse across most of its range.
First study of little-known mammal reveals climate change threat
(10/28/2013) One of the world's least-known flying foxes could face extinction by rising seas and changing precipitation patterns due to global warming, according to a new study in Zookeys. The research, headed by Donald Buden with the College of Micronesia, is the first in-depth study of the resident bats of the remote Mortlock Islands, a part of the Federated States of Micronesia.
Small invertebrates could be key to uncovering the mysteries of killer amphibian fungus
(10/22/2013) In 2004, the first-ever Global Amphibian Assessment (GAA) reviewed all 5,743 amphibian species known to science and concluded that 32% were threatened with extinction - a number far exceeding corresponding figures for birds and mammals (12 to 23% respectively). In addition to the usual culprits of climate change and habitat destruction, a startling 92.5% of amphibians listed as Critically Endangered were found to be undergoing enigmatic declines linked to an unexpected perpetrator - the chytrid fungus, Batrachochytrium dendrobatidis (Bd).
Climate change pushing tropical trees upslope 'exactly as predicted'
(09/27/2013) Tropical tree communities are moving up mountainsides to cooler habitats as temperatures rise, a new study in Global Change Biology has found. By examining the tree species present in ten one-hectare plots at various intervals over a decade, researchers found that the proportion of lowland species increased in the plots at higher elevations. The study, which was undertaken in Volcan Barva, Costa Rica, adds to a growing body of evidence that climate change is having an impact on species range distributions.
'Ecological Armageddon': mammals vanish entirely from forest fragments after 25 years
(09/26/2013) As tropical forests worldwide are increasingly cut into smaller and smaller fragments, mammal extinctions may not be far behind, according to a new study in Science. Tracking native smalls mammals in Chiew Larn Reservoir, Thailand for over 25 years, scientists found a stunning and rapid decline in mammal populations, until most forests were almost completely emptied of native mammals.
Climate change could kill off Andean cloud forests, home to thousands of species found nowhere else
(09/18/2013) One of the richest ecosystems on the planet may not survive a hotter climate without human help, according to a sobering new paper in the open source journal PLoS ONE. Although little-studied compared to lowland rainforests, the cloud forests of the Andes are known to harbor explosions of life, including thousands of species found nowhere else. Many of these species—from airy ferns to beautiful orchids to tiny frogs—thrive in small ranges that are temperature-dependent. But what happens when the climate heats up?
Global warming may ‘flatten’ rainforests
(09/12/2013) Climate change may push canopy-dwelling plants and animals out of the tree-tops due to rising temperatures and drier conditions, argues a new study published in Proceedings of the Royal Society B. The development may be akin to 'flattening' the tiered vegetation structure that characterizes the rainforest ecosystem.
Ground zero for endangered species: new program to assist animals on the brink across Southeast Asia
(08/27/2013) Organizations within the international conservation community are joining forces to minimize impending extinctions in Southeast Asia, where habitat loss, trade and hunting have contributed to a dramatic decline in wildlife. The coalition is aptly named ASAP, or the Asian Species Action Partnership.
Zoo races to save extreme butterfly from extinction
(08/15/2013) In a large room that used to house aquatic mammals at the Minnesota Zoo, Erik Runquist holds up a vial and says, 'Here are its eggs.' I peer inside and see small specks, pale with a dot of brown at the top; they look like a single grain of cous cous or quinoa. Runquist explains that the brown on the top is the head cap of the larva, a fact that becomes more clear under a microscope when you can see the encased larva squirm. I'm looking at the eggs of a Poweshiek skipperling, a species that is more imperiled than pandas, tigers, or bluewhales. Once superabundant, only several hundred Poweshiek skipperlings may survive on Earth today and the eggs I'm looking at are the only ones in captivity.
Forest fragmentation leading to higher extinction rates
(08/13/2013) The world's species are in worse trouble than widely-assumed, according to a new paper in the Proceedings of the National Academy of Sciences (PNAS), which reevaluates how scientists estimate extinction rates. The new model takes into account the impact of forest fragmentation on extinction rates for the first time, filling in a gap in past estimates. Much of the world's tropical forests, which house the bulk of the world's species, have been whittled down to fragments: small forest islands that no longer connect to larger habitat. According to the paper, species confined to fragments have a higher likelihood of vanishing.
Nutrient deficiency in Amazon rainforest linked to megafauna extinction
(08/12/2013) Around twelve thousand of years ago, the Amazon was home to a menagerie of giant creatures: the heavily armored glyptodons, the elephant-sized ground sloth, and the rhino-like toxodons among others. But by 10,000 B.C. these monsters were largely gone, possibly due to overhunting by humans or climatic changes. There's no question that the rapid extinction of these megafauna changed the environment, but a new study in Nature Geoscience posits a novel theory: did the mass extinction of big mammals lead to nutrient deficiency, especially of nitrogen, in parts of the Amazon rainforest?
Florida declares two butterfly species extinct as pollinator crisis worsens
(08/01/2013) Conservationist’s faced a crushing blow last month as two butterfly species native to Florida were declared extinct. 'Occasionally, these types of butterflies disappear for long periods of time but are rediscovered in another location,' said Larry Williams, U.S. Fish and Wildlife state supervisor for ecological services. We think it’s apparent now these two species are extinct.'
Climate could warm more rapidly than any time in the last 65 million years
(08/01/2013) According to a new review of 27 climate models, scientists say the global climate is likely to experience a warmth as great as any in the last 65 million years, only much, much faster. According to the study published today in Science, the Earth's land temperature will rise by 4 degrees Celsius (7.2 degrees Fahrenheit) from pre-industrial levels by 2100 if we continue on our current emissions trajectory.
Famous extinct animals
The Elephant bird (Aepyornis maximus) of Madagascar was hunted to extinction by humans after they arrived on the Indian Ocean island. The bird, which stood over three meters (10 feet) tall and weighed more than 500 kilograms (1100 pounds), disappeared in the 15th or 16th century. Its egg was about 160 times the size of a chicken egg. Reconstructed eggs are commonly sold in markets in Madagascar.
The black or King Island emu (Dromaius ater) of King Island (between Australia and Tasmania) was first discovered by western science in 1802. It was extinct by 1822. Hunting and fires set by visiting sailors caused its demise.
The Great Auk (Pinguinus impennis) was once found in great numbers on islands off eastern Canada, Greenland, Iceland, Norway, Ireland and Great Britain but was hunted to extinction by the mid-nineteenth century. The Great Auk was mostly hunted for its down.
The Passenger Pigeon (Ectopistes migratorius) may have one been the world's most abundant bird with a single flock reportedly numbering up to several billion birds. Hunting for sport and food lead to its rapid demise. The last wild Passenger Pigeon was shot by a 14-year-old boy in Ohio in 1900, while the last known individual of the passenger pigeon species, named "Martha" after Martha Washington, died at 1 p.m. on the 1st of September 1914 in the Cincinnati Zoological Garden. She was 29. Some scholars have argued that massive passenger pigeon flocks were the result of ecological imbalance caused by the massive decline in North American human populations following the arrival of Europeans in the 15th and 16th century. The theory holds that the disappearance of indigenous populations gave passenger pigeons an unprecedented opportunity to access resources previously appropriated by humans.
The Dodo (Raphus cucullatus) of Mauritius is perhaps history's most famous extinct bird. Hunting, coupled with widespread forest loss caused by Dutch settlers and their introduced animals killed off the last Dodo in 1681, within 80 years after the arrival of humans. The dodo bird was famously believed to be a key disperser of the Tambalacoque tree, seeds of which were said to require gut passage through the dodo in order to germinate. While this is a nice story, it's controversial.
Carolina Parakeet (Conuropsis carolinensis) was the only parrot species native to the eastern United States. Hunting and habitat loss due to forest conversion for agriculture led to its demise. The last wild specimen was killed in Okeechobee County in Florida in 1904, and the last captive bird died at the Cincinnati Zoo in 1918. The extinction of the Carolina Parakeet resulted in a boom of cocklebur, a common weed that was a favorite food of the bird..
The North American Ivory-billed Woodpecker (Campephilus principalis principalis) may or may not be extinct. The last confirmed sighting of North America's largest and most famous woodpecker is hotly debated. To date no conclusive evidence has been put forward to end the controversy. Regardless of its fate, the Ivory-billed Woodpecker's demise was fueled by destruction of its habitat -- hardwood swamps and pine forest in the southern United States -- due logging in the early part of the 20th century.
At least 15 species of Hawaiian honey creepers (various species) have gone extinct since the arrival of Polynesians. Often compared to Darwin's finches for their high degree of adaptation to ecological niches on the Hawaiian islands, honey creepers mostly died out as the result of introduced species, including rats and mosquitoes.
The Heath Hen (Tympanuchus cupido cupido) was hunted to extinction by European colonists who settled in North America. In fact some historians speculate that the first Thanksgiving featured Heath Hen, not turkey. The last heath hen was seen on March 11, 1932. Heath Hens were one of the first bird species that the United States sought to protect: in 1791 New York legislature introduced a bill to protect the species. Nevertheless, the effort eventually failed.
The Moa were giant flightless birds (15 known species) native to New Zealand. Peculiar for their total lack of wings, the largest species, the giant moa (Dinornis robustus and Dinornis novaezelandiae), reached 3.6 m (12 ft) in height and 250 kg (550 lb) in weight. They were the dominant herbivores in the New Zealand forest ecosystem and their disappearance a few hundred years after the arrival of Polynesians resulted in significant ecological change including the extinction of other species. Moa were doomed by forest clearing and hunting by the Polynesian invaders.
Steller's Sea Cow (Hydrodamalis gigas) was a giant sea mammal that once roamed the Bering Sea in the North Pacific. The sea cow grew up to 7.9 meters (26 ft) long and weighed up to three tons. It was hunted to extinction by sailors and traders. The last known sea cow was seen in 1768.
The Thylacine or Tasmanian Tiger (Thylacinus cynocephalus) of Australia and New Guinea was the largest known carnivorous marsupial of modern times. The species went extinct through most of its range well prior to the arrival of Europeans, but managed to survive on the island of Tasmania until the mid-20th century. Disease, hunting, habitat destruction, and the introduction of dogs fueled its demise. While the last known Thylacine died at the Hobart Zoo in 1936, unconfirmed sightings continue today.
The Barbary Lion (Panthera leo leo) is a subspecies of lion that went extinct in the wild, though some descendants may survive in captivity. It was the largest subspecies of lion and lived in the woodlands in North Africa. Its demise stemmed primarily from hunting and habitat loss.
The Caribbean Monk Seal (Monachus tropicalis) was the only seal ever known to be native to the Caribbean sea and the Gulf of Mexico. It was last spotted in 1952 at Seranilla Bank, Jamaica. The Caribbean Monk Seal was said to lack fear of man, while having an unaggressive and curious nature -- attributes that likely contributed to its demise from habitat loss and hunting.
The lesser Puerto Rican Ground Sloth (Acratocnus odontrigonus) was one of the last remnants of the giant ground sloths that once dominated South America. The species was driven to extinction as recently as the 16th century due to the introduction of rats and pigs by Europeans explorers. Pre-Colombian populations likely diminished the populations of this 50-pound forest dwelling beast by forest clearing and hunting.
The Baiji or Yangtze river dolphin (Lipotes vexillifer) was declared functionally extinct in 2006 meaning that even if has not yet completely disappeared, its population is so low that it will never recover. The freshwater river dolphin was driven to extinction by pollution in the Yangtze and unsustainable fishing practices. The construction of the Three Gorges Dam and other hydroelectric projects also led to habitat loss.
The Bali tiger (Panthera tigris balica) of the Indonesian island of Bali was the smallest of three sub-species of tiger found in Indonesia. It was driven to extinction by conversion of its forest habitat for agriculture. The last tiger to be shot was in 1925.
The Javan tiger (Panthera tigris sondaica) was a tiger found only on the Indonesian island of Java. Highly threatened by hunting and habitat destruction, last minute efforts to create protected areas for the species during the 1950s and 1960s failed: the credible sighting was in 1972.
The Formosan Clouded Leopard (Neofelis nebulosa brachyura) was a subspecies of Clouded Leopard endemic to the island of Taiwan. It is now believed to be extinct due to habitat destruction by loggers.
Considered to be one of the most spectacularly colored toads on Earth with its brilliant yellow-orange coloring, the Golden toad is believed to be limited to only a single mountain in Costa Rica, Monteverde. Although always rare, for a few weeks in April every year, hundreds on these brilliant toads gathered in pools in a breeding orgy. However, the toad population dropped sharply since its discovery in 1967 from several thousand gathered in 1987 to just 10 in 1988, none of which were breeding. In 1989 only a single male toad, seeking a mate, was observed. This individual may have been the last Golden toad on Earth; no golden toads have been seen since. The disappearance of the golden toad is of particular significance since its habitat is in a national preserve.
Among the casualties of the current human-induced mass extinction event are the two species of Gastric Brooding Frog from the rainforest of Queensland, Australia: the Northern Gastric Brooding Frog (Rheobatrachus vitellinus) and the Gastric Brooding Frog (Rheobatrachus silus). These two recently discovered species [R. silus was discovered in 1972; R. vitellinus 1984] are presumed extinct as R. silus was last seen in the wild in September 1981 and R. vitellinus was last seen in March 1985. Gastric Brooding Frogs are notable for their reproductive habits. The female swallows her clutch of eggs and the tadpoles hatch in her stomach. The tadpoles secrete chemicals that cause the female to cease feeding and switch off the production of hydrochloric acid in the stomach wall. The young are birthed through the mother's mouth once fully developed as froglets. After leaving the mother's mouth, the young frogs are independent. Scientists have been interested in these species' ability to shut down the secretion of digestive acids the implications of which could have an important bearing in the treatment of people who suffer from gastric ulcers.
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