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6e extinction massive / The 6th massive extinction

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Principales Causes / Main causes. Global bird extinctions are increasing warns new research. The Alaotra grebe, endemic to Madagascar, was declared extinct in 2010.

Global bird extinctions are increasing warns new research

Photo credit Chris Rose. 279 bird species and subspecies from across the globe have become extinct in the last 500 yearsOctober 2012. The rate of bird extinctions is accelerating at an alarming rate according to a new paper by BirdLife International and Charles Darwin University. Global Patterns and Drivers of Avian Extinctions at the Species and Subspecies Level, published in PLoS One, reveals 279 bird species and subspecies from across the globe have become extinct in the last 500 years. The study shows that species extinctions peaked in the early 20th century, then fell until the mid-20th century, and have subsequently accelerated.

Pacific islands suffered mostLead author Dr Judit Szabo of Charles Darwin University, said "Until this study it had been hoped the rate of extinction was slowing. The study shows that the destruction of native habitat for agriculture is currently the main cause of extinctions. 'Ecological Armageddon': mammals vanish entirely from forest fragments after 25 years. 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.

'Ecological Armageddon': mammals vanish entirely from forest fragments after 25 years

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. "It was like ecological Armageddon," says lead author Luke Gibson from the National University of Singapore. "Nobody imagined we'd see such catastrophic local extinctions. " In the late 1980s a hydroelectric project flooded 162 square kilometers of tropical forest in Thailand, creating—literally—small forest islands of varying sizes, allowing scientists to track how quickly small mammals vanished from 16 differently-sized forests.

In fragments covering less than ten hectares, native mammals vanished almost entirely within just five years. Citations: Luke Gibson, Antony J. Related articles. The outlook: Averting the sixth extinction. Kittlitz's Murrelet Denied Endangered Species Act Protection, Despite up to 90 Percent Species Loss. Oct 05, 2013 12:10 PM EDT The Kittlitz's murrelet, an Alaskan seabird whose numbers have been declining, has been denied protection under the Endangered Species Act.

Kittlitz's Murrelet Denied Endangered Species Act Protection, Despite up to 90 Percent Species Loss

The announcement was made this week by the U.S. Fish and Wildlife Service in response to a 2001 petition to protect the birds, which forage on fish and zooplankton in glacier runoff flowing into ocean waters. The news was met with dismay by the Center for Biological Diversity, the organization that appealed for the birds' protection. "The Kittlitz's murrelet is one of America's most imperiled birds, but federal officials have decided not to save the species from extinction," said Shaye Wolf, the Center's climate science director. Populations of Kittlitz's murrelet -- which is also sometimes called the glacier murrelet -- have "plummeted" in Alaska, the Center said, noting that the number of birds has declined by 80 to 90 percent in recent decades in core areas such as Glacier Bay and Prince William Sound. Humanité et Biodiversité - La communauté des adhérents et sympathisants de l'association "Humanité et Biodiversité"

Une étude prédit un effondrement planétaire irréversible imminent. EcosystèmeUne étude prédit un effondrement planétaire irréversible imminent En se basant sur des théories scientifiques, des modélisations d'écosystèmes et des preuves paléontologiques, une équipe de 18 chercheurs, incluant un professeur de la Simon Fraser University (SFU, Vancouver), prédit que les écosystèmes terriens vont faire face à un effondrement imminent et irréversible.

Une étude prédit un effondrement planétaire irréversible imminent

Dans un article récemment publié dans Nature, les auteurs examinent l'accélération de la perte de biodiversité, les fluctuations climatiques de plus en plus extrêmes, l'interconnexion grandissante des écosystèmes et le changement radical dans le bilan énergétique global. Ils suggèrent que tous ces éléments constituent des précurseurs à l'apparition d'un état planétaire de seuil ou encore d'un point de basculement. Si cela s'avérait exact, ce que les auteurs prédisent pour le siècle en cours, les écosystèmes de la planète, en l'état de connaissances actuelles, pourraient rapidement et irréversiblement s'effondrer. Portraits Nature : quand l'Homme et l'animal se rencontrent.

Qu’est-ce qu’une extinction de masse ? Ce chapitre est le second d'une série de 19 films courts sur la biodiversité éditée en DVD. Filmé à l'université Claude Bernard de Lyon et dans les collections de paléontologie, Gildas Merceron, paléontologue, évoque les extinctions majeures de la biodiversité. Il explique le pourquoi et les conséquences de la disparition en masse de nombreuses espèces en s’appuyant sur l’exemple des dinosaures. Extinction Symbol.