Extinctions

Of the 300 extinctions, alien species were solely to blame for 42 percent -- 126 extinctions.

Mass extinctions are relatively rare events; however, isolated extinctions are quite common.

Invasive species are a significant cause in 60% of all documented plant or animal extinctions, one of five main drivers along with habitat loss, global warming and pollution, according to the findings.

Localised extinctions or population strains have been caused by the decimation of eucalypt forests for agriculture, mines and human settlement.

Experts from the University of Southampton, which led the study, said these events triggered significant biological upheavals, including mass extinctions of marine species.

For example, avian malaria, introduced by people, has triggered large numbers of extinctions in Hawaii - particularly among the endemic Hawaiian honeycreepers - where the birds possessed no natural immunity.

If the tides disappeared it would quickly upset important food chains around the world, and could lead to mass extinctions.

Meanwhile, the Australian government is spending millions on a captive breeding program as the federal environment minister - who has promised no new extinctions - reviews salmon farming in the harbour.

Resort closures and extinctions are difficult or impossible to undo.

The U/Pb isotopic dating technique is wonderfully accurate and mighty helpful in dating geologic events from volcanic eruptions, continental movements to mass extinctions.

Cited by the independent daily "O Pais", Pereira said these criminal networks were partly responsible for the fact that extinctions of species are now running at 100 times the normal background extinction rate.

If enough frogs move between different regions, there is a chance that they could recolonize areas that undergo local extinctions.

These eruption events can release enough carbon dioxide to cause catastrophic climate change on Earth, including mass extinctions.

But there is agreement that the extinctions we’re seeing now are our fault.

Experts estimate that in the last 700 years, 77 species and subspecies of birds in the Hawaiian Archipelago have gone extinct, accounting for 15 percent of bird extinctions worldwide.

Should cats be culled to stop extinctions?

Multiple extinctions of birds in Hawaii are predicted as the mosquito-borne avipoxvirus spreads into mountain forests where it was once too cold for mosquitoes to live.

Adaptive radiations commonly follow mass extinctions : following an extinction, many niches are left vacant.

Almost all scientists acknowledge that the rate of species loss is greater now than at any time in human history, with extinctions occurring at rates hundreds of times higher than background extinction rates.

Along with human-made changes in climate (see above), some of these extinctions could be caused by overhunting, overfishing, invasive species, or habitat loss.