• @kassem
    Kassem CC BY-NC-SA
    2
    @lyco
    @thibnton
    2

    Rapid loss of top predators ‘a major environmental threat’
    ▻http://www.theguardian.com/environment/2014/jan/10/rapid-loss-of-top-predators-a-major-environmental-threat

    The rapid loss of top predators such as dingoes, leopards and lions is causing an environmental threat comparable to climate change, an international group of scientists has warned.

    A study by researchers from Australia, the US and Europe found that removing large carnivores, which has happened worldwide in the past 200 years, causes a raft of harmful reactions to cascade through food chains and landscapes.

    Small animals are picked off by feral pests, land is denuded of vegetation as herbivore numbers increase and streams and rivers are even diverted as a result of this loss of carnivores, the ecologists found.

    Kassem CC BY-NC-SA
    • @lyco
      Lyco

      Over 75 percent of large predators declining
      ▻http://news.mongabay.com/2014/0109-hance-big-predator-decline.html

      Looking at 31 large-bodied carnivore species (i.e those over 15 kilograms or 33 pounds), the researchers found that 77 percent are in decline and more than half have seen their historical ranges decline by over 50 percent. In fact, the major study comes just days after new research found that the genetically-unique West African lion is down to just 250 breeding adults.
      [...]
      According to the study, the major trend underpinning this global decline in big predators is the rapidly-rising population of another predator: humans.
      [...]
      Despite growing knowledge about the importance of top predators, the ecological role of most of the world’s large-bodied predators remains unknown. Perhaps more alarming still, scientists lack good data on the population sizes of many of the world’s top predators, leaving conservationists guessing. But where information is available: it is disheartening. Lion populations have fallen from an estimated 100,000 in 1960 to 15,000-35,000 today. There are currently more captive tigers in the U.S. alone than there are tigers in the wild worldwide (about 3,200). The Ethiopian wolf (Canis simensis) has lost 98 percent of its historical range and sports a total population of less than 500.

      #biodiversité #écologie

      Lyco
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