Butterflies and insects declining in Britain – 04/16/2004

  • September 30, 2013 at 8:18 pm #461


    by David Suzuki 04.16.04

    Recently, I wrote about a report from Birdlife International that
    described how birds around the world were in trouble. The authors
    noted that birds were an indicator species—canaries in the coalmine,
    you might say—and they argued that if birds were faring poorly, then
    other species, and the environment in general, probably weren’t doing
    so hot either.

    Just days after the report, results of a long-term study of bird,
    butterfly and plant populations in Great Britain were published in
    the journal Science. The results confirmed that, in Great Britain at
    least, many bird species are indeed declining. But even more
    disturbing, the researchers found that birds and other vertebrates
    may not necessarily make good indicator species because lesser-known
    creatures, like insects, seem to be faring much worse.

    For the Great Britain study, researchers looked through 15 million
    records of species amassed by some 20,000 volunteers. Over 40 years,
    these volunteers kept detailed records of more than 3,000 separate
    ten-square-kilometre test areas across the country. Great Britain is
    the only place in the world where such detailed records have been
    maintained for so long.

    After studying the data for a year, researchers concluded that 28 per
    cent of plant species and 50 per cent of bird species have
    disappeared from at least one study area. Butterflies fared the
    worst, with 71 per cent of those species disappearing from at least
    one area over the past 20 years. In fact, two butterfly species went
    extinct from Britain during the study period, as did six native

    These findings are disturbing because insects account for more than
    half of the known species on the planet. According to the
    researchers, if insects are disappearing faster than birds, then
    biologists have actually been underestimating the loss of life on
    Earth, thus “strengthening the hypothesis that the natural world is
    experiencing the sixth major extinction event in its history.”

    While the last major extinction event occurred when an asteroid
    collided with the planet some 60 million years ago, current
    extinction levels have a much more mundane cause—human activities.
    Sometimes the effects of these activities are obvious, like when we
    fill in a wetland to build a parking lot. Others are more subtle. For
    example, results of a study published in Science found that excess
    nitrogen from intensive agricultural production and air pollution in
    Great Britain is reducing plant biodiversity by creating conditions
    more favourable to plant species that are better adapted to high
    nutrient levels.

    When most of us think of species extinction, we tend to think about
    the big, charismatic species that we feel an affinity towards,
    species like tigers, gorillas and whales. But plants and insects form
    the backbone of biodiversity on the planet. To a certain extent,
    everything else, including us, relies on them. Humans evolved at a
    time of plenty on Earth. A stable climate, bountiful natural
    resources, high levels of life diversity and vibrant ecosystem
    services have all helped provide us with everything we needed to
    develop our modern society. By degrading these services and driving
    so many species to extinction, we put our own future in peril.

    The good news is that if humans are causing the problem, we can still
    fix it. It won’t be easy, but it’s not impossible either. Across
    Canada, municipalities are banning the cosmetic use of insecticides
    and herbicides. That will help. As we learned from the Great Britain
    plant study, reducing air pollution and developing more sustainable
    agricultural practices will help too. And Canada’s new species at
    risk act will help, if it ever shows some teeth. These are a start,
    but we have along way to go. If butterflies and plants are indeed
    canaries in the coalmine, we don’t have any time to lose.

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