Bizarre behavior in animals – 09/24/2004

  • October 1, 2013 at 3:34 am #566

    Hi SAD members,
    What complete bs ~ polution.
    again sorry if I’m being redundant.
    — In, Rocky Ward <rachelleward> wrote:
    “Pollution” my ***.

    Pollution Triggers Bizarre
    Behaviour In Animals
    By Andy Coghlan

    Hyperactive fish, stupid frogs, fearless mice and seagulls that fall
    over. It sounds like a weird animal circus, but this is no freak
    show. Animals around the world are increasingly behaving in bizarre
    ways, and the cause is environmental pollution.

    The chemicals to blame are known as endocrine disruptors, and range
    from heavy metals such as lead to polychlorinated biphenyls (PCBs)
    and additives such as bisphenol A.

    For decades, biologists have known that these chemicals can alter
    the behaviour of wild animals. And in recent years it has become
    clear that pollutants can cause gender-bending effects by altering
    animals’ physiology, particularly their sexual organs.

    But now two major reviews have revealed that the chemicals are
    having a much greater impact on animal behaviour than anyone
    suspected. Low concentrations of these pollutants are changing both
    the social and mating behaviours of a raft of species. This
    potentially poses a far greater threat to survival than, for
    example, falling sperm counts caused by higher chemical

    Snails and quails

    The two research teams have independently collected evidence
    revealing the effects on egrets and gulls, snails, quails, rats and
    macaques, minnows, mosquito fish, falcons and frogs. Behaviours
    altered include mating and parenting, nest building, learning,
    predator avoidance, foraging, activity levels and even balance.

    In one study, for instance, male starlings exposed to dicrotophos
    insecticide decreased their singing, displaying, flying and foraging
    activities by 50%. And newts exposed to low levels of the pesticide
    endosulfan found it harder to sniff out the attractive pheromones of
    potential mates.

    Researchers have also shown that increasing numbers of male western
    gulls hatched from eggs exposed to DDT attempt to mate with each
    other. In recent years, scientists have also found that lead affects
    the balance of gulls, while atrazine makes goldfish hyperactive and
    the chemical TCDD makes the play behaviour in macaques rougher.

    Despite this wealth of evidence, these effects have gone largely
    unnoticed by toxicologists, says Ethan Clotfelter of Amherst College
    in Massachusetts, lead author of one of the reviews, published in
    August 2004 in Animal Behaviour (vol 68, p 465).

    Missing a trick

    Not only are we failing to acknowledge the scale of the problem
    caused by endocrine disruptors, but toxicologists may be missing a
    trick: changes in animal behaviour could be an early warning that
    certain chemicals are harmful. “You might see behavioural effects
    long before you see a population crash,” Clotfelter says.

    Dustin Penn and Sarah Zala of the Konrad Lorenz Institute of
    Comparative Ethology at the Austrian Academy of Sciences in Vienna
    agree. They have just published a second review of the effects of
    endocrine disruptors in the same journal (DOI:
    10.1016/j.anbehav.2004.01.005). “The most important point is the
    incredible amount of evidence that this is a widespread problem,”
    Penn says.

    Both research groups say that biologists must wake up to the fact
    that endocrine disruptors might explain bizarre behaviour in wild
    animals. And both reviews reveal that different concentrations of
    chemicals can have unexpected effects.

    Male mice exposed to low doses of some pesticides increase their
    scent-marking behaviour, for instance, but decrease it when exposed
    to higher concentrations.

    Damaging doses

    “Pollutants that have been considered safe when tested at medium
    doses could have damaging effects at lower doses,” Penn and Zala
    warn in their review. And conversely, toxicologists might exaggerate
    the risks posed by higher doses.

    Other behavioural biologists back the authors’ call for biologists
    and toxicologists to work more closely to determine the scale of the
    problem. “It’s been decades since the first evidence appeared that
    chemicals in the environment can influence behaviour,” says John
    McCarty of the University of Nebraska in Omaha, who researches the
    impact of pollutants on birds.

    “It seems to me that this body of evidence was pushed to the
    background while most environmental scientists and regulators
    focused on mortality and cancer rates [caused by endocrine
    disruptors and other pollutants].”

    The US Environmental Protection Agency says it cannot provide a
    detailed comment on the research, but promises it will investigate
    further. “We’ll review these two scientific articles as we continue
    to develop an endocrine screening and testing programme,” a
    spokeswoman told New Scientist.

    Geoff Brighty, ecosytems science manager at the UK Environment
    Agency, agrees that studying the effects of chemicals on animal
    behaviour should be given a higher priority. “It is becoming
    recognised that behaviour is important to look at to make sure a
    chemical is safe, and we ignore it at our peril.”

    © Copyright Reed Business Information Ltd.

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