Hyperactive fish, stupid frogs, fearless mice and seagulls that suddenly crashed while flying, animals sounds like a weird circus. But this is not the show. Many animals in the world have odd behavior due to environmental pollution.
Chemicals that become triggers this anomaly known as the disruptor (bullies) endocrine. Disruptor range from heavy metals such as lead to polychlorinated biphenyls (PCBs) and additive substances such as bisphenol A.
For decades, biologists have actually learned that the chemicals may affect animal behavior. And lately become clear that pollutants can cause gender-bending effects by influencing the physical animal, particularly their sexual organs.
But now two studies have found that toxic chemicals turned out to have a greater effect on animal behavior than previously thought. Low concentrations of pollutant materials that change social behavior and mating behavior of some species. This is potentially a greater threat to the continuity of it than, for example, decrease in sperm counts caused by higher chemical concentrations.
There are two research teams that independently gather evidence about the effect of pollutants on the heron and gulls, snails, quail, mice and monkeys, fish, eagles and frogs. Other behaviors observed between mating behavior and raising children, making nests, learn, avoid predators, find food, and others.
In one study, where the birds are affected male starling insecticides, seen a decrease in the ability of singing, flying and foraging up to 50 percent. While salamanders exposed to similar low-pesticide endosulfan to be difficult smell pheromon issued her partner, so there is no marriage.
Also found that male seagulls hatching from eggs contaminated with DDT experiencing strange behavior in which they attempted to marry a fellow male. While the lead would affect the balance of gulls, seagulls flying, while atrazine makes fish become hyperactive and TCDD chef made the monkeys more rough play.
Although much evidence has been obtained, but this effect was not so taken by the toksikolog an expert in the field of poison, says Ethan Clotfelter of Amherst College in Massachusetts, one of the team leaders, as written in the journal Animal Behaviour, August 2004.
Not only fails to know the size of the problem caused by endocrine disruptor, the toksikolog may also forget that the changes in animal behavior can be a sign of just how real and keeping dangerous chemicals. "We could see a change of behavior and consider it normal, then suddenly we realized that the population of this species has been threatened by it," Clotfelter said.
Something similar is disclosed Dustin Penn and Sarah Zala of the Konrad Lorenz Institute for Comparative Ethology at the Academy of Sciences in Vienna, Austria. They published a second study of the effects of endocrine disruptor in the same journal. "The thing that should realize is that this problem has been widespread," said Penn.
Both groups were appealing that biologists realized endocrine disruptor is a source of odd behavior in animals. It added that the pollutant concentrations can vary due to different causes.
Male rats exposed to pesticides in low doses, for example, will more often mark territory with the smells, but if the doses of pesticides increased, mice lose their behavior at all.
"Materials of pollutants that are considered safe when tested in medium doses, may have damaging effects even at lower doses," Penn and Zala said in his writings. "And mostly, risks also arise in high doses."
Therefore, they suggested that the effects of pollutants on animal behavior should be given high priority. "It has been increasingly aware of animal behavior is an important indication to determine whether a chemical is safe, in both low and high doses, a fact which we previously ignored.