It’s no surprise that a chemical as potent as methylmercury harms wildlife when it enters an ecosystem in high concentration. In the case of wetland birds, researchers have found, it can even change sexual orientation, causing males to pair off with other males.
“We knew mercury could depress their testosterone (male sex hormone) levels,” explained Dr Peter Frederick from the University of Florida, who led the study. “But we didn’t expect this.” [BBC News]
Frederick and Nilmini Jayasena examined white ibises from South Florida for their study in the Proceedings of the Royal Society B. They gathered 160 of the birds and broke them up into four groups that ate food laced with different concentrations of methylmercury. Some ate 0.3 parts per million of mercury, some 0.1, some 0.05, and some none at all.
Birds exposed to any mercury displayed courtship behaviour less often than controls and were also less likely to be approached by females when they did. As the level of mercury exposure increased, so did the degree and persistence of homosexual pairing. Males that engaged in homosexual parings were also less likely to switch partners from year to year, which Frederick says ibises tend to do if they have been unsuccessful in mating during their first breeding season. [Nature]
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This week federal officials said they want to ban the importation of nine large and exotic snake species. The move is designed to quell the spread of those slithering reptiles that have gotten loose and thrived in Florida and especially in the Everglades, and that threaten to spread further across the country.
More than a million of these snakes—including the giant Burmese python, boa constrictors, and several kinds of anaconda—have come to the United States in the last 30 years as pets. But invariably, over the years, some slithered loose — or were released by owners who found their reptile[s] more than they could handle. Today, many thousands nest wild in Florida’s suburban yards, parks and the Everglades [Science News]. At least one of the species, the northern African rock python, is considered dangerous to humans.
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The burgeoning 150,000-snake python population in Florida’s Everglades National Park threatens crops, livestock, and native animals. And, as the July 1 story of the toddler killed by a pet python demonstrates, the snakes can also threaten human lives. The snake overpopulation began when python owners discarded their unwanted pets in the wild; now, lawmakers are pushing for legislation to combat this invasive species. Not surprisingly, there is disagreement over the best way to do it.
Florida Senator Bill Nelson, who filed a bill in February to ban the importation of Burmese pythons, told a Senate panel on Wednesday that the snakes are slithering their way into a wider geographical area. Then he explained in graphic detail how a pet python… strangled a toddler in her crib last week in a town northwest of Orlando. ”It’s just a matter of time before one of these snakes gets to a visitor in the Florida Everglades,” Nelson said [Miami Herald]. Nelson said he’s been pestering the U.S. Fish and Wildlife Service for three years to halt the growth of the snake population, but the agency has not yet taken action. In addition, an environmental scientist at the panel emphasized the need to majorly restructure the policies that regulate and control import of exotic species like the python.
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An ambitious, multibillion-dollar effort to restore Florida’s Everglades is floundering due to bureaucratic delays, and the ecosystem may be close to a tipping point, according to a new congressionally mandated report. The longer the project remains stalled, the higher its cost will rise — even as the River of Grass that it’s supposed to rescue declines, the report from the National Research Council says. “If we don’t do something soon, we’re going to lose this really precious resource,” said [report coauthor] William Graf [St. Petersburg Times].
The report criticizes progress on the Comprehensive Everglades Restoration Plan, which was approved by Congress in 2000. The massive effort to restore natural water flow to about 4 million acres of wetlands was originally estimated to cost about $7.8 billion and take 30 years to complete — a price tag that has since ballooned due to rising costs…. The 2000 plan made the federal government and Florida 50-50 partners. To date, the state has committed more than $2 billion and pushed ahead alone with a few projects. Congress has only appropriated several hundred million dollars [AP].
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The governor of Florida announced yesterday that the state is putting its money where its mouth is when it comes to conservation of the imperiled Everglades. The state has agreed to buy out U.S. Sugar for $1.75 billion, and will switch the company’s 187,000 acres of land from sugar cane fields to natural wetlands. U.S. Sugar’s property lies just south of Lake Okeechobee, the heart of the Everglades’ unique ecosystem.
Florida Governor Charlie Crist said the deal is “as monumental as the creation of our nation’s first national park, Yellowstone. This represents, if we’re successful, and I believe we will be, the largest conservation purchase in the history of the state of Florida” [AP]. Environmentalists are delighted by the conservation coup, and will be keeping their fingers crossed that everything goes as planned; under the proposal, U.S. Sugar will farm the land for six more years before turning it over to the state.
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