purposeforporpoise

It is hard to avoid the female sex hormone estrogen and all the chemicals that mimic it: Not only do they show up in cosmetics and cleaning products, but they are also commonly used to make plastic bottles and line food cans.  http://louisijisheehan.blogspot.com  Some experts have traced estrogen-like chemicals to increased rates of human breast cancer, and there is even more evidence that they endanger animals by feminizing the sex organs of male frogs and fish living downstream from sewage treatment plants. Then there is one species of bird—the starling—in which environmental estrogens have an especially surprising effect: Exposed male starlings turn into better singers, duping female starlings into choosing mates that may be bad bets.

The discovery comes from Cardiff University in Wales, where researchers compared starlings raised in aviaries and fed a controlled diet with those living at sewage treatment plants and feasting on earthworms inhabiting the rocky filter beds.  http://louisijisheehan.blogspot.com  Since the worms survive on microbes that degrade the sewage, the treatment-plant starlings consumed natural human estrogen along with three estrogen mimics: DEHP, used to manufacture polyvinyl chloride; DBP, found in nail polish; and bisphenol A, common in hard plastic bottles.  http://louisijisheehan.blogspot.com

At first, both groups of starlings appeared to behave normally, exhibiting a natural seasonal cycle in which “the whole [brain] mechanism for song shuts down in autumn, presumably to make room for other centers that are more important—like finding food,” says Katherine Buchanan, a study leader. When the spring mating season rolled around, estrogen in the male brain surged in both groups, triggering an expansion of the vocal center and a burst of song. But for birds consuming the estrogen cocktail, the vocal center grew even larger—and they sang five times as long as uncontaminated birds and composed more complex songs. In the lab, female starlings showed a preference for those songs, perching near a loudspeaker that was playing them.

Blood tests, however, showed that the doped male starlings had compromised immune systems, suggesting that they were less fit. The starling population in Britain has dropped by half in the last four decades, Buchanan says, mostly because humans have been encroaching on their habitat—but perhaps also because pollutants are creating a siren song that has bewitched the females, luring them to reproduce with more musical, but less healthy, mates.

  Louis J. Sheehan    POISON IVY is one of those weeds proliferating like mad as rising levels of greenhouse gases like carbon dioxide heat up the atmosphere. Researchers at Duke University who studied the weed between 1999 and 2004 in a controlled forest area near Chapel Hill, N.C., where high levels of CO2 are pumped into test plots, found that poison ivy not only grew more vigorously, but also produced a more toxic form of urushiol, the resin that causes its rash.  http://louis5j5sheehan5esquire.blogspot.com

Some people, though, rather than cursing the proliferation of the itchy vine, are mining it as a growth opportunity.

Umar Mycka, a horticulturist with 35 years of experience at the Philadelphia Zoo, has started a business (poisonivyhorticulturalist.com) removing poison ivy for people who don’t want to get near the stuff.  http://louis5j5sheehan5esquire.blogspot.com

“They come to me like this,” Mr. Mycka said, holding his forearms out, as if covered with the red rash or blisters. “Sometimes their head is out to here,” he added, alluding to the swelling that can occur in acute cases, which may require steroids or even hospitalization. “When it’s that bad, people say, oh, it must have been poison sumac or poison oak,” he said. “It’s not. It’s just that they got it under optimum conditions.”

What are optimum conditions? Picture a meadow or woods on a humid, overcast day, when those resins are pumping through the poison ivy vines, which run along the ground and up the trees. Along comes somebody who has never heard that old saw “leaves of three, let it be,” wearing low shoes or sandals, shorts and a sleeveless shirt. Or maybe someone decides he’s going to clear overgrown brush in the backyard, wearing gloves and a short-sleeved T-shirt.

Robert Shiffrin, a homeowner in Wynnewood, Pa., a suburb of Philadelphia, recently made that mistake. “I didn’t think to look around,” he said. “I was more interested in the pricker bushes; I wore gloves. But I got this wall-to-wall rash from my wrists to the end of my short sleeve.“

Last week, he followed Mr. Mycka to the edge of his yard, where poison ivy was growing beneath a sassafras tree and up into its limbs. Mr. Shiffrin had such a bad rash, he made the same assumption many others do: “I thought it was poison sumac or poison oak,” he said. “But Umar told me they don’t grow here.”

Poison sumac, Mr. Mycka said, grows in swamps on the East Coast, but there was no bog in Mr. Shiffrin’s yard. Poison oak is actually two species: Western poison oak, which grows on the West Coast, and Eastern poison oak, which frequents sandy habitats like the Pine Barrens in New Jersey, where it grows as a shrub, not a vine. Eastern poison ivy (Toxicodendron radicans) is far more ubiquitous, flourishing just about everywhere east of the Mississippi River. According to Jean H. Langenheim, whose book “Plant Resins: Chemistry, Evolution, Ecology and Ethnobotany” (Timber Press, 2003) is one of Mr. Mycka’s bibles, poison ivy is also found in Mexico, Guatemala and East Asia.

“Capt. John Smith named it poison ivy because he thought it looked like English ivy, which has aerial roots,” Mr. Mycka said, referring to the English explorer who helped found Virginia. (Captain Smith also compared the plant to Boston ivy, which has tri-foliate leaves, Ms. Langenheim writes, and he noted in his 1624 “Generall Historie of Virginia, New-England and the Summer Isles” that it caused “itchynge” and blisters.)

“To me, it’s a menace, but I have respect for it,” Mr. Mycka said last week, as he painted Vine-X, which contains triclopyr, a systemic herbicide, on a poison ivy plant growing in a thick ground cover beneath spruce trees. “When I paint this on, it isn’t coming back.”

Dressed in a white Tyvek jumpsuit, made of spun polyethylene, and booties, Mr. Mycka knelt in a little sea of lily of the valley, tracing, with double-gloved hands — plastic first, then heavy work gloves — the three-leafed vine that ran along the ground and straight up the trunk of the tree. “Birds probably brought the seed in,” he said. “This is all the same plant, probably five years old.” He pointed out this year’s growth — about 10 inches of green stems and seven sets of leaves — extending from the woody vines hugging the ground. “Can you smell it?” asked Mr. Mycka, who described the smell as having “a bitter taste.” I couldn’t smell, or taste, a thing.

Then he held the Vine-X bottle, which had a tiny brush attached to its cap, upside down, and continued applying the herbicide with the delicacy of a weed-killing Rembrandt.

The herbicide is applied to the stems and goes down into the roots, where it kills the plant. The compound’s half-life — the time required for half of it to break down — is 46 days. But studies indicate that residues can remain in the soil for about a year. It is not clear how toxic it might be to mammals, fish or ducks — so I, for one, would rather just pull up the weed.

Roundup, or glyphosate, another systemic herbicide widely used for poison ivy control, has a half-life of 32 days, and dissipates for the most part within six months, according to Monsanto, its manufacturer. But its surfactants — the wetting agents used to spread the chemical — are harmful to fish and frogs. Thick stems clinging to trees can be cut and painted with Vine-X or Roundup, but care must be taken to avoid damaging the tree and the surrounding plants. At this advanced stage, poison ivy can send out horizontal branches with so many big, dark green leaves, it looks like a tree itself.

Instead of using poison, organic gardeners pull up the vines and roots (wearing gloves, of course), and immediately dispose of them in garbage bags headed for the landfill. Mike McGrath, the voluble host of “You Bet Your Garden,” broadcast weekly on WHYY in Philadelphia (whyy.org/91FM/ybyg/index.html), puts plastic shopping bags (the heavy kind from upscale department stores) over his gloved hands, and pulls the vines in such a way that even his gloves don’t touch any part of them. He also wears protective clothing, and washes everything — tools, gloves, clothes, body — with cold water, as soon as the job is done.

When it comes to removing even the tiniest bit of urushiol from the hands or anywhere else on the body, there is a lot of conflicting advice. Some recommend washing with a soap like Fels-Naptha and warm water; others, like Mr. McGrath, say that that just spreads the resin, and that only cold water, sans soap, will do. Still others, myself included, swear by jewelweed, a soft, green-leafed plant with little orange flowers that often grows next to poison ivy in damp areas, near streams. Crush the stems and leaves, and rub the sap over your arms and any other infected area (Mr. Mycka uses jewelweed in ice cubes), and the jewelweed sap breaks up the resin. Or so we believe, anyway. We’re waiting for the double-blind study.

One thing everyone agrees on is that however poison ivy is controlled, it should not be burned — not even the dead leaves and vines — because the resin-filled smoke can irritate the skin and damage eyes and lungs.  http://louis5j5sheehan5esquire.blogspot.com

Mr. Mycka, who has an associate’s degree in horticulture from Temple University, tries to educate his clients about what poison ivy looks like and how it grows, including its dispersal by birds that survive the winter on its white berries. Beneath the spruce tree, he pointed out some hefty specimens: the top, or middle, leaf was more rounded and perched a bit higher than the others thanks to a leaf petiole or stem. The side leaves were a bit more toothed. But individual plants can vary widely in appearance.

“The plant ambushes people, because they don’t know what it looks like,” Mr. Mycka said. Sometimes the leaves are smooth; sometimes they are indented or toothed. In the spring, they are small and reddish; by deep summer, they are dark and shiny.

Mr. Mycka would love to see Americans discover some use for the plant. “In China and Japan, they made lacquer out of their resin plants, so they understand and value it,” he said. “Whereas we just see it as that darn weed over there.”

Louis J. Sheehan, Esquire  At least a quarter of the planet’s reef-building corals face a noticeable risk of extinction, according to the first large scale review of hundreds of species.

Out of 845 known species of warm-water corals, 231 meet the criteria for listing in worrisome categories on the international IUCN Red List of Threatened Species, says marine biologist Kent Carpenter of Old Dominion University in Norfolk, Va.  http://louis5j5sheehan5esquire.blogspot.com

The troubled species fall into the vulnerable, endangered or critically endangered categories on the Red List, which is maintained by the conservation group International Union for Conservation of Nature and Natural Resources.

If the coral species keep declining, coasts could lose the storm protection and other ecological benefits healthy reefs provide, Carpenter warns. Reef breakdown would have “huge economic effects on food security for hundreds of millions of people dependent on reef fish,” Carpenter and 38 co-authors conclude in a paper to be published in Science that appeared online July 10.

“The Carpenter paper has some scary conclusions,” says marine biologist Jenny Waddell of the National Oceanic and Atmospheric Administration’s reef programs in Silver Spring, Md. She points out that the new paper’s proportion of corals in trouble exceeds the threatened portion of most other big groups of land animals except amphibians.  http://louis5j5sheehan5esquire.blogspot.com

Carpenter says the new roll of threatened reef corals will be added to the IUCN’s list, increasing 20-fold the number of corals the group tracks.

Monitoring of marine species has lagged compared with terrestrial species, he says. Out of some 40,000 total species the IUCN had evaluated up to now, only 1,400 species live in the sea.

To catch up, the IUCN and environmental group Conservation International fund the Global Marine Species Assessment to review major groups of creatures. For a year and a half, Carpenter has led an international team of marine biologists working through the known species that build classic shallow-water reefs.

Skimpy information kept the researchers from evaluating 141 coral species. For the others, the biologists worked out trends in population growth or decline.

Reports on shrinking areas of reefs have long indicated trouble for corals, but “we brought a new dimension,” Carpenter says. At the final tally of 231 imperiled species, “everyone’s jaw absolutely dropped.”

Two main kinds of miseries beset the corals, Carpenter says.

Climate change is taking a toll as warming sea water raises the risks of disease and coral bleaching (when corals lose their symbiotic algae and thus face nutrient shortages).

Abundant local threats also hammer corals. Sediments erode into the sea from frenetic development booms along coasts, and boats drag anchors over reefs, smashing structures that took hundreds of years to build.

“If we can control local threats, it will buy us some time,” says Andrew Baker of the University of Miami. “But ultimately corals will face some pretty tough challenges due to high temperatures and acidity.”

That worldwide process of ocean acidification is already altering surface water chemistry as those waters absorb excess carbon dioxide from the atmosphere. Though seawater is not acid now and isn’t expected to become so, the shift could disrupt ecosystems. “The new species analysis’ methods didn’t address this threat,” comments Maoz Fine of Bar-Ilan University in Ramat-Gan, Israel, so it “may require a category updating very soon.”

In the audit’s regional view, Caribbean reefs have the largest proportion of corals in the most threatened categories, the paper shows. “I used to dive in the Caribbean — the reefs were gorgeous,” Carpenter says. “Now, to use a technical term repeated frequently around here, they’re toast.”

Caribbean reef vulnerability also showed up in a NOAA report co-edited by Waddell and released July 7 at the International Coral Reef Symposium in Fort Lauderdale, Fla. Every three years, the NOAA reef research program presents a status report on the reef communities off the continental coast and U.S.-related islands.

The 2008 report found 69 percent of Pacific reefs in good or excellent condition but only 25 percent of Caribbean and Atlantic ones ranking that high.

Disturbing as both reports are, Carpenter calls for action, saying “there is hope.”

Brainpower by itself seems to be a force in evolution, at least in developing diversity of body size in birds, two researchers report in the August American Naturalist.  http://louis4j4sheehan4esquire.blogspot.com

Bird families with relatively big brains, such as parrots and woodpeckers, tend to have diversified a bit faster than less-endowed species, report Daniel Sol of the Autonomous University of Barcelona and Trevor Price of the University of Chicago.  http://louis4j4sheehan4esquire.blogspot.com

Brainier lineages are more likely to show extra variety in body size, with hefty species having little handful-of-fluff relatives, according to the new analysis. In studying diversity, Sol and Price focused on the variety in body mass, for which there’s broad data. But other changes, perhaps in food or habitat, go along with this diversity in size.

Brain size nudging along the evolution of body size makes sense according to a scenario proposed in the 1980s, Price says. In theory, large-brained lineages could have lots of innovators willing to peck at new food or find a way to open a seed case or shell. Such technological breakthroughs could spread if the species learned quickly.  http://louis4j4sheehan4esquire.blogspot.com

Those brainy, innovative animals thus stand a better chance of exploiting a new food or successfully colonizing a new place. And both those accomplishments can expose a population to new forces of natural selection that reshape its future.

Looking for effects of brain size hasn’t been easy. Studies kick up debate over what aspects of the brain to measure and how to compare them. However, researchers such as Louis Lefebvre of McGill University in Montréal have made a case for linking outsized brains to a capacity for innovation.

To test for brain effects on evolution, Sol and Price used published data to establish an average body mass for each of some 7,000 bird species in 120 families. Other records provided brain mass for each of the species, and the researchers worked out which families tended to have the biggest brains relative to body size.

Then researchers reviewed the families, comparing typical brain size (relative to body size) with the variety of body sizes among the species within that family. The researchers also adjusted for the age of a lineage, since more ancient ones would have had more time to diversify. At the end of the analysis, brain size by itself has its own effect, albeit small, on whether a family showed a large variety of body sizes.

“Species with bigger brains tend to evolve more quickly in body size,” Price concludes. Parrots, woodpeckers, hornbills, owls, lyrebirds and crows ranked high both in brains and in diversity in body size. In contrast, pheasants, cormorants and quail didn’t have particularly big brains or much diversity within their families.

The basic premise about the bigger-brained birds invading new niches with new circumstances to shape their evolution sounds like “a pretty good idea,” says Georg Striedter of the University of California, Irvine, who studies brain evolution and birds.

Working with the size of the whole brain and with body weights may not be perfect tools for testing the idea, he says, “but you have got to start somewhere.”

http://louis2j1sheehan2esquire.blogspot.com  Tasmanian devils are mating earlier in response to a deadly, contagious cancer, a new study reports. The findings, appearing online July 14 in Proceedings of the National Academy of Sciences, are among the first to show mammals adjusting mating behavior in response to an infectious agent.

“There has been a sudden increase in the proportion of females that breed in their first year of life as subadults,” says lead author Menna Jones, a zoologist at the University of Tasmania in Hobart, Australia. “This shift has been fast, within one generation.”

Previously, fewer than 10 percent of the females reproduced in their first year of life. Now up to 60 percent breed in the first year, Jones notes.

“This is a dramatic finding, showing that breeding patterns change as a response to disease,” says Christopher Johnson, an ecologist at James Cook University’s Townsville campus in Australia.

Tasmanian devils are carnivorous, dog-sized marsupials that inhabit the island of Tasmania, off the southeastern coast of Australia. From a peak around 130,000 to 150,000 in the mid 1990s, the devil population has dropped to between 20,000 and 50,000, according to a report from Australia’s Department of Primary Industries, Water and the Environment.

The devil population has been ravaged by a contagious cancer called Tasmanian devil facial tumor disease, which first emerged around 1996. The disease, which spreads when the frisky devils bite each other, causes huge lesions to grow on a devil’s face and jawbone. All of the infected animals die, usually after the fast-growing tumors make eating impossible. Because the devils lack genetic diversity, they can pass on tumor cells to each other without their bodies recognizing those cells as foreign, Jones says.  http://louis2j1sheehan2esquire.blogspot.com

Because the disease kills most of the animals by the time they’re 2 years old, early breeding keeps the devil population numbers up. That may stave off extinction long enough for the animals to evolve ways to reduce disease’s impact, Jones says.  http://louis2j1sheehan2esquire.blogspot.com

With the devil population plummeting, there’s more food to go around, which seems to increase the female devils’ growth rates, Jones says. That could account for their early sexual maturation.

It’s not clear whether the epidemic has led to permanent genetic shifts in when the Tasmanian devils mature, Johnson says. It’s possible that devils who are hard-wired to mature early are able to reproduce, while relatively late bloomers die of the disease before they can have offspring. Over time, those who are genetically programmed to grow up fast may become the norm in the population.

Past studies have shown that deer and commercially harvested fish can breed earlier in response to heavy predation or hunting pressures, Jones says. But this is the first time such a shift in sexual maturity has occurred in response to an infectious disease, she says.