With the cause of a rampantly deadly bat illness still unknown, biologists have no solution to the problem but have proposed at least a quick fix that may be able to slow it down. At least half a million bats throughout the northeast United States have died from white-nose syndrome (WNS), a fungal infection that was first observed only two years ago. The fungus is thought to grow on bats’ facial skin and flight membranes, possibly causing them to starve. No one knows where the fungus came from, or if it is what is directly killing the bats. But in caves where it has been observed, bats have suffered morality rates ranging from 75 to 100 percent [Scientific American]. With the cause of the fungus not yet determined, researchers worry about the fate of bats, which play an important role in controlling the populations of insects that can damage wheat, apples and dozens of other crops [AP].
While it won’t solve the problem, a temporary stop-gap is now being considered that would place battery-operated heated boxes inside bats’ hibernation caves, and may give the animals the energy they need to fight off, or at least survive, the fungal infections [Scientific American]. The idea is based on the fact that the bats with WNS appear emaciated, as if they’ve starved to death during their winter hibernation; researchers theorize that afflicted bats rouse from hibernation more often than normal bats and thus burn more fat to stay warm [AP]. When they temporarily stir, the bats’ body temperature and metabolism spike.
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In another step toward erasing the environmental footprint left by his predecessor, President Obama issued a memo yesterday temporarily requiring federal agencies to once again consult wildlife experts on how their actions might affect endangered species. The memo will revive a decades-old practice under the Endangered Species Act that calls for agencies to consult with either the Fish and Wildlife Service or the National Oceanic and Atmospheric Administration on whether their projects could affect imperiled species. On Dec. 16, the Bush administration allowed agencies to waive such reviews if they decided, on their own, that the actions would not harm vulnerable plants and animals [Washington Post].
In an effort to “help restore the scientific process to its rightful place at the heart of the Endangered Species Act,” President Obama directed the Interior and Commerce Departments to review the Bush regulation, and until the review is complete, Mr. Obama’s memorandum says, agencies must return to the former practice of seeking and acting on scientific advice [The New York Times]. (more…)
Over the past 30 years, the salamanders that used to thrive in the tropical cloud forests of Mexico and Guatemala have been disappearing, and until now no one had even noticed that the stealthy amphibians may be spiraling downward towards extinction. Back in the 1970s, biologist David Wake studied salamanders in the San Marcos region of western Guatemala, and he recently returned to the region to survey the current salamander population and compare it to his previous data. What he found shocked him, Wake says. “Cold facts written on a piece of paper don’t convey the impact on my psyche when I went there,” he said. Species that could be seen 10 to 15 times an hour in the 1970s were “completely gone” [National Geographic News]. Studies in Mexico that compared current salamander populations to historical data produced similar results.
Since the 1980s biologists have raised alarms about worldwide declines in amphibians attributed to habitat destruction, disease and climate change, among other menaces [Science News]. Scientists studying dwindling frog populations have focused largely on chytrid, a fast-killing fungus, as the possible culprit, but Wake says that only a few of the salamanders he found on his recent trips showed signs of chytrid fungus. Instead, he blames global warming. Wake says that warming temperatures on the steep, forested slopes of Guatemala’s volcanoes are forcing the salamanders up to higher to less hospitable elevations.
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An extinct mountain goat that was once common in the Pyrenees briefly became the first animal to be brought back from extinction, as researchers used frozen DNA to produce a clone. But the newborn kid died within minutes of birth due to breathing difficulties, signaling that the Jurassic Park dream of resurrecting extinct species is still some way off.
The Pyrenean ibex, or bucardo, is a subspecies of the Spanish ibex that is believed to have died out completely in 2000. Before the death of the last known individual (a 13-year-old female known as Celia), biologists captured her and took cells from her skin and ears, which were frozen in liquid nitrogen. An earlier cloning attempt using the skin cells failed during gestation. But the latest attempt involved the creation of 439 ibex-goat hybrid cloned embryos made by inserting the cell nuclei of the ibex’s skin cells into the egg cells of domestic goats which had their own cell nuclei removed. Of these cloned embryos, 57 were transferred into surrogate mothers and seven resulted in pregnancies, but only one goat gave birth and the newborn clone died after seven minutes as a result of lung deformities [The Independent].
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Three pods of killer whales in the Pacific Northwest have now earned the unfortunate title of being the most contaminated wildlife on Earth, according to a new study. These killer whales, known as southern residents, live in the coastal waters near the U.S.-Canadian border and survive almost exclusively on contaminated Chinook salmon. The salmon contain high levels of polychlorinated biphenols (PCBs) and other industrial chemicals, which accumulate in even higher levels in the killer whales. Researcher Peter Ross says whales are particularly sensitive because they eat massive amounts of fish over a long life – killer whales can live for 80 or 90 years – creating a massive buildup of toxins. That means the whales, particularly the southern resident population, have become some of the most contaminated marine mammals in the world [AP].
Researchers estimate that the southern resident killer whales carry 6.6 times more PCBs than a different group of whales just 200 miles to the north, known as the northern residents. They found that the Chinook salmon in the southern waters, including Puget Sound near Washington state, not only had the highest concentrations of contaminants but also the least amount of body fat. This means the southern residents are suffering a “double whammy” because they are forced to eat extra helpings of heavily contaminated salmon. Ross and his colleagues discovered that 97 percent to 99 percent of contaminants in the Chinook eaten by these whales originated from the salmon’s time at sea, in the near-shore waters of the Pacific. Only a small amount came from the time the salmon spent in rivers, although many of the rivers are contaminated, too, Ross said. “Salmon are telling us something about what is happening in the Pacific Ocean,” Ross said. “They are going out to sea and by the time they come back, they have accumulated contaminants over their entire time in the Pacific Ocean” [Scientific American].
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The Tasmanian tiger may have been threatened by inbreeding before humans hunted the marsupial into extinction, a new genetic analysis suggests. The last captive tiger died at a Tasmanian zoo in 1936 after a decades-long effort by farmers and hunters to kill the creatures and collect a government bounty, but the new study suggests that the tigers’ lack of genetic diversity left them particularly vulnerable to the human onslaught and outbreaks of disease. “It’s looking like the thylacines were sort of on their last legs,” says Webb Miller [Science News], one of the coauthors.
Researchers sequenced the mitochondrial DNA of two Tasmanian tigers, more properly known as thylacines, from tissue samples preserved at museums in Sweden and the United States. And while the researchers’ main goal was to investigate the roots of the thylacine’s extinction, they acknowledge that having a complete genome at their disposal is sure to prompt talk of cloning. Says Miller: “Our goal is to learn how to prevent endangered species from going extinct…. I want to learn as much as I can about why large mammals become extinct because all my friends are large mammals,” Professor Miller added. “However, I am expecting that publication of this paper also will reinvigorate discussions about possibly bringing the extinct Tasmanian tiger back to life” [BBC News]. Some scientists think that the thylacine would be one of the easiest extinct animals to resurrect, as it died out recently and several well-preserved specimens exist in museums.
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Disoriented and emaciated brown pelicans are turning up in California’s suburban backyards and parking lots, far from their coastal habitats, and biologists are struggling to figure out what’s wrong with the ailing birds. The pelicans are exhibiting very strange behavior, they say. A social animal, it is rarely found alone. So it was startling to find one bewildered bird in a Kmart parking lot in Lompoc, another outside a Costco in Goleta and a third on the runway at Los Angeles International Airport. One pelican was found at an elevation of 7,200 feet in the New Mexico snow…. “Normally, they’re on piers and places where they can find fish,” said Rebecca Ryan of the Peninsula Humane Society in San Mateo, which has stabilized several sick birds. “Now they are appearing in really unusual places” [San Jose Mercury News].
Researchers first wondered in the culprit might be neurotoxin domoic acid, which is produced by microscopic algae in the coastal waters; the birds ingest the acid by eating fish that consumed the algae. But researchers say that the pelicans’ symptoms don’t match the usual pattern seen in a domoic acid outbreak. Domoic acid poisoning usually causes seizures, researchers say, and these birds have had none. The toxin also typically affects marine mammals as well as birds, and no such problems have been reported in sea lions or other mammals. Finally, most of the hundreds of ailing pelicans are thin, but birds poisoned by domoic acid are typically of good body weight [AP].
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On the slopes of the Wolf volcano at the northern tip of one of the Galapagos Islands prowls a pink iguana, which until recently had entirely escaped the notice of the island’s visitors–including the eagle-eyed Charles Darwin. But now researchers have spotted the rosy reptile and declared it a new species, which diverged from the Galapagos’s other land iguana species about 5.7 million years ago. Says lead researcher Gabriele Gentile: “What’s surprising is that a new species of megafauna, like a large lizard, may still be [found] in a well-studied archipelago” [National Geographic News].
The creature was first noticed by park rangers on the island of Isabela in 1986, but researchers only began to study the animal in the last few years. A genetic analysis revealed that the pink iguana was quite distinct from the two known land iguana species, but the date of their genetic divergence poses a puzzle. “At 5.7 million years ago, all of the western islands of the archipelago did not exist,” said Gabriele Gentile…. “That’s a conundrum, because it’s now only inhabiting one part of Isabela that formed less than half a million years ago” [BBC News]. In fact, even the oldest parts of the current archipelago may be less than five million years old, researchers say. One possible explanation is that volcanoes that are now underwater may have been above the waves millions of years ago, allowing some marine iguanas to clamber onto those shores and begin evolving.
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The growth of the world’s largest coral reef system has slumped to its slowest rate in at least four centuries, according to a new report in Science [subscription required]. Researchers studying coral colonies in the Great Barrier Reef found that calcification, the process that builds the reefs, has dropped 13.3 percent since 1990. They fear the decline is indicative of a worldwide threat to coral reefs caused by rising seawater temperatures and ocean acidification. The loss of coral growth threatens food webs and may lead to “precipitous” changes in biodiversity, the authors said [Bloomberg].
The Great Barrier Reef along the northeast coast of Australia stretches more than 1,200 miles and is visible even in space. Coral reefs, delicate undersea structures resembling rocky gardens made by tiny animals called coral polyps, are important nurseries and shelters for fish and other sea life. They also protect coastlines, provide a critical source of food for millions of people, attract tourists and are potential storehouses of medicines for cancer and other diseases [Reuters]. Massive coral reefs materialize from the gradual accumulation of calcium carbonate by billions of coral polyps over thousands of years.
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Researchers had high hopes for Cedric the Tasmanian devil: They believed he was the first member of the species to be immune to the deadly facial cancer that is rapidly devastating devil populations. Now, in a major setback, Cedric has grown two small tumors and researchers are back to square one. Many experts believe that the infectious cancer, called devil facial tumor disease, could drive the species to extinction within 20 years if it goes unchecked.
Cedric was captured in western Tasmania last year, along with his half-brother, Clinky. Both were injected with dead tumours by scientists. Clinky produced no antibodies, but Cedric did, and appeared to have built-in defences against the illness [BBC News]. However, the next step yielded worse results. Researchers injected two live strains of the disease into Cedric’s cheek in an attempt to prove his immunity, but two small tumors grew at the injection sites. The tumors were surgically removed last week, and while Cedric is expected to make a full recovery, his love life has been put on hold by the researchers. They were trying to get him to mate so he would pass on his genes. Now they’re unsure if Cedric is naturally immune to the disease [ABC News].
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Six penguin species will receive “threatened” status and one will receive “endangered” status under the Endangered Species Act, the U.S. federal government announced today. But to the disappointment of wildlife advocates, three other penguin species including the famous emperor penguin (featured in the movie “Happy Feet”) were denied protection under the act. “There are certainly issues with those species, but we did not believe at this time that the populations were reduced or that there were significant threats to lead us to make a determination that they are threatened with extinction,” said Kenneth Stansell, deputy director of the Fish and Wildlife Service [AP], the government agency responsible for the decision.
The “threatened” species include the yellow-eyed penguin, white-flippered penguin, Fiordland crested penguin, Humboldt penguin, erect-crested penguin, and some populations of southern rockhoppers; the “endangered” species is the African penguin. The birds’ habitats range from Antarctica to Peru to South Africa. None of the species are native to American soil, so their new status will have little direct bearing on U.S. policy. But listing the penguins under the act will raise awareness about the species and could give the U.S. leverage in international negotiations to protect them from fishing, habitat loss, development and other threats [AP]. These species will join the polar bear, which was recognized as “threatened” earlier this year, as some of the first species to be officially protected because of threats from global warming.
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Captive elephants die much younger than their wild counterparts, a new study reports. Researchers comparing pachyderms in European zoos and in the wild found that those in captivity had lifespans decades shorter and a greater number of stillbirths. Obesity, limited roaming space, and lack of companionship are thought to contribute to the early deaths. Says study leader Georgia Mason: “Currently zoos are consumers rather than producers of elephants…. We feel that’s not really appropriate” [The New York Times].
As reported in Science [subscription required], the researchers analyzed data on 4,500 African and Asian elephants, mostly female (zoos usually keep female elephants), kept in European zoos; they also looked at wild populations in Kenya and Myanmar. They found that African elephants in zoos had a median lifespan of 16.9 years compared to 56 years for elephants living in national park in Kenya. For Asian elephants, which are more endangered, the median lifespan for those in zoos was 18.9, compared to 41.7 years for those working on a timber enterprise in Myanmar but allowed to roam free. These numbers excluded premature and still-births, but researchers say still-births are also more common in zoo elephants.
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The oceans are getting noisier, and that’s bad news for whales, dolphins, and sea turtles who use sound to communicate and navigate, researchers declared at a United Nations wildlife conference. Rumbling ship engines, seismic surveys by oil and gas companies, and intrusive military sonars are triggering an “acoustic fog and cacophony of sounds” underwater, scaring marine animals and affecting their behavior. “There is now evidence linking loud underwater noises with some major strandings of marine mammals, especially deep diving beaked whales” [Reuters], says Mark Simmonds of the Whale and Dolphin Conservation Society.
Researchers have long worried that high-powered sonar pulses confuse whales and dolphins and may cause the animals to beach themselves. Marine mammals are turning up on the world’s beaches with tissue damage similar to that found in divers suffering from decompression sickness. The condition, known as the bends, causes gas bubbles to form in the bloodstream upon surfacing too quickly. Scientists say the use of military sonar or seismic testing may have scared the animals into diving and surfacing beyond their physical limits, Simmonds said [AP]. He points to two recent strandings as possible results of the noisy waters (although a link has not been proved): the 100 melon-headed whales that were found on a Madagascar beach, and the two dozen dolphins that got stranded in southern England.
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It’s a question that has fascinated scientists for decades: When sea turtles and salmon decides to give up the freedom of the open ocean and head back to their birthplaces to breed, how do they find their way back? Some species of sea turtle migrate thousands of miles across entire oceans back to their birthplaces after leaving more than 10 years earlier. And after hatching in rivers, salmon travel hundreds of miles out to sea before returning home to spawn years later [Press Association]. Now one researcher thinks he has the answer. Marine biologist Kenneth Lohmann believes that these marine animals can detect the distinctive magnetic fields of different spots and use them to navigate.
“What we’re proposing is the sea turtles and salmon, when they begin life, basically learn or imprint on the magnetic field that marks their home area,” he said. “They retain this information. And years later, when it is time for them to return, they are able to exploit this information in navigating back to their home area” [National Geographic News]. Lohman says this doesn’t contradict the existing theory that when salmon reach coastal waters, chemical scents guide them upriver to the particular stream where they were born; those olfactory cues probably have a limited range, he says, and couldn’t extend thousands of miles into the ocean to guide the salmon all the way home.
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Ocean acidification is happening at 10 to 20 times the rate predicted by existing climate models, according to an eight-year study. The rapid acidification of the oceans is linked to global warming and may be a sign that the oceans, the largest absorber of atmospheric carbon dioxide, may not be as hardy as presumed. The changes threaten disaster for marine life with shells that are easily corroded by acid. Marine biologist Nancy Knowlton said, “This is typical of so many climate studies—almost without exception things are turning out to be worse than we originally thought.” [National Geographic News].
The study was done around Takoosh Island off the coast of Washington state and represents the first detailed dataset on variations of coastal pH at a temperate latitude, where the world’s most productive fisheries are found [Times of India]. The researchers took over 24,000 measurements of ocean pH over an 8-year period. During that time, the pH of the seawater was predicted to decrease by only 0.015 points. Instead, the data showed that seawater pH dropped by 0.36 to about 8.1. “The increase in acidity we saw during our study was about the same magnitude as we expect over the course of the next century,” said study co-author Timothy Wootton [National Geographic News].
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