Number of Eggs in a Nest Depends on Climate

Some birds lay one egg while others lay up to 50 or more, and now researchers have figured out why, to the point where they can accurately predict egg counts for virtually all bird species.
Their forecasting might seem like an egg conjuring trick, but the secret comes down to predictors, such as the type of nest the bird builds and how close each avian species is to the poles.
Tropical birds, as it turns out, have a more laid-back approach, with generally fewer eggs within each clutch.
"You'd think it would be just the opposite, as the hypothesis for years was that the large amount of resources in the tropics would lead to more egg laying productivity, but we determined that wasn't the case," lead author Walter Jetz told Discovery News.
"Seasonality is far more important than the absolute amount of resources," added Jetz, an associate professor of biology at the University of California at San Diego.He explained that the closer birds are to the poles, the more extreme seasons they experience. Species in these locations often have higher mortality rates. It's therefore to their advantage to lay more eggs when they can, before it's too late.
Defined seasons also lead to peak periods of food and habitat availability, such as during spring. Suddenly birds find themselves with "huge amounts of resources, so they capitalize on them much more than at the tropics, where no such peaks exist," Jetz said.
For the study, he and his colleagues compiled information on clutch size, avian body mass, migratory behavior, nest type, bird diet, latitude, temperature and more. The scientists observed patterns in the numbers of eggs birds laid, allowing them to create a model that predicts variations in clutch sizes both on global and more localized levels.
The findings are published in the latest PLoS Biology.
In addition to seasonality, whether or not a bird lays its eggs in a protective cavity or just out in the open helps to predict its number of eggs.
"The hypothesis is that cavities are better protected, so woodpeckers, chickadees and other cavity nesters are less likely to be raided, so they tend to invest more in egg laying," Jetz said.

"Ground nesters, on the other hand, shouldn't put all of their eggs in one basket," he added, since predators are then more likely to find themselves with a free and easy egg dinner.

It would seem logical that all birds would hide their eggs in protective cavities, but he explained that, "not all the world is covered with trees." Birds in the desert, for example, often have no choice but to lay their eggs more in the open. Cavity nesting also is an ability that only a select group of birds evolved.

The scientists additionally determined that migrating birds tend to lay more eggs. Birds within certain families also tend to share similar clutch sizes. Big, flightless birds, for example, may often have large clutches containing anywhere from 10 to 74 eggs.

Robert Ricklefs, a professor of biology at University of Missouri at St. Louis, told Discovery News that, "Dr. Jetz's study is notable for its comprehensiveness and the excellent analytical applications."
Ricklefs added that he was "especially gratified to see that seasonality of temperature, migration, and nest type play the dominant roles, as these factors have been particularly prominent in the literature."
Given the importance of climate to birds, the global egg count, and consequently avian populations worldwide, may be in jeopardy due to climate change.
It has the potential of not only harming a "bird's way of life, but also its where of life," Jetz said, referring to how many species may be forced to shift their geographical ranges.
In the future, the new clutch size prediction model could help conservationists and other avian experts to better understand bird egg laying patterns in what Jetz and his colleagues call "a world of change."

Poaching May Erase Elephants From Chad Wildlife Park

The elephant population in one of central Africa's remaining wildlife strongholds may vanish within the next two to three years if poaching continues at recent levels, according to conservationists who recently surveyed the park.

Researchers conducted two sample surveys this year of African elephant populations in Chad's Zakouma National Park. Both counts indicate that there may be just a thousand members of the species left in this 1,200-square-mile (3,100-square-kilometer) refuge.
That represents a significant decrease from 2005, when the population was estimated at 3,885. In 2006 conservationists counted 3,020 elephants.

After the 2006 census, nearly 120 elephant carcasses leftover from ivory poaching were discovered in herds in and around park.
Because some elephants leave Zakouma during their winter migration, the 2008 numbers—from both the Chadian government, in conjunction with the European Union, and the Wildlife Conservation Society (WCS)—are rough estimates. WCS will conduct a full census next spring, when elephants have migrated back to the park and its replenished water sources.

But the organization's director for Africa programs, James Deutsch, said he expects the worst.

"A thousand is our best educated guess," Deutsch said. "It would be pretty surprising if the number was above 1,500."

Increased Poaching

WCS biologist and National Geographic Explorer-in-Residence J. Michael Fay points the finger at poaching, which he says has intensified in and around Zakouma since 2005 due, in part, to the increased acceptability of and access to the global ivory trade.

The 2008 population estimates are based, in part, on reports of poaching and the discovery of at least 300 elephant carcasses.

"What we do know [now], is that we have an enormous poaching problem that didn't exist two years ago," Fay said.
Fay helped conduct the 2006 census with partial funding from the National Geographic Society's Expeditions Council.

"Even if you are looking at the most optimistic estimates [closer to 2,000 left], that means your elephants will last three years [if poaching continues at current rates], which is catastrophic," Fay added.
"There is a massacre going on, unless something drastic happens."

To the chagrin of many conservationists, the first officially sanctioned ivory trade in a decade happened in October. The UN Convention on International Trade in Endangered Species (CITES) allowed Botswana, Namibia, South Africa, and Zimbabwe to sell 108 tons of government ivory stock to Chinese and Japanese buyers.
"Just in the past two years, the world thinks it is okay to buy ivory again," Fay said. "Anyone who thinks you can control ivory on the market is dreaming."

CITES officials argue that there is no proven connection between controlled sales and increased poaching.

"In fact, levels of illegal ivory trade decreased in the two years following the first one-off sale [in 1999]," CITES spokesperson Juan-Carlos Vasquez said in an email.

"Poaching levels appear to be more closely related to governance problems and political instability in certain regions of the continent … ."

Protective Measures

After the 2006 survey and graphic images of the slaughtered elephants captured global attention, Chad's president burned ivory stocks and donated armed trucks to the park for poaching patrols.

But political turmoil last year and a change in park management complicated the situation, making it more difficult to monitor wildlife, Fay said.

2007 was the worst year on record for poaching, according to WCS pilot Darren Potgieter, who conducts aerial anti-poaching patrols and censuses.

"It was all-out war," he said. "We lost five guards and one army lieutenant, compared with six guards and two regular employees in the preceding 16 years, and hundreds of elephants."

The good news, according to Fay and Potgieter, is that since May 2008, WCS and the Chadian government have been able to make daily flyovers of the park with a newly designated anti-poaching patrol plane. Guard forces are also increasing, with help from the Chadian Army.

The poaching situation has improved this year, according to conservationists. "Already … this aircraft has helped the park guard force to locate poached elephants and poachers," Fay said. "We are optimistic that with increased armed protection we can keep a lid on the poaching this year."

Dogs Can Feel Envy, Study Suggests

The first scientific study to find envy in non-primates affirms what many already know: dogs can get jealous.

"Everybody who has a dog at home probably [suspects] that dogs can be very jealous of other dogs and also of people," said lead author Friederike Range of the University of Vienna, Austria
In experiments with 43 dogs, Range's team showed that the canines reacted to inequity.

The team had one dog watch another dog receive a reward for doing a trick. When the watching dog performed the same trick and was not rewarded, that dog refused to do the trick again, Range said.

The experiments were modeled after recent studies that observed resentment in capuchin monkeys and chimpanzees when the animals weren't compensated equally after performing the same tasks as a partner.

Dogs are not as sensitive to inequality as the primates, Range and her team found. The canines participating in the study didn't seem to mind if a nearby dog got a better reward or didn't work as hard for the reward—but the primates did.

The study was published online today in the journal Proceedings of the National Academy of Sciences.
Equal Rights

Range and her team tested the dogs in the presence of partner dogs they were already acquainted with—a playmate, or a pet from the same household.

The dogs were asked to place their paws in the experimenter's hand. The animals were rewarded—or not—with dark bread and sausage.

"If both of them didn't get a reward, they continued working more or less," Range said. "But if one of them didn't get food, the one that didn't get food just said, No."
The indignant dogs' refusal to participate further was accompanied by scratching, yawning, mouth licking, and avoiding the gaze of the partner dog as well as the experimenter.

The dogs didn't seem to worry if their partner got sausage—a premium treat—and they only got bread, or if the other dog didn't perform the trick but was rewarded anyway.
"It gets more complicated if it's about both effort and the reward, and maybe dogs can't do that yet," Range suggested.

Dogs' more basic form of envy—and the insistence on some degree of equality—is probably critical to survival in cooperative activities. Wolves and wild dogs are known to hunt and raise their pups in groups, where individuals who don't insist on compensation would likely be taken advantage of.
Double or Nothing

Primatologist Frans de Waal at Emory University in Atlanta, Georgia, said he would expect this kind of envy—really an aversion to unequal reward—in all animals that regularly cooperate.

"The dogs showed a stronger reaction when they received nothing for the task in the presence of a rewarded companion than with no companion at all," he noted.

"They were OK with no reward if no one else got one, which shows that it is a social reaction."

Scott Creel, a behavior ecologist at Montana State University, said the research suggests many social species may have mental processes scientists once believed were unique to humans, or at least primates.

"It seems logical that many of the same selection pressures that have shaped our cognition and emotions also operate in other social species," said Creel, who has studied the behavior of African wild dogs but was not involved in this study.

Venter Lab Makes Progress on Artificial Life

Scientists have discovered a more efficient way of building a synthetic genome that could one day enable them to create artificial life, according to a study.
The method is already being used to help develop next-generation biofuels and biochemicals in the labs of controversial celebrity scientist Craig Venter.
Venter has hailed artificial life forms as a potential remedy to illness and global warming, but the prospect is highly controversial and arouses heated debate over its potential ramifications and the ethics of engineering artificial life.
Artificially engineered life is one of the Holy Grails of science, but also stirs deep fears as foreseen in Aldous Huxley's 1932 novel "Brave New World" in which natural human reproduction is eschewed in favor of babies grown in laboratories.
The J. Craig Venter Institute succeeded in synthetically reproducing the DNA of a simple bacteria last year.
The researchers had initially used the bacteria E. coli to build the genome, but found it was a tedious, multi-stage process and that E. coli had difficulty reproducing large DNA segments.
They eventually tried using a type of yeast called Saccharomyces cerevisiae. This enabled them to finish creating the synthetic genome using a method called homologous recombination, a process that cells naturally use to repair damage to their chromosomes.
They then began to explore the capacity for DNA assembly in yeast, which turned out to be a "genetic factory," the Institute said in a statement Wednesday.
The researchers inserted relatively short segments of DNA fragments into yeast cells through homologous recombination method.
They found they were able to build the entire genome in one step, according to the study set to be published in the Proceedings of the National Academy of Sciences.
"We continue to be amazed by the capacity of yeast to simultaneously take up so many DNA pieces and assemble them into genome-size molecules," said lead author Daniel Gibson.
"This capacity begs to be further explored and extended and will help accelerate progress in applications of synthetic genomics."
Senior author Clyde Hutchison added, "I am astounded by our team's progress in assembling large DNA molecules. It remains to be seen how far we can push this yeast assembly platform but the team is hard at work exploring these methods as we work to boot up the synthetic chromosome."
Venter and his team continue to work towards creating a living bacterial cell using the synthetic genome sequence of the Mycoplasma genitalium bacteria.
The bacteria, which causes certain sexually transmitted diseases, has one of the least complex DNA structures of any life form, composed of just 580 genes.
In contrast, the human genome has some 30,000.
Using the genetic sequence of this bacteria, the Maryland-based team has created a chromosome known as Mycoplasma laboratorium.
They are working on developing a way to transplant this chromosome into a living cell and stimulate it to take control and effectively become a new life form.

Malaria Vaccine Shows Promise

A vaccine that may become the world's first to prevent malaria shows promise in protecting African children, researchers said Monday, calling the results a "major milestone."
In early tests, the experimental vaccine was more than 50 percent effective in preventing the deadly disease in infants and toddlers in two countries in Africa, the scientists said. A larger and longer test is expected to begin early next year, the latest effort at slowing a disease that kills nearly 1 million people annually.
It is the first malaria vaccine to make it this far, and if further studies are successful, marketing approval could be sought as early as 2011. The vaccine was developed by the British-based GlaxoSmithKline PLC.
The results "add to our confidence that we are closer than ever before" to a malaria vaccine for African children, Dr. Christian Loucq, director of the PATH Malaria Vaccine Initiative, said during a teleconference from New Orleans.
The nonprofit group was started with a grant from the Bill and Melinda Gates Foundation to help develop malaria vaccines and make sure they're available where needed. The group teamed up with GlaxoSmithKline, and both paid for the vaccine studies.
The findings were presented Monday at a New Orleans meeting of the American Society for Tropical Medicine and Hygiene and will be in Thursday's New England Journal of Medicine. Some of the researchers work for the nonprofit group or the drugmaker.
Malaria is a tropical disease whose victims are mostly young children in sub-Saharan Africa. It is caused by a parasite and spread through a bite from an infected mosquito. The parasite travels quickly to the liver where it matures, enters the bloodstream and causes fever, chills, flu-like symptoms and anemia. The GlaxoSmithKline vaccine is designed to attack the parasite before it can infect the liver.
"Given the magnitude of malaria in Africa, the results represent a major milestone," said Dr. Ally Olotu, one of the researchers from Kilifi, Kenya.
The World Health Organization estimates that some 247 million people worldwide get malaria each year, but the most dangerous type is mainly in Africa. Government and private programs to control it have shown some progress in recent years with the distribution of bed nets, mosquito spraying and better malaria drugs. The United Nations announced a program in September to step up efforts against the disease with the goal of eliminating it by 2015.
The two studies reporting findings Monday were done in rural areas of East Africa.
One study involved 894 children ages 5 months to 17 months in Kenya and Tanzania. During the eight months the children were followed, there were half as many cases of malaria in those who got three vaccine shots compared to those who didn't get them -- an effectiveness rate of 53 percent.Because malaria is so deadly, a vaccine that provides significant protection would be a public health victory.
"The vaccine -- even a partially effective vaccine -- has the potential to save hundreds of thousands of lives each year," Loucq told reporters.
The study was the first test of a version of the vaccine that used a new additive to boost the immune response. The older version was 35 percent effective in earlier tests.
The second study tested whether the malaria vaccine could be given to young infants along with routine childhood vaccines provided through a WHO program. In the study of 340 infants in Tanzania, the researchers found that the malaria vaccine could be safely added and didn't interfere with the effectiveness of the other vaccines.
During six months of follow-up, the vaccine was 65 percent effective against new malaria infections in the infants.
Dr. Salim Abdulla, lead author of the infant study, said the WHO vaccine program reaches even the remotest areas of Africa and would be an ideal way to get a malaria vaccine to the most vulnerable children.
William Collins, a malaria expert at the Centers for Disease Control and Prevention, said that for the vaccine to work, it must recognize and stop the malaria-carrying parasite from invading the liver within just a few seconds to a few minutes.
"To be that effective, and yet have only a short period of time to attack the parasite, it's remarkable that it's that effective at all," said Collins, who wrote an editorial that accompanied the studies, along with John Barnwell, also of the CDC.
They noted that the level of malaria infections was low in the study areas, and that the true test will come in areas with more malaria.
"It is, indeed, a hopeful beginning," they wrote.

"Stem Cell Tourists" Go Abroad for Unproven Treatments

When Robert Ramirez was diagnosed with Parkinson's disease in 2006, his doctor gave him medication, but little hope: "He told me there wasn't much I could do except wait to 'pass to the other side.'"

Ramirez, a Peruvian-American mechanic in northern New Jersey, watched helplessly as his symptoms worsened. His left arm grew weak. His leg muscles went rigid. His trembling intensified.
Then his wife, Elvira, saw Jorge Tuma on a Peruvian news show. The Peruvian doctor, based in Lima, claimed to be treating Parkinson's and other diseases with injections of stem cells. They checked out his Web site: For $6,000, relief could be theirs. They booked a flight to Lima.

Ramirez is one of an increasing number of patients seeking stem cell therapies overseas—experts put the number in the thousands. And Tuma is one of dozens of non-U.S. doctors offering such treatments.

The trend is significant enough that the International Society for Stem Cell Research (ISSCR) released guidelines today for doctors using stem cells and would-be "stem cell tourists."

U.S. experts fear that some foreign doctors are rashly treating patients without waiting for clinical trials to validate the safety of their procedures.

"There are many doctors tapping into the public's sense of stem cells' potential to cure in countries with looser medical regulations," said Sean Morrison, director of the University of Michigan Center for Stem Cell Biology, and treasurer of ISSCR. "But the details of stem cell treatment are much more complicated."

Yet stem cell therapies are becoming a lucrative area of medical tourism, even though science has yet to divine their potential and controversy plagues the field.

The cells, found in embryos and certain adult body tissues, have the potential to grow into many different types of cells. But ethical issues surrounding the use of embryos as stem cell sources has slowed research in countries such as the U.S. and U.K.

Researchers in the U.S. are conducting clinical trials using both adult and embryonic stem cells to treat diseases, but the U.S. Food and Drug Administration has yet to license any such treatment.
The new ISSCR guidelines require that every treatment must be evaluated by experts with no vested interest in the procedure. The guidelines also advocate for an informed consent process, which would provide patients with full information about their procedure, and transparency in reporting of clinical trial results.

The ISSCR's handbook for patients advises against experimental stem cell treatments—those that are not part of official clinical trials. It also lists warning signs for dubious treatments, such as the claim that multiple diseases can be treated with the same type of cell.
That's just one of many optimistic assertions being made by foreign doctors, often on Web sites.

Timothy Caulfield at the University of Alberta's Health Law Institute surveyed 19 sites proffering stem cell treatments, and released his findings today. Ten sites portrayed the treatments as "very ready for public access," rather than experimental.

Most people learn about stem cell treatment offerings from "direct-to-consumer advertising" on the Internet, he said.

"There is a mismatch between what is being offered and what the existing scientific literature says," Caulfield said. "The people offering the treatments are able to trade on two things: the genuine excitement about stem cell research and the social controversy around it."

Clinics charge on average U.S. $21,500 for stem cell treatment, the survey noted, but recent news reports indicate that clinics in China may be charging as much as $70,000.

Researchers have found that unproven stem cell treatments can also cause complications for patients. In 2006, neurologist Bruce Dobkin, of the University of California, Los Angeles, found that some patients contracted meningitis after operations for chronic spinal cord injuries.

Nervous system complications and infections have also been reported after the use of stem cells to treat blood diseases.

Caulfield said that not all doctors offering stem cell therapy are quacks, but he also believes that anyone selling treatment should be publishing data to back up their claims.

"There are still real scientific barriers to this research—even the top stem cell researchers at Stanford University and in the United Kingdom are struggling with clinical trials," Caulfield said.

In the Trenches

Tuma, the cardiologist sought out by Ramirez, the Parkinson's patient, promises to restore ailing organs and tissues using adult stem cells harvested from the patients' own bodies.

Since 2005, Tuma has treated some 600 patients—about a quarter from outside Peru—for a range of conditions from Parkinson's to Type 2 diabetes to emphysema.

His method: injecting the affected organ with stem cells from the patient's own bone marrow.

"I always tell my patients this is not a cure, but I believe it is a tremendous new alternative to improve quality of life," Tuma said.

He operated on Ramirez in October 2007 in a simple procedure lasting 45 minutes. Tuma extracted and prepared bone marrow cells from Ramirez's spine and injected them into an artery in the brain. There, Tuma said, they began to generate new cells that would inhibit the advance of Parkinson's.

Within a week, Ramirez said he began to notice his legs loosen. Then some strength returned to his left arm. He feels better than before the operation and his symptoms are less discernible.

"I can dance with my wife and live almost a normal life," Ramirez said. "I'm very grateful to Dr. Tuma."

Like many doctors offering stem cell treatments, Tuma's approach has not been sanctioned by his country's government.

Though he's published small-scale results of his heart therapies in journals including the Journal of Cardiac Failure and Cardiovascular Revascularization Medicine, he's yet to release papers on the efficacy of his other treatments.

According to Insoo Hyun, a professor of bioethics at Case Western Reserve University and the chairman of the ISSCR Stem Cell Guidelines Task Force, charging patients for unproven treatments is considered unethical.

"Either you're doing research or you're offering a proven therapy, but some of these stem cell doctors seem to want it both ways," Hyun said.

No Time to Wait

Timothy Henry, a cardiologist at the Minneapolis Heart Institute/Abbott Northwestern Hospital, is authorized by the FDA to conduct randomized clinical trials using adult stem cells for heart conditions. He has treated 150 people and said the early data are promising.

But the United States has lagged behind the rest of the world in stem cell research because of the ethical concerns raised over embryonic stem cell research, he admits.

"Adult stem cell research has been very challenging with all the misinformation and confusion about embryonic stem cells," Henry said.

Desperate patients like Ramirez are reluctant to wait on hard evidence and FDA approval, however.

Roberto Brenes is another doctor performing adult stem cell implants. He attracts patients to a clinic in San Jose, Costa Rica, through the Web site cellmedicine.com.

He and his colleagues have treated between 50 and 70 multiple sclerosis patients with stem cells taken from fat tissue, charging between $15,000 and $25,000, with what he said are "pretty good success rates."

While Brenes acknowledges that there has never been a clinical trial demonstrating the efficacy of stem cell therapy for MS, he said many patients do not want to wait.

"This area is going to progress a lot in the next ten to 15 years, but a lot of patients need therapeutic help now and want to go through with the procedure," Brenes said.

Even if it means expensive follow-up visits: Tuma has told Ramirez to see him every six months so that he can check on his progress. And Tuma said that if the Parkinson's symptoms return, another procedure might be needed.

"I know the therapy is not a complete cure, but I don't think it's dangerous and would do it again," Ramirez said.

The ISSCR's Morrison, however, remains skeptical.

"A lot of patients will spend $6,000 to buy hope, but that still doesn't make it right to sell snake oil."

Walruses Threatened by Shrinking Ice

A conservation group is going to court to force the federal government to consider adding the Pacific walrus to the list of threatened species.
The Center for Biological Diversity sued the U.S. Fish and Wildlife Service and Interior Secretary Dirk Kempthorne on Wednesday for failing to act on a petition seeking protection for walruses under the Endangered Species Act.
Walruses are threatened by global warming that melts Arctic sea ice, according to the group, one of the parties that successfully petitioned to list polar bears as threatened. The group also has filed petitions to protect Arctic seals.
The walrus petition was filed in February. The Fish and Wildlife Service was required by law to decide by May 8 whether the petition had merit, which would trigger a more thorough review and a preliminary decision after 12 months. The agency missed the deadline.Rebecca Noblin, an attorney for the Center for Biological Diversity, said the delay would harm walruses.
"Every day that goes by without protecting the walrus, we're emitting more greenhouse gases, accelerating the ice melt," Noblin said.
"In addition to the climate change, the other main threat is oil and gas development that continues to go forward without any consultation regarding walrus," she said.
Fish and Wildlife spokesman Bruce Woods said Wednesday the agency anticipates making a decision on the petition soon but has limited resources. Decisions on endangered species listings are driven by litigation, he said, forcing the agency to rank actions by court order rather than species need.
Global warming is blamed for Arctic sea ice shrinking to record low levels.
The National Snow and Ice Data Center said summer sea ice in 2008 reached the second lowest level, 1.74 million square miles, since satellite monitoring began in 1979. The loss was exceeded only by the 1.65 million square miles in 2007.
Like polar bears, listed as a threatened species in May, walruses depend on sea ice to breed and forage.
Walruses dive from ice over the shallow outer continental shelf in search of clams and other benthic creatures. Females and their young traditionally use ice as a moving diving platform, riding it north as it recedes in spring and summer, first in the northern Bering Sea, then into the Chukchi Sea off Alaska's northwest coast.
Sea ice in the Chukchi Sea, shared with the Russian Far East, for the last two years receded well beyond the outer continental shelf over water too deep for walruses to dive to reach clams. In the fall of 2007, herds congregated on Alaska and Siberia shores until ice re-formed.
According to the Center for Biological Diversity, warming sea temperatures and sea ice loss may also be reducing walrus prey at the bottom of the ocean.
The group hopes a listing could slow plans for offshore petroleum development. Oil companies in February bid on 2.7 million acres in the Chukchi Sea. Other lease sales are planned.
The Fish and Wildlife Service, along with its Russian counterparts, has nearly completed a comprehensive population count of walruses. The numbers are anticipated in the coming weeks, possibly by the end of the year, Woods said.

Alien-like Squid With "Elbows" Filmed at Drilling Site

A mile and a half (two and a half kilometers) underwater, a remote control submersible's camera has captured an eerie surprise: an alien-like, long-armed, and—strangest of all—"elbowed" Magnapinna squid.In a brief video from the dive recently obtained by National Geographic News, one of the rarely seen squid loiters above the seafloor in the Gulf of Mexico on November 11, 2007.

The clip—from a Shell oil company ROV (remotely operated vehicle)—arrived after a long, circuitous trip through oil-industry in-boxes and other email accounts.

"Perdido ROV Visitor, What Is It?" the email's subject line read—Perdido being the name of a Shell-owned drilling site. Located about 200 miles (320 kilometers) off Houston, Texas (Gulf of Mexico map), Perdido is one of the world's deepest oil and gas developments.

The video clip shows the screen of the ROV's guidance monitor framed with pulsing inputs of time and positioning data.

In a few seconds of jerky camerawork, the squid appears with its huge fins waving like elephant ears and its remarkable arms and tentacles trailing from elbow-like appendages.

Despite the squid's apparent unflappability on camera, Magnapinna, or "big fin," squid remain largely a mystery to science.

ROVs have filmed Magnapinna squid a dozen or so times in the Gulf and the Pacific, Atlantic, and Indian Oceans.

The recent video marks the first sighting of a Magnapinna at an oil development, though experts don't think the squid's presence there has any special scientific significance.

But the video is evidence of how, as oil- and gas-industry ROVs dive deeper and stay down longer, they are yielding valuable footage of deep-sea animals.

Some marine biologists have even formed formal partnerships with oil companies, allowing scientists to share camera time on the corporate ROVs—though critics worry about possible conflicts of interest.

Real Deal

The Perdido squid may look like a science fiction movie monster, but it's no special effect, according to squid biologist Michael Vecchione of the U.S. National Oceanic and Atmospheric Administration (NOAA), who is based at the National Museum of Natural History in Washington, D.C.
In 1998 Vecchoine and University of Hawaii biologist Richard Young became the first to document a Magnapinna, based on juveniles of the Magnapinna pacifica species. M. pacifica was so unusual that the scientists had to create a new classification category to accommodate it: the family Magnapinnidae, which currently boasts four species.

In 2001 the pair released the first scientific report based on adult Magnapinna specimens, as seen via video. The study demonstrated that Magnapinna are common worldwide in the permanently dark zone of the ocean below about 4,000 feet (1,219 meters).
In 2006 a single damaged specimen from the North Atlantic led to the naming of a second Magnapinna species, M. talismani. And in 2007 the scientists documented two more: M. atlantica and a species based on a specimen from the mid-Atlantic.

That fourth Magnapinna species remains nameless, because its arms were too badly damaged for a full study. "However, it was clearly different from the three known species," Vecchione said.

The Magnapinna species apparently have only slight physical differences, mainly related to tentacle and arm structure in juveniles.

The subtlety of those variations makes it impossible to identify which species is in the oil-rig video, given that at least two Magnapinna species—M. atlantica and M. pacifica—are known to inhabit the Gulf of Mexico, Vecchione said.

Enduring Mystery

Based on analysis of videos not unlike the one captured at the Perdido site, scientists know that the adult Magnapinna observed to date range from 5 to 23 feet (1.5 to 7 meters) long, Vecchione said. By contrast, the largest known giant squid measured about 16 meters (52 feet) long.

And whereas giant squid and other cephalopods have eight short arms and two long tentacles, Magnapinna has ten indistinguishable appendages that all appear to be the same length.

"The most peculiar structure is that of the arms," said deep-sea biologist Bruce Robison of the Monterey Bay Aquarium Research Institute in California.

Referring to the way the tentacles hang down from elbow-like kinks, Robison said: "Judging from that structure, we think the animal feeds by dragging its arms and the ends of its tentacles along the seafloor as it drifts slowly above it."

The elbow-like angles allow the tentacles to spread out, perhaps preventing them from getting tangled.

"Imagine spreading the fingers of a hand and dragging the fingertips along the top of a table to grab bits of food," he added.

But NOAA's Vecchione suggests a feeding behavior that is more like trapping than hunting. He speculates that Magnapinna passively waits for prey to bump into the sticky appendages.

Strange Bedfellows?

As oil companies and their ROVs spend more time in the bathypelagic zone, more discoveries are sure to follow, experts say.

Eager for hard-to-come-by deep-sea video and data, some biologists are formally aligning themselves with the companies.

The U.K.-based SERPENT (Scientific and Environmental ROV Partnership using Existing iNdustrial Technology) project, for example, matches oil companies with researchers "to make cutting-edge ROV technology and data more accessible to the world's science community," according to the project's Web site.

Despite such partnerships, Monterey Bay's Robison said, most sightings of the Magnapinna squid have come from research vessels, not oil companies. The November 2007 video, for the record, was captured without scientific involvement.

Some scientists, including Robison, are not entirely comfortable relying on corporations for new data.

Andrew Shepard, director of NOAA's Undersea Research Center, is excited about the potential for new ocean resources, but he does have concerns.

"Oil companies are there to develop hydrocarbons, not find new species," Shepard said.

"These discoveries may, in fact, have a negative impact on very expensive and valuable lease tracts if someone decides a rare species needs to be protected."

But given how expensive and time consuming ROV-based deep-sea research is, scientific cooperation with industry is crucial, SERPENT project oceanographer Mark Benfield said.

"There are relatively few research vessels and far fewer ROVs and manned submersibles capable of working down through [extremely deep regions of the ocean]," said Benfield, who teaches at Louisiana State University.

Research funds are getting scarcer, he added, and "with SERPENT we gain access to sophisticated ROVs for free.

"These systems are based on vessels or rigs that spend months to years at a single location. This allows us to build up a much more complete picture of life in the deep-sea than would be possible with [only] academic ships and deep-submergence vehicles."

NOAA's Vecchione said he has "gotten a lot of interesting observations from the SERPENT project and other petro sources."

But the oil-industry collaborations "should not get in the way of purely scientific exploration," Vecchione said. "We need to be careful about deep-sea conservation."

New Field Could Explain How Salmon, Turtles, Find Home

Sea turtles and salmon may use their sensitivity to Earth's magnetic field to guide them home at the end of their epic coming-of-age journeys, suggest scientists aiming to solve one of nature's enduring mysteries.

The newly proposed theory is one of several ideas being explored under the banner of an emerging scientific field dubbed movement ecology.

According to the field's proponents, the study of movement is central to understanding where animals and plants live, how they evolve and diverge, and why they become extinct.

By making movement central to ecological studies, scientists hope general theories about movement will emerge.

Such theories could, for example, help scientists predict how organisms will respond to global climate change and prevent the spread of pests and diseases.

Kenneth Lohmann, a marine scientist at the University of North Carolina, Chapel Hill, applied the concept of movement ecology to sea turtles and salmon.

His aim was to develop a hypothesis for how such animals navigate to their natal areas from distant oceanic locations.

Juvenile sea turtles and salmon leave their birthplaces with an inescapable wanderlust, swimming hundreds or even thousands of miles away.

But after years on the high seas, the biological urge to reproduce calls the creatures home, and they return to the very spots in which they were born.

How they do this has eluded scientists for decades. Lohmann says the secret to the marine animals' navigational success may lie in the variability of Earth's magnetic field.

Each coastal area has a unique magnetic signature, he said.

Previous studies, including work in Lohmann's lab on sea turtles, indicated both the turtles and salmon are sensitive to the magnetic field.

"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," Lohmann 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."
Once the animals reach their native coastal areas, other senses, such as vision or smell, may guide them the rest of the way. Salmon, for example, are known to use smell to locate spawning grounds once the fish are nearby.

Lohmann and colleagues propose the theory in a paper published this week in a special package about movement ecology in the journal Proceedings of the National Academy of Sciences.

"We are excited about [the theory], because it really is the first plausible explanation for how sea turtles and salmon might be able to return," he said.

An Ancient Idea

Some 2,300 years ago, the Greek philosopher Aristotle searched for common features that unified animal movements of all types, noted Ran Nathan, an ecologist at the Hebrew University, Jerusalem.

This kicked off a long tradition of movement-ecology research.

But over the years, Nathan said, researchers have focused on different types of movement in specific species or landscapes, without looking at how different patterns impacted each other.

These scientists "never meet each other, they never talk to each other, they never go to the same conference, they publish in different journals," Nathan said.

In an effort to bring the scientific community together, Nathan led a yearlong project to establish a unifying framework for studying movement ecology.

Twelve teams of scientists were asked to address four basic questions: Why, how, where, and when do organisms move?

The methodology, Nathan said, applies to all types of organisms, from animals such as salmon, sea turtles, and elephants to bacteria and plants.

"If you give a legitimate field for the study of movement itself ... then people will study movement-related questions more thoroughly," Nathan said.

Martin Wikelski is a zoologist at the Max Planck Institute of Ornithology in Seewiesen, Germany, who specializes in animal movement.

The initiative to raise the prominence of movement ecology is "absolutely essential" to the understanding of wild animals, especially in an era complicated by a changing climate, Wikelski said.

"Every animal moves around and if we don't know the fate of these animals during movement, and how movement contributes to selection, then I think we are pretty much lost," he said.

For example, by understanding what animals encounter as they move about their environment, scientists may be able to determine the factors that cause some to go extinct.

Birds and Bees

James Mandel, an ecologist at Cornell University in Ithaca, New York, said the new paradigm is ideal for his research, which seeks connections between weather patterns and animal movement.

His team outfitted turkey vultures with GPS tags and two-way radio transmitters to collect data on the birds' hourly and daily movements.

One turkey vulture even carried a heart rate monitor to measure how much energy the bird expended during flight.

The researchers combined this data with information on the wind speed, atmospheric turbulence, and cloud height wherever the birds were.

The team found that turkey vultures soar from one billowing updraft of warm air to the next as they migrate thousands of miles between their summer and winter homes.

While many questions remain, Mandel said the data indicate the birds "are highly dependent on favorable weather conditions from energy source to energy source as they go."

Other teams applied the movement ecology framework to the study of elephants in Africa, elk in Canada, lynx in Spain, and butterflies from Estonia, Finland, and China.

Still other groups tested the methodology on seeds in Panama and various plants in the eastern U.S.

The Max Planck Institute's Wikelski, who is also a 2008 National Geographic emerging explorer (the National Geographic Society owns National Geographic News), is pioneering new tracking technology that allows scientists to study the movement of even the smallest creatures, such as bees.

The combination of Nathan's movement-ecology initiative and new technologies, he said, will open "a new era in biology."

"Zombie" Roaches Lose Free Will Due to Wasp Venom

The parasitic jewel wasp uses a venom injected directly into a cockroach's brain to inhibit its victim's free will, scientists have discovered.

The venom blocks a chemical substance called octopamine in the cockroach's brain that controls its motivation to walk, the study found.

Unable to fight back, the "zombie" cockroach can be pulled into the wasp's underground lair, where an egg is laid in its abdomen. The larva later hatches and eats the still living but incapacitated cockroach from the inside out.

"The whole thing takes about seven to eight days, during which the meat has to be fresh," said study co-author and neurobiologist Frederic Libersat of Ben-Gurion University of the Negev in Be'ér Sheva, Israel.

"If you kill a cockroach, it rots within a day."

The mature wasp emerges from the bug victim's body after about a month.

The study recently appeared in the Journal of Experimental Biology.

Zombie Science

The team of researchers at Ben-Gurion University believe that the octopamine discovery is an important piece of the puzzle of how the tropical wasp's venom turns its victims into the living dead.

Octopamine is a brain substance that places insects in an alert state, inspires them to move, and allows them to perform demanding physical tasks.

"It serves the same functions as noradrenaline, which is involved in the fight-or-flight reaction ... in the vertebrate brain," Libersat said.

The team determined that the wasp injects its venom into a specific area of the cockroach's brain, the protocerebrum.

This region, which contains octopamine-secreting nerve cells, controls the ability to start walking. The venom interferes with the release of octopamine, they found.

The researchers then reversed the process: they injected an octopamine-like substance directly into the protocerebrum of cockroaches that had already been turned into zombies by wasp stings.

The result was significant recovery and restoration of the cockroach's free will.

"This helps us understand how movement is initiated in animals," Libersat said. "We know how movement itself is generated, but to understand what makes an animal decide to move or not to move is a different issue."

Parasite Strategies

The jewel wasp is the only parasite known to inject its venom directly into its host's brain.

But other parasites also control the behavior of their hosts, said David Richman, curator of the Arthropod Museum at New Mexico State University in Las Cruces, who was not involved in the new study.

"This is not uncommon. There are a tremendous number of parasites, and they all have different strategies for survival and for propagation of their species," Richman said.

The behaviors of land snails, grasshoppers, and types of ants, for example, can all be affected by parasites.

"Not only that," Richman added, "[some parasites] can take over certain aspects of the host's biology, particularly as you get into microorganisms."

Shark Ate Amphibian Ate Fish: First "Food-Chain Fossil"

About 290 million years ago, Earth's lakes were a shark-eat-amphibian-eat-fish world, new fossil evidence reveals.

A new fossil discovery looks like a set of Russian dolls: It's the preserved remains of a fish, which was eaten by an amphibian, which was then eaten by a shark.

The fossil provides the first ever snapshot of an ancient, three-level, vertebrate food chain.

An animal's last meal is very rarely preserved, because corrosive acids quickly erupt from the decaying stomach, dissolving any food remnants before fossilization can take place.

But in this case, "the shark didn't just die and sink down and decompose," said Jürgen Kriwet, a paleontologist from Berlin's Museum of Natural History and co-author of a new study on the find.

"It was probably still alive when it got trapped under a rapid influx of sediment from surrounding hills," he said.

A Single Food Chain

The fossilized trio lived 290 million years ago in the shallow coastal waters of a freshwater lake in the Saar-Nahe Basin of southwestern Germany. The lake had previously been linked to the sea but was landlocked for millions of years before the three animals lived and died.

Several pieces of evidence suggest the animals must have formed part of a single food chain.

For one thing, "the orientation of the fossils fits perfectly," Kriwet said.

Permian-period sharks—like the one in the fossil—were only 19 inches (50 centimeters) long and ambushed their prey, swimming up from behind and swallowing it whole.

The fossilized amphibian is also in exactly the right position to suggest it had been eaten—it was lying tail-first along the shark's digestive tract, according to Kriwet.

"Also, the fish remains are fully enclosed within the amphibian's outer covering of scales," he added. That confirms that it was indeed eaten by the amphibian and not the shark.

Before the shark ate it, the amphibian had caught a young fish known as an acanthodian, which was covered in bony spines.

"The fish was swallowed side on, otherwise the spines could have got stuck in the amphibian's mouth or throat," Kriwet said.

"The fish is situated in quite the correct area of digestive tract of the amphibian," said said study co-author Ulriche Heidtke, a paleontologist from the National History Museum of the Palatinate in Bad Dürkheim, Germany.

"It clearly shows the hallmarks of digestion, [such as] disintegration," he added.

If the shark had eaten the fish first and then the amphibian, they would be placed one after the other in the shark's stomach, he explained.

John Maisey, a curator of paleontology at the American Museum of Natural History in New York, was not involved in this study.

"Well-documented examples of predator-prey relationships such as this are very rare," he said.

Such fossils allow scientists to reconstruct parts of extinct food chains, Maisey added.

"Three tiers are exceptional—if [only] we could find a four-tier example."

Unusual Sharks

Unlike their ancient ancestors, no modern-day sharks are fully adapted to living in fresh water.

"Today we find some rays and skates—close relatives of sharks—living in fresh water, but sharks invade lakes and rivers only for a short time," said study co-author Kriwet.

"We don't understand why this is," he said.

Another odd difference is that none of the sharks that swim through the oceans today are known to eat amphibians.

"There are no reports of sharks eating amphibians, even in the tropics, where there are large amphibians living close to the lakes and rivers that sharks temporarily enter," Kriwet said.

These ancient amphibians—known as temnospondyls—were reminiscent of modern-day crocodiles but lived in a world that was still crocodile free. (Related news: "Ancient Amphibians Bit Instead of Sucking, Skull Study Says" [April 16, 2007].)

"The amphibians had a short legs, long snouts, big teeth, and a long tail that they used as a rudder, much like crocodiles today," Kriwet said.

"Before the Permian extinction event, amphibians and sharks were the main top predators," he said.

The Permian extinction, Earth's most extreme die-off, occurred 251 million years ago.

"But by the end of the Triassic [199.6 million years ago]," Kriwet said, "there was a shift to crocodiles and bony fish being the top predators."

Moonlight Triggers Mass Coral "Romance"

Australian and Israeli scientists have discovered the trigger for the planet's biggest group sex spectacle: the mass spawning of hard corals along Australia's Great Barrier Reef.

One week each year in spring, after a full moon, millions of corals release eggs and sperm in what Bill Leggat, a co-author of the new study, called "a slow symphony."

But until now how the primitive animals—which lack brains or eyes—synchronized the mass spawning was a mystery.

In today's issue of the journal Science, researchers reveal that they have isolated an ancient gene in the corals' DNA that can detect moonlight.

By exposing corals to different colors and intensities of light, the team found that the gene—known as Cry2—was most active in Acropora corals during a full moon.

Leggat, a lecturer at James Cook University in Cairns, Australia, said Cry2 encodes a type of protein known as a cryptochrome, which appears to trigger the corals' reproductive cycle.

"This particular gene allows the coral to sense blue light and to actually work out what phase the moon is in," he added.

The research also suggests that the basic ability to sense changes in light and adapt a 24-hour cycle appeared early in the evolution of animals.

Sophisticated Spawning

Cry2 prompts a series of biochemical reactions that is surprisingly sophisticated, Leggat said.

Some 400 or 500 species of corals all spawn simultaneously during the week, creating vast slicks across the ocean, he pointed out.

"It's just magical," Leggat said. "To just sit in front of an individual coral and watch the pink sperm bundles get slowly pushed out of the corals' mouth and float away—it's incredible to watch."

"It's one of the greatest sights in nature, but the amazing thing is that, after going on for millions of years, it wasn't witnessed until the 1980s," he added.

How the right sperm ends up with the right egg is a complicated process that may rely on refined chemical pathways, he said. But scientists are still working on unraveling the exact details.

"To me, the really exciting thing is this huge, well-orchestrated symphony [is] going on, yet we still don't know how it works," Leggat said.

"We're only really just starting to understand corals and reefs in general, and something that's both exciting and worrying is that these reefs are threatened, that they may not be around in 50 years."

Night and Day

The new research also offers insights into the development of vision and the evolution of daily rhythms in animals.

Ove Hoegh-Guldberg, director of marine science at the University of Queensland, said cryptochromes are closely linked to primitive proteins known as photolyases—which harness blue light to repair DNA damaged by ultraviolet radiation.

"[In the Precambrian era] there were very high doses of ultraviolet reaching the planet surface, so organisms probably had to retreat out of range of the UV" in addition, said Hoegh-Guldberg, who was also a co-author on the new research.

"One way to do that would be to go into the deeper layers of the ocean during the day and to rise during the night as levels dropped" by adapting the light-sensing properties of the photolyases, he added.

From there, it was "a very simple step to evolve cryptochromes to set your clock to do the right things at the right time," he said.

"The first creatures wouldn't have had eyes," Hoegh-Guldberg continued. "They would have been depending on cellular biochemistry to detect changes in light. So cryptochromes are, in a sense, the functional forerunners of eyes."

Cryptochromes are still present in humans and other mammals, as well as insects, he said. They play an important role in regulating the circadian system, a "body clock" attuned to Earth's 24-hour rhythms that regulates things like cycles of metabolism and alertness.

"[These proteins] are the Swiss timing mechanism of biology," Hoegh-Guldberg said.

Surprising Complexity

In addition, the work shows the surprising level of sophistication of even the earliest animals.

"We think of corals as being very simple, but they're not," Leggat, of James Cook University, said. "They're actually incredibly complex—they have almost the same number of genes and proteins as humans.

"Many of these genes developed in deep time, in the earliest phases of organized life on the planet," he added. "They were preserved for hundreds of millions of years before being inherited by corals when they developed about 240 million years ago, and are still found today in modern animals and humans."

They are an indicator that corals and humans are in fact distant relatives, sharing a common ancestor way back."

Hoegh-Guldberg said the team would head back to the reef this spring to delve deeper into the secrets of cryptochromes.

"We've got all the smoking guns of this mechanism," he said. "The next step is to track down the way they drive things like reproduction. We fully expect to uncover other behavior that they are controlling."

"Vibrating Mice" Develop Less Fat, Study Shows

A new study in mice could shake up the fight against fat.

Laboratory mice that spent 15 minutes a day on a vibrating platform developed 28 percent less fat than control mice during a recent experiment.

But forget the ads for waistband-jiggling vibration belts guaranteed to "burn away fat." These mice experienced very subtle, almost undetectable, tremors.

Scientists theorize that as the mice developed, the vibrations mimicked muscle activity and induced their stem cells to develop into bone or muscle cells rather than fat cells.

"We're not burning fat or taking fat mice and making them skinny," said lead author Clinton Rubin, a biomedical engineer at the State University of New York, Stony Brook.

"We're taking mice who are growing and ... influencing the decision of stem cells [so that they don't] become fat cells."

The finding came in part from research in human spaceflight. Rubin and colleagues are trying to induce stem cells to become bone cells in order to offset the bone loss that results in zero-gravity space environments.

Rubin has also co-founded a for-profit company, Juvent Medical, that is using a similar concept to treat osteoporosis.

The study will appear this week in the journal Proceedings of the National Academy of Science.

Fighting Fat Before it Appears

The human body needs fat cells, which store food energy for future use.

Most doctors believe that obesity is the result of consuming more calories than a body burns. Recent research suggests that genetics and other factors may also play a role.

Rubin cautions that the study is preliminary and raises as many questions as it answers.

But the possibilities for human weight control are intriguing, and they may include developmental as well as metabolic factors.

"Just imagine a way to keep people from getting fat that is not [only] about how many Oreos they eat or how much they exercise—but about keeping them from forming fat cells in the first place," he said.

No Guilt-Free Solutions

But if the prospect of consequence-free overeating and sloth sounds too good to be true, it probably is, experts say.

"The reason we have those cells is to take [in] excess fat," said Roger Unger, an obesity researcher at the University of Texas Southwestern Medical Center.

"If you inhibit [fat cells] and overeat, you haven't done that person a favor," said Unger, who was not involved in the new research.

"The surplus lipids would end up in organs where you don't want to have surplus lipids—like the heart and the liver."

"People that don't have [as many] fat cells, if they overeat, get very sick—[they get] sicker at a much earlier age than people who first get fat and then develop complications."

Rexford Ahima is a University of Pennsylvania endocrinologist.

"The idea that 'non-strenuous work' can reduce body fat is intriguing; however, the findings have to be interpreted with caution," he said.

Ahima noted that key information regarding the mice's energy expenditure, hormones, and metabolism remains unknown and may have impacted the results.

Rare Gorillas at Risk as Rebels Seize Congo Park

Heavy fighting continues to rage in the Democratic Republic of the Congo's (DRC) troubled Virunga National Park, one of the last remaining homes for rare mountain gorillas.

On Sunday rebels loyal to renegade general Laurent Nkunda—who have been clashing with DRC military forces in the area since September 3—took control of the park's gorilla sector.

The fighting has sparked further fears for the safety of the critically endangered mountain gorillas, which have been left largely unprotected for more than a month, ever since the clashes forced rangers to evacuate the park.

Today the fighting between rebels and the Congolese army heated up near Bukima, the park's main gorilla monitoring station.

Rangers could also hear the exchange of heavy gunfire near park headquarters at Rumangabo, according to Norbert Mushenzi, director of Virunga's gorilla sector for the Congolese Institute for the Conservation of Nature (ICCN).

"Rangers and local inhabitants are fleeing from all around the park, and the mountain gorillas are totally unprotected," Mushenzi said.

"This whole situation is precarious and frustrating."

Rebels vs. Rangers

About 700 wild mountain gorillas remain in the world, roughly 380 of which live in the Virunga Volcanoes Conservation Area shared by the DRC, Rwanda, and Uganda.

Of these, about 120 are found in the DRC.

But rangers there have been able to track only one family of gorillas since the fighting started five weeks ago, and they have yet to account for 54 of the region's 72 habituated gorillas.

Until last week the situation had appeared to be calming, and rangers were hoping to re-enter the sector to track the gorillas.

But last Friday rangers who had been monitoring gorillas from a post inside the park had to flee when the rebels reportedly tried to force them to become combatants.

Rebel leader Nkunda, who is an ethnic Tutsi, maintains that the government is collaborating with ethnic Hutu rebels hiding in the DRC who are accused of involvement in the 1994 genocide against Tutsis in neighboring Rwanda.

On September 3 the rebels surrounded two ranger stations inside Virunga. The men seized rifles and communications equipment and forced park workers and their families to evacuate.

Since then the rebels have consolidated their grip on the park, conservationists say.

"The army seems to be weakening vis-à-vis the rebels—and this does not bode well for the gorilla sector at all," said Samantha Newport, a spokesperson for WildlifeDirect, an environmental group that supports the DRC rangers.

Fighting for Control

Conservationists said control of the park is important for the rebels.

"The gorilla sector is a key strategic point in this conflict. The rebels want to control it and have access to neighboring countries to replenish their materials and equipment," said Emmanuel de Merode, head of WildlifeDirect.

"The mountain gorillas are stuck right in the middle."

At least ten gorillas have been killed in Virunga this year, and some of the deaths have been blamed on the rebels.

The worst attack occurred on July 22 when five gorillas, including a silverback, were shot dead execution-style.

That attack was linked to the burgeoning charcoal trade in the park. (Read "Congo Gorilla Killings Fueled by Illegal Charcoal Trade" [August 16, 2007].)

In September a dead infant female was found in the hands of alleged traffickers who are now facing judicial procedures in the city of Goma, just south of Virunga.

Newport said there is a strong possibility that the rebels may soon cut off the road between Goma and park headquarters at Rumangabo, thereby totally isolating the 34 rangers there.

The rangers have removed all valuable tracking equipment from Rumangabo in case the clashes reach the area.

One ranger also died this week in a car accident.

The man was coming back with his colleagues from an anti-charcoal burning patrol when he fell out of the pick-up truck they were riding in. He was taken to a hospital, but later died from brain damage.

Cycad Plants "Woo" Insects With Heat, Odor

A primitive type of cycad plant from Australia relies on a surprisingly sophisticated system of meting out food to ensure successful pollination.

These plants take an active role in their reproduction by selectively attracting and repelling small insects known as thrips, a new study shows.

Scientists had long thought that cycads were passively wind-pollinated.

But in a push-pull system, male cones of this "living fossil" species heat up and emit strong odors to send pollen-bearing insects fleeing.

Female cones then emit a more attractive perfume to lure the bugs back in.

Pollination accomplished.

"I think the work demonstrates that plants aren't just sitting there looking pretty or just smelling good to attract their pollinators and that there's a lot more dynamics involved," said study co-author Irene Terry, a biologist at the University of Utah.

The mechanics of such primeval systems could provide insight into how pollination occurs in natural environments such as forests, something that Terry says there is still much to learn about.

The study appears this week in the journal Science and was funded in part by the National Geographic Society, which owns National Geographic News.

Nagging Mystery

Cycads are one ancient lineage of seed-producing plants called gymnosperms, which also include firs, spruce, pines, sequoias, and redwoods.

Found in tropical and subtropical areas, all species of cycads have separate male and female parts, often producing cones that look similar to a pinecone.

Tiny cracks between the tightly woven scales of the cones allow thrips to gain access to pollen in male cones and to structures containing eggs in female cones.

Both larval and adult thrips prefer the male cones, because the insects feed only on pollen.

But using some chemical tricks, the plants looked at in the new study ensure that thrips carry the male reproductive cells into the female cones.

"Twenty-five years ago when I began studying cycad pollination, it was still widely believed that cycads, like other gymnosperms, were wind-pollinated," said William Tang, an entomologist with the U.S. Department of Agriculture.

"Although I was involved in some of the early studies on cycad insect behavior, cone physiology, and odor analyses that supported the notion of insect pollination in this group, the precise details of this mutualism remained a nagging mystery," added Tang, who was not involved with the new study.

"This paper presents an elegant use of biochemistry, physiology, and field ecology to reveal the fine details of how this plant and its insect pollinator interact," he said.

"Through the use of heat and volatile chemicals, the plant choreographs a dance with its pollinators."

Stinky Males

Cycads have variable pollination periods, with reproduction occurring once a year to once every several years and lasting up to four weeks.

During that time, male cones use stockpiles of sugars and fats to heat themselves up, sometimes reaching 100 degrees Fahrenheit (38 degrees Celsius).

The cones also spew out huge doses of an odorous chemical called beta-myrcene.

"The odors get so strong that I don't want to be around them," study co-author Terry said.

"Some plants produce a stinky odor like a dead animal or poop, but this odor is just very harsh, hard to describe in terms of something similar."

Beta-myrcene attracts thrips at low concentrations, but in the amounts emitted by male cones, it becomes highly repellant, explained Robert A. Raguso, a chemical ecologist from Cornell University who was not involved in the study.

"This is a rather emphatic invitation for the thrips [to] leave home, and they do so bearing pollen," he said.

The plants do this "without dramatically changing their structural or visual characteristics, or even the chemistry of their scent," he added.

Tricky Females

Female cones emit much less beta-myrcene, so fleeing thrips searching for more pollen are drawn there.

When the thrips get inside the female cone, the ovule—containing the female reproductive cells—releases a little droplet, similar to a nectar droplet.

This draws the insects farther in. If they are carrying pollen, pollination is inevitable.

"The [study] highlights an elegant physiological mechanism by which cycads manipulate the behavior of thrips, transforming them from neutral or perhaps detrimental pollen predators to helpful pollinators," Raguso said.

Birds Can "See" Earth's Magnetic Field

To find north, humans look to a compass. But birds may just need to open their eyes, a new study says.

Scientists already suspected birds' eyes contain molecules that are thought to sense Earth's magnetic field. In a new study, German researchers found that these molecules are linked to an area of the brain known to process visual information.

In that sense, "birds may see the magnetic field," said study lead author Dominik Heyers, a biologist at the University of Oldenburg.

Magnetic Orientation

Human-made compasses work by using Earth as an enormous magnet and orienting a tiny magnet attached to a needle to the planet's north and south poles.

Scientists have thought for years that migratory birds may use an internal compass to navigate between their nesting areas and wintering grounds, which can be separated by thousands of miles.

The new research helps explain how this natural compass may work.

Heyers and his colleagues injected migratory garden warblers with a special dye that can be traced as it travels along nerve fibers.

The team put one type of tracer dye into the eyes and another in a region of the brain called Cluster N, which is most active when birds orient themselves.

When the birds got their bearings, both tracers traveled to and met in the thalamus, a region in the middle of the brain responsible for vision.

"That shows there is direct linkage between the eye and Cluster N," Heyers said.

The finding strongly supports the hypothesis that migratory birds use their visual system to navigate using the magnetic field.

"The magnetic field or magnetic direction may be perceived as a dark or light spot which lies upon the normal visual field of the bird," Heyers said, "and which, of course, changes when the bird turns its head."

The study was published in a recent issue of the Public Library of Science journal PLoS ONE.

More Navigational Tools

Scientists not involved with the study said it is impressive and well done, but cautioned that there are more pieces to the puzzle of how birds navigate on their long migrations.

"An animal that has to migrate over great distances needs to have both a compass and a map," said Cordula Mora, a biologist who recently completed her postdoctoral research at the University of North Carolina, Chapel Hill.

Mora's work suggests that birds may use magnetic crystals in their beaks to sense the intensity of the magnetic field and thus glean information on their physical location.

"If you have a compass, you know where north, south, east, [and] west [are], but you don't know where you are, so you don't know where you should be going," she said.

Study author Heyers said "both [map and compass] systems may act in concert."

Robert Beason is a wildlife research biologist with the U.S. Department of Agriculture in Sandusky, Ohio, and an expert on bird navigation.

He noted that stars may also either fully or in part provide the birds with their visual bearing—not the magnetic field.

The next step is to figure out where all this information comes together in the bird brain, he noted.

"That's probably going to tell us where the navigation center for birds is," he said.

Giant Bugs a Thing of the Past, Study Suggests

For the giant insects that roamed Earth 300 million years ago, there was something special in the air.

A higher concentration of oxygen in the atmosphere let dragonflies sometimes grow to the size of hawks, and some millipede-like bugs reached some six feet (two meters) in length, a new study suggests.

Now that the proportion of oxygen has decreased, however, bugs can't grow much larger than they do now, the authors write.

The reason: The bigger an insect, the bigger the proportion of its body devoted to its tracheal system, which functions like a lung but is far less efficient at large sizes.

"[The tracheal system] explains why they are small," said study co-author Jon Harrison, a professor of environmental physiology at Arizona State University. "It takes up all the room."

The study appears this week in the journal Proceedings of the National Academy of Sciences.

Bigger Bodies, Bigger Lungs

Scientists have long puzzled over why bugs once grew to gigantic proportions but are now among Earth's more diminutive creatures.

"There were hundreds of ideas to explain the small size, but none of them could be proven," said lead study author Alexander Kaiser, of Midwestern University's Department of Basic Sciences.

So Kaiser and colleagues decided to test the idea that it was it was an insect's respiratory system that limited its size by studying beetles and fruit flies.

The team looked at beetles by peering through their exoskeletons with new x-ray beam technology at Argonne National Laboratory in Illinois.

This allowed the scientists to see how much room was dedicated to the respiratory system among four species of darkling beetles ranging from 0.1 to 1.3 inches (3.2 to 33 millimeters) in length.

Insects carry oxygen to cells differently from humans. Instead of a single breathing tube, bugs have several pairs of holes known as spiracles along their bodies.

These holes connect to tubes called tracheae, which transport oxygen to cells and remove carbon dioxide.

The x-ray scans revealed that as beetles become larger, tracheae take up proportionally more room in their bodies because they need to be longer and wider to deliver enough oxygen. This, in turn, inhibits growth by crowding other organs.

The tracheae in the larger beetles took up 20 percent more room than in smaller beetles.

The area where the body and legs meet is particularly limiting, because that opening can only get so big, Harrison noted.

In the smallest beetle, tracheae take up 2 percent of the region, compared with 18 percent in the largest.

Using that information, Harrison estimated that the maximum beetle size under current oxygen levels would be about six inches (15 centimeters).

That coincides roughly with the largest known living beetle, the Titanic longhorn.

"This paper is really interesting in part because there is still a lot we don't know about how insects breathe," said Scott Kirkton, an assistant professor of biology at Union College in Schenectady, New York, who was not associated with the study.

Something in the Air

During the late Carboniferous period (354 to 290 million years ago), however, oxygen levels were much higher than they are now, partly because coal swamps that leaked the gas into the air were very common.

"Back then, there was 31 to 35 percent oxygen in the air," study lead author Kaiser said. "Now we have about 21 percent."

That meant insects needed smaller quantities of air to meet their oxygen demands, allowing the creatures to grow much larger.

"The tracheal diameter can be narrower and still deliver enough oxygen for a much larger insect," Kaiser said.

The team, though, is still trying to definitely show that this phenomenon explains why Carboniferous insects were so large.

Neither fruit flies nor beetles were around, or even had close relatives, during the Carboniferous, so the team hopes to extend its research to more ancient insects such as dragonflies, Kaiser said.

The scientists have already experimented with fruit flies in a lab at Arizona State, raising them in tanks with different levels of oxygen.

Under higher concentrations of oxygen the fruit flies definitely get bigger, Harrison said.