Full Moon Energizes Birds

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- If the night sky seems less tranquil on nights when the moon is bright, the observation probably isn't imagined since a new study has determined that at least one bird's level of activity dramatically increases with moonlight.

The finding adds to a growing body of evidence that lunar phases affect the behavior of insects, birds, fish and mammals -- including humans.

The study, which has been accepted for publication in the journal Animal Behavior, is among the first to provide direct evidence for the "full moon effect," since many other claims have been based on indirect observations and even folklore, such as werewolf tales.

In the case of streaked shearwaters, the focus of the study, this marine bird flew for longer periods and landed on water more frequently on nights with a full moon. But because sharks and other bird predators also appear to be more energized on such nights, the shearwaters didn't stay on the water for long.

"Pelagic seabirds, including shearwaters, are known to be preyed upon by sharks or seals at sea, so birds are attacked from under the sea, not from the air," lead author Takashi Yamamoto explained to Discovery News.

"When birds are sitting on the water's surface at night with a full moon, it shades moonlight passing through into the sea, so predators might be able to detect seabirds using such shades," added Yamamoto, a researcher at Japan's National Institute of Polar Research.

He and his colleagues captured 48 streaked shearwaters at Sangan Island in Japan. They attached global location sensors to the birds. These devices recorded time, light levels, immersion in seawater and water temperature. Geographical locations were estimated using the light data. At the end of the study, the researchers recaptured the birds and removed the sensors.

Since the birds are in the middle of the food chain, they not only move more to escape full moon-stimulated predators, but they also seem to take advantage of the improved light situation by feeding at night on squid and fish, especially their favorite: anchovies.

The scientists believe other marine birds, such as albatrosses, receive a comparable caffeine-like behavior jolt from a full moon.

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Yamamoto further pointed out that prior research found that lunar cycles change insect and bird hormones. They also help to influence fish reproduction. In rodents, they even appear to affect the way food tastes to rats.

Chanchal Bhattacharjee of the Accident and Emergency Department at Bradford Royal Infirmary and colleagues additionally found that animals bite more when the moon is full. Over a two-year study at the infirmary, based on patient numbers, they discovered that during such nights the chances of suffering a bite from any animal -- mostly dogs -- double.

As for humans, Yamamoto says the connection has proven trickier to establish "because many implicating factors may influence human behavior," such as interaction with others or stressful situations.

"But," he added, "there could be a possible explanation that lunar cycles affect hormone changes in humans and such changes consequently control human behavior, such as becoming violent."

He hopes future studies, on both birds and other animals, will help to better identify exactly how lunar phases change behavior and the biophysical processes that underlie these changes.

Kangaroo Rats Get Space-Based Census

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- Scientists plan to use satellite photos to count giant kangaroo rats, the first-ever monitoring of an endangered species from outer space.

Scientists will examine images taken from the same satellite used by Israeli defense forces to find the circular patches of earth denuded by the rats as they gather food around their burrows. From that they plan to get the first-ever accurate population count of the rodents, a bellwether for the health of a parched plains environment.

By comparing the photos to 30 years of satellite images being released this month by the U.S. Geological Survey, researchers hope to better understand how the population has fluctuated in response to climate change and as the arrival of state and federal canal water turned the arid San Joaquin Valley into a patchwork of intensely cultivated farms and forced Giant Kangaroo Rats to concentrate on higher ground.

The information will help scientists determine when cattle might be used to reduce nonnative grasses, allowing the rats to more easily find food.

This study using satellite technology is taking place on the vast Carrizo Plain, a 390-square-mile desert grassland 150 miles southwest of here that is home to the most concentrated remaining populations of kangaroo rats.

The technology replaces trapping and tedious airplane fly-overs as a means of taking census.

"It allows us to more quickly recognize whether populations are declining where we want them to exist," said Scott Butterfield, a biologist with of The Nature Conservancy. "If they go below a threshold, that is when we would consider intervening."

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Giant kangaroo rats, nocturnal rodents so named because they hop on back legs, adapted to their desert environment by extracting moisture from seeds and in their nasal passages from the humid air they exhale. For food, they pile seeds from native grasses in circles outside their burrows, which provide shelter for the endangered San Joaquin antelope squirrel and blunt-nosed lizards. Their fat five-inch bodies are a favored source of food for the endangered kit fox.

High rainfall encourages the growth of taller nonnative grasses, which overrun the shorter grasses that kangaroo rats depend on for food. Less food means fewer offspring. When kangaroo rats decline, so do the endangered native plant and animal species that depend on them for survival, the researchers say.

Determining at what point rainfall affects foraging will help the U.S. Bureau of Land Management establish grazing policy to control nonnative grasses and encourage a healthy kangaroo rat population.

"Without them the entire ecosystem would go out of whack," said Tim Bean, a doctoral student with the department of environmental policy and management at the University of California, Berkeley. "It's fairly rare for something so small to be a keystone species. It's easier to track, say, bison."

Farming has taken 90 percent of the kangaroo rat habitat since the middle of the last century.

The Carrizo Plain National Monument is California's largest remaining undisturbed tract of grasslands similar in biology and geography to the San Joaquin Valley, and it supports many plant and animal species that once thrived on the valley floor.

"Carrizo is like a Yosemite for grasslands, and there are decisions people are learning to make to manage it in a way that preserves its natural state," Bean said. "Since the kangaroo rat is so important to its function, we've got to get a handle on it."

Spider Venom Recipe Could Be Key to Antidote

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-- Brown recluse spider venom is powerful enough to destroy human tissue, at times leading to gangrenous lesions. Now, after figuring out the venom's ingredient list, scientists are an important step closer to finding an antidote.

Spider venom concoctions have inspired everything from environment-friendly pesticides to treatments for arthritis and erectile dysfunction, so it's likely the newly identified recipe will have pharmacological applications beyond the cure for bites.

The study, published in this week's Proceedings of the National Academy of Sciences, found that brown recluse spider venom contains both big and small molecules.

Enzymes and proteins make up most of the "big" compounds, but lead author Frank Schroeder told Discovery News that he and his team identified "additional components that have been previously overlooked."

Schroeder, a scientist at Cornell's Boyce Thompson Institute and Department of Chemistry and Chemical Biology, and his colleagues discovered a new family of chemicals in the venom known as sulfated nucleosides.

These compounds, he explained, are based on one of the building blocks of RNA, a molecule in living cells that helps build proteins. A seemingly minor switch in an RNA component appears to contribute to the venom's toxic properties.

The researchers made the discovery after analyzing venom samples from more than 70 different types of spiders, including black widows and three members of the deadly recluse family: the Arizona, desert and brown recluse spiders. To obtain their samples, the researchers electrically stimulated a gland in the spiders that allowed the scientists to "milk" the venom.

The scientists then employed two high-tech methods -- proton nuclear magnetic resonance spectrometry and mass spectrometry -- that enabled them to look at the molecular structure of compounds, in this case, right down to their most basic components.

Although black widow and recluse spiders equally terrify most people, the scientists found that their venoms are very different.

"Our results show that black widow venom does not contain sulfated nucleosides," said Schroeder.

Instead, it seems that one of the hourglass-marked spider's most important venom ingredients is the deadly neurotoxin latrotoxin, which can invade a bite victim's cardiovascular system, as well as the muscles and nervous system.

The research "nicely demonstrates that molecules can be identified from mixtures without the often large amount of work involved in purification," said Arthur Edison, director of the Advanced Magnetic Resonance Imaging and Spectroscopy Facility and an associate professor at the University of Florida.

In fact, he pointed out that conventional purification methods would destroy the newly identified compounds, so the spectrometry method may be the best, and only, way to study such venoms.

Schroeder, who said he had spiders crawling on his laboratory notebooks during the research, can now create synthetic versions of the venoms, which will be used in future studies.

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Giant Pythons Invade Florida

Burmese Python

- Giant pythons capable of swallowing a dog and even an alligator are rapidly making south Florida their home, potentially threatening other southeastern states, a study said.

"Pythons are likely to colonize anywhere alligators live, including north Florida, Georgia and Louisiana," said Frank Mazzotti, University of Florida Institute of Food and Agricultural Sciences professor, in his two-year study.

The pythons thriving in Florida are mostly Burmese pythons from Myanmar that were brought over as pets and then turned loose in the wild.

From 2002-2005, 201 of the beasts were caught by state authorities, but in the last two years the number has more than doubled to 418, Mazzotti said in his study published on the university Web site.

The largest python caught so far in Florida measured 16.4 feet and weighed 154 pounds.

Mazzotti said the serpents, despite their awesome size, are not poisonous, but are excellent swimmers and able to cover great distances in little time. Some, trapped and released with radio transmitters, swam 37 miles in a few hours.

Highly adaptable, pythons prey on cats, dogs, hares, foxes, squirrels, raccoons and even alligators, allowing them to thrive in a variety of environments.

After populating the Florida Everglades -- a vast marshland -- where it is estimated they number 30,000, the giant python is now spreading across the rest of the peninsula.

"Females may store sperm, so they can produce fertile clutches for years. And a 100-something pound snake can easily be producing 60, 80 eggs a year," said Mazzotti, adding that the reptile could eventually populate the entire southern United States.

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At One Undersea Volcano, Star Heaven

Brittle Star City

Marine scientists surveying a large undersea mountain chain were amazed to find millions of tiny brittle stars swirling their arms to capture food in the undersea current.

An expedition by 19 scientists studied the geology and biology of eight Macquarie Ridge sea mounts. They are part of a string of underwater volcanoes -- dormant for millions of years -- that stretches 875 miles from south of New Zealand toward Antarctica.

The scientists also investigated the world's biggest ocean current -- the Antarctic Circumpolar Current -- amid expectations they would find evidence of climate change in the Southern Ocean.

While the expedition's cameras found a wide range of corals and a high density of cardinal fish, the vast collection of brittle stars was the highlight of the voyage.

"I've personally never seen anything like this -- all these animals, the sheer volume -- all waiting for food from the current," expedition member and marine biologist Mireille Consalvey said Monday. "It challenged what we as scientists thought we knew."

Expedition leader and marine biologist Ashley Rowden said brittle stars usually cover only slopes away from the top of the undersea mountains.

"It got us excited as soon as we saw it," Rowden said of the site, dubbed "Brittle Star City."

The animals are about 0.4 inch across, with arms about 2 inches long.

The expedition began March 26 and returned to port in New Zealand's capital Wellington on April 26.

Tasmanian Devil Endangered as Cancer Hits

Going, Going...

Australia's Tasmanian devil will be listed as an endangered species this week as a result of a deadly and disfiguring cancer outbreak, the state government said Monday.

The disease, a fast-growing head tumor which spreads over the marsupial's face and mouth and prevents it from eating, often killing it within months, has cut the island's devil population in the wild by as much as 60 percent.

A spokeswoman for Tasmania's Primary Industries Minister David Llewellyn said the small, black-haired animal would be listed as an endangered species by state officials on Wednesday.

The minister told the Australian Broadcasting Corporation that the animal would be upgraded from a vulnerable to an endangered species so that the "appropriate resources and effort" can be poured into protecting it.

The government has also backed a plan to build an "insurance population" of healthy Tasmanian devils at wildlife reserves, zoos and other protected areas.

"If required, these animals could be utilized to help re-establish Tasmanian devil numbers in the wild," Llewellyn said.

The facial tumor is extremely unusual in that it is a contagious cancer, spread from devil to devil by biting.

The devil is the world's largest marsupial carnivore and now only lives in Australia's southern island state.

Early European settlers named the feisty marsupial the devil for its spine-chilling screeches, dark appearance and reputed bad temper which, along with its steeltrap jaw, made it appear incredibly fierce.

Rat Mojo All in the Tail

It's All in the Tail

- The function of tails has somewhat stumped scientists over the years, but now researchers have determined that female rats' tails play a very important role in the rodent mating process.

Female rats use their tails to direct, stimulate and balance their male partners, scientists determined.

Tails have been known to provide animals with extra sensory perception, since a tail can "feel" around itself, and to help with heat regulation, balance and navigation.

According to the research team who worked on the project, the new findings, which add mating facilitation to the tail's known list of functions, could also apply to cattle, cats, dogs, rabbits and certain primates, such as the spider monkey.

Every part of the tail appears to be important.

Pablo Pacheco, who led the study, told Discovery News that "the base of the female's tail facilitates, modulates and even permits the male's lateral mounting, which guarantees that the penile tip will find the vaginal opening," while the tip of her tail then offers the male stimulation.

Pacheco, a researcher at the Institute of Neuroethology at the University of Veracruz and the Institute of Biomedical Investigations at the National Autonomous University of Mexico, and his colleagues surgically removed both female and male rat tails and then observed how the removals affected their mating.

Normally males sniff out receptive females, produce ultrasonic mating calls and engage in urine marking. They then join the female and initiate rhythmic pelvic thrusts, which lead to the actual mating.

Neither the males nor the females found the tail-less subjects to be any less attractive. Males without tails seemed to move a bit awkwardly, but it was the tail-less females that really threw off the normal pattern, according to the study, which was published in the journal Animal Behavior.