Madagascar Dinosaur Bone Is Most Massive Osteoderm Ever Found

What more can we learn about long-necked dinosaurs that we don't already know? A Macalester professor and her colleagues have found that Madagascar dinosaurs carried giant, hollow bones in their skin that may have helped them survive the harsh environments they inhabited. This discovery has shed new light on the anatomy and function of these bones in the biggest animals to ever walk on land.

Biology/Geology Prof. Kristi Curry Rogers is the lead author of a paper in Nature Communications about bizarre, gigantic bones that grow in the skin of Rapetosaurus, a species of huge plant-eating dinosaur from the island country located in the Indian Ocean off the southeastern coast of Africa.

"This is the biggest osteoderm ever found for any backboned-animal," said Curry Rogers, "The fact that it's hollow debunks all sorts of ideas about how these bones functioned in long-necked dinosaurs."

Osteoderms are bones embedded within the skin and are common among reptiles and some mammals. They create the unique pattern on the backs of crocodiles, the armor body covering on armadillos, and the distinctive plates of dinosaurs like Stegosaurus and Ankylosaurus.

Among the long-necked dinosaurs called sauropods, osteoderms are found in one globally distributed subgroup -- the Titanosauria. For more than a century, paleontologists have been trying to figure out how these weird bones were distributed in the skin of the long-necked titanosaurs and what they might have been used for. Were they for protection, like in armadillos and crocodiles? Were they for display? Could they have helped regulate body temperature?

"Knowing something about the lives of these dinosaurs, particularly in the context of the drought-prone paleoenvironment they lived in, tells us that osteoderms may have been important for storing minerals, which allowed Rapetosaurus to survive the rough times," said Curry Rogers.

Instead of the hundreds of interlocking plates in living animals with osteoderms, Rapetosaurus had only a few osteoderms in its skin. This means that they were less likely to serve as protection or as body temperature regulators.

"The discovery of these giant osteoderms provides new insights into what these bizarre structures may have done for the dinosaurs that had them," said Curry Rogers. "It helps us clarify what these Madagascar dinosaurs looked like with their skin on. Our sample also includes both adult and juvenile osteoderms, which tells us how the osteoderms changed over the lifespan of the dinosaur," said Curry Rogers.

Read more at Science Daily

Poop-Throwing Chimps Provide Hints of Human Origins

Pick up an object that’s close at hand. Throw it at something, or even someone (but gently, of course!) You’ve just reenacted what appears to be a pivotal stage in human evolution, when a propensity for projectiles shaped cognitive powers that later became language and symbolic thought.

That, at least, is one hypothesis for how humans became so smart. And now researchers have found support in chimpanzees, among whom the ability to throw goes hand-in-hand with increased intelligence and brain development.

“Imagine you’re an early hominid throwing at a rabbit. There’s increased selection for the cognitive demands of throwing, and that has some consequences for the development of the brain,” said psychologist Bill Hopkins of Emory University. “That’s where the throwing part becomes really interesting.”

In a study published in the January Philosophical Transactions of the Royal Society B, Hopkins and colleagues tracked several years’ worth of throwing behaviors in captive chimpanzees. (“If I was going to get s–t thrown at me, I was going to get something out of it,” said Hopkins.) Chimps are the closest living ancestor to humans, and the only species aside from ourselves in which throwing is regularly seen.

The researchers were especially interested in relationships between throwing, cognition and lateralization, or the way certain activities are concentrated in the left or right hemispheres of our brains. Language processing occurs in the left side, which also controls our right hands; and most people use their right hands to throw, as do chimpanzees.

While throwing at first might not seem demanding, coordinating it requires intensive, on-the-fly calculations. An equation for throwing a ball, for example, would include the distance to a target, the ball’s heaviness and the thrower’s strength. A moving target makes it even harder. Other psychologists and anthropologists have put throwing at the beginning of a cognitive cascade into higher-order thought, but Hopkins said his team is the first to test this proposition.

From brain scans of chimps that threw most often and accurately, Hopkins found heightened development in and connections between the motor cortex, where physical actions are coordinated, and the Broca’s area, which in humans is central to speech production. Better throwing meant more sophisticated, left hemisphere-reliant brains.

“It supports the idea that these areas could have been selected for as a consequence of throwing,” said Hopkins. “If you imagine that throwing started off as left hemisphere-dominant, before the emergence of speech, then speech and language would have co-opted that side of the brain.”

In behavioral tests, true-throwing chimps also proved especially apt in social intelligence and communication. Intriguingly, they fared no better than poor-throwing chimps on physical problem-solving tests, suggesting that throwing behaviors emerged not for hunting, as is commonly assumed, but to interact with peers.

“Why did these chimps learn to throw in a captive context? I’ve never in my life seen a chimp be given a banana for throwing s–t at someone,” said Hopkins. “The reward is not something food-based. The reward is that they can control a person’s behavior. They get a pile of something to throw, and usually the person tries to run. The chimp learns, ‘If I can do this, I can have some control over the world outside my cage.’”

Read more at Wired

Stonehenge Reveals New Clues of Ancient Worship

Stonehenge may have been a place for sun worship long before the iconic stones were erected more than 5,000 years ago, according to archaeologists who are carrying out the biggest-ever virtual excavation.

Using non invasive technologies such as ground-penetrating radar and geophysical imaging, a team from the University of Birmingham's IBM Visual and Spatial Technology Centre (VISTA) and the Ludwig Boltzmann Institute for Archaeological Prospection and Virtual Archaeology in Vienna, discovered evidence of two huge pits positioned on a celestial alignment at Stonehenge.

Measuring more than 16 feet across and at least 3 feet deep, the pits lie within the Cursus, a large enclosure north of Stonehenge which pre-dates the prehistoric monument by up to 500 years.

"This is the first time we have seen anything quite like this at Stonehenge," said project leader Vince Gaffney, an archaeologist from the University of Birmingham.

"When viewed from the Heel Stone, a rather enigmatic stone which stands just outside the entrance to Stonehenge, the pits effectively mark the raising and setting of the sun at midsummer days," he said.

According to the archaeologists, the pits may have contained tall stones, wooden posts or even fires to mark the sun rising and setting. Most likely, they defined a processional route used to celebrate the passage of the sun across the sky at the summer solstice.

"It is possible that processions within the Cursus moved from the eastern pit at sunrise, continuing eastwards along the Cursus and, following the path of the sun overhead, and perhaps back to the west, reaching the western pit at sunset to mark the longest day of the year," said Gaffney.

The hypothesis gained more weight when the researchers measured the walking distance between the two pits.

They discovered that the procession would reach exactly half-way at midday, when the sun would be directly on top of Stonehenge.

"This is more than just a coincidence, indicating that the exact length of the Cursus and the positioning of the pits are of significance," said Henry Chapman, senior lecturer in archaeology and visualization at the University of Birmingham.

According to the researchers, the presence of the pits within the Cursus suggest that the Stonehenge area, which features England's densest complex of Neolithic and Bronze Age monuments, was already sacred before construction work began to build the enigmatic stone circle.

"Even though Stonehenge was ultimately the most important monument in the landscape, it may at times not have been the only, or most important, ritual focus," said Gaffney.

"The area of Stonehenge may have become significant as a sacred site at a much earlier date. Other activities were carried out at other ceremonial sites only a short distance away," he said.

The researchers have already found a henge-like monument, several other small monuments, and a new horseshoe arrangement of large pits north-east of Stonehenge which may have also contained posts.

They believe that these structures functioned as minor shrines, perhaps serving specific communities visiting the ceremonial centre.

The team is confident that the project will produce new discoveries soon.

Read more at Discovery News

Chimpanzees Self-Medicate With Food

An extensive look at what chimpanzees consume each day reveals that many of the plants they consume aren't for nutrition but are likely ingested for medicinal purpose.

The findings, published in the journal Physiology & Behavior, indicate that the origins of medicine go way back, beyond the human species.

"We conclude that self-medication may have appeared in our ancestors in association with high social tolerance and lack of herbivorous gut specialization," lead author Shelly Masi and her colleagues write.

Masi, a researcher at the National Museum of Natural History in Paris, and her team recorded the items consumed by a community of over 40 wild chimpanzees at Kibale National Park, Uganda. They also documented the availability of the foods, as well as the social interactions between the chimps.

They also documented the same information for about a dozen wild western gorillas in Dzanga-Ndoki National Park, Central African Republic.

Unusual food consumption in chimpanzees, meaning foods not normally associated with nutritional needs, was twice as high as it was for gorillas. Gorillas turn out to have more specialized guts that are better capable of detoxyifying harmful compounds, making them have have less of a need to self-medicate than chimps and humans may need to.

Chimpanzees and people are extremely social and both learn from each other, including what to eat.

"Older and more successful individuals (such as those that are high ranking) are expected to be the best model to copy, and are mainly responsible for generating and transmitting food traditions," according to the authors.

Analysis of the mostly non-nutritional and sometimes slightly toxic foods consumed determined that most had medicinal properties. Based on the study, the chimpanzee medicine chest appears to include the following: Antiaris toxicaria leaves (anti-tumor), Cordia abyssinica pith (anti-malarial and anti-bacterial), Ficus capensis (anti-bacterial), Ficus natalensis bark (anti-diarrheal), Ficus urceolaris leaves (de-worming agent), and many more.

The primates seemed to strategically go for the medicinal parts of these plants, and would consume them even when other more nutritious and palatable foods were available.

While chimps and humans appear to be the world's most self-medicating animals, another new study, accepted for publication in the journal Small Ruminant Research, documents how both wild and domesticated herbivores also consume plants for medical reasons.

Juan Villalba of Utah State University's Department of Wildland Resources, and co-author Serge Landau of Israel’s Volcani Center explain how goats sometimes nibble on the anti-parasitic plant Albizia anthelmintica. This was "followed by expulsion of worms in the feces and alleviation" of the worm problem.

Stacy Lindshield, an Iowa State University researcher, also identified a medicated body scratcher invented by wild spider monkeys.

"Spider monkeys have been observed rubbing crushed and chewed leaves on their bodies," Lindshield told Discovery News, explaining that "some primates select plants or invertebrates with chemical properties." In addition to medicinal purposes, she said the resulting smelly ointment might also facilitate olfactory communication.

Read more at Discovery News

Study Debunks Stereotype That Men Think About Sex All Day Long

Men may think about sex more often than women do, but a new study suggests that men also think about other biological needs, such as eating and sleep, more frequently than women do, as well.And the research discredits the persistent stereotype that men think about sex every seven seconds, which would amount to more than 8,000 thoughts about sex in 16 waking hours. In the study, the median number of young men's thought about sex stood at almost 19 times per day. Young women in the study reported a median of nearly 10 thoughts about sex per day.

As a group, the men also thought about food almost 18 times per day and sleep almost 11 times per day, compared to women's median number of thoughts about eating and sleep, at nearly 15 times and about 8 1/2 times, respectively.

The college-student participants carried a golf tally counter to track their thoughts about either eating, sleep or sex every day for a week. Each student was assigned to just one type of thought to record. Before receiving the tally counter, they had completed a number of questionnaires and were asked to estimate how often they had daily thoughts about eating, sleeping and sex.

Overall, a participant's comfort with sexuality was the best predictor for which person would have the most frequent daily thoughts about sex.

"If you had to know one thing about a person to best predict how often they would be thinking about sex, you'd be better off knowing their emotional orientation toward sexuality, as opposed to knowing whether they were male or female," said Terri Fisher, professor of psychology at Ohio State University's Mansfield campus and lead author of the study. "Frequency of thinking about sex is related to variables beyond one's biological sex."

Correcting this stereotype about men's sexual thoughts is important, Fisher noted.

"It's amazing the way people will spout off these fake statistics that men think about sex nearly constantly and so much more often than women do," she said. "When a man hears a statement like that, he might think there's something wrong with him because he's not spending that much time thinking about sexuality, and when women hear about this, if they spend significant time thinking about sex they might think there's something wrong with them."

The study appears online and is scheduled for publication in the January issue of the Journal of Sex Research.

The study involved 163 female and 120 male college students between the ages of 18 and 25 who were enrolled in a psychology research participation program. Of those, 59 were randomly assigned to track thoughts about food, 61 about sleep and 163 about sex. Most students were white and self-identified as heterosexual. The college-student sample made it comparable to previous research and involved an age group at which gender differences in sexuality are likely at their peak.

Before the thought-tracking began, the participants completed a number of questionnaires. These included a sexual opinion survey to measure a positive or negative emotional orientation toward sexuality (erotophilia vs. erotophobia); a sociosexual orientation inventory measuring attitudes about sex and tracking sexual behavior and levels of desire; a social desirability scale to measure respondents' tendency to try to appear socially acceptable; and an eating habits questionnaire and sleepiness scale. They also were asked to estimate how many times in an average day that they thought about sleeping, eating and sex.

Researchers then gave each student a tally counter device and told those assigned to the sexual thoughts condition to click the device to maintain a count their of thoughts about sex. They were told to count a thought about any aspect of sex: sexual activity of any kind, fantasies and erotic images, sexual memories and any arousing stimuli.

Others were instructed to use the device to record thoughts about eating that included food, hunger, cravings, snacking or cooking, and thoughts about sleep that included dreaming, sleeping, napping, going to bed or needing rest.

The questions about food and sleep were designed to mask the true intent of the study's focus on thoughts about sex, Fisher said. However, the results about these additional thoughts provided important information about differences in thinking among males and females.

"Since we looked at those other types of need-related thoughts, we found that it appears that there's not just a sex difference with regard to thoughts about sex, but also with regard to thoughts about sleep and food," she said. "That's very significant. This suggests males might be having more of these thoughts than women are or they have an easier time identifying the thoughts. It's difficult to know, but what is clear is it's not uniquely sex that they're spending more time thinking about, but other issues related to their biological needs, as well."

And when all of those thoughts were taken into account in the statistical analysis, the difference between men and women in their average number of daily thoughts about sex wasn't considered any larger than the gender differences between thoughts about sleep or thoughts about food.

In raw numbers, male participants recorded between one and 388 daily thoughts about sex, compared to the range of female thoughts about sex of between one and 140 times per day.

"For women, that's a broader range than many people would have expected. And there were no women who reported zero thoughts per day. So women are also thinking about sexuality," Fisher said.

The questionnaire data offered some additional clues about the influences on sexual thoughts. When all participants were analyzed together, those measuring the highest in erotophilia -- or comfort with their sexuality -- were the most likely to think more frequently about sex.

But when the analysis considered males and females separately, no single variable -- erotophilia score, unrestrictive attitudes about sex or a lack of desire to be socially acceptable -- could be defined as a predictor of how often men think about sex.

But for women, the erotophilia score remained a good predictor of more frequent sexual thoughts. On the other hand, women who scored high on the desire to be socially acceptable were more likely to think less frequently about sex.

"People who always give socially desirable responses to questions are perhaps holding back and trying to manage the impression they make on others," Fisher explained. "In this case, we're seeing that women who are more concerned with the impression they're making tend to report fewer sexual thoughts, and that's because thinking about sexuality is not consistent with typical expectations for women."

The participants' estimates about how often they thought each day about eating, sleeping and sex were all much lower than the actual number of thoughts they recorded. This suggested to Fisher that previous research in this area -- especially on thoughts about sex -- was weak because almost all previous studies were based on participants' retrospective estimates about how often they thought about sex.

"There's really no good reason that our society should have believed that men are thinking so much more about sex than women. Even the research that had been done previously doesn't support the stereotype that men are thinking about sex every seven seconds," she said.

Read more at Science Daily

First Dogs Came from East Asia, Genetic Study Confirms

Researchers at Sweden's KTH Royal Institute of Technology say they have found further proof that the wolf ancestors of today's domesticated dogs can be traced to southern East Asia -- findings that run counter to theories placing the cradle of the canine line in the Middle East.

Dr Peter Savolainen, KTH researcher in evolutionary genetics, says a new study released Nov. 23 confirms that an Asian region south of the Yangtze River was the principal and probably sole region where wolves were domesticated by humans.

Data on genetics, morphology and behaviour show clearly that dogs are descended from wolves, but there's never been scientific consensus on where in the world the domestication process began. "Our analysis of Y-chromosomal DNA now confirms that wolves were first domesticated in Asia south of Yangtze River -- we call it the ASY region -- in southern China or Southeast Asia," Savolainen says.

The Y data supports previous evidence from mitochondrial DNA. "Taken together, the two studies provide very strong evidence that dogs originated in the ASY region," Savolainen says.

Archaeological data and a genetic study recently published in Nature suggest that dogs originate from the Middle East. But Savolainen rejects that view. "Because none of these studies included samples from the ASY region, evidence from ASY has been overlooked," he says.

Peter Savolainen and PhD student Mattias Oskarsson worked with Chinese colleagues to analyse DNA from male dogs around the world. Their study was published in the scientific journal Heredity.

Approximately half of the gene pool was universally shared everywhere in the world, while only the ASY region had the entire range of genetic diversity. "This shows that gene pools in all other regions of the world most probably originate from the ASY region," Savolainen says.

"Our results confirm that Asia south of the Yangtze River was the most important -- and probably the only -- region for wolf domestication, and that a large number of wolves were domesticated," says Savolainen.

In separate research published recently in Ecology and Evolution, Savolainen, PhD student Arman Ardalan and Iranian and Turkish scientists conducted a comprehensive study of mitochondrial DNA , with a particular focus on the Middle East. Because mitochondrial DNA is inherited only from the mother in most species, it is especially useful in studying evolutionary relationships.

"Since other studies have indicated that wolves were domesticated in the Middle East, we wanted to be sure nothing had been missed. We find no signs whatsoever that dogs originated there," says Savolainen.

Read more at Science Daily

Early Humans Were Skilled Deep-Sea Fishermen

Prehistoric humans living more than 40,000 years ago had mastered the skills needed to catch fast-moving, deep ocean fish such as tuna, a remarkable new archaeological find has revealed.

In a small cave at the eastern end of East Timor, north of Australia, archaeologist Sue O'Connor from the Australian National University has unearthed the bones of more than 2,800 fish, some of which were caught as long as 42,000 years ago.

The find shows that the people living in the region had the sophisticated cognitive skills needed to haul in such a difficult catch, O'Connor says.

Her findings appeared in the journal Science.

"What the site has shown us is that early modern humans in island Southeast Asia had amazingly advanced maritime skills," she said.

"They were expert at catching the types of fish that would be challenging even today -- fish like tuna. It's a very exciting find."

It isn't clear exactly what techniques the people living in the area at the time used to catch these fish.

Tuna can be caught using nets or by trolling hooks on long lines through the water, O'Connor said.

"Either way it seems certain that these people were using quite sophisticated technology and watercraft to fish offshore."

The site where the discoveries were made, known as Jerimalai cave, is a small rock overhang hidden behind in foliage, a few hundred meters from the shore.

"When I discovered it in 2005, I didn't think that Jerimalai would tell us about the very early occupation of Timor," O'Connor said. "I was quite surprised when I found all these fish bones and turtle bones."

So far, she and her colleagues have only excavated two small test pits at the cave, which contained a number of stone artifacts, bone points, animal remains, shell beads and fish hooks.

In just one of those pits, 1 meter square and 2 meters deep, they found 39,000 fish bones.

They also unearthed another rare find -- a small piece of fishing hook made from a shell, which dates to between 23,000 and 16,000 years ago.

Read more at Discovery News

Gold-Flecked Stars Give Hint to Past Lives

With only hydrogen, helium and a bit of lithium to work with initially, the earliest generations of stars kept things simple. So how to explain abnormally high concentrations of gold, platinum, uranium and other heavy elements in a handful of the Milky Way's senior residents?

One theory is that they could have been enriched when a partner star exploded nearby, giving the survivor a rich dusting in heavy elements.

A new study however unhinges that theory.

By tracking the orbital motions of the metal-rich ancient stars, scientists realized the vast majority of them are traveling solo in a halo above and below the galaxy's flat central disc.

"A companion star -- if there was one -- would have left behind an optically undetectable black hole, neutron star, or faint white dwarf," astrophysicist Terese Hansen, with the Niels Bohr Institute at the University of Copenhagen, told Discovery News.

But the remnant companion would have a gravitational influence on the visible star's orbit, which would be detectable, she added.

The other explanation for why 1 to 2 percent of the galaxy's most ancient stars are flush with heavy metals is that they formed from a cloud of molecular gas enriched with the exploded remains of earlier stars.

"The great thing about these stars is that there has only been one generation of stars before then. So by looking at these stars we see clear footprints from the first generation of stars and can hence look even further back in time," Hansen wrote in an email.

Read more at Discovery News

Worms Reveal Secrets of Wound-Healing Response

The lowly and simple roundworm may be the ideal laboratory model to learn more about the complex processes involved in repairing wounds and could eventually allow scientists to improve the body's response to healing skin wounds, a serious problem in diabetics and the elderly.

That's the conclusion of biologists at the University of California, San Diego who have discovered genes in the laboratory roundworm C. elegans that signal the presence of surface wounds and trigger another series of chemical reactions that allow the worms to quickly close cuts in their surfaces that would turn fatal if left unrepaired.

The scientists report in the December 6 issue of the journal Current Biology that these two findings and a third discovery they made in the worms, involving genes that inhibit wound healing, could allow scientists one day to design ways to improve the healing of cuts and sores by possibly blocking the action of these inhibitory genes or finding ways to enhance the chemical signaling and wound healing process. An advance copy of their paper is being published online this week by the journal.

"What we've shown in this paper is that a biochemical pathway is activated by wounding in the worms that involves calcium," said Andrew Chisholm, a professor of biology at UC San Diego, who headed the research effort. "It's been known for some time that one of the things that happens when you damage a cell is that calcium levels within the cell increase."

But in a series of experiments with C. elegans, Chisholm and postdoctoral fellow Suhong Xu found out much more. They took time-lapse movies of areas around the transparent worms where they punctured the skin with a needle or laser. Then they monitored the calcium with a fluorescent protein so they could see how the calcium molecules spread from the point of injury. They also developed genetic screens to pinpoint the specific calcium pathway or "channel" that is signaling the presence of the wound and stimulating the healing process.

"We think the channel is playing an important role in either sensing damage or responding to some other receptor that senses damage," said Chisholm. "Is it sensing a change in the tension of the cell? Is it sensing some kind of change in electrical potential? We don't know."

While biomedical scientists have made great strides in understanding how the body responds to infections and chemically rebuilds the skin when the wound healing process is underway, very little is known about what happens within the cell or the body in the minutes or hours following injury. "That's still a big, big question," Chisholm said. "But we think we've made a start that will help us answer that question."

He thinks the lowly roundworms may be the ideal animals to probe that question and others involving wound healing for a variety of reasons: they are small, transparent, have a delicate surface susceptible to injury and a rapid wound response mechanism that keeps their surface wounds from being fatal.

"They have a hydrostatic skeleton in which the skin and muscles are under pressure to allow the animal to stay semi-rigid, so when you jab a worm with a needle it will, in effect, explode," he said. "But remarkably, they don't die when you do that because they have evolved ways to very rapidly close wounds to survive in the wild. In their natural environment, their predators try to exploit the worm's vulnerable exoskeleton. There are a whole group of fungi with tiny spikes that just sit around waiting for the worms to crawl over them so they can poke holes through their cuticle."

"For us, they are easy to work with, because worms are small, easy to grow and they're transparent, so when you put them on a slide, you can see the calcium clearly," he said.

The transparent worms also allowed Chisholm and Xu to get their first glimpse of how the worms rapidly close their wounds. In a time lapse movie and in a series of photographs detailed in the paper, the researchers show how actin, a protein found in all cells that plays a role in muscle contraction, is recruited to and surrounds the wound, then closes the cut by tightening the actin like a purse string.

"We think that calcium is regulating this process," said Chisholm, "because if you knock out calcium with a drug that chelates calcium, essentially locking it up, you don't get the ring. If you have a genetic mutant worm with low levels of calcium, you don't get the ring. But if you bathe this mutant in calcium, you can restore this ring."

In addition, the researchers discovered in roundworms that a protein called DAPK-1 acts to inhibit the closure of wounds, raising the possibility that drugs that inhibit the action of this protein could improve the wound healing process in humans.

Read more at Science Daily

Child Abuse in Birds: Study Documents 'Cycle of Violence' in Nature

For one species of seabird in the Galápagos, the child abuse "cycle of violence" found in humans plays out in the wild.

The new study of Nazca boobies by Wake Forest University researchers provides the first evidence from the animal world showing those who are abused when they are young often grow up to be abusers. The study appears in the October issue of the ornithology journal, The Auk.

"We were surprised by the intense interest that many adults show in unrelated young, involving really rough treatment," said Wake Forest Professor of Biology Dave Anderson, who led the study with Wake Forest graduate student Martina Müller. "A bird's history as a target of abuse proved to be a strong predictor of its adult behavior."

In Nazca boobies, traumatic abuse of developing young significantly increases the chances those maltreated individuals will exhibit the same maltreatment later in life as adults, Müller said. She is now at the University of Groeningen in the Netherlands.

The ocean-going seabirds live in colonies in the Galápagos Islands off the coast of Ecuador. Among Nazca boobies, victimization by adults on other birds' chicks is widespread. They raise solitary nestlings on the ground and frequently leave their offspring unattended while foraging at sea. So, there is much opportunity for adult birds to bully and beat up neighbor nestlings.

The abusive adults patrol the breeding colony, searching for unguarded chicks. They frequently bite and peck the chicks, and even make sexual advances, sometimes leaving the chicks bleeding and stressed. Female adults show more aggressive behavior than males do, on average.

The young birds nest years later in the colony where they were born, making them ideal models for studying the effects of "chick" abuse on lifelong behavior.

The researchers collected data during three breeding seasons documenting which nestlings suffered abuse or neglect, then several years later evaluated their behavior as adults in the same colony. They tracked the birds and identified them using leg bands.

The findings shed important light on animal behavior. "This is not some contrived experimental situation with freaked out captive animals. This is an animal in a natural situation experiencing natural stressors when young. And, the outcome is their behavior later is influenced by the social stress they experienced," Anderson said. "As we determine how similar the physiology of this response is to the human situation, we may find opportunities for research on this stress response that are not possible to do with humans."

Co-authors on the study included Wake Forest graduate students Elaine T. Porter, Jacquelyn K. Grace, Jill A. Awkerman, and Mark A. Westbrock and technicians Kevin T. Birchler, Alex R. Gunderson, and Eric G. Schneider.

The Wake Forest team of researchers is already exploring physiological responses to abuse and have found a dramatic increase in corticosterone, the primary avian stress hormone, after a chick has experienced abuse. The surge in stress hormone may influence adult bird behavior. The study, led by doctoral student Jacquelyn Grace, was published recently in the journal, Hormones and Behavior.

Read more at Science Daily