First Proof: Ancient Birds Had Iridescent Feathers

John Roach
for National Geographic News

Just like modern-day starlings, some ancient birds had glossy black feathers with a metallic, glimmering sheen, scientists report in a new study.

The discovery is based on 40-million-year-old fossils of an unidentified bird species that were stored at the Senckenburg Museum in Frankfurt, Germany for up to 30 years. The fossils represent the first evidence of ancient iridescence in feathers.

Iridescence is caused by an interaction of light with the material that the light hits. The color changes depending on the angle of observation, like the rainbow sheen on an oil slick.

The research moves scientists a step closer to determining the true colors of extinct creatures, said study co-author Richard Prum, an ornithologist at Yale University in New Haven, Connecticut.

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Just like modern-day starlings, some 40-million-year-old birds had glossy black feathers, according to the first evidence of iridescence ever seen in a fossilized feather (pictured).

The August 2009 research also moves scientists a step closer to determining the true colors of extinct creatures, the study authors say.

Photograph courtesy Jakob Vinther/Yale University

Ten New Studies Show Impact on Coast

Communities: Deep Ties, Deeper Pain

 Photograph by Meggan Haller, Keyhole Photo/Corbis

A man takes a break from refurbishing a boat in Bayou La Batre, Alabama—one of the fishing communities deeply affected by the Gulf spill.

Although community attachment is generally seen as a positive that aids in resilience, researchers from Louisiana State University found the negative mental health impacts of the spill were greatest for longtime residents with complex social networks of relatives, friends, and acquaintances. This sense of connectedness, and the accompanying pain, was underscored as people also depended on local resources for their livelihood.

The study is one of the first to systematically collect and analyze public health data on coastal populations affected by the spill. In a late June 2010 telephone survey of 935 households living in the coastal portions of Plaquemines, La Fourche, and Terrebonne parishes, the study found individuals with stronger community attachment exhibited higher self-reported levels of anxiety, worry, nervousness and fear.

Under normal circumstances, community attachment promotes better physical and mental health, but in times of crisis it can be problematic as people's way of life is threatened, the researchers noted.

"In crisis conditions, among those whose resources are threatened, we find that community attachment is associated with higher levels of negative affect," said the study, published in October 2011 in the journal American Behavioral Scientist.

This held true even for people who were not directly employed by the fishing and oil industries, suggesting that community attachment is strong in this area, and that people felt concerned about others whose livelihoods were directly affected.

But attachment may aid in recovery in the long run. Study lead author Matthew Lee, associate vice chancellor in the Office of Research and Economic Development at LSU, said that follow-up surveys have demonstrated that residents who had high community attachment and increased distress early on, "over time, they also recovered more quickly than those who were not highly attached to their communities." He said the findings are consistent with survey results of people recovering from Hurricane Katrina.
—Stacey Schultz

Dinosaur True Colors Revealed by Feather Find

Fossil Feather Melanosomes 

photograph courtesy University of Bristol

An international team of researchers reported finding fossilized rod-shaped eumelanosomes, shown here in a scanning electron micrograph, and spherical phaeomelanosomes in 125-million-year-old fossil birds and dinosaurs from China.

Eumelanosomes and phaeomelanosomes are two types of sub-cellular structures called melanosomes that are packed with the dark pigment melanin. A close packing of eumelanosomes from the extinct bird Confuciusornis suggests black was part of its color pattern, the new Nature study says.

Melanosomes are found in abundance within the feathers of living birds, and they have been reported before in fossil feathers.

This is the first time, though, that melanosomes have been found in the fossilized feathers of non-avian dinosaurs—such as Sinosauropteryx and Sinornithosaurus—and in the exquisitely preserved fossil birds from Liaoning Province, China.
 
Finding melanosomes in dinosaurs shows that the controversial hairlike structures seen in many feathered dinosaur fossils are indeed related to feathers. Analysis of fossilized melanosomes in creatures that lived and died millions of years ago promises to open up exciting new avenues of research and provide a glimpse into the previously unknown world of prehistoric color.

Ten New Studies Show Impact on Coast

Dead Zone: Mixed Views

 

 Photograph by NASA-GSFC, Science Faction/Corbis

 

Each September, a giant low-oxygen "dead zone" forms in the Gulf of Mexico as nutrients from agricultural runoff into the Mississippi River support the growth of oxygen-hungry algae, which can choke out other sea life. It can be seen here as the teal blue area along the Louisiana coastline.

A major question was whether this hypoxic area would be worsened by the assault of crude oil from the BP spill.

Researchers from Louisiana State University and the Louisiana Universities Marine Consortium concluded in a study published in February in Marine Pollution Bulletin that the net effect of the spill on the dead zone's size appeared to be "negligible."  The hypoxic area was 20,000 square kilometers in 2010, close to the size predicted in a new model the researchers developed. (The dead zone has ranged between 40 square kilometers and 22,000 square kilometers from 1985 through 2010, and has averaged 13,600 square kilometers, or 5,200 square miles.)

But the Louisiana researchers cautioned that Tropical Storm Bonnie, which crossed the Gulf during July 2010, may have had a great enough impact to disguise the impact of the crude oil on the Gulf dead zone.

When oil spilled into the Gulf from the Macondo well, that zone expanded, leading scientists to study the situation and offer a number of explanations.

Other scientists have noted impact from the BP spill on Gulf  oxygen levels. A study from the University of California, Santa Barbara, which appeared in the January 2012 issue of the journal Science indicated that abnormally large blooms of methane-consuming bacteria had reduced the Gulf of Mexico's methane and oxygen levels.

Barbara Mulligan

Dinosaur True Colors Revealed by Feather Find

Dinosaur-Feather Doppelganger? 

 

 

Photographs courtesy University of Bristol

The feather of an extinct Confuciusornis bird may have had colors similar to those in this modern feather from a zebra finch, according to the new study.

Feather color in Confuciusornis—an early beaked bird found in 120- to 130-million-year-old fossil beds in Liaoning Province, China—was inferred from microscopic melanosomes preserved in a fossil specimen.

Two types of melanosomes were found. Eumelanosomes (such as the finch eumelanosomes inset at left) are rodlike and associated with the colors black and grey in living birds. Phaeomelanosomes (inset right) are spherical and produce colors ranging from reddish brown to yellow. A lack of melanosomes makes white.

Using a scanning electron microscope, the researchers found that a fossil Confuciusornis feather contained both types of melanosomes and was likely multicolored in life.

Ten New Studies Show Impact on Coast

Northern Gannet: Delayed Impact 

Photograph by Brian Skerry, National Geographic

A northern gannet coasts on the water. Among the 102 species of birds harmed in the wake of the Deepwater Horizon explosion and oil spill, this long-distance migrating bird, known by the scientific name Morus bassanus, suffered the highest levels of oil damage. New research indicates much greater impact on immature birds than traditional counting methods would suggest, with long-term effects that remain to be seen.

"Seabirds are among the most obvious and immediate indicators of wildlife and environmental damage during marine pollution events," said William Montevecchi  of Memorial University, Newfoundland, Canada. He led a study published in Biology Letters, a journal of the Royal Society, that took advantage of advances in tracking technology to focus on the northern gannet, the largest seabird that breeds in the North Atlantic, and the only species of solely Canadian origin to be significantly affected by the spill. Using bird-borne global location sensors (GLS) and satellite tags to assess migration patterns, the researchers concluded the gannet population saw a much higher level of "oiling" than traditional assessment methods—bird "banding" or body counts—would suggest.

The Memorial University scientists extrapolated from GLS and satellite tags that the number of gannets of all age classes that winter in the Gulf of Mexico was 118,633 birds, more than double the number (54,905) estimated by traditional banding techniques.

In addition, the study authors stated that researchers traditionally assess seabird mortality by counting dead and dying animals along coasts, so they see only a fraction of those affected.

Most mature gannets had already returned to their breeding colonies in Canada before the Gulf spill in April, but the study concluded more than 50,000 immature gannets were in the Gulf during the spill and suffered oil-related mortality. The long-term effects of those gannet deaths will not show up until those birds would have reached sexual maturity—at about five or six years of age.

—Barbara Mulligan

Dinosaur True Colors Revealed by Feather Find

Showing Its Stripes

Photograph courtesy Institute of Fossil Paleontology and Paleoanthropology, Beijing

The feathers of Sinosauropteryx have been the subject of controversy ever since they were first described.

To the naked eye, the fossilized feathers are fine hairlike filaments that give the impression of being soft and downlike. Some researchers proposed that these structures were not feathers at all, however, but the remains of collagen from inside the tail.

The new study shows that these structures—visible in this fossil Sinosauropteryx as dark patches along the back and tail—are packed with melanosomes, pigment-carrying, sub-cellular structures found in the feathers of living birds but not in collagen.

This strengthens the argument that the fossil hairlike structures are protofeathers, an early stage in feather evolution before feathers had central shafts with vanes out to each side, as seen in modern birds.

How do fossil fuel emissions affect our health?

The substances that come out of a car's tailpipe, such as carbon monoxide, sulfur oxide, nitrogen oxide, hydrocarbons and carbon dioxide, are harmful to our health and to the environment. Carbon monoxide affects the blood supply and can cause heart disease; sulfur dioxide causes acid rain; nitrogen oxide causes the haze over populated cities; carbon dioxide gases produce the greenhouse effect; and hydrocarbons cause cancer. The federal government set up regulations to limit car emissions, ensuring a safer, healthier environment.

Notable Feathered Dinosaurs: Nomingia

Historical Period: Late Cretaceous (70-65 million years ago)

Size and Weight: About 6 feet long and 25 pounds

Diet: Probably omnivorous

Distinguishing Characteristics :Long legs; clawed hands; fan on end of tail

About Nomingia:

In most cases, the similarity between small theropod dinosaurs and birds is limited to their size, posture, and feather coats. Nomingia took its birdlike attributes one step further: this is the first dinosaur ever discovered to have sported a pygostyle, that is, a fused structure on the end of its tail that supported a fan of feathers. (All birds have pygostyles, though some species' displays are more garish than others, as witness the famous peacock.)

Despite its avian features, Nomingia was clearly more on the dinosaur than on the bird end of the evolutionary spectrum. It's likely that this dino-bird used its pygostyle-supported fan as a way of attracting mates--the same way a male peacock flashes its tail feathers to reel in available females.

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Check out Bob's Dinosaur Blog !

Bob Strauss is a freelance writer and book author; one of his specialties is explaining scientific concepts and discoveries to both a lay and professional audience.

Bob Strauss is the author of two best-selling question-and-answer books that range across the expanse of science, biology, history and culture: The Big Book of What, How and Why (Main Street, 2005) and Who Knew? Hundreds & Hundreds of Questions & Answers for Curious Minds (Sterling Innovation, 2007).

Ten New Studies Show Impact on Coast

Dolphins: Signs of Serious Illness

Photograph courtesy Reuters

In the depths of the ocean and on shore, science is only beginning to measure the long-term impact of the worst oil spill in U.S. history.

On the second anniversary of the Deepwater Horizon drilling rig explosion, a slew of new studies paint a complex picture of how the Gulf of Mexico's ecosystems absorbed the insult of 4.9 million barrels of crude oil.

The catastrophic failure of BP's Macondo well off the coast of Louisiana on April 20, 2010, triggered a blast and fire that took the lives of 11 rig workers and sent oil spewing from the deep sea bed for 87 days. Unprecedented steps were taken to minimize the amount of oil that reached shore, including the application of some 800,000 gallons (3,028,000 liters) of dispersants directly at the wellhead nearly a mile (1,500 meters) below the surface. Still, the oil left its mark, scientists now say, on marine mammals, salt marshes, corals, tiny organisms and coastal communities. The new studies track both lingering harm and recovery.

Bottlenose dolphins in oil-contaminated Barataria Bay off the coast of Louisiana are showing signs of serious illness, including extremely low weight, anemia, low blood sugar, and some symptoms of liver and lung disease, according to a health assessment conducted by U.S. National Oceanic and Atmospheric Administration (NOAA) scientists and their partners.

The scientists, who performed comprehensive physicals last summer on 32 dolphins from the bay, also found that half of the tested dolphins showed abnormally low levels of hormones that regulate stress response, metabolism, and immune function, indicating adrenal insufficiency. One of the dolphins in the survey was found dead on Grand Isle in January.

Lori Schwacke of NOAA, the project's lead investigator, said the findings were preliminary and could not be conclusively linked to the oil spill. But she added that control groups of dolphins living along the Atlantic coast and in other areas that were not affected by the 2010 spill did not manifest those symptoms.

"The findings that we have are consistent with other studies that have looked at the effects of oil exposure in other mammals," she said.

The study is a part of an ongoing examination of the U.S. government-led Natural Resource Damage Assessment process and the Gulf of Mexico Dolphin Unusual Mortality Event. Since February 2010, more than 675 dolphins have stranded in the northern Gulf of Mexico—a much higher rate than the usual average of 74 dolphins per year.

BP's Houston office did not respond to requests for comment on this research or the other scientific studies related to the Gulf Oil Spill.



—Barbara Mulligan

This story is part of a special series that explores energy issues. For more, visit The Great Energy Challenge.