October 11, 2006, 4:57 AM CT

Some Butterflies Travel Farther, Reproduce Faster

Scientists have uncovered physiological differences among female Glanville fritillary butterflies that allows some to move away from their birth place and establish new colonies. These venturesome butterflies are stronger fliers and reproduce more quickly in comparison to their less mobile female relatives.

The study is a window to how genetic differences influence behavior and how the environment influences genetic change by favoring individuals with certain traits, said lead author Howard W. Fescemyer. The new study found significant physiological differences that may account for the more adventuresome behavior of certain of the females.

The work is important because human activity is disrupting a number of animal habitats, forcing more and more species to do what the fritillary has long done in its naturally fragmented environment. Researchers want to know how this fragmentation influences a species' evolution.

"We may be selecting for genes that enhance the dispersal or migratory capability of animals when we fragment the landscape," Fescemyer said. The animals best able to migrate are more likely to survive and reproduce. "What we learn could apply to any organism that has to move to find food," he added.



land Islands are natural laboratory........

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October 11, 2006, 4:50 AM CT

Giant Insects Might Reign

The delicate lady bug in your garden could be frighteningly large if only there was a greater concentration of oxygen in the air, a new study concludes. The study adds support to the theory that some insects were much larger during the late Paleozoic period because they had a much richer oxygen supply, said the study's lead author Alexander Kaiser.

The study, "No giants today: tracheal oxygen supply to the legs limits beetle size,'' will be presented Oct. 10 and 11 at Comparative Physiology 2006: Integrating Diversity. The conference will be held Oct. 8-11 in Virginia Beach. The research was carried out by Alexander Kaiser and Michael C. Quinlan of Midwestern University, Glendale, Arizona; J. Jake Socha and Wah-Keat Lee, Argonne National Laboratory, Argonne, IL; and Jaco Klok and Jon F. Harrison, Arizona State University, Tempe, AZ. Harrison is the principal investigator.

The Paleozoic period, about 300 million years ago, was a time of huge and abundant plant life and rather large insects -- dragonflies had two-and-a-half-foot wing spans, for example. The air's oxygen content was 35% during this period, in comparison to the 21% we breathe now, Kaiser said. Scientists have speculated that the higher oxygen concentration allowed insects to grow much bigger.

Tubes carry oxygen........

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October 9, 2006, 9:21 PM CT

mammalian 'disorderly' proteins

Investigators at St. Jude Children's Research Hospital turned up the heat on "disorderly" proteins and confirmed that most of these unruly molecules perform critical functions in the cell. The St. Jude team completed the first large-scale collection, investigation and classification of these so-called intrinsically unstructured proteins (IUPs), a large group of molecules that play vital roles in the daily activities of cells.

The new technique for collecting and identifying IUPs is important because although scientists have been aware of the existence of flexible proteins for many years, they have only recently realized that these molecules play major biological roles in the cell, according to Richard Kriwacki, Ph.D., an associate member of the St. Jude Department of Structural Biology. Moreover, he said, previous work by other researchers suggested that a large proportion of IUPs in mammalian cells play key roles in transmitting signals and coordinating biochemical and genetic activities that keep the cell alive and functioning. Kriwacki is senior author of a report on this work that appears in the prepublication online issue of Journal of Proteome Research.

"Until now there was no way to separate IUPs in large numbers from the more structured proteins and confirm their roles in the cell," Kriwacki said. "Our new technique selectively concentrates the IUPs that are involved in regulating functions in the cell and transmitting signals within them".........

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October 8, 2006, 6:48 PM CT

Rearing An Army To Save Wheat

With wheat stem sawfly natural enemies in demand, Montana State University entomologists are investigating ways of increasing their availability.

This fall, the entomologists are concluding a two-year study that involved mass-rearing parasitic wasps that attack wheat stem sawfly larvae that tunnel the interior of developing wheat plants. The team includes entomologists David Weaver, master's graduate Godshen Pallipparambil-Robert and undergraduate Melissa Frazier of Kalispell.

Pallipparambil-Robert's work, as part of his completed master's degree, used large cages placed over wheat at the Post Agronomy Farm west of Bozeman. He deliberately infested the enclosed wheat with wheat stem sawflies, and then introduced the parasitic wasps. His research explored whether supplemental food provided as nectar from flowering plants or as honey water increases the number of parasitic wasps produced in each cage. Another part of his thesis project examined whether using special ultraviolet and visible light-transmitting windows increases the number of parasites.

"After two years, the research shows that the added light consistently causes small increases in the number of parasitic wasps, while the food supply is probably not important in these mass-rearing cages, because the parasitoids were added in large numbers, and attacked the available sawflies before the need to feed may have become critical " Weaver said. At lower parasitoid densities, supplemental food might be much more important, and research from other systems suggests that this is definitely true in natural settings. However, the goal of the research is to find ways to increase the supply of parasitoids from a controlled system to Montana wheat growers.........

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October 8, 2006, 6:36 PM CT

Whiskers Sense Three-dimensional World

Many mammals use their whiskers to explore their environment and to construct a three-dimensional image of their world. Rodents, for example, use their whiskers to determine the size, shape and texture of objects, and seals use their whiskers to track the fluid wakes of their prey.

Two Northwestern University engineers have been studying the whisker system of rats to better understand how mechanical information from the whiskers gets transmitted to the brain and to develop artificial whisker arrays for engineering applications.

Mitra J. Hartmann, assistant professor of biomedical engineering and mechanical engineering in the McCormick School of Engineering and Applied Science, and Joseph H. Solomon, one of Hartmann's graduate students, have now developed arrays of robotic whiskers that sense in two dimensions, mimicking the capabilities of mammalian whiskers. They demonstrate that the arrays can sense information about both object shape and fluid flow.

A paper about the arrays, which may find application on assembly lines, in pipelines or on land-based autonomous rovers or underwater vehicles, was published in the Oct. 5 issue of the journal Nature.

"We show that the bending moment, or torque, at the whisker base can be used to generate three-dimensional spatial representations of the environment," said Hartmann. "We used this principle to make arrays of robotic whiskers that in many respects closely replicate rat whiskers." The technology, she said, could be used to extract the three-dimensional features of almost any solid object.........

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October 4, 2006, 10:19 PM CT

Loss Of Trout Habitat In The Southern Appalachians

USDA Forest Service (FS) research projects that between 53 and 97 percent of natural trout populations in the Southern Appalachians could disappear due to the warmer temperatures predicted under two different global climate circulation models. In an article published October 2 in the online version of the Transactions of the American Fisheries Society, Patricia Flebbe, research biologist at the FS Southern Research Station unit in Blacksburg, VA, maps out trout habitat in a future, warmer climate.

The three species of trout that live in the Southern Appalachians--native brook and the introduced rainbow and brown trout --all require relatively low stream temperatures to survive. Average air temperature in the United States has increased by about 0.6 C (1o F) over the last 100 years, and is projected to increase 3 to 5C (5.4 to 9o F) over the next century, causing a corresponding warming of stream temperatures.

"Trout species in the Southern Appalachians are already at the southern limits of their ranges," says Flebbe. "If temperatures warm as much as predicted, trout habitat in the region will definitely shrink".

To estimate trout habitat in relation to higher temperatures, Flebbe and fellow researchers Laura Roghair from the Virginia Tech Conservation Management Institute and former FS employee Jennifer Bruggink produced a regional map of wild trout habitat based on information from stream samples, expert knowledge, and suitable land cover. They then developed a model that uses elevation and latitude as surrogates for temperature, producing spatially explicit information about how much trout habitat will be left as temperatures rise over the next 100 years.........

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October 3, 2006, 9:33 PM CT

Fisheries Linked To Decline In Albatross Population

Fishermen caught and killed about 1 percent of the world's waved albatrosses in a year, as per a new study by Wake Forest University biologists.

"If that happens every year, that is not sustainable," said Jill Awkerman, a Wake Forest graduate student who is the lead author of the study published online Sept. 26 in the journal Biological Conservation. "In a matter of decades, you could be talking about extinction".

Awkerman's research shows the waved albatrosses are unintentionally killed when caught in fishing nets or on fishing hooks, but are also intentionally harvested for human consumption.

She worked with David Anderson, professor of biology at Wake Forest, on the study. Since 1999, Anderson and his research team have studied survival rates of waved albatrosses on Española Island in the Galapagos Islands, located off the coast of Ecuador. Española is a small island where almost all of the waved albatrosses in the world nest and breed.

Identification bands from 23 waved albatrosses killed in 2005 were returned to the scientists by fishermen. The scientists put bands on a total of 2,550 albatrosses, so almost one out of every 100 birds is being killed unintentionally or intentionally by fishermen.

As part of the study, the scientists and his colleagues in Peru also surveyed 37 major fishing communities to investigate albatross interactions with fisheries in the main areas where they forage for food off the Peruvian coast. They sent observers out on fishing vessels to find out what happens when fishermen encounter the giant seabirds. The observers observed that some albatrosses became tangled accidentally in submerged gillnets. Eventhough some of the birds caught in nets could be released, fishermen often killed them for food instead. The fishermen also intentionally caught albatrosses on baited hooks.........

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October 3, 2006, 5:20 AM CT

Reintroducing Megafauna To North America

Dozens of megafauna (large animals over 100 pounds) such as giant tortoises, horses, elephants, and cheetah went extinct in North America13,000 years ago during the end of the Pleistocene. As is the case today in Africa and Asia, these megafauna likely played keystone ecological roles via predation, herbivory, and other processes. What are the consequences of losing such important components of America's natural heritage?.

In the recent issue of The American Naturalist, a group of 12 ecologists and conservationists provide a detailed proposal for the restoration of North America's lost megafauna. Using the same species from different locales or closely related species as analogs, their project "Pleistocene Rewilding" is conceived as carefully managed experiments in an attempt to learn about and partially restore important natural processes to North American ecosystems that were present for millennia until humans played a significant role in their demise 13,000 years ago.

"Over the past 30 years, more and more evidence suggests that if we lose large animals from ecosystems, they often collapse and biodiversity, along with society, are the ultimate losers," says Josh Donlan (Cornell University). "For millions of years, large animals were the norm all over the world we should start thinking about reintroducing these large animals and restoring these important processes back to ecosystems."........

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October 3, 2006, 5:16 AM CT

Chilly Bugs At Bottom Of The World

The larvae of Antarctic midges never stop producing special proteins that minimize environmental stress, allowing them to withstand a range of intense environmental conditions in one of the world's harshest environments.

Researchers observed that adult midges (Belgica antarctica) lose their ability to continually express these protective heat-shock proteins. Instead, like most animals, adult midges produce these proteins only when they are stressed. The discovery currently appears in the online edition of the Proceedings of the National Academy of Sciences.

The proteins help defend the larval midges against environmental stresses including temperature changes as well as changes in water, oxygen and pH levels, said David Denlinger, the study's lead author and a professor of entomology at Ohio State University.

"They've somehow figured out a way to maintain a level of these heat-shock, or stress, proteins and still make proteins that are vital for growth and development," he said.

This mechanism seems to offer the larvae protection during their two-year life span, most of which is spent encased in ice.

All animals, including humans, make heat shock proteins, but normally they only do so during times of extreme physical stress. Curiously, adult midges don't express these proteins all the time - only during periods of extreme environmental stress. Yet when most insects express stress proteins, it temporarily compromises the production of other proteins, Denlinger said.........

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October 1, 2006, 8:56 PM CT

Big Welcome For A Big Cat

A feline ambassador from Pakistan made his debut in the Himalayan Highlands of the Bronx Zoo on September 25, following an historic ceremony that united the Pakistani and U.S. governments. Endangered snow leopard cub Leo was transferred to the Bronx Zoo this past summer after he was discovered orphaned in the wild, unable to fend for himself.

Click here to read more about the expedition and diplomatic collaboration that led to Leo's relocation.

First lady of Pakistan Sebha Musharraf was among the honored guests to officially welcome Leo. "Wildlife is among our greatest resources," she said. "It provides both beauty and a discovery of the natural world around us. Leo is a most fitting wildlife ambassador, representing both Pakistan and his species. It is our hope that he will inspire others to care".

Assistant Secretary of State for Oceans, Environment and Science Claudia A. McMurray also attended the welcome ceremony. She commented, "Today we celebrate the arrival of this beautiful snow leopard cub as a symbol of hope for the global effort to save endangered wildlife. I am particularly pleased that diplomacy between the United States and Pakistan played a key role in making this accomplishment possible".

The 14-month-old male cub will remain at the Bronx Zoo until an appropriate facility can be constructed in Pakistan. As a world leader in snow leopard care-and the first zoo in the Western Hemisphere to exhibit these big cats, in 1903-the Bronx Zoo will provide a secure refuge for the growing cub.........

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