October 25, 2007, 10:30 PM CT

Frog study takes leaf out of nature's book

A brightly coloured tropical frog under threat of extinction is the focus of a new research project hoping to better understand how environment and diet influence its development and behaviour.

Biologists from The University of Manchester have teamed up with experts at Chester Zoo in the hope that their findings will not only help save the splendid leaf frog Cruziohyla calcarifer from extinction in the wild but provide clues as to how it can be better catered for in zoos and aquariums.

Loss of habitat in its native Costa Rican rainforest, combined with global declines in amphibian populations generally through a combination of environmental change and disease, have all contributed to the splendid leaf frog's precarious situation.

"This research aims to contribute to our understanding of the basic factors that influence the development and survival of these frogs," said Dr Richard Preziosi, a lecturer in the University's Faculty of Life Sciences, who is supervising the project.

"For instance, with the exception of certain mammals, we know surprisingly little about what animals should be eating. And yet the diet of splendid leaf frogs affects their colouration which, in turn, determines their mating behaviour.

"The global decline in amphibian populations means research such as this, carried out ex situ, is therefore critical for both conservation projects in the wild and for maintaining and successfully breeding the frogs in zoos and aquariums"......... Posted by: Kelly      Read more         Source

October 25, 2007, 10:15 PM CT

Why Do Autumn Leaves Bother to Turn Red?

Soils may dictate the array of fall colors as much as the trees rooted in them, as per a forest survey out of North Carolina.

By taking careful stock and laboratory analyses of the autumn foliage of sweetgum and red maple trees along transects from floodplains to ridge-tops in a nature preserve in Charlotte, N.C., former University of North Carolina at Charlotte graduate student Emily M. Habinck observed that in places where the soil was relatively low in nitrogen and other essential elements, trees produced more red pigments known as anthocyanins.

Habinck's discovery supports a 2003 hypothesis put forward to explain why trees bother to make red pigments, by plant physiologist William Hoch of Montana State University, Bozeman. Hoch observed that if he genetically blocked anthocyanin production in red-leafed plants, their leaves were uncommonly vulnerable to fall sunlight, and so sent less nutrients to the plant roots for winter storage.

For trees living in nutrient-poor soils, then, it makes sense to produce more anthocyanins, which protect the leaves longer, so as much nutrient as possible can be recovered from leaves before winter sets in. It is, after all, the process of recovering of nutrients from leaves which turns leaves from green to yellow, orange and sometimes anthocyanin-red......... Posted by: Erica      Read more         Source

October 25, 2007, 10:07 PM CT

Secrets Behind Butterfly Wing Patterns

The genes that make a fruit fly's eyes red also produce red wing patterns in the Heliconius butterfly found in South and Central America, finds a new study by a UC Irvine entomologist.

Bob Reed, assistant professor of ecology and evolutionary biology, discovered that genes involved in making insect eye pigments evolved over time to also make wing pigments in butterflies. This finding sheds light on the genetic causes of wing patterns and why, in the Heliconius, those patterns can vary widely from region to region.

"We observed that evolution is achieved primarily through recycling old genes into new functions, as opposed to evolving entirely new genes from scratch," Reed said.

Results of the study appeared online this week in the Proceedings of the Royal Society B.

Within one species of the butterfly genus Heliconius, more than 20 distinct wing patterns can exist in different geographic regions. Over time, the Heliconius evolves to look like local unrelated butterfly species that are poisonous to birds, a phenomenon called mimicry.

"It is a very basic textbook example of natural selection," Reed said. "If you look like you're poisonous, you're not going to get eaten and you can produce offspring".

Reed's study also explains under which conditions certain genes will cause a stripe on a Heliconius wing to become yellow or red......... Posted by: Kelly      Read more         Source

October 24, 2007, 8:27 PM CT

Parasites a key to the decline of red colobus monkeys

Forest fragmentation threatens biodiversity, often causing declines or local extinctions in a majority of species while enhancing the prospects of a few. A new study from the University of Illinois shows that parasites can play a pivotal role in the decline of species in fragmented forests. This is the first study to look at how forest fragmentation increases the burden of infectious parasites on animals already stressed by disturbances to their habitat.

The study, of black-and-white colobus monkeys and red colobus monkeys in tropical forests in western Uganda, appears in the American Journal of Primatology.

Once dominated by vast forests, Uganda now has less than one-twentieth of its original forest cover. As per the World Resources Institute, its tropical forests are being logged and converted to agricultural land at a rate that outpaces sub-Saharan Africa as a whole. Small tracts remain, however, hemmed in by pastures and croplands. A number of of the species that thrived in the original forests are struggling to survive in these parcels, which can be as small as one hectare in size.

"In Uganda, just looking at the primates, it's one of the most biodiverse places on the earth," said Thomas Gillespie, a professor of pathobiology and of anthropology, who is principal investigator on the study. "You've got 12 to 13 species of primates in a core undisturbed forest. But if you go into these forest fragments, you'll find only three or four species of primates"......... Posted by: Kelly      Read more         Source

October 24, 2007, 7:59 PM CT

Humans and monkeys share Machiavellian intelligence

When it comes to their social behavior, people sometimes act like monkeys, or more specifically, like rhesus macaques, a type of monkey that shares with humans strong tendencies for nepotism and political maneuvering, as per research by Dario Maestripieri, an expert on primate behavior and an Associate Professor in Comparative Human Development and Evolutionary Biology at the University of Chicago.

After humans, rhesus macaques are one of the most successful primate species on our planet; our Machiavellian intelligence may be one of the reasons for our success wrote Maestripieri in his new book Macachiavellian Intelligence: How Rhesus Macaques and Humans Have Conquered the World.

Maestripieri has been studying monkeys for more than 20 years and has written extensively on their behavior. He has studied them in Europe, at a research center in Atlanta, and on an island in Puerto Rico, where scientists established a rhesus macaque colony for scientific and breeding purposes.

Rhesus macaques live in complex societies with strong dominance hierarchies and long-lasting social bonds between female relatives. Individuals constantly compete for high social status and the power that comes with it using ruthless aggression, nepotism, and complex political alliances. Sex, too, can be used for political purposes. The tactics used by monkeys to increase or maintain their power are not much different from those Machiavelli suggested political leaders use during the Renaissance......... Posted by: Kelly      Read more         Source

October 23, 2007, 10:09 PM CT

Right of Passage for Moose

A new study shows that pregnant moose move closer to town when it's time to give birth. It's not the pickles and ice cream they're after, however, but security from road-shy grizzly bears. The study, by Wildlife Conservation Society (WCS) biologist Dr. Joel Berger, focused on moose in the Greater Yellowstone Ecosystem. By moving closer to people, the animals can better shield their calves from becoming bear dinner. The study was reported in the journal Biology Letters.

WCS scientists tracked both moose and bears, finding that pregnant moose have shifted their movements each year for the past decade about 125 meters closer to roads during calving season.

"Given that brown bears avoid areas within approximately 500 meters of roads in Yellowstone and elsewhere, moose mothers have apparently buffered against predation on offspring using roadside corridors," Berger said.

He also cited similar examples where prey species use humans as cover, including vervet monkeys in Kenya and axis deer in Nepal. Both have learned to avoid big cats by staying close to ranger stations. The bears and cats do their best to stay away from people for a simple reason, as per Berger: "We humans tend to be less kind to predators".

Berger's study reveals another interesting fact. National parks are not necessarily showcases of natural ecosystems; in some cases, the parks and the infrastructure we build to support the parks may unwittingly change or shape the behavior of wildlife in new ways......... Posted by: Kelly      Read more         Source

October 23, 2007, 9:42 PM CT

Taking Wolves Into Classrooms

To celebrate National Wolf Awareness Week, the California Wolf Center, located in rural San Diego County, approximately four miles from Julian, is bringing its wolves to classrooms throughout the world.

The National Science Foundation (NSF) funds HPWREN, an interdisciplinary and multi-institutional University of California, San Diego, research and education program in order to assess the feasibility of wireless data networking technologies. Its connectivity is now used for a variety of activities at the California Wolf Center ranging from motion sensing cameras and real-time acoustics sensors to live presentations from the hard-to-reach facility to metropolitan university classrooms.

Erin Hunt, caretaker of the 35 wolves living onsite, explains that the HPWREN connectivity assists the Wolf Center in achieving its overall goals, such as carrying out research correlation to wolf vocalization, feeding behavior and natural pack interaction. "Anyone who has access to the Internet can view our wolves in real-time while they are exhibiting their natural behaviors and that's a great education tool," she says.

Cameras and microphones networked through HPWREN are used to study behavior and vocalization of wolves, how they interact with one another, and how best to manage them. Specifically, the real-time monitoring equipment includes two antennae for the wireless access point. These antennae support mobile stations that allow scientists and students to make live presentations from the Wolf Center to remote locations such as university classrooms......... Posted by: Kelly      Read more         Source

October 23, 2007, 9:39 PM CT

Mercury Emissions from U.S. Forest Fires

Forest fires and other blazes in the United States release about 30 percent as much mercury as the nation's industrial sources, as per a new study by researchers at the National Center for Atmospheric Research (NCAR)in Boulder, Colo.

Fires in Alaska, California, Oregon, Louisiana and Florida emit especially large quantities of the toxic metal, and the Southeast emits more than any other region, as per the study.

The researchers estimate that fires in the continental United States and Alaska release about 44 metric tons of mercury into the atmosphere every year.

The study was funded by the National Science Foundation (NSF), NCAR's principal sponsor, as well as by the Electric Power Research Institute and the Environmental Protection Agency.

"It's important to understand the movement of mercury through the environment," said Cliff Jacobs of NSF's atmospheric sciences division. "This study offers new insights, and points to the need for additional research to reduce uncertainty and improve our understanding of the chemical and physical processes at work".

It is the first study to estimate the amount of mercury emissions for each state, based on a new computer model developed at NCAR. The authors caution that their estimates for the nation and for each state are preliminary, and are subject to a 50 percent margin of error......... Posted by: Erica      Read more         Source

October 23, 2007, 9:36 PM CT

Duckling Mole Rats Might Hold Key To Longevity

Who would have thought that the secrets to long life might exist in the naked, wrinkled body of one of the world's ugliest animals? Probably not a number of, but current research may be leading seekers of the Fountain of Youth to a strange little beast - the naked mole rat.

The naked mole rat is certainly not one of nature's cuddliest species. These small rodents are hairless, wrinkled, blind and buck-toothed. Stan Braude, Ph.D., lecturer in biology in Arts & Sciences at Washington University in St. Louis, however, is attracted to these animals and has been studying them for over 25 years, with about 20 of those years being in the field in Kenya.

Braude is currently working on a new book that will serve as a synthetic review of the past 20 years of research on naked mole rats. While various research has been conducted on naked mole rats in a lab setting, Braude and his students are the only researchers out in the wild with them.

"I make the case [in my book] that if you really want to understand the lab work you also have to know what these animals are doing in the wild," said Braude.

Some of the "hottest" research on naked mole rats today concerns senescence, or aging. Naked mole rats in the lab have reached up to 28 years of age. And it's not just the controlled environments of their captivity that are doing this. Braude has observed mole rats in the wild that are 17 years and older. But these are the breeders. Lab researchers didn't realize that in the wild workers only live two or three years......... Posted by: Kelly      Read more         Source

October 23, 2007, 9:02 PM CT

New population of Iberian lynx raises hope

Spanish authorities have announced they have discovered a previously unknown population of Iberian lynx, triggering hope for one of the worlds most endangered cat species, said World Wildlife Fund today.

We are excited and amazed by this discovery, said Luis Suarez, head of WWFs Species Program in Spain. However, we are a long way from saving the Iberian lynx from imminent extinction.

It appears that the new population was discovered in previously unsurveyed estates in Castilla - La Mancha (Central Spain). This Iberian community is one of the most sparsely populated of Spain's autonomous communities.

At present, the exact numbers and location of the newly discovered population are being kept confidential, but the population is believed to be made up of both adults and cubs.

Until the exact location is known, conservationists cannot confirm if this population is genetically distinct from the larger and more stable population of lynx found in Andujar (South).

As per the most recent comprehensive survey previous to this discovery, there were about 100 adult Iberian lynx in two isolated breeding populations in southern Spain. The population is thought to have since risen to some 110 adults.

The Iberian Lynx faces myriad threats - a lack of prey, accidental deaths from cars and trucks on Spanish roads, and new construction work destroying habitats......... Posted by: Kelly      Read more         Source