June 7, 2007, 7:37 PM CT

Chimpanzees Can Sustain Multiple-tradition Cultures

Researchers have long wondered if local animal cultures exist, and now, based on findings by scientists at the Yerkes National Primate Research Center at Emory University, the University of Texas and St. Andrews University, Scotland, they have their answer: Yes.

The study, available in todays online edition of Current Biology, confirms captive chimpanzees have the capacity to sustain the same kind of multiple-tradition cultures a number of scientists believe exist in the wild, providing further evidence chimpanzees and humans shared a common ancestor five to six million years ago who had a similar level of cultural complexity.

For years, primatologists have suggested different communities of chimpanzees across Africa vary in a number of behavior patterns, indicating they have cultures specific to each community. In the wild, however, it is difficult to prove behaviors are passed on by observation and learning.

In this study, members of the international collaborative research team taught forms of tool use and food extraction techniques to high-ranking individuals in four different captive chimpanzee communities. Scientists then observed as those individuals passed on the techniques to other members of their communities. The scientists included Frans de Waal, PhD, Victoria Horner, PhD, and Kristin Bonnie from the Yerkes Research Center, lead scientists Andrew Whiten, PhD, and Antoine Spireti from St. Andrews University, and Susan Lambeth, PhD, and Steven Schapiro, PhD, from the University of Texas......... Posted by: Kelly      Read more         Source

June 6, 2007, 9:33 PM CT

Caribbean Frogs Started From South America

Nearly all of the 162 land-breeding frog species on Caribbean islands, including the coqui frogs of Puerto Rico, originated from a single frog species that rafted on a sea voyage from South America about 30-to-50-million years ago, as per DNA-sequence analyses led by a research group at Penn State, which would be reported in the 12 June 2007 issue of the Proceedings of the National Academy of Sciences and posted in the journal's online early edition this week. Similarly, the researchers observed that the Central American relatives of these Caribbean frogs also arose from a single species that arrived by raft from South America.

"This discovery is surprising because no prior theories of how the frogs arrived had predicted a single origin for Caribbean terrestrial frogs and because groups of close relatives rarely dominate the fauna of an entire continent or major geographic region," explained Penn State's Blair Hedges, the evolutionary biologist and professor of biology who directed the research. "Because land connections among continents have allowed land-dwelling animals to disperse freely over millions of years, the fauna of any one continent is commonly a composite of a number of types of animals".

The field work for the study mandatory nearly three decades to complete because a number of of the species are restricted to remote and isolated mountain tops or other inaccessible areas. Some species included in the study now are thought to beextinct because of habitat degradation and possibly other causes such as climate change......... Posted by: Kelly      Read more         Source

May 31, 2007, 11:54 PM CT

Threats to wild tigers growing

The wild tiger now occupies a mere 7 percent of its historic range, and the area known to be inhabited by tigers has declined by 41 percent over the past decade, as per an article reported in the June 2007 issue of BioScience. Growing trade in folk medicines made from tiger parts and tiger skins, along with habitat loss and fragmentation, is thought to bethe chief reason for the losses. The assessment, by Eric Dinerstein of the World Wildlife Fund and 15 coauthors, describes the wild tiger's population trajectory as "catastrophic" and urges international cooperation to ensure the animal's continued existence in the wild.

Despite the discouraging numbers--there are thought to beonly about 5,000 wild tigers left--some conservation programs have been successful. Dinerstein and his coauthors highlight a program in the Terai-Arc Landscape of northwestern India and southern Nepal as a notable victory. The scheme features wildlife corridors that connect 12 reserves. Tiger conservation efforts have also been successful in the Russian Far East. A number of tiger reserves in the India, in contrast, have been mismanaged and have failed to protect the animals, as per the article.

Plans to make use of tiger parts harvested from farmed tigers in China represent an emerging threat, the authors argue. Any trade in tiger parts encourages poaching, because products made from animals farmed at great expense cannot be distinguished from products made from wild tigers......... Posted by: Kelly      Read more         Source

May 30, 2007, 0:07 AM CT

Sharks Use Their Noses And Bodies To Locate Smells

Sharks are known to have a keen sense of smell, which in a number of species is critical for finding food. However, as per new research from Boston University marine biologists, sharks can not use just their noses to locate prey; they also need their skin specifically a location called the lateral line. The lateral line is an organ used by all fish to detect, with exquisite sensitivity, movement and vibration in the surrounding water. As per the research team, this is similar to how humans can sense air flow with the small hairs on the face. Until now, it had not been demonstrated that the lateral line also aids in the tracking of odor plumes.

"Odor plumes are complex, dynamic, three-dimensional structures used by a number of animal species to locate food, mates, and home sites. However, odor itself has no directional properties, so animals must use a variety of senses to get the directional information for a smell," said Jelle Atema, professor of biology at Boston University and co-author of study.

The new study examined the contribution of the olfactory system, the lateral line, and vision in odor source detection and localization in the smooth dogfish shark. The results, which appear in the June 1 issue of the Journal of Experimental Biology, show that this shark is severely handicapped in its ability to locate the source of an odor when deprived of information from its lateral line, especially in the dark......... Posted by: Kelly      Read more         Source

May 30, 2007, 0:00 AM CT

Eavesdropping comes naturally to young song sparrows

Long before the National Security Agency began eavesdropping on the phone calls of Americans, young song sparrows were listening to and learning the tunes sung by their neighbors.

University of Washington scientists exploring how male song sparrows (Melospiza melodia) acquire their song repertoires have found the first evidence that young birds choose a number of of their songs by eavesdropping on the tuneful interactions between other sparrows.

In laboratory experiments, the young sparrows were exposed to two adult "tutors," one of which they directly interacted with vocally and a second one that they only overheard singing with another young bird. Even though they learned from both tutors, the young birds acquired more than twice as a number of songs from the tutor on which they eavesdropped, said Michael Beecher, lead author of the study and a UW psychology and biology professor.

Researchers study song learning in songbirds in part because it has many parallels with human language learning, and Beecher thinks eavesdropping also could play a role in how infants learn language.

Sparrows in the wild are thought to learn their songs in two phases. The first phase occurs in their first summer, when they hear and memorize songs sung by adult birds. The following spring, when the young birds are establishing their own territory, they modify and prune their repertoire so their songs are more similar to their neighbors. A song sparrows repertoire crystallizes at around 10 to 11 months of age and does not change......... Posted by: Kelly      Read more         Source

May 23, 2007, 8:11 PM CT

No sex please, we're female sharks!

Female sharks can reproduce without having sex, researchers have found. A female hammerhead shark has given birth without mating with a male and its offspring has no paternal DNA.

An international team of scientists from Queen's University Belfast, the Guy Harvey Research Institute at Nova Southeastern University in Florida and the Henry Doorly Zoo in Nebraska has found evidence that sharks can reproduce asexually by an unusual method known as "parthenogenesis". This is the first scientific report of asexual reproduction in sharks.

Head of the Queen's research team and co-author of study, Dr Paulo Prodohl, from the School of Biological Sciences, said: "The findings were really surprising because as far as anyone knew, all sharks reproduced only sexually by a male and female mating, requiring the embryo to get DNA from both parents for full development, just like in mammals".

"The discovery that sharks can reproduce asexually by parthenogenesis now changes this paradigm, leaving mammals as the only major vertebrate group where this form of reproduction has not been seen".

The long-term study was prompted by the unexpected birth of a baby hammerhead shark in an aquarium at the Henry Doorly Zoo in December 2001. The astonishing thing about the birth was that none of the three candidate mother hammerheads in the tank, all of whom been caught in Florida waters as babies themselves, had been exposed to any male hammerhead sharks for the three years since their captivity......... Posted by: Kelly      Read more         Source

May 23, 2007, 8:05 PM CT

One in six European mammals threatened with extinction

The first assessment of all European mammals, commissioned by the European Commission and carried out by the World Conservation Union (IUCN), shows that nearly one in every six mammal species is now threatened with extinction. The population trends are equally alarming: a quarter (27%) of all mammals has declining populations and a further 33% had an unknown population trend. Only 8% were identified as increasing, including the European bison, thanks to successful conservation measures.

Europe is now home to the world's most threatened cat species, the Iberian Lynx, and the world's most threatened seal, the Mediterranean Monk Seal, both classified as Critically Endangered.

Environment Commissioner Stavros Dimas said: "The results of the report highlight the challenge we currently face to halt the loss of biodiversity by 2010, as European governments have promised. It is clear that the full implementation of the Habitats Directive, which covers nearly all mammals found threatened in this assessment, is of utmost importance to protect Europe's species".

World Conservation Union (IUCN) Director-General Julia Marton-Lefèvre said: "This new assessment proves that a number of European mammals are declining at an alarming rate. However, we still have the power to reverse that trend, as the case of the European bison which was brought back from extinction clearly shows."........ Posted by: Kelly      Read more         Source

Thu, 24 May 2007 01:36:46 GMT

Toad eggs

These are, I think, the eggs of a Woodhouse’s toad. This critter seems to go by several names, and there are at least three kind with overlapping ranges, but at least one makes my part of Missouri its home.

We came across these eggs during our counterclockwise walk around the lake the last time we were there. They were floating near the shore on the south side of the lake. Coincidentally, or maybe not, we rarely see fish in the shallows on this side of the lake. I’m sure the water on the other side of the lake is warmer since it gets nearly constant sun, so the little fishies would, possibly, more likely congregate over there. And that means that this side of the lake might be more egg friendly.

The throngs of tadpoles we had seen before were mostly gone. We still saw many, but they weren’t all jostling for space as they had been. Perhaps this succession of egg laying and hatching reduces the competition for food for the new tadpoles. It seems just as likely to me, though, that these late-hatching tadpoles might just become convenient meals for the tadpoles that hatched out weeks before.

You can go here to click on a link (scroll down) and listen to the call of these toads. I can’t say that I can recall hearing this call when I’ve been at Roundrock, but the toads are mostly nocturnal, and I haven’t been there at night when the lake has been full, so maybe I’ll be hearing a new sound in the woods this year.

Missouri calendar:

• Green sunfish and bluegill begin nesting.
• Antlers begin to grow on white-tailed deer bucks.

Posted by: Roundrockjournal      Read more     Source

Mon, 21 May 2007 02:56:09 GMT

Cyclones Threatening Green Turtles

Global warming is posing many problems to our environment and as it’s getting worse, it is said that species like the green turtles are increasingly at risk and they may extinct within 100 years.

Change in climate contributes to stronger tropical cyclones which are very likely to kill or wash away the green turtles.

Ph.D. candidate David Pike and his fellow researchers from the School of Biological Sciences at the University of Sydney have studied around 40,000 sea turtles nests on an uninhabited 24-mile stretch of beach along the Atlantic coast of Florida.


For around ten years the researchers surveyed the beach for turtles emerging to lay eggs or for nesting at the beginning in April and end in late September. This nesting season coincides with tropical storm season, which runs from June to November.

Leatherback turtles and loggerhead turtles nest and hatch earlier to storm season but the nesting season of green turtles occurs during Floridas tropical cyclone season, which means that their nests and the developing eggs are at risk of being washed away and killed.

The report of the finding is online in the journal Oecologia.

Image Credit: [1], [2]
Source: Discovery Posted by: Rajni      Read more     Source

May 17, 2007, 7:04 PM CT

Spread Of Rabies In Raccoon Outbreak

Analyzing 30 years of data detailing a large rabies virus outbreak among North American raccoons, scientists at Emory University have revealed how initial demographic, ecological and genetic processes simultaneously shaped the virus's geographic spread over time. The study appears online in the Proceedings of The National Academy of Sciences.

"Our study demonstrates the combined evolutionary and population dynamic processes characterizing the spread of a pathogen after its introduction into a susceptible host population," says Leslie Real, PhD, Emory University Asa G. Candler professor of biology. During invasion, emerging pathogens, such as rabies, ebola and hantavirus, undergo rapid evolution while expanding their numbers and geographic range; yet, it is difficult to demonstrate how these processes interact, says Dr. Real.

However, this particular outbreak, which went largely unchecked until relatively recently, was uncommonly well documented both spatially and temporally. Data were methodically collected and stored since the outbreak began in the mid-1970s. In addition, the Centers for Disease Control and Prevention (CDC) had been stockpiling viral samples from the outbreak since 1982, giving researchers a treasure trove of genetic data ripe for analysis......... Posted by: Kelly      Read more         Source