October 29, 2007, 7:37 PM CT

Social standing influences elephant movement

When resources are scarce, who you know and where you're positioned on the social totem pole affects how far you'll go to search for food. At least that's the case with African elephants, as per a research studyled by ecologists at the University of California, Berkeley, who collaborated with scientists at Save the Elephants, a non-profit research organization based in Kenya, and at the University of Oxford in England.

An analysis of social dominance relationships and roaming patterns of free-ranging elephants in the Samburu and Buffalo Springs National Reserves in northern Kenya observed that elephants led by older, more dominant matriarchs tromped significantly fewer miles to seek food than those a few rungs lower on the social ladder.

During the dry season, when water and vegetation were harder to come by, dominant groups traveled an average of 4-5 kilometers per day, about half the distance of subordinate groups that would trek 8-11 kilometers per day.

Additionally, dominant groups in the study were more likely to stick to the preferred central, protected areas of the park, where fewer humans and more water can be found.

"This work shows, for the first time, the role social factors play in the dispersal of elephants in an ecosystem," said lead author George Wittemyer, a post-doctoral researcher at UC Berkeley's College of Natural Resources and a National Science Foundation International Research Fellow. "The findings have significant policy implications for how elephant populations are managed"......... Posted by: Kelly      Read more         Source

October 28, 2007, 1:49 PM CT

Burrowing mammals: how do they do that?

Next time you see a mole digging in tree-root-filled soil in search of supper, take a moment to ponder the mammal's humerus bones. When seen in the lab, they are nothing like the long upper arm bones of any other mammal, says Samantha Hopkins, a paleontologist at the University of Oregon.

Hopkins, a professor of geology in the UO's Robert D. Clark Honors College, studies the evolutionary history of burrowers, in search of why and how they adapted a physique for digging in response to environmental influences or other forced changes in habitats.

In a talk at the annual meeting of the Geological Society of America, Hopkins presented preliminary findings of one line of her research. Moles and mole rats, she said, are examples of mammals that have adapted to moving soil in rocky, root-packed soils, in opposition to most other burrowing mammals that prefer softer, dryer sandy soils.

"It requires a lot of morphological adaptation, a lot of tradeoffs, to be good at digging," she said. "That's intuitive to us as humans who have handled a shovel in the backyard. We know that it's really hard work to shift soil. Burrowing mammals acquire a complex of features that lets them handle whole days moving soil. They make for a great case for understanding convergent evolution because in spite of how difficult it is to do this -- in spite of all the costs of doing this -- it seems to be worthwhile enough that a number of mammals have done it through time"......... Posted by: Kelly      Read more         Source

October 26, 2007, 5:13 AM CT

Primates in peril

Mankinds closest living relatives the worlds apes, monkeys, lemurs and other primates are under unprecedented threat from destruction of tropical forests, illegal wildlife trade and commercial bushmeat hunting, with 29 percent of all species in danger of going extinct, as per a new report by the Primate Specialist Group of IUCNs Species Survival Commission (SSC) and the International Primatological Society (IPS), in collaboration with Conservation International (CI).

Titled Primates in Peril: The Worlds 25 Most Endangered Primates20062008, the report compiled by 60 experts from 21 countries warns that failure to respond to the mounting threats now exacerbated by climate change will bring the first primate extinctions in more than a century. Overall, 114 of the worlds 394 primate species are classified as threatened with extinction on the IUCN Red List.

Hunters kill primates for food and to sell the meat; traders capture them for live sale; and loggers, farmers, and land developers destroy their habitat. One species, Miss Waldrons red colobus of Ivory Coast and Ghana, already is feared extinct, while the golden-headed langur of Vietnam and Chinas Hainan gibbon number only in the dozens. The Horton Plains slender loris of Sri Lanka has been sighted just four times since 1937......... Posted by: Kelly      Read more         Source

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, 10:06 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

Thu, 25 Oct 2007 03:45:27 GMT

Cage Diving With Great White Sharks

Spectacular video of cage diving with Great White Sharks in Guadalupe. Original footage shot by Rob Breskal, video compiled and edited by Alex Finn. Posted by: Gerard      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