September 2, 2006, 9:39 PM CT

Mother Deer Cannot Recognize Offspring

In a new study from The American Naturalist, scientists from the University of Zurich studied vocal communication between fallow deer mothers and their offspring. They observed that only adult females have individually distinctive calls, meaning that fawns are able to distinguish their mother's calls from those of other females, but mothers are not able to distinguish between the calls of their own offspring and other fawns. This is in contrast to prior studies and provides a novel insight into parent-offspring recognition mechanisms.

"Newborn fawns lie concealed and silent in vegetation away from their mothers to avoid detection by predators, and mothers return intermittently to feed them," write Marco Torriani, Elisabetta Vannoni, and Alan McElligott. "Vocal communication is very important for ungulate hider species because mothers and offspring rely on contact calls for reunions to occur".

The scientists tested vocal recognition on Swiss fallow deer farms using recordings and playback experiments. Similar research on domestic sheep and reindeer has shown that both mothers and offspring are able to recognize each other based on individually distinctive contact calls. However, reindeer and sheep tend to populate open habitats lacking cover, and the scientists argue that the recognition system employed by deer evolved in habitats providing abundant cover for newborns. While sheep and reindeer are mobile soon after birth and thus remain in constant close contact with the mother mother-offspring contact for deer is limited during the first few weeks of life to when nursing occurs.........

Posted by: Kelly      Permalink         Source

August 31, 2006, 5:15 AM CT

Ammunition Main Source Of Lead Poisoning In Condors

A study led by environmental toxicologists at the University of California, Santa Cruz, has confirmed what wildlife biologists have long suspected: Bullet fragments and shotgun pellets in the carcasses of animals killed by hunters are the principal sources of lead poisoning in California condors that have been reintroduced to the wild.

Lead poisoning is a major factor limiting the success of efforts to rebuild populations of the endangered California condor. Since the mid-1980s, condors have been bred in captivity and released back into the wild in California, Arizona, and Baja California. The birds, which feed on carrion, can ingest lead from ammunition in animal carcasses or gut piles left behind by hunters.

The UCSC scientists used a "fingerprinting" technique based on the unique isotope ratios found in different sources of lead. The technique enabled them to match the lead in blood samples from condors to the lead in ammunition. Their findings were published online today by the journal Environmental Science & Technology.

"There had been anecdotal reports for years about condors being exposed to lead from ammunition, but there was never enough clear evidence to document the extent of the problem. We knew that we could probably identify the sources of the lead using isotopic signatures," said Donald Smith, professor and chair of environmental toxicology at UCSC and a coauthor of the paper.........

Posted by: Kelly      Permalink         Source

August 29, 2006, 9:32 PM CT

Collecting Data about Nantucket Sound

Ferries that connect Cape Cod and the islands of Martha's Vineyard and Nantucket are taking on another role - research vessels.

Woods Hole Oceanographic Institution (WHOI) biologist Scott Gallager and his colleagues have installed a package of sensors on the 235-foot freight ferry Katama to measure water quality and to photograph plankton as the ferry crisscrosses the western side of Nantucket Sound year-round, several times daily.

"Hitchhiking science on a ferry provides a terrific opportunity for us to better understand how water quality and ocean life change over time," Gallager said. The measurements for the Nantucket Sound Ferry Scientific Environmental Monitoring System began in May.

With the interest and cooperation of the Woods Hole, Martha's Vineyard and Nantucket Steamship Authority, which operates the ferry service between Cape Cod and the islands, Gallager and his colleagues developed a sensor package to measure water temperature, salinity, oxygen, chlorophyll, and water clarity, and take images of plankton living in the water column. Real-time data from the sensors travel over a wireless connection to Gallager's shore-based lab, where he and WHOI colleagues Steve Lerner, Emily Miller, Andrew Girard, Andy Maffei, and collaborator Kevin Fall from Intel Corporation make them available to researchers and the public on the project Web site, http://4dgeo.whoi.edu/ferries.........

Posted by: Kelly      Permalink         Source

August 28, 2006, 4:46 AM CT

How crucian carp survive months without oxygen?

Cooling water temperature during the fall prompts the crucian carp to store vast amounts of glycogen in its brain to keep the brain functioning and healthy from February to April, when there is no oxygen left in the ponds, a new study finds.

The study from Finland observed that the amount of glycogen in the brain was at its peak in February, when the pond becomes nearly depleted of oxygen (anoxic). Glycogen, an energy supply that the carp brain uses to survive anoxia, was 15 times higher in February, in comparison to brain glycogen content in July, when oxygen in the pond is at its peak.

At the same time, the carp brain's sodium-potassium pump activity, a measure of energy demand, decreased 10-fold to its low point between February and April, said the study's lead author, Vesa Paajanen. Taken together, these findings indicate the carp extends the amount of time it can survive without oxygen in frigid water by 150-fold. Further, the study observed that it was the dropping water temperature that sets these physiological changes into motion.

"This is the first study to show that sodium pump activity is controlled by water temperature, not by the amount of oxygen available in the water" Paajanen said. The findings help explain how the carp pulls off the remarkable physiological feat that allows its brain to survive for months in a nearly anoxic state.........

Posted by: Kelly      Permalink         Source

August 27, 2006, 6:59 PM CT

Organs Monitoring During Development

How are you? In biological terms this question could involve a feedback loop that lets the body check in on itself and then act on that information. Eventhough feedback loops are essential and they abound in biology, they aren't well understood. Feedback loops enable an organ such as the liver to detect if it is injured, ascertain if it is growing and developing normally, and if it needs to regenerate itself. When such loops derail, cancer and other diseases can arise.

Researchers at NYU School of Medicine have unraveled the signals in a feedback loop governing ovarian development. This work has been several years in the making and is being published on 27 August in the Advance Online issue of the journal Nature.

"I think our study has indeed important implications that extend beyond understanding of how a gonad such as the ovary develops," explains Dr. Ruth Lehmann, Ph.D., Julius Raynes Professor of Developmental Genetics and Howard Hughes Medical Investigator. "In every organ, may it be a gonad, a liver, or a thymus, different tissues contribute to the organ, and the growth of the different tissues has to be coordinated both during normal development and during regeneration."

Tapping into that kind of powerful feedback loop could help treat a number of kinds of disorders and show how the power of stem cells could be harnessed to help organs call different cell types into action and regenerate, the scientists said. Stem cells are cells that have still not specialized and can develop into any number of different cell types. They also have the remarkable ability to self-renew indefinitely.........

Posted by: Kelly      Permalink         Source

August 27, 2006, 8:19 AM CT

Hummingbird Hawkmoth

Hummingbird Hawkmoth (macroglossum stellatarum).

Spotted between showers yesterday in Cambridgeshire. Only the second time I've seen one of these. They really are like humming birds.........

Posted by: Kelly      Permalink         Source

August 24, 2006, 9:32 PM CT

Avian Flu Detection Information

Researchers are now using the newly developed database and Web application called HEDDS (HPAI Early Detection Data System) to share information on sample collection sites, bird species sampled, and test results.

The database is available to agencies, organizations, and policymakers involved in avian influenza monitoring and response. Researchers will use the data to assess risk and refine monitoring strategies should HPAI be detected in the United States. Public access is more limited, but shows the states where samples have been collected and includes numbers of samples collected from each state.

HEDDS is a product of the federal government´s NBII Wildlife Disease Information Node (WDIN) housed at the USGS National Wildlife Health Center. With financial support from the U.S. Fish and Wildlife Service, U.S. Geological Survey, and U.S. Department of Agriculture´s Animal and Plant Health Inspection Service, and participation by State wildlife agencies, universities and nongovernmental organizations, the HEDDS Web site provides a current picture of where sampling has taken place and the results of testing. "HEDDS provides a critical comprehensive view of national sampling efforts at a time when the demand for this type of information is increasing, along with the growing interest in HPAI surveillance efforts in wild birds," said WDIN Project Leader Joshua Dein.........

Posted by: Kelly      Permalink         Source

August 24, 2006, 7:38 PM CT

Thailand's Amazing Insects

This site is about the fun of watching insects in the wild. I am neither an entomologist nor a photographer, I just love taking pictures of insects. I live in Chiang Mai and started looking for insects in January 2000.The site contains over 2000 photographs of insects including butterflies, moths, dragonflies and damselflies, flies, wasps, ants, caterpillars, cicadas, grasshoppers, mantids, bugs and beetles plus spiders and some others (including frogs and snakes). Wherever possible I identify the species. Recent additions are places on a separate page updated every month and there is also a 'Bug of the Week' page updated when I remember. There are also audio files of cicadas, crickets and a few birds. Other sections have articles on insects in.

Thailand (particularly relating to conservation issues), edible insects in the Thai diet, the results of a survey on Thai people's attitudes to insects, insects in Thai proverbs, insects on Thai postage stamps.

John Moore Chiang Mai.........

Posted by: Kelly      Permalink         Source

August 24, 2006, 5:04 AM CT

Eating Habits Of Rain Forest Insects

A study initiated by University of Minnesota plant biologist George Weiblen has confirmed what biologists since Darwin have suspected - that the vast number of tree species in rain forests accounts for the equally vast number of plant-eating species of insects.

"This is a big step forward in the quest to understand why there is so much biodiversity in the tropics," said Weiblen, principal investigator and senior author for the National Science Foundation-funded research. The study is reported in the Aug. 25 issue of the journal Science.

The research showed that insect species in tropical and temperate forests dine on about the same number of tree species, despite the more diverse menu in the tropics.

"The tropical forest cafeteria offers a number of more options than the temperate forest," Weiblen said. "Our study confirms that the choices tropical insects make are quite similar to those of insects in less diverse forests of places like Minnesota".

The study rejected an alternative theory that tropical insects are actually picky eaters who prefer fewer host plants than their temperate counterparts.

"Theory predicts that similar species coexist by dividing up resources like food and space," Weiblen said. "The unparalleled diversity of plant-eating insects in the tropics could be explained as per this theory if tropical insects were more choosy than those in temperate forests. But it hasn't been possible to compare what's on the menu until now".........

Posted by: Erica      Permalink         Source

August 24, 2006, 4:59 AM CT

Even microbes favor their own kin

New research published by Rice University biologists in this week's issue of Nature finds that even the simplest of social creatures single-celled amoebae have the ability not only to recognize their own family members but also to selectively discriminate in favor of them.

The study provides further proof of the surprisingly sophisticated social behavior of microbes, which have been shown to exhibit levels of cooperation more typically linked to animals.

"By recognizing kin, a social microbe can direct altruistic behavior towards its relatives," said postdoctoral researcher Natasha Mehdiabadi, the lead author of the study.

Recognizing one's own family is a common trait among animals be they chimpanzees, ground squirrels or paper wasps and because kin recognition can strongly influence cooperative behaviors it can also significantly impact the social evolution of species.

While researchers have repeatedly documented cases of kin recognition, the Rice study is among the first to document the more sophisticated trait of kin discrimination in a social microorganism.

The new study is based on an examination of single-celled Dictyostelium purpureum, a common soil microbe that feeds on bacteria. In the wild, when food runs short, D. purpureum aggregate together by the thousands, forming first into long narrow slugs and then into hair-like fruiting bodies. Resembling miniature mushrooms, these fruiting bodies consist of both a freestanding stalk and the spores that sit atop it. Ultimately, the spores are carried away, commonly on the legs of passing creatures, to start the life cycle all over again. But in order to disperse the spores, some of the colony's individuals must altruistically sacrifice themselves in order to make the stalk.........

Posted by: Erica      Permalink         Source