Wed, 16 May 2007 03:40:07 GMT

Blue-throated Hummingbird Spotted

A glance of the worlds smallest bird with that iridescent emerald green and electric blue patch on the throat would surely be mind-blowing for all. But unfortunately, this newly discovered species is already in need for protection against its biggest enemy — human encroachment.

Named, gorgetethe new species is easily twice as big as its otherwise thumb-sized counterparts found in the eastern United States. It measures between 3.5 inches and 4 inches (90 and 100 mm) in length.

In a statement, Andr Weller of the Brehm Fund for International Bird Conservation/Zoological Research Museum A. Koenig said,

We immediately suspected the bird as a new species. Further study has shown that this is certainly the most spectacular discovery of a new hummingbird taxon during the last decade or more.

With obvious excitements, Ornithologists Alexander Corts-Diago, who made three sightings of the hummingbird in 2005, termed this discovery as completely unexpected!

But, the destruction of the mountain cloud forest habitat of the southwest Colombia is threatening the bird towards extinction especially with the coca fields migration from the Caqueta and Putumayo areas to the Pacific.

If this human encroachment is not barred, this would perhaps be the last view of the brilliant-colored hummingbird species.Image Posted by: Irani      Read more     Source

May 14, 2007, 10:45 PM CT

Remote Sensing Tools To Predict Bird Species Richness

Researchers at the Woods Hole Research Center, NASA Goddard Space Flight Center and the University of Maryland have taken a novel approach to studying biological diversity by making use of laser remote sensing (lidar). Lidar data provide unique measurements of the 3-dimensional structure of vegetation, an important aspect of habitat diversity. Habitat heterogeneity and complexity have been shown in a number of places to be directly correlation to animal species richness a more complex environment provides a greater number of ecological niches to be filled by different species. Using this basic principle, WHRC researchers examined the relationships between bird species richness and habitat metrics derived from lidar data acquired by aircraft. They then explored the efficacy of predicting bird richness and abundance based on these metrics. The first phase of this research, profiled in the current issue of Remote Sensing of Environment, focuses on results from study sites in the Patuxent Wildlife Refuge in Maryland.

As per Scott Goetz, a senior scientist at the Center who is leading the project, "Lidar is the most unique and exciting technology to come along in the past decade in the remote sensing research community. We now have the ability to characterize vegetation in three dimensions, and that has implications not only for biodiversity research but also for improved estimates of biomass and carbon stocks."........ Posted by: Erica      Read more         Source

Sun, 13 May 2007 13:10:21 GMT

Ape facial expressions foster group harmony

Com munication through facial expressions isn't the domain of humans alone, a study has found: facial expressions may foster social harmony among apes and our closer monkey relatives.

The results seem to back up a theory that such expressions evolved to maintain group cohesion, according to the scientist who conducted the invest igation.

Anthropologist Seth Dobson of Dartmouth College studied 12 primate species and found that greater variety of facial expressions was linked to average group size.

The size of a part of the brain that controls facial expression-the facial nucleus-was also linked to group size and the amount of time animals spent grooming each other, he reported. For this part of the study, he analyzed a somewhat larger range of species.

Dobson reported the findings late last month at the annual meeting of the American Association of Physical Anthro pologists in Philadelphia. He said he also plans to submit the results for publication to the group's flagship journal, the American Journal of Physical Anthro pology.

"The evolution of facial expression tracks the evolution of group size and social organ ization," wrote Dobson in an email. He added that increased reliance on facial expressions evolved multiple times in different lineages.

Animals living in larger groups are under greater evolution ary pressure "to resolve conflicts peacefully," he added; facial expressions can become part of the arsenal they have to achieve that.

Dobson focused on anthropoids, a sub-order of the primate order, the group of mammals with opposable thumbs of which humans are a member. Anthropoids are more "human-like" primates that include monkeys, apes and humans but exclude "lower" primates such as lemurs.

Even within the anthropoids, Dobson said his findings reached statistical significance only if certain more evolution arily distant or unusual groups were excluded. These were the New World Monkeys-believed to be separated from the other anthropoids by about 40 million years of evolution-and orangutans, which are solitary but have a large facial nucleus. That's probably because they made an evolution ary switch from group to lone living just relatively recently, he said.

"This study was part of my dissertation, in which I developed a method for quantifying the mobility of the facial muscles in monkeys and apes," Dobson wrote in the email. "My measure of facial mobility allows for comparisons across species to test evolution ary hypotheses concerning facial expression."

The twelve species that Dobson studied for the facial mobility study were the chimpanzee, western lowland gorilla, white-cheeked gibbon, hamadryas baboon, lion-tailed macaque, De Brazza's monkey, black-and-white colobus, dusky leaf monkey, black-handed spider monkey, black howler monkey, white-faced saki and cotton-top tamarin. Posted by: JoslynV      Read more     Source

Sun, 13 May 2007 07:21:23 GMT

Monkeys wearing perfume?

Move over Ralph Lauren, Dolce & Gabbana and other purveyors of glamor perfumes. The next rage in masculine fragrance might be Eau de spider monkey.

Scientists reported seeing two wild, male members of this primate group repeatedly dabbing themselves with something that seemed hard to describe as anything other than home-made cologne.

The crushed-leaf scents "may play a role in the context of social communication, possibly for signaling of social status or to increase sexual attractiveness," the researchers wrote in the Nov. 14 issue of the research journal Primates.

The researchers, Matthias Laska and colleagues of the University of Munich Medical School described watching a group of free-ranging Mexican black-handed spider monkeys over a 250-hour period.

In that time, they recorded "20 episodes of self-anointing, that is, the application of scent-bearing material onto the body," they wrote.

"The animals used the leaves of three species of plants," including wild celery, for the surprising rituals, the researchers reported. The animals would mix the crushed leaves with saliva before rubbing it on themselves, they continued. "The leaves of all three plant species spread an intensive and aromatic odor when crushed."

The monkeys swiped the fragrant paste only on their armits and breastbone areas, Laska and colleagues noted, and the occurrences of this were independent of time of day, season, temperature or humidity.

All these considerations together, they added, clash with the notion that the substance might function as an insect repellent or a sort of skin self-medication.

The black-handed spider monkey, Ateles geoffroyi, is one of four species of spider monkeys, small, very acrobatic primates with long, slender limbs that live between southern Brazil and central Mexico. They travel in small bands by making huge leaps among the treetops, sprawling out like spiders and grasping branches with their tails, which they use as a "fifth hand."

Their diet includes fruits and nuts. The black-handed monkeys "bark" when threatened, and often hurl branches, jump up and down, and shake branches upon the approach of humans.

The plant species used were the Alamos pea tree, Brongniartia alamosana; the trumpet tree Cecropia obtusifolia; and wild celery, Apium graveolens. Posted by: JoslynV      Read more     Source

May 10, 2007, 10:27 PM CT

Personality-Gene makes Songbirds Curious

There is already evidence that variations (polymorphisms) in neurotransmitter-related genes are linked to personality differences among humans. Research from the last decade suggested a promising link between the Drd4-gene and the trait curiosity (novelty-seeking). Researchers from the Max Planck Institute for Ornithology in Seewiesen, together with a former lab member who is now at the Cawthron Institute in Nelson (New Zealand) and with colleagues from the Netherlands Institute of Ecology in Heteren, have shown that the choice of the Drd4-gene in the study of the great tit turned out to be a good bet.

In the Drd4 gene of this bird, they discovered 73 polymorphisms, of which 66 were so-called Single Nucleotide Polymorphisms (SNPs), where only a single nucleotide has been exchanged between the two variants. One such SNP, located at position 830, is indeed linked to the exploratory behaviour (read: curiosity) of the birds. This is first shown in two breeding lines of great tits, which the scientists had selected over four generations as per their level of curiosity (a low and a high curiosity line). The researchers assessed the curiosity of the birds in a test which shows similarities to the traditional "open-field" test used by psychology experts. They tested the exploratory behaviour of each bird soon after it left the nest (Early Exploratory Behaviour, EEB), as follows. In one behavioural test, the biologists measured the time until a bird had visited four artificial "trees" (see figure 1) after being released in the observation room. In a second test, they quantified the reaction of the bird towards each of two unknown objects that had been put in its cage. One such novel object was a pink panther......... Posted by: Kelly      Read more         Source

May 9, 2007, 11:18 PM CT

DNA reveals hooded seals have wanderlust

Scientists have discovered a new fact about hooded seals, a mysterious 200 to 400 kilogram mammal that spends all but a few days each year in the ocean.

An international team of scientists led by Dr. David Coltman, an evolutionary geneticist at the University of Alberta, have learned that all the hooded seal populations in the world share the same genetic diversity. The scientists reached their conclusions after analysis of more than 20 years of DNA samples taken from hundreds of hooded seals from around the world.

"These results mean that if you brought me a DNA sample of a hooded seal, I wouldn't be able to tell you where in the world you got that sample because of the genetic similarity between populations," Coltman said.

"This is important information because it helps shed light on an animal that we know very little about," he added.

Female hooded seals give birth (whelp) and wean their pups on ice floes over a period of three to four days once every year in the spring. Male seals wait until the females finish weaning for the one time of year when they will mate. The scientists believe the genetic similarities among the seals indicate these seals intermingle and mate among populations.

The research is published this month in the journal Molecular Ecology......... Posted by: Kelly      Read more         Source

Tue, 08 May 2007 01:55:10 GMT

Biologists out to Find Bear Population in Pennsylvania

Bear biologist Mark Ternent is busy these days with his daredeentering the dens to assess the health and size of Pennsylvania’s bruin population. Ternent, must complete 30 dens by the end of this month to figure out the optimal ratio of bears to people to determine how many bears need to be killed to keep the population under control.

Black bear encounters are growing in Pennsylvania and other Eastern states even though of the 20 bear attacks over the last three decades did not claim a single life.

The bear-human conflict has become a concern for the bear biologists from around the eastern United States and Canada who are meeting in West Virginia next month to discuss ways to curb the encounters.

Steve Williams, president of the Wildlife Management Institute and former director of the U.S. Fish and Wildlife Service said,

I think most states are becoming more aggressive in managing these populations, and it’s a direct result of human-wildlife encounters.

Photo Credit: AP/Matt Rourke Posted by: Irani      Read more     Source

May 6, 2007, 4:59 PM CT

Gene mutation linked to increased athletic performance

Whippets are bred for speed and have been clocked at speeds approaching 40 miles per hour over a 200-yard racing course. Researchers at the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), have now discovered a genetic mutation that helps to explain why some whippets run even faster than others. Reported in the open-access journal PLoS Genetics, their findings will make for a fascinating experiment in applied genetics and human nature: what will dog breeders do with this information, and what are the implications for human athletic performance?

A research team led by Elaine Ostrander, chief of the Cancer Genetics Branch in NHGRIs Division of Intramural Research, reports that a mutation in a gene that codes for a muscle protein known as myostatin can increase muscle mass and enhance racing performance in whippets. Like humans, dogs have two copies of every gene, one inherited from their mother and the other from their father. Dr. Ostrander and his colleagues found those whippets with one mutated copy of the myostatin (MTSN) gene and one normal copy to be more muscled than normal and are among the breeds fastest racers. However, their research also showed that whippets with two mutated copies of the MTSN gene have a gross excess of muscle and are rarely found among competitive racers......... Posted by: Kelly      Read more         Source

May 6, 2007, 4:43 PM CT

Light sticks may lure turtles to fishing lines

Thousands of loggerhead turtles die every year when they get tangled or hooked in commercial fishing longlines meant for tuna or swordfish. New research suggests a possible reason why turtles swim into the lines. The glowing light sticks that lure fish to longlines also attract turtles, as per a University of North Carolina at Chapel Hill study.

The light sticks used in longline fisheries resemble the disposable plastic tubes popular with children on Halloween. The steady glow draws fish, which then find baited hooks and are caught on the lines. The lights also seem to fascinate turtles, however, which are equally likely to chomp on fish bait, or get snagged in the hooks and lines.

"Juvenile turtles are indiscriminant eaters and bite nearly everything small that they encounter," said Ken Lohmann, UNC-Chapel Hill professor of biology and senior author of the study. "Under natural conditions, most small objects floating or swimming through the sea are potential sources of food. But nowadays, with fishing lines, plastic, and garbage in the ocean, biting everything is not such a great strategy".

The study appears in the May 2007 issue of the journal Animal Conservation. John Wang, a former graduate student at Carolina and now a research associate with the Joint Institute for Marine and Atmospheric Research at the University of Hawaii, was the lead author of the study. Grants from the National Oceanic & Atmospheric Administration (NOAA) and the National Science Foundation provided funding......... Posted by: Kelly      Read more         Source

April 29, 2007, 7:29 PM CT

Female ticks have market on gluttony

Sex makes you fat. If you're a female tick, that is.

The "truly gluttonous" female ixodid tick increases her weight an astounding 100 times her original size after she mates, so a University of Alberta researcher investigated what it is about copulation that triggers such a massive weight gain.

In a new research paper reported in the Journal of Insect Physiology, Dr. Reuben Kaufman, from the Department of Biological Sciences, suggests several differences between the ixodid tick and her blood-sucking counterparts that help explain the weight gain. Using mosquitoes, tsetse flies, bed bugs and kissing bugs as comparison, Kaufman observed that no one in comparison to this female African tick when it came to weight gain following mating.

Kaufman suggests that the ixodid tick displays a significant difference in lifestyle from the other insects and that it is adaptive for the virgin to remain small before mating.

First, this species of tick remain on the host for many days, rather than minutes. "In this family of ticks, mating takes place on the host," says Kaufman. "Most other insects mate before or after their brief blood meal -the two acts are totally separate, but not with these ticks."

Female ticks require six to 10 days to engorge fully. First, she attaches herself to the skin. Then she feeds to 10 times her unfed weight and finally, after copulation she increases her weight a further tenfold......... Posted by: Kelly      Read more         Source