July 3, 2008, 8:52 PM CT

Agriculture and frog sexual abnormalities

A farm irrigation canal would seem a healthier place for toads than a ditch by a supermarket parking lot.

But University of Florida researchers have found the opposite is true. In a study with wide implications for a longstanding debate over whether agricultural chemicals pose a threat to amphibians, UF zoologists have observed that toads in suburban areas are less likely to suffer from reproductive system abnormalities than toads near farms where some had both testes and ovaries.

"As you increase agriculture," said Lou Guillette, a distinguished professor of zoology, "you have an increasing number of abnormalities".

Guillette is one of several UF authors of a paper on the research appearing in the online version of the journal Environmental Health Perspectives The lead author is Krista McCoy, who did the work as part of her UF School of Natural Resources and the Environment dissertation.

Several past studies have suggested a link between herbicides usually used in farming and sexual abnormalities in tadpoles and frogs. Such deformities may be responsible for declines in frogs documented in areas affected by agricultural contaminants, such as Sierra Nevada, Calif., McCoy said. Amphibians are declining worldwide and agricultural chemicals are considered to be one likely cause, she said. Others include pathogenic infections and habitat loss......... Posted by: Kelly      Read more         Source

July 3, 2008, 3:32 PM CT

A very notable birth at the Los Angeles Zoo

To kick off the Los Angeles Zoo's summer activities, the Zoo is cutting admission prices for the July 4 weekend. From Friday, July 4, to Sunday, July 6, 2008 everyone can slash $4 off the price of Zoo admission! In addition to the discount, guests will also be able to buy a delicious BBQ meal, get free samples of Nestle Juicy Juice and enjoy the music of a local surf band. Take advantage of this special holiday deal to visit all of the Zoo's adorable babies!

The Zoo has also had a flurry of spring births. One of the most notable was the birth of two male peninsular pronghorns on March 25, 2008. These fawns are the first of their kind ever born at a Zoo. As per Senior Animal Keeper Kelley Greene, "the brothers have been pulled for hand rearing to ensure that they are given every opportunity to thrive." When the pair is old enough, they will be sent to the Living Desert in Coachella Valley, Calif.

The parents of these two healthy boys were just fawns themselves when they arrived at the L.A. Zoo in July of 2006. These pronghorns originally came here from a breeding center in Mexico and are the first of their species to be on exhibit outside of their home country. The older pronghorns are located in the North American section of the Zoo.

Typically, a pronghorn mother will have one or two fawns weighing in at around seven or eight pounds. When they reach adulthood, pronghorns weigh up to 125 pounds and reach a height of 35 inches. The females are commonly 10 to 25 percent smaller then males......... Posted by: Kelly      Read more         Source

July 1, 2008, 9:26 PM CT

Human influences challenge penguin populations

The ecology of penguins makes these iconic swimming and diving seabirds of the Southern Hemisphere uncommonly susceptible to environmental changes. Pronounced warming in the Antarctic, as well as commercial fishing, mining, and oil and gas development at lower latitudes, has led to declines in a number of species, as per P. Dee Boersma, of the University of Washington in Seattle. In the July/August 2008 issue of BioScience, Boersma provides a first-person account based on 30 years of studying the birds. Counts of the penguin populations at the 43 remaining breeding "hotspots," even once every five years, could provide valuable insights into the variability of the ocean ecosystem and the populations' viability, Boersma writes. Yet counts are carried out only rarely, if at all.

The task is urgent, because a number of populations seem to be in rapid decline even as some temperate populations have expanded their range southward. Rapid reductions of sea ice off Antarctica in recent years threaten Adlie and emperor penguins, which need ice, but may benefit some populations of relatively ice-intolerant gentoo and chinstrap penguins. Increased snow and rain, another result of the changing climate, reduce breeding success in some gentoo and Adlie penguins.

Temperate penguins, such as Galpagos, Peruvian, and African species, are all declining. Mining of guano, egg harvesting, commercial fishing, and oil spills are the chief causes, as per Boersma, eventhough tourism and increasingly severe El Nio events, probably resulting from climate change, are also partly responsible......... Posted by: Kelly      Read more         Source

June 26, 2008, 9:25 PM CT

'Early bird' project really gets the worm

Researchers from the LSU Museum of Natural Science, or MNS, recently participated in a project joining together the most prominent ornithological research programs in the world. This study the largest study of bird genetics ever completed has not only shaken up the avian evolutionary tree, but completely redrawn it. The results of this massive research project, which relied heavily upon the LSU MNS' genetic resources collection, will be published in Science on June 27.

The results of the study are so broad that the scientific names of dozens of birds will have to be changed, and biology textbooks and birdwatchers' field guides will have to be revised.

LSU participants in the study include: Fred Sheldon, director of the LSU MNS; Ben Marks, recent graduate of LSU's biological sciences doctoral program; and Chris Witt, former LSU graduate student and current assistant professor in the Department of Biology and Museum of Southwestern Biology at the University of New Mexico.

For more than five years, the Early Bird Project, funded by the National Science Foundation's "Assembling the Tree-of-Life" research program, has been collecting DNA sequence data from all major living groups of birds.

"One thing that makes this project unique is its breadth; both in its taxonomic scope and in terms of the amount and type of data we collected," said Marks......... Posted by: Kelly      Read more         Source

June 26, 2008, 8:52 PM CT

What It's Like to Be a Bat

Not a number of people think about what it's like to be a bat, but for those who do, it's enlightening and potentially groundbreaking for understanding aspects of the human brain and nervous system.

Cynthia Moss, a member of the Neuroscience and Cognitive Science program at the University of Maryland, College Park, Md., is one of few scientists who spend time trying to get into the heads of bats.

Her new research suggests there is more to studying bats than figuring out how they process sound to distinguish environments. Partially supported by the National Science Foundation, her research paper appears in the June 18 online edition of the Proceedings of the National Academy of Sciences.

"For decades it's been recognized that a bat's voice produces sounds that give the bat information about the location of objects," says Moss. "We're now recognizing that every time a bat produces a sound there are changes in brain activity that may be important for scene analysis, sensorimotor control and spatial memory and navigation".

The research could help neurobiologists understand mechanisms in the human brain and ultimately benefit human health, but that may not happen for some time as more studies are needed.

Moss and her colleague, Nachum Ulanovsky from the Weizmann Institute of Science in Israel, evaluated more than 100 studies and determined the brief calls emitted through a bat's mouth or nostrils and their returning echoes play a pivotal role in motor control and have other behavioral implications......... Posted by: Kelly      Read more         Source

June 25, 2008, 10:26 PM CT

Where Are You Now, My Love?

Having a good nose is essential to a Japanese beetle's survival. The beetle's sense of smell helps it avoid enemies and zero in on a mate. Meanwhile, the potential mate is programmed to release sex pheromones in exactly the right proportions. Like cheap perfume, there is such a thing as too much: Excessive pheromones can get the attention of a passing fly, leading her to the beetle. The fly can then lay her eggs on the beetle's back, setting up emerging fly larvae for their first meal (fresh Japanese beetle).

If all of this isn't challenging enough, the male beetles have to track females while they're both flying. This requires a mechanism within the males that loses the pheromone scent from a moment before and picks up the latest scent as the females move through the air.

This mechanism is well understood by Walter Leal, a chemical ecologist at the University of California, Davis. With funding from the National Science Foundation, Leal has isolated, identified, cloned and expressed a pheromone-degrading enzyme that allows receptors in the beetle's nose to lose the pheromone scent from the female's earlier locations as she moves to new places.

Isolating this enzyme offers the potential to eliminate entirely the beetle's reception of the pheromone scent, making them unable to find females, mate and reproduce. This potential could be useful to agricultural pest control, since the Japanese beetle is an invasive species responsible for millions in damages to crops each year......... Posted by: Kelly      Read more         Source

June 24, 2008, 10:40 PM CT

Bird watchers, space technology come together

Almost every June for 30 years, Terry McEneaney drove around Yellowstone National Park and listed every bird he heard along three routes.

Park ornithologist at the time, he would drive to a designated spot and identify the birds there. Then he'd drive another half mile, repeat the process and continue until he had stopped 50 times in 24.5 miles for the North American Breeding Bird Survey. Trying to finish before the birds quit singing, he'd ignore the scenery as best he could and try not to let the traffic bother him.

"You have to start very early and have to be done about 9:30. Birds stop singing about 9:30," McEneaney said. "You have to really hustle from point to point".

McEneaney no longer works for the National Park Service. He retired in November. But the information he gathered is part of a new Montana State University study that looks at biodiversity across North America. Thousands of bird watchers and a satellite sensor developed at the University of Montana yielded data for the continental study.

"I had a feeling somebody would use it somehow," McEneaney said.

MSU's results will be described in at least three scientific papers, the first would be published this summer in the journal "Remote Sensing of Environment," said Linda Phillips, lead author and a research scientist at MSU. Co-authors are Andy Hansen, an MSU ecologist; and Curtis Flather with the USDA Forest Service in Fort Collins, Colo......... Posted by: Kelly      Read more         Source

June 24, 2008, 10:18 PM CT

Genomics of large marine animals showcased

Though the slow moving purple sea urchin may look oblivious, lacking a head, eyes and ears, this prickly creature has an impressive suite of sensory receptors to detect outside signals. And don't overlook this animal's self-defense abilities: it has much more ammunition to activate its innate immune system than humans have. The starlet sea anemone lives in coastal areas that face increasing pollution, and it is better equipped than a number of land, ocean, and freshwater animals to tolerate environmental stress.

These insights into the biology of marine organisms didn't come from findings based on observation; they were revealed by deciphering and comparing the animals' genomes. The powerful advantages of using gene catalogs to infer biological function in marine animals are highlighted in a virtual symposium in the recent issue of The Biological Bulletin, published by the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts.

Emerging research on the genomic structure of marine organisms is giving researchers new clues as to how certain physiological systems evolved. The genomes of ancient Cnidarians, of which the jellyfish is best known, are being used to discern how cells adhere to form organs and organisms. The genome of Ridgeia piscesae, a tubeworm that has co-evolved with bacteria to thrive in the extreme environment of deep-sea hydrothermal vents, is illuminating the molecular underpinnings of symbiosis......... Posted by: Kelly      Read more         Source

June 23, 2008, 8:15 PM CT

African frogs can morph toes into claws

Biologists at Harvard University have determined that some African frogs carry concealed weapons: When threatened, these species puncture their own skin with sharp bones in their toes, using the bones as claws capable of wounding predators.

The unusual defense mechanism is described by Harvard's David C. Blackburn, James Hanken, and Farish A. Jenkins, Jr., in a forthcoming issue of the journal Biology Letters

"It's surprising enough to find a frog with claws," says Blackburn, a doctoral student in Harvard's Department of Organismic and Evolutionary Biology. "The fact that those claws work by cutting through the skin of the frogs' feet is even more astonishing. These are the only vertebrate claws known to pierce their way to functionality".

"Most vertebrates do a much better job of keeping their skeletons inside," he adds.

Blackburn first became aware of the clawed frogs while conducting fieldwork in the central African nation of Cameroon. When he picked up one of the hulking fist-sized frogs, it flailed its hind legs violently, scratching him and drawing blood.

Back in the U.S., Blackburn examined museum specimens of 63 African frog species. He noticed that in 11 species -- all in the genera Astylosternus, Trichobatracus, and Scotobleps and all native to central Africa -- the bones at the ends of the toes were pointed and hooked, with smaller, free-floating bones at their tips. Eventually he determined that these small nodules at the tips of the frogs' feet were connected to the rest of the toe by a collagen-rich sheath......... Posted by: Kelly      Read more         Source

June 23, 2008, 8:11 PM CT

Primate's scent speaks volumes about who he is

Perhaps judging a man by his cologne isn't as superficial as it seems.

Duke University researchers, using sophisticated machinery to analyze hundreds of chemical components in a ringtailed lemur's distinctive scent, have observed that individual males are not only advertising their fitness for fatherhood, but also a bit about their family tree as well.

"We now know that there's information about genetic quality and relatedness in scent," said Christine Drea, a Duke associate professor of biological anthropology and biology. The male's scent can reflect his mixture of genes, and to which animals he's most closely related. "It's an honest indicator of individual quality that both sexes can recognize," she said.

Lemurs, distant primate cousins of ours who split from the family tree before the monkeys and apes parted ways, have a complex and elaborate scent language that until recently was completely undiscovered by humans. Drea said it's language that is undoubtedly richer than we can imagine.

"All lemurs make use of scent," she said. "The diversity of glands is just amazing."

Ringtailed males have scent glands on their genitals, shoulders and wrists, each of which makes different scents. Other lemur species also have glands on their heads, chests and hands. Add to these scents the signals that can be conveyed in feces and urine, and there's a lot of silent, cryptic communication going on in lemur society......... Posted by: Kelly      Read more         Source