Tag: frogs

Deadly Fungus Invades Frogs' Last Safe Haven in Central America

By Veronique Greenwood | June 14, 2011 5:07 pm

frog

What’s the News: A fungus that his been wiping out frog species all over the world is creeping into the last area patch of tropical mountains in the Americas escape its scourge, the Darien National Park in Panama, and scientists are scrambling to save what species they can.

Frogs have been taking a beating over the last three decades, due in large part to a ruthless killer called chytrid fungus. Identified in the late ’90s, the fungus is startlingly lethal, driving 50% of species into extinction and killing 80% of individuals within five months of appearing at one location in Panama. It spreads through water via spores, affecting even areas where humans have not penetrated. “It is the worst infectious disease ever recorded among vertebrates in terms of the number of species impacted, and its propensity to drive them to extinction,” wrote a team of scientists in a 2005 World Conservation Union report [pdf].

Read More

CATEGORIZED UNDER: Environment, Living World

Found: Six Endangered Haitian Frogs, Feared Lost for Good

By Eliza Strickland | January 13, 2011 7:13 pm
burrowing-frog
cloud-forest
crowned
glandulosa
hillside
juvenile-macaya
la-selle
macaya
mozart-s
ventriloqual-frog

Yesterday marked a year since the devastating earthquake in Haiti, which killed at least 200,000 people and ruined much of Port-au-Prince. And while the human inhabitants of Haiti are still struggling back, there’s been a bit of good news from the wildlife sector. Biologists have rediscovered six frog species in the Haitian forest that haven’t been seen in two decades and were feared lost.

“I am very wary of highlighting frogs at this time in Haiti. Obviously the country has very pressing needs, but I think ultimately they are a symbol of something more hopeful,” said Robin Moore, an amphibian expert with Conservation International who helped lead the expedition that found the frogs. [MSNBC]

Moore’s expedition set out in search of the La Selle Grass frog (E. glanduliferoides), which hasn’t been seen since 1985 and is feared extinct; the mission was part of Conservation International’s “Search for Lost Frogs” campaign. The researchers didn’t find the La Selle Grass frog, but they found plenty of other frogs that they hadn’t expected to catch sight of.

Read More

CATEGORIZED UNDER: Environment, Living World

Photos: The Glamorous New Species of Papua New Guinea

By Eliza Strickland | October 6, 2010 2:46 pm
spider
fruit-bat
green-frog
pink-eyed-katydid
possum
spiny-leg-katydid
yellow-frog

Related Content:
80beats: Search for Long-Lost Amphibians Finds Its First Three
80beats: The “Lost Frog” Quest: Researchers Seek the World’s Rarest Amphibians
80beats: Saving the Rainforest Could Make Economic Sense
80beats: Papua New Guinea’s Forests Falling Fast
DISCOVER: 10 Science Hotspots–Where Mother Nature Reveals Her Secrets

CATEGORIZED UNDER: Living World

Search for Long-Lost Amphibians Finds Its First Three

By Andrew Moseman | September 22, 2010 3:16 pm

ReedFrog1

In August, Conservation International launched its globe-spanning search for amphibians that haven’t been seen in decades, but still could exist. This month, they’ve tracked down their first three slippery specimens. Scientists turned up two long-lost African frogs and a salamander from Mexico.

“It’s pretty extraordinary to think about just how long it has been since these animals were last seen,” observed project co-ordinator Robin Moore of Conservation International (CI). “The last time that the Mexican salamander was seen, Glenn Miller was one of the world’s biggest stars. The Omaniundu reed frog disappeared the year that Sony sold its first ever Walkman.” [BBC News]

The three rediscovered animals are:

ReedFrog2The Mount Nimba reed frog (right). Last seen in 1967, it lives in the Ivory Coast. A local scientist spotted it.

The find was made “in a swampy field in Danipleu, an Ivorian village near the Liberia border.” [MSNBC]

Omaniundu Reed Frog (top). The most recently seen of the three, Omaniundu was last noted in 1979. It lives in the Democratic Republic of the Congo. According to Conservation International’s account of the rediscovery:
Read More

CATEGORIZED UNDER: Living World

How Many Tiny Frogs Can Dance on the Tip of a Pencil?

By Andrew Moseman | August 25, 2010 3:21 pm

TinyfrogBehold its minute majesty.

The micro frog’s moniker is Microhyla nepenthicola. It grows to just a half-inch long or less. It lives in pitcher plants, and it’s the smallest Old World frog species ever found. (The only smaller frog in the entire world is found in Cuba.)

Dr Indraneil Das of the Institute of Biodiversity and Environmental Conservation at the Universiti Malaysia Sarawak said the sub-species had originally been mis-identified in museums. “Scientists presumably thought they were juveniles of other species, but it turns out they are adults of this newly-discovered micro species,” he said [Reuters].

Read More

CATEGORIZED UNDER: Living World

How to Turn a Frog Egg Into a Robot’s Artificial Nose

By Joseph Calamia | August 24, 2010 5:35 pm

robotsmellResearchers have found the secret to improving a robot’s sense of smell: Shove frog eggs up its nose. A team at the University of Tokyo has developed a sensor made from a genetically modified frog egg that can help a robot pick out insect smells and pheromones.

As useful as a moth-smelling robot may seem, researchers believe the study published yesterday in Proceedings of the National Academy of Sciences is just one step towards an inexpensive but sensitive chemical detector. Study coauthor Shoji Takeuchi explains that such a device could pick out gases like carbon dioxide:

“When you think about the mosquito, it is able to find people because of carbon dioxide from the human. So the mosquito has CO2 receptors. When we can (extract) DNA (from the mosquito) we can put this DNA into the frog eggs to detect CO2.” [Reuters]

Here’s how they did it.

Step 1 — Get Some Frog Eggs

Read More

CATEGORIZED UNDER: Living World, Technology

The "Lost Frog" Quest: Researchers Seek the World's Rarest Amphibians

By Eliza Strickland | August 9, 2010 3:05 pm

frog-mapIn 18 countries around the world, biologists are setting out what may be fruitless quests. Conservation International is sponsoring expeditions to seek 40 amphibian species that haven’t been spotted for over a decade, and that may well be extinct. The group hopes its “Search for Lost Frogs” project will draw attention to the plight of amphibians, which are threatened by fungal diseases, toxic chemicals, habitat loss, and climate change–some researchers even say the global population decline is a sign that the world’s sixth mass extinction event is underway.

Dr Robin Moore, of Conservation International, a US-based charity, said: “This role as the global ‘canary in a coalmine’ means that the rapid and profound change to the global environment that has taken place over the last 50 years or so – in particular climate change and habitat loss – has had a devastating impact on these incredible creatures.” [The Guardian]

Still, the biologists hope they’ll find that some of these 40 species are still hanging on. “Although there is no guarantee of success,” Conservation International said in a press release, “scientists are optimistic about the prospect of at least one rediscovery.”

The group also compiled a list of the 10 “most wanted” species. Photo gallery after the jump.

Read More

CATEGORIZED UNDER: Living World, Photo Gallery

Common Weedkiller Chemically Castrates Frogs; Turns Males Into Females

By Smriti Rao | March 2, 2010 1:35 pm

frogsAtrazine, one of the world’s most widely used herbicides, is wreaking havoc on the sex lives of male frogs. In a new experiment, exposure to the chemical emasculated more than half of the male African claw frogs in the study, and made one in ten turn into females. The results, which were published in the Proceedings of the National Academy of Sciences, have raised concerns that the herbicide found in waterways is altering amphibians’ hormones, and could potentially have similar effects on other animals, including humans.

Biologist Tyrone Hayes studied 40 male control tadpoles along with 40 male tadpoles reared in water tainted with atrazine. The levels of the chemical matched the levels the frogs would encounter in their natural settings, and was also within the drinking water standards set by the Environmental Protection Agency. The results showed that 75 percent of male tadpoles reared in atrazine-contaminated water developed into frogs that had low testosterone levels, decreased breeding gland size, feminized laryngeal development, suppressed mating behavior, reduced sperm production and decreased fertility, while the control group showed features typically found in male frogs [AFP]. Most of these “chemically castrated” frogs were unable to reproduce.

The rest of the results were even more dramatic. Ten percent of tadpoles raised in the chemically tainted water developed into frogs with male genetics but female anatomy, and some of these were actually able to breed and produce eggs. The offspring, researchers found, were all male because both parents contributed male genes. Scientists worry that the sex-reversed males and the subsequent production of all-male offspring is skewing the sex ratio of wild frog populations, and may be contributing to the decline of frog populations worldwide.

Read More

CATEGORIZED UNDER: Environment, Living World

A Gentleman Frog That Takes Monogamy & Parenting Seriously

By Smriti Rao | February 24, 2010 6:13 pm

frogMonogamy isn’t popular in the amphibian world. From frogs to salamanders, life in cold blood is all about meeting new ladies and hitting the road once the kids are born. So the male of a species of Peruvian poison frog (Ranitomeya imitator) stands out by proving that he is quite the keeper. He’s not only the first monogamous frog ever found, he also stays home and makes sure the tadpoles are fed.

Scientists studying these frogs say this unusual behavior–monogamy and co-operative parenting–could be directly attributed to the limited resources available to the frogs. They note that a broad study of 404 frog species show that species that deal with reduced food availability and greater difficulty in tadpole-rearing are more likely to have frog couples that work together to raise the young.

These findings could possibly shed some light on the way our hunter-gatherer ancestors approached monogamy. Details of the findings are to be published in the April issue of The American Naturalist.

Read More

CATEGORIZED UNDER: Environment, Living World
MORE ABOUT: amphibians, frogs, monogamy

An Early Education: As Embryos, Frogs Sniff Out Predators

By Brett Israel | November 2, 2009 7:00 am

tadpole-webFrog tadpoles have a good nose for danger: Scientists know that they go from headlong swimming to total stillness when they smell a predator. Now, researchers have discovered that frogs get that odoriferous training very early on. When they’re still embryos, they can learn to assess the threat level by sniffing for a predator’s pheromones.

Embryos put into water containing the odour of a salamander and the odour of injured tadpoles learned that the predator’s smell was a threat [BBC News]. The idea was to see if the amphibian embryos could learn to associate the smell of injured tadpoles with the smell of a predator. This type of learning behavior has also been observed in previous experiments with fish, larval amphibians, and larval mosquitoes, however this was the first study to document the behavior in embryos.

In an experiment sure to make PETA squirm, crushed tadpoles were mixed with water in which a tiger salamander had been swimming. Embryos were raised in this water with different concentrations of crushed tadpoles. Once the embryos had hatched into tadpoles, researchers tested their response to only the salamander odor. The tadpoles that were exposed to a higher concentration of the injured tadpole odour stayed motionless for longer in response to the salamander cue [BBC News]. The scientists say this demonstrates that these tadpoles learned as embryos that salamanders were more dangerous predators. The researchers published their findings in the journal Behavioural Ecology and Sociobiology.

Related Content:
80beats: Meet the Sexually Irresistible Fruit Fly
80beats: Do Humans Communicate Via Pheromones? The Jury Is Still Out
80beats:  Sniffing Out Sickness: Mouse Noses Respond to the Urine of Diseased Mice

Image: Maud Ferrari, UC Davis

CATEGORIZED UNDER: Living World
MORE ABOUT: frogs, pheromones
NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

80beats

80beats is DISCOVER's news aggregator, weaving together the choicest tidbits from the best articles covering the day's most compelling topics.
ADVERTISEMENT

See More

ADVERTISEMENT
Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »