ScienceDaily (Sep. 29, 2011) — Research published in the October issue of The American Naturalist shows that Australian green tree frogs survive the dry season with the help of the same phenomenon that fogs up eyeglasses in the winter.
According to researchers from Charles Darwin University in Australia, tree frogs often plop themselves down outside on cool nights during the dry season in tropical Australia. When they return to their dens, condensation forms on their cold skin -- just like it does on a pair of glasses when we come in from the cold. The researchers found that frogs absorb this moisture through their skin, which helps to keep them hydrated during periods of little or no rain.
Before this study, the frogs' dry-season excursions were a bit mysterious.
"Every once in a while, we would find frogs sitting on a stick under the open sky, on nights when it was so cold they could barely move," said Dr. Chris Tracy, who led the research. "It was a real puzzle."
Tracy and his colleagues thought this behavior might enable the frogs collect condensation, but the hypothesis had never been tested.
The researchers designed a series of experiments using real frog dens in eucalyptus trees and artificial ones made from PVC pipe. They wanted to see if the frogs could collect enough moisture through condensation to compensate for what they lost being in the cold. They found that a cold night out cost a frog as much as .07 grams of water. However, a frog could gain nearly .4 grams, or nearly 1 percent of its total body weight, in water upon returning to the warm den.
The researchers also tested how well a frog's skin could absorb water, and found that as much as 60 percent of each water drop could be absorbed.
The results show that frogs can use condensation to hydrate themselves. And in a place as arid as the Australian savannahs during the dry season, where there is essentially no rain from June through August, every little bit counts.
"When there's no water available, even a small amount can mean the difference between surviving the dry season or not," Tracy said.
OF HOW HUMMINGBIRDS CROSS OCEANS.
THEY CAN GO WITHOUT FOOD AND WATER FOR LONG PERIODS OF TIME ,BY PUTTING THEMSELVES INTO A STATE OF TORPOR,.
IT'S LIKE ENERGY EFFICIENCY SETTINGS, THEIR BODIES USE AS LITTLE ENERGY AS POSSIBLE, KINDA LIKE RUNNING ON AUTOPILOT.
SO, THEY CAN CROSS OCEANS DURING MIGRATION.
SO SMALL,YET SO STRONG.
I HAD A HUMMINGBIRD NEST ON MY WINDCHIME,ONE SUMMER, GAVE BIRTH TO TWO BABIES, ONE SURVIVED....WOULD WATCH HER COME AND GO,TO FEED HERSELF AND THE BABIES.
IN LAKOTA,HUMMINGBIRD'S ARE THE SYMBOL FOR JOY.
THEY REALLY DO LIFT THE SPIRITS WHEN THEY FLY BACK TO THE NEST.
very interesting story, animals are so amazing.
they have been given some amazing survival skills.
not enough to save them from the human monsters, that want to ruin every beautiful place , and wild animals, reptiles,amphibians, etc.
By destroying their natural habitats.
we need more saving, and less destruction!!!!!!!!!
Hummingbirds are amazing Insects. They got the idea to make Helicopters from Hummingbirds as a matter of fact. No other insecty can hover and go backwards for so long. Interesting Tersa my friend. Thanks for Posting
Wonderful observances here, folks. I'd like to correct you Vinnie, if you don't mind. Hummingbirds are not insects....they're birds. The smallest and fastest species in the bird family. A wonder to see up close. Their tiny wings move so fast that you can hardly see them flutter and all you hear is a buzz.
Teresa, thanks for the extremely interesting article. Frogs are amazing, aren't they?
I should have written "observations", not observances. The mind is a little fuzzy today. It's been raining for so long and it's so humid that I think jungle rot has set in!!!!
NICE TO SEE YOU.
THE REST OF THE COUNTRY IS SNOWING.
NOT FOR US,YAY.