Toads Sniff for Earthquakes.
Stories of animals fleeing an area well before an earthquake strikes have fascinated scientists and laymen alike. Rachel Grant, a biologist, was studying toad populations in a lake in L’Aquila, Italy. Just before the 2009 earthquake there, Grant noticed that the entire population of toads left their lake suddenly, even though there had been no discernible disruptions. She published a paper on the phenomenon. Meanwhile, NASA scientists had been studying recent measurements of the chemical changes that rocks undergo due to geothermal pressure just before an earthquake occurs. One of those scientists, Friedemann Freund, came across Grant’s paper describing the strange toad exodus. Now collaborating, the pair has theorized that pre-earthquake chemicals from molten rocks below the lake had suffused into the L’Aquila lake water and had been quickly detected by the highly sensitive toads and other amphibians. Whether the discovery will have earthquake predictive utility remains to be seen.
Read more at The Telegraph.
Ravens Communicate With Gestures.
The ever-surprising intelligence of ravens, crows and magpies (Watch the full A Murder of Crows PBS NATURE episode) has a new chapter. Researchers now believe that ravens use their wings and beaks to communicate— similar to how we use our hands and arms. The researchers observed that the communication often took place as part of the mating ritual, with one partner presenting an object for the other to inspect, which often led to that partner looking at the object. Researchers believe this is the first observed instance of non-primate communication by gestures.
Read more at Live Science.
Subtracting Human Conflict Means Addition for Ugandan Wildlife.
An encouraging surge in wildlife populations in Uganda’s national parks has been attributed to the reduction of hostilities by rebel forces in that country. The armed conflict between the rebels and government forces meant that for years poaching could not be enforced inside the national parks. Now, with a reduction in hostilities, poaching enforcement has led to a wildlife comeback. According to Global Animal, zebra, giraffe, impala and waterbuck have increased three-fold in the past decade.
Jaguars Join the Migration from Mexico.
Jaguars are large cats second in size only to lions and tigers. They are seen, if at all, in the jungles of Central and South America. Recently, however, there have been a handful of jaguar sightings in southern Arizona. Apparently, the animals have migrated north from Central America into Mexico and are crossing over the Arizona border. In an article in the New York Times, a professional guide who takes tourists to see mountain lions in Arizona described his surprising and hair-raising close encounter with a wild jaguar.
Strange Bedfellows: Inbreeding Confers Advantage to Urban Bedbugs.
Genetic diversity is usually a necessary element to keep a species healthy and thriving within a particular environment. Normally, excessive inbreeding causes mutations and disease in a colony of insects leading to its eventual collapse. However, bedbugs prove to be an exception to the rule. According to the American Society of Tropical Medicine and Hygiene, bedbugs in urban centers have been able to use their tolerance for inbreeding to explode their populations. Since a single egg-laying female can produce many progeny, it would be a great advantage if those siblings could mate and produce an ever-growing colony of inbred bedbugs. In urban apartments in the United States, that is exactly the mechanism that is driving the recent bedbug infestations that can spread throughout an entire building. And, it should not come as any surprise that cockroaches enjoy the same inbreeding resistance.
Global Warming Will Lead to Return of Woolly Mammoth?
For years, scientists have been looking for a way to clone a woolly mammoth. They have been tantalizingly close — recovered remains of the animals from the Arctic have yielded excellently preserved specimens. Still, the DNA of the preserved specimens has been incomplete, up until now. Enter global warming. The disappearance of ice in Siberia as a result of warmer temperatures there has led to the uncovering of new mammoth remains. Now, scientists have extracted organic material from the thigh bone of one of the new specimens that they believe contains intact DNA sufficient for cloning. The cloning will involve the use of an elephant egg which, after being denucleated, will have a mammoth cell nuclei inserted. If successful, the experiment will spawn the first mammoth to walk the earth in thousands of years.
Read more at Discovery.
Its Face Is Worse Than Its Bite.
If you are a fruit-eating bat, you might be able to out-compete your peers if you can sink your teeth into something harder than they can handle. The price, however, is a face which is, well, quite ugly. The Centurio senex bat is a member of the fruit-eating bat family. Scientists believe that in times of food scarcity, it evolved a skull and facial structure that is extremely wide and short, giving its jaws better leverage. In fact, although it clearly will win no beauty pageant, the evolved skull of this bat gives it a 20% stronger bite than its rivals.
Read more at BBC News.
Amphibious Hellbenders Reproduce in Captivity.
Like all amphibians, Hellbenders are very sensitive to pollution and other changes in their ecosystem. These salamander-like creatures once thrived in the rivers of Missouri and Arkansas, but they have been in serious decline over the past few years with their numbers dropping to less than 10% of what was measured in a previous census. The St. Louis Zoo, however, has come to the rescue. Zoologists there have created streams and specially equipped rooms that provide ideal conditions for the Hellbenders to reproduce. This November, the zoologists were rewarded with the birth of 63 larvae that will hopefully mature and help repopulate the Hellbenders in the wild.
Read more at Discovery.
Cowbirds and Mockingbirds Display Competing Strategies Over Parasitic Eggs.
Cowbirds are infamous for their habit of laying eggs in the nests of other birds, expecting their chicks to be fed and cared for by their unwitting hosts. In fact, they often break open a few, but not all, of the host’s eggs to give their own offspring better odds of surviving. Here, the strategy is to leave enough host eggs so that the host parents do not completely abandon the nest. Mockingbirds have adapted to this predatory behavior by cowbirds with a peculiar strategy of their own. Rather than destroy the detected cowbird eggs, they ignore them. Why? It appears that leaving the cowbird eggs increases the likelihood that the next cowbird to visit the nest will destroy the previous cowbird’s eggs and leave at least some of the mockingbird eggs alone.
Read more at New Scientist.
Amazon Frog Species More Numerous Than Thought.
Chris Funk is a biologist with Colorado State University’s Department of Biology. He and his team have carefully catalogued frogs in the Amazon basin, a region that includes parts of six different countries. What they found may be good news for conservationists. Twelve new species of tiny tree frogs were discovered in the expedition. In the past, many of the new species had been mistaken for closely related species. However, DNA analysis helped make the difficult distinctions. Extrapolating these results to other amphibians that also inhabit the same area, Funk believes that “as many as 1,900 new species could be unveiled.”
Read more at Colorado State University.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.