Kermit the cannibal? Frogs sometimes eat each other

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A large frog snacks on a smaller frog. (Les Minter)

It’s a frog-eat-frog world out there.

While it may seem like frogs are insectivores (a long tongue snatching a fly comes to mind), these amphibians are actually “generalist” carnivores. They will eat just about any small critter they can swallow, including other frogs, according to a new study.

It’s no secret that frogs sometimes snack on their cousins. In fact, biologists have conducted studies showing that certain frogs eat their “siblings” (i.e., members of their own species), in addition to frogs of other species. [40 Freaky Frog Photos]

While scientists have known about this frog-on-frog predation, they haven’t really looked at the reasons behind it. What factors make a frog want to hunt other frogs, for example? And are certain frogs more likely than others to gobble up their own kind?

To get to the bottom of the mystery, researchers in South Africa recently conducted a review of the available scientific literature on frog diets from all over the world. About one-fifth of the 355 studies included in the review mentioned frogs eating other frogs. The finding reinforced what the researchers already knew: It’s not uncommon for a frog to chow down on another frog.

“It seems that frogs, if they are in the right place at the right time, will eat anything that moves,” John Measey, a senior researcher at the Centre for Invasion Biology at Stellenbosch Universityin South Africa and lead author of the new study, told Live Science.

Alien amphibians

Measey said he became interested in frog diets while studying African clawed frogs at the Cape of Africa. He and his colleagues noticed that the clawed frogs, which are not native to the area, were gobbling up frogs that were native to the cape. This was troubling to the researchers, who wondered if the invasive clawed frogs might be more likely than other, local frogs to engage in anuraphagy, or frog-eating.

Measey and his colleagues from the University of Cape Town analyzed the 355 studies, looking for patterns. They looked at instances of anuraphagy in frog species that had invaded new habitats, and compared that to the same frogs’ likelihood of eating other frogs when located in their own, native habitats.

“People who study invasive frogs have often said that one of the biggest effects of an invasive species is that they eat other frogs. So, we were interested in testing that as a hypothesis,” Measey said.

The researchers found that frogs were about 40 percent more likely to eat other frogs when they were living in a non-native habitat compared to in their native habitat. That’s a big discrepancy, one that Measey said is important, especially for those responsible for protecting native creatures from the effects of invasive species. Now, biologists or rangers who care for nature preserves can say with certainty that an invasive frog poses a threat to other species and may need to be removed, Measey said.

Frogs on the menu

In addition to finding that invasive frogs like snacking on other frogs, the researchers discovered a few other factors that can help predict how likely one frog species is to eat other frogs. For one thing, bigger frogs are more likely than smaller frogs to indulge in a frog-flavored meal. In fact, with every 0.04 inch increase in body size, a frog becomes 2.8 percent more likely to eat other frogs, the researchers found. [Eye-Swallowing and Mouth Birth: Freaky Facts About Frogs]

“If you have two frogs and one is 10 millimeters [0.4 inches] longer than the other, we would say the bigger one is 28 percent more likely to eat anurans [frogs] than the smaller one,” Measey said.

And it’s not just size that matters in anuraphagy. The researchers also looked at how other factors, including biodiversity, affect a frog’s appetite for frogs. They found that, in places where there are many species of frogs living in one area, the amphibians are more likely to eat other frogs than if they lived in an area where there were only a few other species of anurans.

“You would be more likely to find frogs eating other frogs in the Amazon than you would in New York state. That seems to be because there are just more frogs in the Amazon,” Measey said.

All this frog-eat-frog talk may seem morbid, but Measey said people should keep in mind that a frog eating a frog of a different species is a lot like a human eating a cow, or a chicken eating a bug. It’s really just an example of one species eating another species, something that happens all the time. What’s a bit harder to swallow is true frog cannibalism, which isn’t unheard of but is also not as common among frogs as cross-species predation, Measey added.

In the studies the researchers reviewed, frogs ate members of their own species about a third as often as they ate frogs of species other than their own. Why do frogs engage in this behavior? Measey said he and his colleagues aren’t sure. However, other researchers are starting to examine whether frogs can even distinguish between members of their own species and frogs of other species.

The new study was published Aug. 25 in the journal PeerJ.

 

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Louisiana homeowners watch gator crawl out of storm drain in middle of block

Homeowners in one Louisiana subdivision say it was like something from the Sci-fi channel when a 10-foot-long alligator crawled out of a storm drain right in the middle of their neighborhood.

Jodi Luna told Fox8Live she couldn’t believe her eyes when she saw the gator emerge from its underground home and stroll towards a neighbor’s house in LaPlace as she snapped a photo on her cellphone.

“I thought I was watching something from the Sci-fi channel,” she said.

Luna told the station the reptilian intruder walked through her neighbor’s garden and then started head-banging the front door.

Luna and her neighbors have seen gators before but nothing like this.

Eventually, the creature crawled into a nearby pond before it could be caught.

 

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Shark bites top of kayaker’s foot in waters off California coast

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A kayaker was bitten by a shark in the waters off the California coast and was taken to the hospital with cuts to the top of his foot, authorities said on Saturday.

Ventura County Fire Capt. Ron Oatman said the kayaker, who was fishing with a friend in Malibu, reported that he was dangling his feet in the water when a shark came up, bumped against or bit his foot before swimming away.

Ventura County officials told Fox 11 Los Angeles the shark was a 10-foot hammerhead.

Lidia Barillas, public information officer with the Los Angeles County Fire Department’s Lifeguards Division told the Los Angeles Times the bite was “nothing severe, but a very deep wound.”

“It was a bite and release,” she said.

The wounded kayaker was able to flag down a fishing boat that was nearby and got onboard, where he was able to control the bleeding. He was then airlifted back to a local hospital, the Los Angeles Times reported.

Oatman said lifeguards paddled to the boat and accompanied the man back to shore. Los Angeles County Lifeguards have said none of the beaches they patrol will be closed.

The shark encounter occurred about a mile off the intersection of Pacific Coast Highway and Deer Creek Road.

Last Saturday, Morro Strand State Beach was closed for three days after a great white shark took a bit out of a surfer’s board. Elinor Dempsey was surfing in the morning when the shark took a 14-inch wide bite out of the surfboard she was paddling on.

“First I thought it was a dolphin and I thought, ‘What the hell is he doing?’” Dempsey told the San Luis Obispo Tribune. “And he kind of landed on my board. Then I realized he had taken a chunk. And I was, like, that’s not what dolphins do.”

Officials closed the beach for 72 hours and posted warning signs at nearby beaches.

The odds of being bit by a great white shark in the waters off the California coastline have dropped by 91 percent, the Los Angeles Times reports, citing analysis from Stanford University and the Monterey Bay Aquarium. Swimmers and divers alike have all seen declines in shark attacks over the last 63 years.

Click for more from Fox 11 Los Angeles.

Click for more from the Los Angeles Times.

The Associated Press contributed to this report.

 

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60,000 antelopes died in 4 days – and no one knows why

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In May 2015, nearly half of all the saigas, a critically endangered antelope that roams the steppe of Kazakhstan, died off. Exactly why is still a mystery. (Credit: Albert Salemgareyev)

It started in late May.

When geoecologist Steffen Zuther and his colleagues arrived in central Kazakhstan to monitor the calving of one herd of saigas, a critically endangered, steppe-dwelling antelope, veterinarians in the area had already reported dead animals on the ground.

“But since there happened to be die-offs of limited extent during the last years, at first we were not really alarmed,” Zuther, the international coordinator of the Altyn Dala Conservation Initiative, told Live Science.

But within four days, the entire herd — 60,000 saiga — had died. As veterinarians and conservationists tried to stem the die-off, they also got word of similar population crashes in other herds across Kazakhstan. By early June, the mass dying was over. [See Images of the Saiga Mass Die-Off]

Now, the researchers have found clues as to how more than half of the country’s herd, counted at 257,000 as of 2014, died so rapidly. Bacteria clearly played a role in the saigas’ demise. But exactly how these normally harmless microbes could take such a toll is still a mystery, Zuther said.

“The extent of this die-off, and the speed it had, by spreading throughout the whole calving herd and killing all the animals, this has not been observed for any other species,” Zuther said. “It’s really unheard of.”

Crucial steppe players

Saigas play a critical role in the ecosystem of the arid grassland steppe, where the cold winters prevent fallen plant material from decomposing; the grazing of the dog-size, Gonzo-nosed antelopes helps to break down that organic matter, recycling nutrients in the ecosystem and preventing wildfires fueled by too much leaf litter on the ground. The animals also provide tasty meals for the predators of the steppe, Zuther said. [Images: Ancient Beasts of the Arctic]

“Where you find saiga, we recognize also that the other species are much more abundant,” Zuther told Live Science.

Saigas, which are listed as critically endangered by the International Union for the Conservation of Nature, live in a few herds in Kazakhstan, one small herd in Russia and a herd in Mongolia. The herds congregate with other herds during the cold winters, as well as when they migrate to other parts of Kazakhstan, during the fall and spring. The herds split up to calve their young during the late spring and early summer. The die-off started during the calving period.

Die-offs of saigas, including one that felled 12,000 of the stately creatures last year, have occurred frequently in recent years. But the large expanse of the country affected by last year’s die-off meant veterinarians couldn’t get to the animals until long after their deaths. The delay hindered any determination of a cause of death, and researchers eventually speculated that an abundance of greenery caused digestion problems, which led to bacterial overgrowth in the animals’ guts.

Detailed analysis

This time, field workers were already on the ground, so they were able to take detailed samples of the saigas’ environment — the rocks the animals walked on and the soil they crossed — as well as the water the animals drank and the vegetation they ate in the months and weeks leading up to the die-off. The scientists also took samples of the ticks and other insects that feed on saiga, hoping to find some triggering cause.

The researchers additionally conducted high-quality necropsies of the animals, and even observed the behavior of some of the animals as they died. The females, which cluster together to calve their young, were hit the hardest. They died first, followed by their calves, which were still too young to eat any vegetation. That sequence suggested that whatever was killing off the animals was being transmitted through the mothers’ milk, Zuther said.

Tissue samples revealed that toxins, produced by Pasteurella and possiblyClostridia bacteria, caused extensive bleeding in most of the animals’ organs. ButPasteurella is found normally in the bodies of ruminants like the saigas, and it usually doesn’t cause harm unless the animals have weakened immune systems.

Genetic analysis so far has only deepened the mystery, as the bacteria found were the garden-variety, disease-causing type.

“There is nothing so special about it. The question is why it developed so rapidly and spread to all the animals,” Zuther said.

Mystery endures

A similar mass die-off of 400,000 saigas occurred in 1988, and veterinarians reported similar symptoms. But because that die-off occurred during Soviet times, researchers simply listed Pasteurellosis, the disease caused byPasteurella, as the cause and performed no other investigation, Zuther added.

So far, the only possible environmental cause was that there was a cold, hard winter followed by a wet spring, with lots of lush vegetation and standing water on the ground that could enable bacteria to spread more easily, Zuther said. That by itself doesn’t seem so unusual, though, he said.

Another possibility is that such flash crashes are inevitable responses to some natural variations in the environment, he said. Zuther said he and his colleagues plan to continue their search for a cause of the die-off.

 

Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

 

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Shark mauls man, injuring leg as attacks continue off Australian coast

A 65-year-old man was mauled by a shark off Australia’s most populous state on Friday, but managed to get back on his surf ski and get help for a serious leg injury, police said.

David Quinlivan was paddling a surf ski near the New South Wales state town of Forster, 185 miles north of Sydney, when he was attacked, police said. They said he fell into the water but got back on the surf ski and managed to get closer to shore, where bystanders were able to help him from the water.

One of those bystanders, Warren Thompson, said he and others ran into the surf to help Quinlivan.

“He had lost his paddle but was able to climb back onto the ski and caught a wave to the shore,” Thompson said.

Thompson added: “It looked to us like he was having a heart attack. When we reached him, he told us to stay out of the water.”

Quinlivan was flown by helicopter for emergency surgery to a leg injury. The state ambulance service described that injury as serious.

Two weeks ago, a 38-year-old surfer suffered life-threatening injuries when he was attacked by a shark at Port Macquarie, 60 miles north of Forster.

Three weeks earlier, a 52-year-old surfer was seriously injured as he repeatedly punched a shark that mauled him off Evans Head, 140 miles north of Port Macquarie, in the 11th attack — including one fatality —  in five months along a 12-mile stretch of northern New South Wales coast.

On Feb. 9, a 41-year-old Japanese tourist was killed around the tourist town of Ballina, also is northern New South Wales. The only fatal attack in Australia since then was in July, when a 46-year-old diver was killed off the island state of Tasmania, 1,000 miles south of Ballina.

Sharks are common off Australia’s beaches, but fatal attacks are rare. The country has averaged fewer than two deadly attacks per year in recent decades.

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A real big bug problem: Iowa fossils show giant sea scorpion was dominant predator of its time

 

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This rendering provided by Yale University shows a Pentecopterus decorahensis. Earth’s first big predatory monster was a weird water bug, newly found fossils show. Almost half a billion years ago, Earth’s dominant large predator was a sea scorpion that grew to 5 feet 7 inches with a dozen claw arms sprouting from its head and a spike tail, according to a new study. (Patrick J. Lynch/Yale University via AP) (The Associated Press)

Earth’s first big predatory monster was a weird water bug as big as Tom Cruise, newly found fossils show.

Almost half a billion years ago, way before the dinosaurs roamed, Earth’s dominant large predator was a sea scorpion that grew to 5 feet 7 inches, with a dozen claw arms sprouting from its head and a spike tail, according to a new study.

Scientists found signs of these new monsters of the prehistoric deep in Iowa, of all places.

Geologists at the Iowa Geological Survey found 150 pieces of fossils about 60 feet under the Upper Iowa River, part of which had to be temporarily dammed to allow them to collect the specimens. Then scientists at Yale University determined they were a new species from about 460 million year ago, when Iowa was under an ocean

Then, all the action was in the sea and it was pretty small scale, said James Lamsdell of Yale, lead author of the study published Monday in the journal BMC Evolutionary Biology.

“This is the first real big predator,” Lamsdell said. “I wouldn’t have wanted to be swimming with it. There’s something about bugs. When they’re a certain size, they shouldn’t be allowed to get bigger.”

Technically, this creature — named Pentecopterus decorahensis, after an ancient Greek warship — is not a bug by science definitions, Lamsdell said. It’s part of the eurypterid family, which are basically sea scorpions.

Those type of creatures “are really cool,” said Joe Hannibal, curator of invertebrate paleontology at the Cleveland Museum of Natural History. Hannibal wasn’t part of the study, but praised it for being well done, adding “this species is not particularly bizarre — for a eurypterid.”

Unlike modern land scorpions, this creature’s tail didn’t sting. It was used more for balance and in swimming, but half this creature’s length was tail, Lamsdell said.

There were larger sea scorpions half way around the world at the same time but those were more bottom feeders instead of dominant predators, he said.

Lamsdell could tell by the way the many arms come out of the elongated head how this creature grabbed prey and pushed it to its mouth.

“It was obviously a very aggressive animal,” Lamsdell said. “It was a big angry bug.”

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Rhino crushes experienced tour guide to death in Zimbabwe game park

A game park director says a rhino crushed a tour guide to death at a private nature reserve in Zimbabwe.

Kate Travers, director of the Imire Game Park, said on Wednesday that Tafadzwa Gosho died on Monday night after he was crushed by a rhino he was tending to.

Travers said Gosho was “an experienced rhino handler” and that such attacks were rare. The Imire Game Park is 40 kilometers (24.86 miles) from the capital, Harare.

On its website, the Imire Game Park is described as “an intensive black rhino breeding station,” which has successfully released 11 rhinos into the wild.

In August, an experienced guide was mauled to death by a lion, while leading a walking tour through Zimbabwe’s Hwange National Park.

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How ‘vampire’ spiders could help in the fight against malaria

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Evarcha culicivora (University of Canterbury)

A study conducted by researchers at the University of Canterbury in New Zealand has highlighted a pair of unlikely recruits in the battle against human malaria – two species of spider.

In particular, the research by Fiona Cross and Professor Robert Jackson citedEvarcha culicivora, an eight-legged vampire, which is drawn to female mosquitoes whose guts are filled with blood.

“Evarcha culicivora has a particular hankering for Anopheles mosquitoes – the very mosquitoes notorious for being malaria vectors,” said Jackson, in astatement. “This little spider is a predator that likes us and eats our enemies.”

The study also highlighted the role of the Paracyrba wanlessi spider, which feeds on mosquito larvae lurking in pools of water inside bamboo.

Both spiders are found in Kenya but live in very different habitats. Evarcha culicivora is typically found on the walls of buildings inhabited by people in East Africa while Paracyrba wanlessi is found in hollow stems of bamboo.

“These two spider species are highly specialised mosquito assassins,” said Cross, in the statement. “Like Bram Stoker’s ‘Dracula’ or Arnold Schwarzenegger in the James Cameron movie ‘The Terminator’, these little specialist predators ignore any other insects that get in the way as they pursue their target victims – mosquitoes.”

Jackson added that, by attacking blood-filled mosquitoes, Evarcha culicivoraacquires a “blood perfume” that is attractive to members of the opposite sex.

The scientists’ study has been published in the Journal of Arachnology. In the Journal, the researchers explained that humans have nothing to fear from the spiders, noting that malaria is a mosquito-borne, not spider-borne disease. “It is exceedingly difficult to make a rational case for worrying about malarial spider bites,” they said.

 

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Iguana relative shows how lizards spread worldwide

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The newfound lizard species Gueragama sulamerica was found at a site in Brazil known for its pterosaurs fossils (Julius Csotonyi)

An 80-million-year-old lizard discovered in southern Brazil has provided a surprising clue about how these reptiles evolved, and where they once lived, according to a new study.

Until now, researchers had found acrodontans only in the Old World, including Africa and Asia. (This is a type of lizard is called an iguanian that has teeth fused to the top of its jaws, a group that includes chameleons and bearded dragons.) But the newfound fossil, a partial lower jaw of a new species of acrodontan, shows that they lived in the New World much earlier than thought.

The fossil suggests that acrodontans managed to distribute themselves worldwide before the ancient supercontinent Pangaea broke up about 200 million years ago, the researchers said. [Image Gallery: 25 Amazing Ancient Beasts]

“This fossil is an 80-million-year-old specimen of an acrodontan in the New World,” study co-author Michael Caldwell, a biological sciences professor at the University of Alberta in Canada, said in a statement. “It’s a missing link in the sense of the paleobiogeography and possibly the origins of the group, so it’s pretty good evidence to suggest that back in the lower part of the Cretaceous, the southern part of Pangaea was still a kind of single continental chunk.”

Paleontologists discovered the fossil in the rock outcrops of desert that dates to the late Cretaceous in the Brazilian municipality of Cruzeiro do Oeste. The researchers named the new species Gueragama sulamericana — guera meaning “ancient” in native Brazilian; “agama” in reference to agamid, a family of iguanian lizards; and “sulamericana” meaning “from South America” in Portuguese.

The jaw is missing a few teeth, but has room for 18 of them, and the teeth almost uniformly increase in size from the front to the back of the mouth, the researchers found.

During the Late Cretaceous, G. sulamericana lived in an arid desert environment, although evidence of ancient wetlands suggests that water was available seasonably, the researchers said. G. sulamericana also had company. Other fossil findings, including “hundreds of bones” of the pterosaur species Caiuajara dobruskii, show that larger animals lived there, too, the researchers wrote in the study.

G. sulamericana may have lived in burrows to avoid extreme daytime heat, just as some modern lizards do today, the researchers added.

Surprise finding

Among living lizards, iguanians comprise one of the most diverse groups, with more than 1,700 species. Previous research has found that acrodontan iguanians dominated the Old World, and nonacrodontan iguanians (such as iguanas) dominated the New World, particularly the American South, Caldwell said.

The oldest known acrodontans are from the early to middle Jurassic period in present-day India. However, now researchers know that acrodontans had spread elsewhere in the world by the late Cretaceous, the researchers said.

“This Gueragama sulamericana fossil indicates that the group is old, that it’s probably southern Pangaean in its origin,” Caldwell said. “After the [Pangaean] breakup, the acrodontans and chameleon group dominated in the Old World, and the iguanid side arose out of this acrodontan lineage that was left alone on South America.”

Eventually, nonacrodontans replaced acrodontans in the Americas. But nonacrodontans remain as natives in the Old World, the researchers said.

“This is an Old World lizard in the New World at a time when we weren’t expecting to find it,” Caldwell said. “It answers a few questions about iguanid lizards and their origin.”

The research was published online Aug. 26 in the journal Nature Communications.

 

Copyright 2015 LiveScience, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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Wildlife officials say they are searching for 8-foot-long king cobra snake that escaped home

 

 

Wildlife officials in Florida say they’re searching for an 8-foot-long king cobra snake that escaped from a home in Orlando.

Florida Fish and Wildlife Conservation Commission spokesman Greg Workman says the snake was reported missing Wednesday by its owner.

Officials say the non-native, venomous snake is green and yellow.

Workman says the snake’s owner has the proper permit to keep it as a pet and officials say the owner is an experienced snake handler.

Wildlife officials say they’ve been canvassing the area looking for the snake. Officials warn residents not to approach the reptile if they see it and instead urge them to contact the agency’s alert hotline.

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