Croc Hunter’s ‘Bum-Breathing’ Turtle Faces Extinction

Before his death two years ago this month, “Crocodile Hunter” Steve Irwin and his father discovered a unique turtle species that, as Irwin said, can “breathe through its bum.”

Researchers are now racing to save the rare and unusual turtle, Elseya irwini, which appears to be dying out as a result of human activities, according to scientists at James Cook Unviersity in Queensland, Australia.

Irwin and his father Bob first found the turtle after accidentally yanking one up on a fishing line during a 1990 family camping trip. It was later determined that the turtle only lives in two places: the Broken-Bowen River and the lower Burdekin River in Australia.

Ivan Lawler, who is now researching the turtle in hopes of saving it, told Discovery News the species was “probably always somewhat restricted in distribution, but changes in water quality, flow regimes and so on from human (induced) change” have reduced its range further.

Lawler, a JCU ecologist, believes only 5,000 of the turtles exist in the wild today.

The turtle’s remaining habitat has extremely poor food sources, which could be why it evolved the odd breathing technique.

Although the turtle can take in air from its nostrils, the second breathing method allows it to also absorb air from water that flows in through its behind, via an organ called the cloaca. It can therefore stay underwater for very long periods of time.

“It might be that (cloaca breathing) allows them to maintain position in flowing currents while feeding, that it helps them to escape predation or that it allows them to reduce energy expenditure on surfacing and thus get by with a lower-energy diet,” Lawler explained.

He and physiologist Suzy Munns have found that the species “seems to have a very low metabolic rate, even for a turtle.”

Ancient Crocodile Bones Could Yield Complete Skeleton

Researchers are hoping a large cache of ancient crocodile bones in western North Dakota will yield the state’s first complete croc skeleton.

“In all the years we’ve been working out there, we’ve never found a complete crocodile skeleton,” said state paleontologist John Hoganson, of the North Dakota Geological Survey. “It’s one of the things we’d like to find, for sure.”

Crocodiles lived in what is now North Dakota about 60 million years ago. Many bones and teeth have been unearthed through the years, but never a complete crocodile to put on display at the North Dakota Heritage Center in Bismarck.

This summer, participants in a public fossil dig on U.S. Forest Service land in southwestern North Dakota found bones and a skull, Hoganson said. They also found preserved crocodile tracks.

“You can actually see the footprints of this crocodile walking across what would have been a silty mud surface,” he said.

The ancient crocodiles were similar to those that live in warm climates today, Hoganson said. One big difference is that they would have been at the top of the food chain 60 million years ago, after the demise of the dinosaur, he said.

Geological Survey paleontologist Jeff Person said crocodile fossils are common, but “finding a complete skeleton would be a little more rare anywhere in the world.”

Full Moon Energizes Birds

If the night sky seems less tranquil on nights when the moon is bright, the observation probably isn’t imagined since a new study has determined that at least one bird’s level of activity dramatically increases with moonlight.

The finding adds to a growing body of evidence that lunar phases affect the behavior of insects, birds, fish and mammals — including humans.

The study, which has been accepted for publication in the journal Animal Behavior, is among the first to provide direct evidence for the “full moon effect,” since many other claims have been based on indirect observations and even folklore, such as werewolf tales.

In the case of streaked shearwaters, the focus of the study, this marine bird flew for longer periods and landed on water more frequently on nights with a full moon. But because sharks and other bird predators also appear to be more energized on such nights, the shearwaters didn’t stay on the water for long.

“Pelagic seabirds, including shearwaters, are known to be preyed upon by sharks or seals at sea, so birds are attacked from under the sea, not from the air,” lead author Takashi Yamamoto explained to Discovery News.

“When birds are sitting on the water’s surface at night with a full moon, it shades moonlight passing through into the sea, so predators might be able to detect seabirds using such shades,” added Yamamoto, a researcher at Japan’s National Institute of Polar Research.

He and his colleagues captured 48 streaked shearwaters at Sangan Island in Japan. They attached global location sensors to the birds. These devices recorded time, light levels, immersion in seawater and water temperature. Geographical locations were estimated using the light data. At the end of the study, the researchers recaptured the birds and removed the sensors.

Since the birds are in the middle of the food chain, they not only move more to escape full moon-stimulated predators, but they also seem to take advantage of the improved light situation by feeding at night on squid and fish, especially their favorite: anchovies.

The scientists believe other marine birds, such as albatrosses, receive a comparable caffeine-like behavior jolt from a full moon.

New Iguana Species Revealed

A new species of Pacific iguana has been uncovered by Australian and U.S. researchers, but already its future is looking grim.

In a paper published online in the Philosophical Transactions of the Royal Society B, the team shows there are three living species of Brachylophus iguanas, not two as indicated in current taxonomy.

The new species is named Brachylophus bulabula after the Fijian word for hello.

“In the reptile world the Fijian iguanas are iconic,” said lead author Scott Keogh, of the Australian National University’s School of Botany and Zoology. “To discover a new species of them is very exciting.”

But he said the new species and its cousins are under threat from habitat loss and attacks by feral cats and mongooses.

Two species of the iguana are already extinct, having been eaten out of existence about 2800 years ago by the earliest arrivals on the island, Keogh said. The surviving three species, the B. vitiensis,, or Fiji crested iguana, is listed as critically endangered and the other two as status unknown, due to lack of information about their numbers.

The new species was uncovered after analysis of the mitochondrial DNA of 61 iguanas from 13 islands.

The study shows the B. bulabula iguana is genetically and physically different from the two other species.

‘Day-Glo’ Fish Shine Red Light

It was staring them in the face, but somehow generations of marine biologists have failed to notice that a lot of fish in the sea glow a fluorescent red, according to a study published Monday.

This unheralded talent for neon-like crimson displays is more than a curiosity, and is sure to create waves — and a bit of embarrassment — among ichthyologists, as fish experts are called.

It has long been axiomatic that red light is simply not part of the mental universe of marine fish because the sunlight’s longest visible wavelengths do not penetrate below a depth of 30 feet.

A fire-engine red diving suit at 65 feet, for example, will appear dark grey or black to anyone — or any fish — that happen to be in the vicinity.

Dive far enough beneath the surface, and there is simply no red to be seen.

This foreshortening of the color spectrum under the waves was also assumed to correspond to a narrowed field of vision in fish, said the study’s lead researcher in an interview.

“The general consensus, which dominated fish literature for 20 or 30 years, was that fish don’t see red very well or at all,” explained Nico Michiels, a researcher at the University of Tubingen in Germany.

From an evolutionary standpoint, in other words, why develop a skill that you will never be able to use?

But conventional wisdom, it seems, was flat-out wrong.

“We have been blinded, literally, by the blue-green light that is available on reefs in the daytime,” said Michiels.

Roadsides Helping Bees Thrive

Roadsides may seem like the crummiest real estate around, but new research suggests that in fact they could serve as nature preserves for crucial pollinators, particularly native bees.

Roadsides planted with native plants hosted more than twice as many total bees and almost 50 percent more bee species than roadsides covered in non-native grasses, according to the study, published in Biological Conservation.

Jennifer Hopwood made the discovery while in graduate school in ecology at the University of Kansas in Lawrence. She started the research after picking up a book on roadside ecology from her colleague’s desk and starting to read.

“I just became really interested in the idea that roadsides could be potential habitat for animals and could also be a haven for plant species,” she said.

Several programs have restored the plants along roadsides in the Midwest to native species, which offer advantages over the non-native plants that were once recommended.

Native plants have deep roots, so they help prevent erosion, and they require less mowing and herbicide use, which saves on maintenance costs, although the up-front cost of planting and establishing the native grasses is higher.

But Hopwood’s primary interest was in bees, so she began investigating bees’ success in such habitats.

Hopwood collected bees from several roadside sites in Kansas that had been restored to native plants, and compared them with nearby, unrestored roadsides. Not only did Hopwood find that native plants hosted more than twice as many bees and almost 30 more types than weedy sites, but she also found that this relationship held regardless of how many flowers were present.

Tiny Frog, Believed Extinct, Found in Australia

A tiny frog species thought by many experts to be extinct has been rediscovered alive and well in a remote area of Australia’s tropical north, researchers said Thursday.

The 1.5 inch-long Armoured Mistfrog had not been seen since 1991, and many experts assumed it had been wiped out by a devastating fungus that struck northern Queensland state.

But two months ago, a doctoral student at James Cook University in Townsville conducting research on another frog species in Queensland stumbled across what appeared to be several Armoured Mistfrogs in a creek, said professor Ross Alford, head of a research team on threatened frogs at the university.

Conrad Hoskin, a researcher at The Australian National University in Canberra who has been studying the evolutionary biology of north Queensland frogs for the past 10 years, conducted DNA tests on tissue samples from the frogs and determined they were the elusive Armoured Mistfrog.

Alford’s group got the results on Wednesday. A spokeswoman for the Queensland Environmental Protection Agency also confirmed Hoskin’s findings.

“A lot of us were starting to believe it had gone extinct, so to discover it now is amazing,” Hoskin said. “It means some of the other species that are missing could potentially just be hidden away along some of the streams up there.”

North American Fish Under Threat

Nearly 40 percent of fish species in North America are imperiled, according to a new survey by fish experts, the U. S. Geological Survey, and the American Fisheries Society, up 92 percent from the last survey done in 1989.

North America hosts perhaps the greatest diversity of temperate freshwater organisms on Earth, including aquatic insects, mussels, crayfish and fish.

The new report, compiling assessments from fish experts in the United States, Canada and Mexico, found that of the 700 types of fish in the survey, 230 are “vulnerable,” 190 are “threatened,” 280 are “endangered,” and 61 are believed extinct.

“A lot of effort has been expended since 1989, but things are still in a sorry state in many ways,” said study author Eric Taylor of the University of British Columbia in Vancouver. “We can’t be complacent with trying to address some of these declines.”

No single cause explains the ongoing fish losses, Taylor and others agree. Habitat loss, invasive species, diseases, dams, and water contaminants all contribute.

“Fish are kind of canaries in the coal mine,” said Howard Jelks of the USGS and lead author of the report, published in Fisheries. “If you change the water to something that’s not able to support these fish, it’s also not going to be as high quality for recreating, for eating the fish out of these streams, for drawing water that’s ultimately used for drinking, or for other things.”

Certain regions were identified as hotspots with both high fish diversity and high degrees of threat. These included the Pacific central valley, the western Great Basin, the Rio Grande, and several river systems in the southeast such as the Tennessee and Mobile.

Pacific Coast salmon and trout were among the most at-risk types of fish, as were minnows, suckers, and catfish across the continent. Almost half of the carp and minnow family and the family of fish including perch and darters were identified in one of the imperiled categories.

The new report lists distinct sub-populations of certain fish separately, even if they are classified as the same species, which accounts for part of the increase.

Africa’s ‘Unicorn’ Caught on Camera

The okapi, an African animal so elusive that it was once believed to be a mythical unicorn, has been photographed in the wild for the first time, the Zoological Society of London (ZSL) said Thursday.

Camera traps set by the ZSL and the Congolese Institute for Nature Conservation (ICCN) captured pictures of the okapi in Virunga National Park in the Democratic Republic of the Congo.

The pictures have dispelled fears that the species had died out in more than a decade of civil war.

Noelle Kumpel, ZSL’s Bushmeat and Forests Conservation Program Manager, said: “To have captured the first-ever photographs of such a charismatic creature is amazing, and particularly special for ZSL given that the species was originally described here over a century ago.

“Okapi are very shy and rare animals, which is why conventional surveys only tend to record droppings and other signs of their presence.”

The okapi, which have a black, giraffe-like tongue and zebra-like stripes on their behind, were last spotted in the Virunga National Park nearly 50 years ago on the west bank of the Semliki River.

The new ZSL survey revealed a previously unknown okapi population on the east side of the river.

Thierry Lusenge, a member of ZSL’s Democratic Republic of Congo survey team, said: “The photographs clearly show the stripes on their rear, which act like unique fingerprints.

“We have already identified three individuals, and further survey work will enable us to estimate population numbers and distribution in and around the park, which is a critical first step in targeting conservation efforts.”

The exact status of the okapi is unknown as civil conflict and poor infrastructure makes access to the forests of DRC difficult.

But ZSL warned that even the newly-discovered okapi population was under threat from poachers.

Okapi meat, reportedly from the Virunga park, is now on sale in the nearby town of Beni and ZSL warned that if hunting continues at the current rate, okapi could become extinct in the park within a few years.

Related Links:

Discovery News blog: Born Animal

How Stuff Works: Extinction

Planet Green

Discovery Earth Live

Ants Slack Off for Colony’s Greater Good

They are capable of carrying up to seven times their body weight, but leaf cutter ants are slacking off for the greater good, according to new research.

In a paper published in today’s Biology Letters, Martin Burd of Australia’s Monash University details how a lower level of productivity by foraging leaf cutter ants improves productivity within the colony.

“What looks inefficient is actually efficiency,” Burd, who is attached to the School of Biological Sciences, said.

Burd measured the work done by worker ants tasked with collecting and harvesting leaf fragments in colonies of Atta colombica. He measured the load the ants carried, the time it took to cut leaf fragments and the rate at which fragments were delivered to the colony.

Burd and co-author Jerome Howard at the Department of Biological Sciences at the University of New Orleans found the ants were carrying about half the maximum load they could manage.

Even when the faster delivery time due to the lighter load was taken into account, they were still 35 percent less productive than their optimal performance.

Burd said it was “pretty clear they were underperforming.” He added that the inefficiency was explicable only if it improved transportation and processing of the leaf matter inside the nest.

Once the leaf fragment is delivered to the colony, its tissue is processed for use to cultivate fungal gardens that provide feed for the colony’s larvae, Burd said.

It is then transported by workers to one of the colony’s fungal gardens where it is cleaned and dissected into tiny particles that are then implanted in the gardens.