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Scientists probe mysterious wave of antelope deaths

 Scientists probe mysterious wave of antelope deaths

By Rory Galloway
BBC Science writer

Around 120,000 Saiga antelope have died so far

Around half of the world’s critically endangered Saiga antelope have died suddenly in Kazakhstan since 10 May.

An unknown environmental trigger is thought to have caused two types of normally benign bacteria found in the antelopes’ gut to turn deadly.

The animals die within hours of showing symptoms, which include depression, diarrhoea and frothing at the mouth.

Because it is calving season, entire herds of female antelope and their new-born calves have been wiped out.

“They get into respiratory problems, they can’t breathe easily. They stop eating and are extremely depressed; the mothers die and then the calves are very distressed and then they die maybe one or two days later,” said Richard Kock from the Royal Veterinary College in London.

Prof Kock spoke to the BBC’s Science in Action programme after joining an international team in Kazakhstan studying the causes of the die-off.

Conservation setback

The Saiga antelope is a species adapted to cope with the extremes of temperature found on the central Asian steppes of Kazakhstan. They are about the size of a large sheep and once roamed in their millions from Great Britain to northern China.

Populations have fallen repeatedly due to hunting, reaching a low of around 50,000 individuals after the fall of the Soviet Union. This rendered the species critically endangered.

Hunting brought Saiga numbers to a low of 50,000 in the 1990s

Conservationists have made great progress with Saiga in recent years, due to international efforts to reduce poaching and monitor their populations.

This die-off is a severe setback to the conservation effort because it has wiped out four of the six calving herds in the largest remaining – and best protected – “Betpak-dala” population, in central Kazakhstan.

Steffen Zuther, head of the Association for the Conservation of Biodiversity in Kazakhstan (ACBK), was monitoring calving in one of the herds containing thousands of affected animals.

“Over two days [in the herd I was studying] 80% of the calving population died,” he told the BBC.

The whole herd then died within two weeks.

Steffen Zuther has been monitoring herds of antelope in Kazakhstan

About 120,000 individual antelope have died, from a global population of approximately 250,000. Fortunately, mortality rates are now dropping, although the deaths continue in some populations.

“What we’re seeing is sort of a perfect storm of different factors,” Prof Kock explained.
Two different bacteria, pasteurelosis and clostridia, have been found in every dead animal studied. These bacteria are naturally found in the animals’ respiratory and gut systems, so something must have reduced the immunity of the animals.

One possible trigger is climatic. This year a very cold winter was followed by a wet spring, and this may have affected the immune competence of the animals, making them more vulnerable to the bacteria.

This, or some other trigger, pushed the animals past a threshold at which the bacteria overcame Saiga immune defences and became deadly enough to transmit to their calves.
dead antelope and calf

Because of its timing, the wave of deaths has claimed mothers and calves
“There’s no infectious disease that can work like this,” said Prof Kock. He added that the wave of Saiga deaths was not unprecedented. “[This] die-off syndrome has occurred on a number of occasions.”

In 1984, 2010 and 2012 there were massive die-offs, but none of these claimed such a massive proportion of the population. ‘Doesn’t make sense’

Despite these huge losses, Saiga antelope are surprisingly well adapted to recover quickly from population crashes.

“Its strategy for survival is based on a high reproductive rate, so [the Saiga] produce triplets and have the highest foetal biomass of any mammal. It’s built, in a sense, to recover from collapse,” Prof Kock said.

The Saiga’s natural habitat has dramatic temperature fluctuations. “In a very severe winter… you could lose 90% of the population.”

But losing 100% percent of some populations within two weeks “doesn’t make any sense” from a biological or evolutionary perspective, Prof Kock said.

There are five main populations of Saiga remaining in central Asia

Saiga antelope have been a conservation success story after recovering from their critical low in the 1990s. The animals now exist in five locations across central Asia, but all individuals affected by the sudden die-off are from the largest remaining Betpak-dala population in Kazakhstan.

This population consists of six major herds, of which four have been completely wiped out.

Steffen Zuther is going back into the field to investigate more remote populations. He hopes to identify what triggered this population collapse, so he can work to stop it happening again.


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Mysterious sea creature stuns onlookers

 

 

 

Mysterious creature stuns onlookers

The sea is big, scary and full of things that want to eat you.

If you ever find yourself in doubt as to whether or not to go in the water, it can be helpful to remember the sheer number of giant teeth, suckers and appendages-yet-unknown-to-science that live in it.

A spine-chilling, luminous, snakelike creature was recently captured in Taiwan by a man who was out fishing at a port in Penghu.

The fisherman, Wei Cheng Jian, caught the strange creature and posted a video of his find on Facebook in hopes of getting a few answers.

However, Jian, who seemed more than a bit nervous in the video, removed the clip from his Facebook page shortly afterwards – but not before the footage was copied, shared, and incited a little internet confusion.

In the video, the three-foot-long bright-green creature is seen slithering slowly across the dock’s concrete floor and shooting out a long pink tongue as if searching for a prey.

The seemingly alien-like critter sparked a huge debate online with persons from science fiction backgrounds to an expertise in the natural world throwing in their two-cents about the creature’s origin.

And though an exact answer has not yet been determined, the stringy green mass is strongly believed to be a ribbon worm (or, Nemertea) – a carnivorous worm that comes in a variety of shapes, sizes, and colors.

Some species live on land or reside in freshwater — but many of them choose to stay in the sea and live burrowed in the sand. They can also grow to be as long as 60 meters.

 

 


Terrifying soul sucking dementor wasp turns victims into ‘ZOMBIES’

 

Terrifying ‘soul-sucking dementor wasp’ turns unlucky victims into ‘ZOMBIES’

Dementor Wasp

This week, the World Wildlife Fund (WWF) reported that 139 new species were discovered in the Greater Mekong region last year, including a species of wasp that can turn a cockroach into a Zombie and eat it alive as it pleases.

The species making headlines is a wasp named after fictional, soul-sucking prison guards known in the Harry Potter universe as Dementors.

WWF describes the wasp as “steal[ing] its prey’s free will with single sting before eating it alive,” and continues:

[Ampulex] dementor hunts cockroaches, injecting a venom into the mass of neurons on its prey’s belly that turns the roach into a passive zombie… the cockroach is still capable of movement, but is unable to direct its own body. Once the cockroach has lost control, the wasp drags its stupefied prey by the antennae to a safe shelter to devour it.

Once the cockroach has lost control, the wasp drags its stupefied prey by the antennae to a safe shelter to devour it.

Though the species is new, this group of wasps is not. Ampulex wasps are part of the Ampulicidae wasp species, known as cockroach wasps for their typical prey. This wasp, however, was named after Dementors as part of a group of researchers’ efforts to bring the public into the process of naming new species.

Here’s the emerald cockroach wasp a cousin of the Dementor which does a similar thing.

The researchers, led by Michael Ohl, invited 300 museum visitors to choose from four possible names for the new species, and explained how each was connected to the wasp. Dementor—“magical beings, which can consume a person’s soul, leaving their victims as an empty but functional body without personality and emotions”—reigned supreme.

 

 


Giant pythons have ‘homing instinct’

Giant pythons have ‘homing instinct’
By James Morgan
Science reporter, BBC News

This enormous Burmese python burst trying to swallow an alligator in Florida in 2005

Giant Burmese pythons have map and compass senses which help them travel “home” over vast distances, scientists have been surprised to discover.

Pythons captured and relocated in Florida’s Everglades – where they are an invasive species – returned 23 miles (36km) to their original start point.

It is the first evidence that snakes may share a similar magnetic compass to other reptiles, such as sea turtles.

The findings are published in the Royal Society journal Biology Letters.

The Burmese python (Python bivittatus) is one of the largest snakes in the world. The biggest specimen ever caught measured more than 17ft (5m) and weighed 164lb (74kg).

The snakes coil around their prey and suffocate it – and have been known to swallow animals as large as alligators.

Although native to South East Asia, they have become established in Florida’s Everglades National Park – where they have been blamed for a staggering decline of mammals.

To study how these invasive predators migrate and spread, researchers captured 12 snakes and fitted them with GPS radiotransmitters.

Half were released where they were captured, but the other six were transported to other suitable habitats in the Everglades 13-23 miles (21-36 km) away.

Using aircraft to track their movements, the researchers were stunned by how quickly the snakes travelled homeward.

The pythons could navigate by the Sun, the stars, or by a magnetic compass

Five of the six returned within 5km of their original capture location – and their movement was faster than the control snakes.

“We were very surprised,” said lead author Shannon Pittman, of Davidson College, North Carolina.

“We anticipated the pythons would develop new home ranges where they were released. We didn’t expect them to orient back to their capture locations.

“This is evidence that Burmese pythons are capable of homing on a scale previously undocumented in any snake species.”

The experiment suggests the snakes have both a map sense (to determine their position in relation to home) and a compass sense (to guide their movement home).

Researchers say the map could be magnetic, like sea turtles, while the compass could be guided by the stars, olfactory (smell) cues, or by polarised sunlight – all of which have been shown to be used by reptiles.

“Other snakes likely do share this ability with pythons. But our understanding is limited by a dearth of research on the subject,” Ms Pittman told BBC News.

Some previous studies found that smaller snakes – sea kraits and garter snakes – can home over short distances, but not large constrictors.

“I’m impressed, but I’m not surprised – this verifies what many of us in the field have been seeing for years,” said Dr Stephen Secor of the University of Alabama, who researches Burmese python physiology.

“Reptiles know where they’re going – it’s not just random. They’re familiar with their home range.

“And I suspect that, if pythons can do this, all snakes can do it – rattlesnakes, vipers, the lot.”

Dr Stephen Secor says the pythons are actually gentle, docile creatures

Keeping in familiar territory may help snakes to find prey and mates, and the homing sense may allow them to return to their territory after exploratory forays, Ms Pittman said.

“We know that snakes tend to come back to some of the same sites throughout their lives – such as overwintering locations or refuges,” she told BBC News.

Understanding how invasive pythons migrate could help control their spread in Florida, she suggested.

But Dr Secor said the threat to the Everglades had been overstated: “Some people want to sell it as an ecological disaster. It’s really not.

“Burmese pythons can’t ever move beyond the Everglades. It’s too cold. The minute it freezes, it kills them,” he told BBC News.

“They’re actually very docile, gentle snakes. People who don’t like them don’t know a lot about them. They’re pretty amazing animals and we can learn a lot from them.”

And the first lesson we can learn from their homing ability, said Dr Secor, is “don’t pick reptiles up”.

“People see turtles crossing the road and try to move them to safety. But if you take them away, they’re just going to try and come back. You are doing more harm than good.

“Likewise with snakes – people find them in their yard, drive them off and dump them a mile down road. Then, three days later, the snake comes back.

“I hear these stories frequently: ‘It came back! The same snake!’ And I’m always kind of sceptical. Is it really the same snake? Or just another one that looks similar?

“But maybe these people were right all along. The snake really did come back.”

Here’s one big Australian python. The cameraman thought it was dead.



 

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