Melting ice is forcing polar bears to swim more, at high energy cost

January 31, 2018 by Todd Hollingshead, Brigham Young University

One result of melting Arctic ice is that polar bears are forced to swim more often and further than ever to forage for food.

New research by BYU biologist Blaine Griffen finds the increase in swimming could permanently affect polar bear populations, leading to smaller bears, reduced reproduction rates and even increased risk of death for the bears.

"Bears can more than double their body weight during the springtime foraging season when they hunt seals on the ice," Griffen said. "As the sea ice melts earlier and earlier, polar bears are forced to swim more and more, both in frequency and distance, to reach seal populations. The time they have to forage is getting cut short and this has huge energetic costs."

According to Griffen's research, recently published in Polar Biology, it costs polar bears five times as much energy to swim as it does to walk the same distance. That cost became enormous in one case Griffen studied, where a female bear swam 687 kilometers over nine days: the bear lost 22 percent of its body weight and, worse, lost the nursing cub that had started the journey with her.

"Their entire world is driven by energy," Griffen said. "Anything that places that extra energetic strain on the bear will affect its ability to survive."

Read more at: 

Side swim style saves shark energy

August 9, 2016 by Pepita Smyth

Hammerhead sharks swim on their sides up to 90 per cent of the time to save energy, a Murdoch University researcher has found.

Dr Adrian Gleiss from the Centre for Fish and Fisheries Research, collaborated on an international study which found the great hammerhead species spends up to 90 per cent of its time swimming at angles of between 50 and 70 degrees.

This is thanks to an exaggerated dorsal fin which generates lift and helps to reduce drag when the sharks are rolled on their sides.

Most sharks use their dorsal fins on their backs like a rudder on a boat, to facilitate quick turns. Their large pectoral fins on their sides are used like aircraft wings to keep them from sinking. It was thought this was how all sharks functioned until this study, which was led by Dr Nicholas Payne from the University of Roehampton, London.

Dr Gleiss and the research team used video cameras and tagging to measure roll angles in hammerhead sharks in Belize, Australia and The Bahamas.

"The co-lead author on our paper, Associate Professor Gil Iosilevskii, developed hydrodynamic modeling to show this swimming method reduces energy use by around 10 per cent, compared with traditional upright swimming," said Dr Gleiss.

Read more at: 

Secret to Swordfish's Speedy Swimming Found

By Mindy Weisberger, Senior Writer | July 7, 2016 07:02am ET

A swordfish's impressive saber-like bill might inspire visions of swashbuckling fencers wielding flashing blades. But in reality, this protruding proboscis is more vulnerable than you might expect.

There is a weak spot at the base of the bill where it joins the skull. The bone thins at this spot to make room for an oversized gland. Scientists have just discovered what this mysterious gland might be used for — faster swimming.

Researchers have found that the gland produces oil that covers the swordfish's head with a slippery coating. By generating this greasy film, the gland could reduce drag and help the fish cut through the water more efficiently, contributing to its swim speed.

Built for speed

Swordfish have powerful yet streamlined bodies that are literally built for speed. They are thought to be the fastest swimmers on Earth and have been clocked at an estimated 62 mph (100 km/h), according to the study authors.

A swordfish uses its signature bill — which can reach up to 40 to 45 percent of its body length — in sweeping motions to slash and stun its prey. But it also plays a part in swimming. The bill's surface is porous and rough, the authors noted — a feature that previous studies had linked to drag reduction.

However, recent studies had also revealed a noticeable weakness at the bill's base that puzzled the scientists, prompting them to take a closer look. 

Luckily, the study's lead author, John Videler, a biologist and professor at Groningen University in the Netherlands, had scanned a pair of adult swordfish in 1996 and 1997 using magnetic resonance imaging (MRI). He captured 657 images showing the insides of the fish, from the tips of their bills to the ends of their tails.

Continued ...

Nightmarish Find: Giant, Venomous Centipede Is a Powerful Swimmer

By Laura Geggel, Senior Writer | July 5, 2016 05:15pm ET

A giant, toothy centipede with countless legs is also a swimming fiend, making it the first known aquatic centipede on record. And it's venomous, to boot, researchers found. 

The newfound giant can grow longer than a person's hand. In fact, researchers caught one measuring 7.9 inches (20 centimeters) long, according to the study.

George Beccaloni, a curator of orthopteroids at the Natural History Museum in London, discovered the critter while honeymooning in Thailand in 2001, according to National Geographic. As was typical for Beccaloni, he was looking for bugs, and lifted up a large rock slab, measuring 5 feet long and 8 inches deep, that was lying next to a stream. 

As soon as he lifted the rock, a giant centipede skittered out and escaped into the stream, where it hid under a rock. Beccaloni scooped it up with a glass container filled with water, and watched as it "swam powerfully on the bottom of the container with vigorous horizontal undulating motions," he and his colleagues wrote in the study, published in the May issue of the journal ZooKeys.

When Beccaloni took the centipede out of the container, water droplets rolled off its body, letting it dry within moments, he told National Geographic.

Beccaloni took the centipede specimen back to his lab at the museum. After talking with colleagues, the group realized that the Thailand centipede was the same as a newfound centipede they had uncovered in Laos, at the Tad E-Tu waterfall.

The researchers named the invertebrate Scolopendra cataracta; Scolopendra for a known genus of giant centipede, and cataracta after the Latin word for "waterfall." The entire species is based on four specimens — two from Laos, one from Thailand and one discovered in Vietnam in 1928 that has been housed at the Natural History Museum's collections ever since, according to National Geographic.

Continued ...

Tasmanian wildlife take to water, with echidna and wombat found swimming far from shore

Fisherman scoops echidna from lake after it appeared to be swimming in an unwise direction, days after ‘distressed’ wombat rescued in similar circumstances

Elle Hunt

Wednesday 2 December 2015 06.26 GMTLast modified on Wednesday 2 December 2015

An echidna, an animal not often seen taking a dip, has been found swimming in Tasmania not long after fishermen hauled a wombat out of a different lake on the island with a net.

Recreational fisherman Nobby Clark said he spotted an echidna in Lake Echo swimming about 150m from shore – and heading further out.

Clark had been fly-fishing for about two hours when he saw the echidna swimming towards him. He told the ABC he’d mistaken it for another monotreme at first.

“I thought it was a platypus heading towards me but it turned out to be an echidna.

“His head would go under water and then his little periscope would come up for a moment and have a breath and head out a few more paddles. He was swimming pretty hard; I think he was trying to figure out how he was going to get home.

Continued and video ...

Convergent evolution: Diverse sea creatures evolved to reach same swimming solution

Date:April 28, 2015

Source:PLOS

Summary:Moving one's body rapidly through water is a key to existence for many species. The Persian carpet flatworm, the cuttlefish and the black ghost knifefish look nothing like each other -- their last common ancestor lived 550 million years ago, before the Cambrian period -- a new study uses computer simulations, a robotic fish and video footage of real fish to show that all three aquatic creatures have evolved to swim using the same mechanical motion.

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The science behind swimming: From whales to larvae, common principles at work in swimming

Date:

September 15, 2014

Source:

Harvard University

Summary:

Using simple hydrodynamics, a team of researchers was able to show that a handful of principles govern how virtually every animal -- from the tiniest fish to birds to gigantic whales propel themselves though the water.

Continued ...

Sea creatures not the only animals to be found along area beaches

By Jannette Pippin, Halfiax Media Services

Published: Saturday, June 21, 2014 at 18:58 PM.

What appeared to be a big dog swimming in Browns Inlet proved to be a big cat.

Cedar Point resident Mike Maroules is no stranger to the area’s waterways, but he was surprised while out on his boat last week to find a bobcat paddling toward a swath of beach in Browns Inlet.

“I thought it was a big dog. I was going to go rescue it in case it was tired from swimming, but when I got close enough I could see it wasn’t a dog,” said Maroules, who snapped photographs of the bobcat during his June 13 outing.

“He was a big cat. He looked full grown,” Maroules added.

Not only was it unusual to see the nocturnal bobcat during the day, Maroules said he’s never seen one in the inlet before.

Continued

Farmer is the last to take cows swimming

A family of Scottish cattle farmers say they are the very last to maintain the ancient tradition of swimming their cows across the sea to fresh pastures.

Ian Macdonald, 82, and his family swim their cows from their croft at Staffin across to Staffainn island.

With their heads just showing above the water, it takes the animals around ten minutes to make the 150 yard crossing.

And, to ensure that nothing goes awry, one of them traditionally strips down and takes to the water to swim with the cattle.

Mr Macdonald remembers: "I pulled the short straw the first year. Swimming wasnae my thing."

From that icy teenage initiation right up until his seventies, he swam with his cows every year.

However, he now drives them across from the safety of his boat and leaves the swimming to son Callum.

The herd are moved from the mainland, 150 yards over the water to Staffainn Island each October.

This gives the main croft a chance to recover and ensures the cows get a good winter feed.

Then in January or February, when the tide is at its lowest point, the cows are driven back across to the mainland.

http://web.orange.co.uk/article/quirkies/Farmer_is_the_last_to_take_his_cows_swimming

The Dog Paddle Is Just an Underwater Jog

Pooches doing the ‘dog paddle‘ are basically just trotting underwater, a new study concludes.

It’s a technique that armadillos, turtles and even humans can use to stay afloat and move in water.

For the research, presented at the 2014 Society for Integrative and Comparative Biology meeting held in Austin, biologist Frank Fish and colleagues started out with eight dogs representing six breeds. They ranged from Yorkshire terriers to the Newfoundland.

Continued

First Documented Report of Swimming and Diving in Apes

Aug. 14, 2013 — Two researchers have provided the first video-based observation of swimming and diving apes. Instead of the usual dog-paddle stroke used by most terrestrial mammals, these animals use a kind of breaststroke. The swimming strokes peculiar to humans and apes might be the result of an earlier adaptation to an arboreal life.

For many years, zoos have used water moats to confine chimpanzees, gorillas or orangutans. When apes ventured into deep water, they often drowned. Some argued that this indicated a definitive difference between humans and apes: people enjoy the water and are able to learn to swim, while apes prefer to stay on dry land.

But it turns out that this distinction is not absolute. Renato Bender, who is working on a PhD in human evolution at the School of Anatomical Sciences at Wits University, and Nicole Bender, who works as an evolutionary physician and epidemiologist at the Institute of Social and Preventive Medicine at the University of Bern, have studied a chimpanzee and an orangutan in the US. These primates were raised and cared for by humans and have learned to swim and to dive.

'We were extremely surprised when the chimp Cooper dived repeatedly into a swimming pool in Missouri and seemed to feel very comfortable,' said Renato Bender.

To prevent the chimp from drowning, the researchers stretched two ropes over the deepest part of the pool. Cooper became immediately interested in the ropes and, after a few minutes, he started diving into the two-meter-deep water to pick up objects on the bottom of the pool. 'It was very surprising behavior for an animal that is thought to be very afraid of water,' said Renato Bender. Some weeks later, Cooper began to swim on the surface of the water.

Continued

Turtles Watch For, Snack On Gelatinous Prey While Swimming

June 12, 2013 — Loggerhead turtles use visual cues to find gelatinous prey to snack on as they swim in open waters, according to research published June 12 in the open access journal PLOS ONE by Tomoko Narazaki and colleagues from the University of Tokyo, Japan.

Tracking underwater movements with 3D loggers and National Geographic Crittercams, the researchers found the turtles relied on sight, rather than sound or smell, to identify and move toward gelatinous, floating prey like jellyfish and other organisms; one turtle even swam toward a floating plastic bag. Turtles in this study foraged for such foods approximately twice every hour, suggesting they may rely on such gelatinous prey for energy more than previously thought.

Previous studies have shown that turtle diets vary with their age, habitat and other factors, but adult turtles depend on deep-sea hard-shelled animals like mollusks for food. The gelatinous prey studied here are low-energy, easily digestible foods that are unlikely to replace these other prey. However, the authors suggest that opportunistic foraging on such prey may benefit loggerhead turtles during oceanic migrations, when prey at the bottom of the sea is harder to reach.

The study also offers insights into the foraging habits of these turtles, listed an endangered species by by the International Union for Conservation of Nature (IUCN). The authors add that the methods used here could be developed to map areas with higher foraging opportunities along oceanic migratory routes for loggerhead turtles.

http://www.sciencedaily.com/releases/2013/06/130612173328.htm

Heat Could Be Stifling Turtles’ Swimming Abilities In Australia

Mar. 10, 2009 — It seems we're not the only ones struggling to adapt to the summer weather – University of Queensland researchers have found the increased temperatures may be affecting turtles too.

Zoologist Dr David Booth, from UQ's School of Biological Sciences, said green turtle hatchlings from Heron Island weren't swimming as well as usual.

“The 2008-2009 green turtle nesting season on Heron Island has seen the highest nest temperatures recorded at this site, with many nests having average temperatures above 31 degrees, and experiencing temperatures above 35 degrees during the last week of incubation,” Dr Booth said.

“Initial impressions are that hatchlings emerging from these hot nests are not as strong swimmers as hatchlings coming from cooler nests recorded in previous years.

“If climate change results in consistently high nest temperatures in the future, then the poorer swimming ability of hatchlings emerging from hot nests may have a negative impact on recruitment of hatchlings from coral cays because predation rate is thought to be related to swimming ability.”

Basing his research at the southern end of the Great Barrier Reef at UQ's Heron Island Research Station, Dr Booth took advantage of the unique laboratory facilities that are within metres of a green turtle nesting beach.

“My research involves going out and collecting fresh eggs as they're being laid by the females, moving them into other nests that are not going to get dug up by other females and then coming back about five to six weeks later to sample the hatchlings to measure their swimming performance,” he said.

“As we all know, the temperature of the earth is changing and as things warm up the nests are going to warm up and I was interested to see if that might have an affect on the quality of the hatchlings.”

Dr Booth said nest temperature determined the sex of sea turtles, suggesting that a warmer climate may have other implications for the endangered species.

“When the eggs are laid they can be either males or females,” he said.

“If it's a relatively cool nest they turn out to be males and if it's a relatively warm nest they turn out to be females.”

Previous research conducted by Dr Booth at Heron Island, and published in the Journal of Experimental Biology, investigated how much energy the hatchlings needed to reach safe deep water.

Calculating the amount of energy the hatchlings consumed during an 18 hour swim, Dr Booth said the turtles carried almost 10 times as much energy in their yolk remnants as they needed to reach safety.

“So the youngsters aren't at risk of running out of energy before making it to safety,” he said.

“They can probably survive 14 days in the open ocean before finding food.”

Stampeding Dinosaurs Were Actually Swimming

Fossilized track marks from a stampede of dinosaurs in Australia actually may have come from swimming animals, new research suggests.

The finding, published in the January issue of the Journal of Vertebrate Paleontology, upends the traditional interpretation of the world's only dinosaur stampede.

Instead of a group of small dinosaurs trying to escape a massive carnivore, the fossils may reveal an ancient dinosaur "superhighway" or river crossing, said study co-author Anthony Romilio, a paleontologist at the University of Queensland in Australia.

Continued:  http://www.livescience.com/26363-stampede-dinosaurs-footprints-swimming.html

Cuba-US Swimmer Quits After Jellyfish Stings

Grandmother Diana Nyad has given up on her fourth attempt to swim from Cuba to the US after being circled by sharks and stung repeatedly by jellyfish.

Pictures show a huge amount of swelling on her face after she was stung by box jellyfish nine times on Monday night alone, as divers tried to drive away sharks stalking her in the black water.

She was hoping to become the first person to swim the 103-mile stretch between Havana and Florida without a shark cage.

But, as a thunderstorm raged and tossed her five support boats around, her team plucked her to safety after nearly 42 hours in the water.

She had set off on Saturday from Havana and hoped to make the Florida Keys on Tuesday, a day ahead of her 63rd birthday.

But it would have taken her another 28 to 40 hours to complete the crossing when she was thwarted by storms, hypothermia and swollen lips.

In a blog posting, crew member Candace Hogan wrote that Ms Nyad angrily shook her head after being pulled from the water and planned to finish the swim after the winds calmed.

"When can I get back in?" she quoted the swimmer as saying. "I want full transparency that I was out. But I have plenty left in me and I want to go on."

"However, the storm went on, too. In a long discussion with her core team, she realised that the obstacles against this swim were too great and agreed at dawn to return to Key West by boat, for the sake of the safety of her team and herself."

She said the winds were so strong they were tossing her support vessel "up and down on the waves like a paper cup".

Ms Nyad had previously said this would be her last attempt, although she made the same promise the last time she attempted the "bear of a swim".

Australian Susie Maroney successfully swam the Florida Straits in 1997, but she used a shark cage.

In June, another Australian, Penny Palfrey, made it 79 miles towards Florida without a cage before strong currents forced her to quit.

http://uk.news.yahoo.com/cuba-us-swimmer-quits-jellyfish-stings-201353877.html;_ylt=AoTaa9b_jdzWETwRWougWaTZEe1_;_ylu=X3oDMTRlMW5oMWdpBG1pdANlZGl0b3Igc2VsZWN0ZWQgY2Fyb3VzZWwEcGtnAzZiMDg0ZDg0LWEyODgtMzkyZi1hZmI5LTEwOTk3ZDFkNTQ4OARwb3MDNARzZWMDTWVkaWFGZWF0dXJlZENhcm91c2VsBHZlcgNiN2Y5ZTVhMS1lZDA2LTExZTEtYWJmZi1mMjRiM2YwNmI2ODk-;_ylg=X3oDMTM5ZjBuNjF2BGludGwDZ2IEbGFuZwNlbi1nYgRwc3RhaWQDZTlmZmNmNDQtYjk1MC0zOGZkLTk3YzQtZmI5YmFjMTlmZTllBHBzdGNhdAN5LXJlcG9ydGVyfGFzc2lnbm1lbnRzBHB0A3N0b3J5cGFnZQ--;_ylv=3

Branson - 'Swim with sharks, don't eat them'

Sir Richard Branson promotes the business of saving sharks

July 2012. Sir Richard Branson, founder of Virgin Group and Virgin Unite, has joined non-profit group WildAid to swim with 300 whale sharks off the coast of Cancun to demonstrate that the economic benefits of shark tourism can drastically outweigh the value derived from killing a shark for its fins. According to WildAid, the lifetime economic value of a single whale shark can exceed US$2 million, compared to a few hundred dollars to kill the same shark for its fins.

Could well-managed whale shark tourism save the species?
Sir Richard and his family, who are in Mexico to celebrate Virgin Atlantic's new direct service from London Gatwick to Cancun, took a detour to swim with these gentle giants and raise awareness of shark conservation. It is estimated that whale shark tourism is worth over US$47 million worldwide per year.

"Sharks play an incredibly vital role in our lives both environmentally and economically," said Sir Richard. "They are at the top of the food chain and balance the ocean's now fragile ecosystem, and the conservation tourism numbers show that they are more useful to coastal communities alive than dead. It goes without saying that we must do everything we can to preserve these highly-threatened, magnificent creatures."

Call for China shark fin ban
Sir Richard has been working with WildAid in support of sharks for the past year. In September 2011, Sir Richard joined WildAid Ambassador Yao Ming in Shanghai to call for a ban on shark fin soup in China, and in March 2012, he joined WildAid Board Member Bo Derek in Toronto to call for increased legislation to end the shark fin trade.

Fins from up to 73 million sharks are used every year to make shark fin soup and related food products. Shark finning is a cruel and wasteful practice - captured at sea and hauled on deck, the sharks are often still alive while their fins are sliced off. Because shark meat is not considered as valuable as the fins, the maimed animals are tossed overboard to drown or bleed to death. The International Union for Conservation of Nature (IUCN) estimates that 1/3 of the world's pelagic shark species are threatened with extinction, with certain species experiencing declines up to 90%.

http://www.wildlifeextra.com/go/news/branson-shark.html#cr

Slowest Greenland sharks hunts sleeping prey

Researchers have measured the swimming speed of the ocean's slowest shark.

Data-logging tags revealed that Greenland sharks "cruise" at 0.34m per second - less than 1mph.

The study showed that, even when the languid fish embarks on a burst of speed in order to hunt, it is far too slow to catch a swimming seal.

Since the species is known to eat seals, the scientists think it probably "sneaks up on them" as they sleep under the water.

The Greenland shark was already known to be the world's slowest swimming shark, but its sluggishness surprised the scientists.

Yuuki Watanabe from the National Institute of Polar Research in Tokyo, who took part in the study, said that, when you account for the size of its body, it is the slowest fish in the ocean.

Previous research had revealed seal remains in the stomachs of the sharks.

Continued:  http://www.bbc.co.uk/nature/18531924

Polar Bears Swim Hundreds of Miles in One Go

Polar bears can swim for days, covering hundreds of miles of open water at a time, accoding to new GPS tracking data. These long swims appear to be a response to declining summer sea ice in the Arctic, the researchers suggest.

Sea ice provides crucial habitat for polar bears, which hunt for prey, primarily seals, from it. But recent years of warming temperatures have brought significant declines in sea-ice cover over Arctic waters. Scientists worry this decline is causing bear cubs to drown on long swims and creating problems for walruses that also depend on the sea ice.   

Over the course of six years, U.S. Geological Survey researchers used GPS collars to track 50 long-distance swims made by 20 adult female bears, some of which had cubs with them. The swims that were documented lasted from 17 hours to nearly 10 days and covered between 33 and 427 miles (54 and 687 kilometers) in the southern Beaufort Sea.

The frequency of the swims appeared to increase over the course of the study, which ended in 2009.

Continued:  http://www.livescience.com/20024-polar-bear-swims-tracked.html

'I'm the king of the swimmers': Rare sighting of orang-utan taking a dip in crocodile infested river

In the Jungle Book, orangutan King Louis wanted nothing more than to be like me and you-oo-oo. And these kings of the swimmers seem to have the same ambition – diving into pools and even fishing for their tea.
The pictures have amazed experts, who have long believed the apes to be scared of water.
But for these two, named Sif and Menteng, not even the threat of crocodiles is enough to keep them home and dry.
The behaviour was witnessed at an orangutan reserve in Indonesian Borneo, by Canadian professor Anne Russon, 64, who has studied the animals since 1989.
She said: 'They're sinkers and they know it, which is why they're very cautious anyway.

'Sif is a real water baby and she'd only try this if she was entirely confident she could reach her target without sinking.

'She uses it for serious purposes like crossing wide bodies of water too deep for wading, but could play in water for more than half an hour.
'Menteng has very advanced skills and in these pictures you see him picking a large fish out and inspecting it.
'Orangutans and other great apes are reputed, incorrectly it seems, to be afraid of water.
'Some probably are, but of course, so are some humans.

'They have drowned in zoos because they've fallen into water-filled moats surrounding their enclosure.

'There are also other things dangerous to them in water like crocodiles and large snakes - so there are many reasons water wouldn't be much of an attraction to them.'
The amazing pictures were taken at an orangutan rehabilitation facility called Nyaru Menteng in Kalimantan, Indonesian Borneo, at the end of the dry season late last year.

Anne, from Toronto, Canada, is a psychologist so her research was psychology-bent - focusing on their behaviour, intelligence and learning.

She added: 'It's really useful for rehab, because rehab is mostly about how they learn the skills they need to survive in the forest.'

For pictures, read more: http://www.dailymail.co.uk/news/article-1394516/Im-king-swimmers-Rare-sighting-orang-utan-taking-dip-crocodile-infested-river.html#ixzz1VCPxJBTZ

Maths proves that giraffes can swim

Scientists have used maths to prove that giraffes can swim - even though they wouldn't be very good at it and nobody has ever seen them do it.


Dr Darren Naish, of the University of Portsmouth, and Dr Donald Henderson, of the Royal Tyrrell Museum of Palaeontology in Canada, decided to investigate whether or not giraffes could swim.

Their study, published in the Journal of Theoretical Biology, examines what happened when scientists placed a 'digital giraffe' in 'digital water'.

Dr Naish said: "Many previous studies have claimed that giraffes cannot swim and that they avoid water like the plague, even in an emergency, but we wanted to put the theory to the test in proper controlled experiments."

Creating a digital giraffe involved calculations on weight, mass, size, shape, lung capacity and centre of gravity. Calculations were made to discover rotation dynamics, flotation dynamics and the external surface area of both a giraffe and - for comparison - a horse.

The authors found that a full-sized adult giraffe would become buoyant in 2.8metres of water. Giraffes can wade across bodies of water that are shallower.

But after becoming buoyant, a giraffe would be unstable in the water due to its long, heavy legs, short body and long neck.

The unusual shape of the giraffe meant that it floated in a peculiar manner, with the long front limbs pulling the body downwards.

Dr Naish said: "Our models show that while it's feasible for a giraffe to swim, it is much harder than it is for a horse.

"It is fair to say that giraffes might be hesitant to enter the water knowing that they are at a decided disadvantage compared to being on solid ground."