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Scientists may have solved mystery of why some sharks bite humans – The Weather Network

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The long-believed theory of why some sharks bite humans may actually ring true after all.

New research from Australia’s Macquarie University has indicated that numerous shark bites by great whites could be a case of mistaken identity because of how close surfers, paddle boarders and swimmers on the ocean’s surface resemble seals and sea lions.

According to the research, white, bull and tiger sharks account for — by a large margin — the most bites on humans.

SEE ALSO: Why more great white sharks are showing up in Atlantic Canada

“We found that surfers, swimmers and pinnipeds (seals and sea lions) on the surface of the ocean will look the same to a white shark looking up from below, because these sharks can’t see fine details or colours,” said lead author Laura Ryan, a postdoctoral researcher in animal sensory systems at Macquarie University’s Neurobiology Lab, in a press release.

“Surfers are the highest-risk group for fatal shark bites, especially by juvenile white sharks.”


(Sharkdiver68/Wikipedia)

Ryan, an avid surfer, stated the study will help scientists gain a better understanding of what provokes certain sharks to bite humans.

The findings have prompted scientists at the Neurobiology Lab to develop non-invasive, vision-based devices as possible protectionary tools for surfers and swimmers from shark bites.

The latest study, published in the Journal of the Royal Society Interface, was a hands-on experiment developed on years of work by the researchers to understand how sharks see — by investigating the neuroscience of white sharks’ visual systems, Ryan said.

The team involved in the study did a comparison of underwater video of rectangular floats, seals and sea lions swimming, humans swimming in different patterns, and humans paddling on surfboards of distinct sizes in a sizable aquarium at Taronga Zoo. This included cameras that were motionless and travelling, directed at the water surface.

“We attached a GoPro to an underwater scooter, and set it to travel at a typical cruising speed for predatory sharks,” says Ryan.


(Getty Images)

At the lab, the group relied on substantial shark neuroscience data to apply filters to the video footage, then establishing modelling programs to simulate how a juvenile white shark would interpret the movements and shapes of different objects.

To a juvenile white shark, humans swimming and paddling on surfboards bear striking similarities to seals and sea lions, the results showed. Because smaller surfboards were harder to differentiate from pinnipeds, they could present a more tempting prey than longboards or standup paddleboards to white sharks, who normally target smaller, young pinniped pups.

RISK OF SHARK BITES IS VERY LOW

Although the chances of a shark bite is very low, Australia remains one of the countries where one most often occurs — registering six of the world’s 10 recorded unprovoked fatal shark encounters in 2020.

The occurrences of sharks biting humans has jumped in the past 20 years, and according to Ryan, surfers may have an elevated risk because they spend “far more time” in the ocean than swimmers, also frequently in deeper water.

“Sharks use a range of sensory cues to distinguish between different objects and zero in on their food, and these differ in sensitivity between shark species,” Ryan said.

People’s fear of sharks, even with the low chance of bites, has led to preventive methods such as shark nets and drumlines, which further threaten marine life, according to the university.

“Understanding why shark bites occur can help us find ways to prevent them, while keeping both humans and sharks safer,” says Ryan.

Thumbnail courtesy of Sharkdiver68/Wikipedia.

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The body of a Ugandan Olympic athlete who was set on fire by her partner is received by family

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NAIROBI, Kenya (AP) — The body of Ugandan Olympic athlete Rebecca Cheptegei — who died after being set on fire by her partner in Kenya — was received Friday by family and anti-femicide crusaders, ahead of her burial a day later.

Cheptegei’s family met with dozens of activists Friday who had marched to the Moi Teaching and Referral Hospital’s morgue in the western city of Eldoret while chanting anti-femicide slogans.

She is the fourth female athlete to have been killed by her partner in Kenya in yet another case of gender-based violence in recent years.

Viola Cheptoo, the founder of Tirop Angels – an organization that was formed in honor of athlete Agnes Tirop, who was stabbed to death in 2021, said stakeholders need to ensure this is the last death of an athlete due to gender-based violence.

“We are here to say that enough is enough, we are tired of burying our sisters due to GBV,” she said.

It was a somber mood at the morgue as athletes and family members viewed Cheptegei’s body which sustained 80% of burns after she was doused with gasoline by her partner Dickson Ndiema. Ndiema sustained 30% burns on his body and later succumbed.

Ndiema and Cheptegei were said to have quarreled over a piece of land that the athlete bought in Kenya, according to a report filed by the local chief.

Cheptegei competed in the women’s marathon at the Paris Olympics less than a month before the attack. She finished in 44th place.

Cheptegei’s father, Joseph, said that the body will make a brief stop at their home in the Endebess area before proceeding to Bukwo in eastern Uganda for a night vigil and burial on Saturday.

“We are in the final part of giving my daughter the last respect,” a visibly distraught Joseph said.

He told reporters last week that Ndiema was stalking and threatening Cheptegei and the family had informed police.

Kenya’s high rates of violence against women have prompted marches by ordinary citizens in towns and cities this year.

Four in 10 women or an estimated 41% of dating or married Kenyan women have experienced physical or sexual violence perpetrated by their current or most recent partner, according to the Kenya Demographic and Health Survey 2022.

The Canadian Press. All rights reserved.

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The ancient jar smashed by a 4-year-old is back on display at an Israeli museum after repair

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TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.

Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.

Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.

The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.

The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.

It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.

Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.

Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.

Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.

Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.

Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.

The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”

The Canadian Press. All rights reserved.

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B.C. sets up a panel on bear deaths, will review conservation officer training

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VICTORIA – The British Columbia government is partnering with a bear welfare group to reduce the number of bears being euthanized in the province.

Nicholas Scapillati, executive director of Grizzly Bear Foundation, said Monday that it comes after months-long discussions with the province on how to protect bears, with the goal to give the animals a “better and second chance at life in the wild.”

Scapillati said what’s exciting about the project is that the government is open to working with outside experts and the public.

“So, they’ll be working through Indigenous knowledge and scientific understanding, bringing in the latest techniques and training expertise from leading experts,” he said in an interview.

B.C. government data show conservation officers destroyed 603 black bears and 23 grizzly bears in 2023, while 154 black bears were killed by officers in the first six months of this year.

Scapillati said the group will publish a report with recommendations by next spring, while an independent oversight committee will be set up to review all bear encounters with conservation officers to provide advice to the government.

Environment Minister George Heyman said in a statement that they are looking for new ways to ensure conservation officers “have the trust of the communities they serve,” and the panel will make recommendations to enhance officer training and improve policies.

Lesley Fox, with the wildlife protection group The Fur-Bearers, said they’ve been calling for such a committee for decades.

“This move demonstrates the government is listening,” said Fox. “I suspect, because of the impending election, their listening skills are potentially a little sharper than they normally are.”

Fox said the partnership came from “a place of long frustration” as provincial conservation officers kill more than 500 black bears every year on average, and the public is “no longer tolerating this kind of approach.”

“I think that the conservation officer service and the B.C. government are aware they need to change, and certainly the public has been asking for it,” said Fox.

Fox said there’s a lot of optimism about the new partnership, but, as with any government, there will likely be a lot of red tape to get through.

“I think speed is going to be important, whether or not the committee has the ability to make change and make change relatively quickly without having to study an issue to death, ” said Fox.

This report by The Canadian Press was first published Sept. 9, 2024.

The Canadian Press. All rights reserved.

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