Posts Tagged ‘whale’

by MICHELLE STARR

A skull long suspected of belonging to a rare Arctic hybrid has now had its unusual biology confirmed via DNA analysis.

According to the results, this strange beast had a beluga whale for a dad and a narwhal for a mum, and would have forged its own path, distinct from the lifestyles of both parents.

The skull was collected in 1990 by a hunter who found three of the unusual animals swimming in the waters off the coast of West Greenland. The animals described by the hunter were like no cetacean ever before seen, so the single skull he preserved from the hunt was taken to the Natural History Museum of Denmark, where it’s been ever since.

In 1993, a paper concluded that, based on its physical characteristics, the specimen was the hybrid of a narwhal (Monodon monoceros) and a beluga whale (Delphinapterus leucas) – the only two species in the Monodontidae family.

The skull didn’t exhibit the narwhal’s characteristic horn; in fact, it was pretty different from both species.

“The anomalous whale’s skull is much larger than those of normal narwhals and belugas. In particular, the rostrum and mandibles are relatively long and massive,” the researchers wrote in that 1993 paper.

“The dentition is unlike that of any known cetacean, but some features of the teeth are considered analogous to those of both narwhals and belugas.”

In the image above, you can see skulls of a beluga whale (top), the anomalous hybrid (middle), and a narwhal (bottom).

But before now, it was also still possible that the skull could have belonged to an anomalous beluga, researchers thought. Now, 26 years later, genetic analysis has clinched it.

Using genetic material extracted from the skull’s teeth, scientists from the University of Copenhagen conducted a genome-wide DNA sequencing and mitochondrial DNA analysis of the specimen.

They then compared the results of these to the genomes of eight living beluga whales and eight living narwhals, all from around the region where the skull was found.

The genome confirmed it. The skull belonged to a ‘narluga’ that the researchers determined to be male – half narwal, half beluga, with narwhal DNA that can only come from the female germline – in other words, mum.

This was a surprise, since narwhals and belugas are thought to have diverged 5.5 million years ago, and the gene flow between them ceased at least 1.25 million years ago.

In addition, narwhal horns are thought to be a secondary sex characteristic, which could indicate male belugas would have difficulty securing a female narwhal mate. The discovery or the narluga’s parentage suggests that successful matings can occur, even when dad isn’t, ahem, horny.

But the skull had more secrets to reveal. By analysing isotopes of carbon and nitrogen in the bone collagen, the scientists were able to reconstruct the animal’s diet. This was compared to the isotopes of 18 beluga whale skulls and 18 narwhal skulls.

The narluga skull had a higher concentration of carbon isotopes than both of its parent species – indicating that its source of food was different. High carbon isotope concentrations generally indicate benthic prey, suggesting that the narwhal foraged deeper for food than either of his parents.

Although the hunter who discovered the skull reported seeing three narlugas in the wild – all uniformly dark grey, with flippers like a beluga and tails like a narwhal – the skull is the only known evidence we have of this interspecies breeding.

But interbreeding between other cetacean species isn’t all that uncommon, such as a dolphin-whale hybrid seen swimming off the coast of Hawaii last year. And at least 16 other similar cases of cetacean hybridisation have been described in scientific literature – so you can bet your blowhole there are probably many others that scientists haven’t spotted.

Some of them may even be hiding in museum collections like this one was, just waiting for someone to come along and sequence their DNA.

The research has been published in Scientific Reports.

https://www.sciencealert.com/a-skull-in-museum-storage-is-the-ultra-rare-hybrid-of-a-narwhal-and-beluga-whale

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by MICHAEL D’ESTRIES

It’s a moment neither whale nor human are likely to forget.

Photographer and dive operator Rainer Schimpf was recently documenting a sardine run off the coast of South Africa when he almost became part of the food chain.

“I was trying to get a shot of a shark going through the bait ball,” Schimpf recalled in a video, “… the next moment, it got dark and I felt some pressure on my hip.”

Based on the kind of pressure, Schimpf says he instantly knew that a whale had grabbed him. As shown in the dramatic footage below, the giant Bryde’s whale got nearly all of the diver into its mouth.

“There is not time for fear in a situation like that,” he said. “You have to use your instincts.”

Fearful that the whale would dive and release him well below the surface, Schimpf says he took a deep breath and waited.

“The next moment I felt the whale was turning either way, and the pressure was released, and I was washed out of the mouth,” he said. “I came back up onto the surface where surely I wasn’t looking too clever.”

Case of mistaken identity

Sardine runs like the kind Schimpf was documenting are a frenzied confluence of various species — gannets, penguins, seals, dolphins, whales and sharks, all working together to round up prey into massive bait balls. When massive marine species like the Bryde’s whale, which average nearly 45 feet in length, soar through the middle of these corralled sardines, anything in their path can accidentally get scooped up.

“As they come up with their mouths open, they can’t see what is in front of them, and I guess the whale thought it was a dolphin,” diver Claudia Weber-Gebert said. “Whales are not man-eaters. This was no attack, it was not the fault of the whale, and they are really sensitive. They are gentle giants, and it was just an accident.”

Schimpf says getting that close to a whale isn’t necessarily something he would recommend.

“It was an interesting experience for me, but surely nothing I want to do again,” he said. “I don’t think I had ‘a whale of a time.’ I now have an inside knowledge of a whale which nobody else has.”

https://www.mnn.com/earth-matters/animals/blogs/diver-makes-lucky-escape-after-whale-swallows-him-whole?utm_source=Weekly+Newsletter&utm_campaign=ba9502706d-RSS_EMAIL_CAMPAIGN_WED0313_2019&utm_medium=email&utm_term=0_fcbff2e256-ba9502706d-40844241

by David Nield

Since the 1980s scientists have spotted a link between naval sonar systems and beaked whales seemingly killing themselves – by deliberately getting stranded on beaches. Now, researchers might have revealed the horrifying reason why.

In short, the sound pulses appear to scare the whales to death, acting like a shot of adrenaline might in a human, and causing deadly changes in their otherwise perfectly calibrated diving techniques.

By studying mass stranding events (MSEs) from recent history, the team found that beaked whales bring a sort of decompression sickness (also known as ‘the bends’ or ‘divers’ disease’) on themselves when they sense sonar. When panicked, their veins fill up with nitrogen gas bubbles, their brains suffer severe haemorrhaging, and other organs get damaged.

“In the presence of sonar they are stressed and swim vigorously away from the sound source, changing their diving pattern,” one of the researchers, Yara Bernaldo de Quiros from the University of Las Palmas de Gran Canaria in Spain, told AFP.

“The stress response, in other words, overrides the diving response, which makes the animals accumulate nitrogen.”

The end result is these poor creatures die in agony after getting the whale version of the bends – not something you would normally expect from whales that are so adept at navigating deep underwater.

Typically, these animals naturally lower their heart rate to reduce oxygen use and prevent nitrogen build-up when they plunge far below the surface. Tragically, it appears that a burst of sonar actually overrides these precautions.

The researchers weighed up the evidence from some 121 MSEs between the years 1960 and 2004, and particularly focussed on the autopsies of 10 dead whales stranded in the Canary Islands in 2002 after a nearby naval exercise.

It’s here that the decompression sickness effects were noticed, as they have been in other stranding events that the researchers looked at.

While the team notes that the effects of sonar on whales seem to “vary among individuals or populations”, and “predisposing factors may contribute to individual outcomes”, there does seem to be a common thread in terms of what happens to these unsuspecting mammals.

That’s especially true for Cuvier’s beaked whale (Ziphius cavirostris) – of the 121 MSEs we’ve mentioned, 61 involved Cuvier’s beaked whales, and the researchers say they appear particularly vulnerable to sonar.

There’s also a particular kind of sonar to be worried about: mid-frequency active sonar (MFAS), in the range of about 5 kilohertz.

Now the researchers behind the new report want to see the use of such sonar technology banned in areas where whales are known to live – such a ban has been in place in the Canary Islands since the 2002 incident.

“Up until then, the Canaries were a hotspot for this kind of atypical stranding,” de Quiros told AFP. “Since the moratorium, none have occurred.”

The research has been published in the Royal Society Journal Proceedings B.

https://www.sciencealert.com/this-is-the-horrifying-reason-why-sonar-makes-beaked-whales-beach-themselves

By Ayana Archie and Jay Croft

A female orca whale is still apparently grieving her dead calf and still swimming with its body after more than two weeks, authorities say.

“It’s heartbreaking to watch,” said Michael Milstein of the National Oceanic and Atmospheric Administration’s West Coast Region. “This kind of behavior is like a period of mourning and has been seen before. What’s extraordinary about this is the length of time.”

The adult — Tahlequah, or J35 as the whale has come to be known by researchers — and corpse were last seen definitively Thursday afternoon, 17 days after the baby’s birth. The female calf died after a few hours.

The mother, preventing the body from sinking to the ocean floor, has been carrying it and nudging it toward the surface of the Pacific off the coast of Canada and the northwestern US.
Orcas, also called killer whales, are highly social, and this pod was spotted Friday afternoon near Vancouver, British Columbia.

Another struggling female in the same pod — J50, also known as Scarlet — was shot with antibiotics to fight an infection, since scientists worry that she has been losing a frightening amount of weight.

These are grim signs. The Southern Resident population the females belong to has about 75 members, and has not had a successful birth in three years. In the last 20 years, only 25% of the babies have survived.

‘Deep feelings’ not uncommon

Scientists says grieving is common among mammals such as whales, dolphins, elephants and deer. Evidence shows the orca brain is large, complex and highly developed in areas dealing with emotions, said Lori Marino, president of the Whale Sanctuary Project.

“It’s not surprising they’re capable of deep feelings, and that’s what (Tahlequah) is showing,” Marino said. “What exactly she’s feeling we’ll never know. But the bonds between mothers and calves are extremely strong. Everything we know about them says this is grieving.”

Center for Whale Research founder Ken Balcomb said it’s “unprecedented” for an orca to keep this going for so long. He said the mother has traveled more than 1,000 miles with the corpse, which has begun to decompose.

“It is a grief, a genuine mourning,” he said.

Dwindling food source

The problem for this group of killer whales is a dwindling food supply, scientists say. Most killer whales eat a wider diet, but this particular group of about 75 resident orcas eats just salmon, which have been overfished in the area for commercial consumption. Manmade contraptions, like hydroelectric power sources, block the salmons’ path to release eggs.

Exacerbating the problem is that orcas do not have babies often or in large numbers, and when they do, it is a long process. It takes a calf a little under a year and a half to fully develop in the womb, and they nurse for another year. They must learn to swim right away, Balcomb said, and rely on their mothers for food for several years — first through nursing, then through providing fish.

“Extinction is looming,” Balcomb told CNN last month, but it is not inevitable if humans restore salmon populations and river systems in time.

https://www.cnn.com/2018/08/10/us/orca-whale-still-carrying-dead-baby-trnd/index.html


Researchers found the first known hybrid between a rough-toothed dolphin and a melon-headed whale near Kauai, Hawaii.


Rough-toothed dolphins.


Melon-headed whales.

By Jessie Yeung

Scientists from the Cascadia Research Collective have discovered a rare dolphin-whale hybrid off the coast of Kauai, Hawaii, according to a report published last week.

The marine mammal monitoring program, funded by the US Navy, first spotted the animal in August 2017. The team tagged various species, including commonly seen rough-toothed dolphins and rarer melon-headed whales.
However, researchers soon noticed that one tagged animal that looked a little odd. Although it had a typical melon-headed whale’s dorsal fin shape and dorsal cape, it was also blotchy in pigmentation and had a sloping forehead, more reminiscent of a rough-toothed dolphin.

A genetic sample soon confirmed their suspicions: it was a hybrid of the two species, the first to ever be found.The cross-species hybridization may seem bizarre, but is made possible by the fact that melon-headed whales aren’t actually whales. They belong to the Delphinidae family, otherwise known as oceanic dolphins, which also includes orcas and two species of pilot whales.

It also isn’t the first discovery of hybridization in the family
— there have also been cases of bottlenose dolphin/false killer whale (Pseudorca crassidens) hybrids, known as Wolphins, and common/bottlenose dolphin hybrids.

This is the first confirmed hybrid between rough-toothed dolphins and melon-headed whales. However, though it’s an exciting discovery, researchers point out it is not, as commonly thought, a new species.

“While hybridization can at times lead to new species, most of the time this does not happen,” Cascadia researcher Robin Baird told CNN, pointing that there was only a single hybrid found this time.

Some hybrid animals, such as the mule — a hybrid of a male donkey and female horse — are mostly sterile and therefore cannot propagate easily.

The dolphin-whale hybridization is especially surprising in this region, as a sighting of melon-headed whales had never before been confirmed near the Pacific Missile Range Facility (PMRF) navy base.

The hybrid was only traveling with one companion — a melon-headed whale. This, too was unusual, given that melon-headed whales typically travel in groups of 200-300. The solitary pair were “found associating with rough-toothed dolphins,” the report read.

The odd pair and their closeness to the other dolphins have led the researchers to speculate that the accompanying melon-headed whale is the hybrid’s mother.
The research team will return to Kauai next week, hoping to confirm their theory.

“If we were lucky enough to find the pair again, we would try to get a biopsy sample of the accompanying melon-headed whale, to see whether it might be the mother of the hybrid, as well as get underwater images of the hybrid to better assess morphological differences from the parent species,” said Baird.

The US Navy is required to monitor these species as part of the Marine Mammal Protection Act and the Endangered Species Act.

They do so through the Cascadia Research Collective, which conducts photo identification, genetic analyzes, and acoustic monitoring to determine the abundance of odontocetes, also known as toothed whales.

https://www.cnn.com/2018/07/30/us/dolphin-whale-hybrid-intl/index.html


Joe Howlett and his son, Tyler

A Canadian lobster fisherman lost his life after freeing a whale which had become tangled up in fishing gear.

Joe Howlett, from Campobello Island, New Brunswick, has saved dozens of endangered whales after they became entangled in fishing nets.

The 59-year-old had boarded a vessel off the province’s eastern coast to help rescue a north Atlantic whale which had become entangled in heavy rope.

Soon after cutting the last piece of rope from the massive whale, Mr Howlett was struck by the mammal, Mackie Green, of the Campobello Whale Rescue Team said.

“They got the whale totally disentangled and then some kind of freak thing happened and the whale made a big flip,” Mr Green, who was not on the vessel at the time, told the Toronto Star.

Mr Howlett has helped rescue around two dozen whales over the past 15 years, his family and friends said.

Days before his death, he had rescued another North Atlantic right whale in the same region.

“Joe definitely would not want us to stop because of this,” Mr Green, who co-founded the Campobello Whale Rescue Team with Mr Howlett in 2012, added.

“This is something he loved and there’s no better feeling than getting a whale untangled, and I know how good he was feeling after cutting that whale clear.”

Federal Fisheries Minister Dominic LeBlanc offered his sympathies to Mr Howlett’s family and friends.

In a statement, he said: “We have lost an irreplaceable member of the whale rescue community. His expertise and dedication will be greatly missed.”

By Drake Baer

Everybody knows that humpback whales make excellent professional wrestlers: With zero hesitation, these gentle giants will leap out of the sea, corkscrew their bodies, and then slam back into the water with 66,000 pounds of fury.

It turns out that these cetaceans aren’t just doing this to show off: According to a recent paper in Marine Mammal Science, the breaching serves as an acoustic telegram, communicating with far-off pods. It’s like how European or African peoples would send sonic signals from village to village via drum, or how wolves howl at the moon. Make a big enough splash, and the percussion speaks for itself.

As noted in the marine-life publication Hakai magazine, University of Queensland marine biologist Ailbhe S. Kavanagh and colleagues observed 76 humpback groups off the coast of Australia for 200 hours between 2010 and 2011. They found that breaching is way more common when pods are at least 2.5 miles apart, with fin- or fluke-slapping deployed when fellow whales are nearby.

The breaching probably carries better than whales’ signature songs: “They’re potentially using [these behaviors] when background noise levels are higher,” Kavanagh tells Hakai, “as the acoustic signal possibly travels better than a vocal signal would.” Given that whale songs have regional accents, you have to wonder if their aerial gymnastics have a certain patois, too.

http://nymag.com/scienceofus/2017/02/why-whales-jump-into-the-air.html

Thanks to Pete Cuomo for bringing this to the It’s Interesting community.