Gray whale population drops by quarter off U.S. West Coast

Researchers say the population of gray whales off the West Coast of the United States has fallen by nearly one-quarter since 2016, resembling a similar die-off two decades ago

SEATTLE (AP) — Researchers say the population of gray whales off the West Coast of the United States has fallen by nearly one-quarter since 2016, resembling a similar die-off two decades ago.

In this May 24, 2019, file photo, teachers and students from Northwest Montessori School in Seattle examine the carcass of a gray whale after it washed up on the coast of Washington’s Olympic Peninsula, just north of Kalaloch Campground in Olympic National Park. Researchers say the population of gray whales off the West Coast of the United States has fallen by nearly one-quarter since 2016, resembling a similar die-off two decades ago. In a paper released Tuesday, Jan. 19, 2021, NOAA Fisheries reported that surveys counted about 6,000 fewer migrating whales last winter, 21,000 as compared to 27,000 in 2016.
Gene Johnson / AP

In a paper released Tuesday, NOAA Fisheries reported that surveys counted about 6,000 fewer migrating whales last winter, 21,000 as compared with 27,000 in 2016.

The agency declared an “unusual mortality event” in 2019 as dozens of gray whales washed up on Pacific Ocean beaches. Scientists aren’t sure what has been causing the die-off. But they believe that it is within the range of previous population fluctuations and that the number of whales may have exceeded what the environment can support.

After an estimated die-off of 23 percent in 1999-2000, the population rebounded to even greater numbers, NOAA said. The agency said it appears the big population swings don’t reflect long-term threats to the whales’ survival.

The eastern north Pacific gray whale has recovered from being hunted to near extinction in the middle of the 20th century. It was removed from the Endangered Species List in 1994.

The whales migrate 10,000 miles (16,093 km) from feeding grounds in the Arctic to birth their calves along Mexico’s Baja Peninsula. Teams of researchers counted the whales as they passed Granite Canyon, California, near Carmel, on their way south from December 2019 to February 2020.



creds to: https://www.opb.org/

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Starting them early: Pregnant dolphins sing their names to their babies in the womb

  • Dolphins teach babies a ‘signature whistle’ two weeks before birth
  • The whistles are sounds made by individual dolphins that identifies them
  • At about two months, the babies then go on to produce their own whistle
  • Humans have a similar phenomenon, in which babies develop a preference for their mother’s voice in the last trimester

Many expectant parents will chat away to their babies in the womb.

But it appears that humans are not the only species who like to communicate with their young before they are born.

New research has shown that dolphin mothers sing to their unborn calves by singing their name. 

The mothers teach their babies their ‘signature whistle’ before birth and in the two weeks after, which the animals use to identify one another.

The mothers teach their babies their ‘signature whistle’, which is our equivalent to a name, before birth and in the two weeks after

Researchers from the University of Southern Mississippi, have suggested that the mothers teach their babies the whistle as part of the imprinting process.

Signature whistles are sounds made by dolphins, used to identify different individuals.

Dolphin calves will eventually make their own individual whistle, but in the first stages of life, they use their mother’s.

Previous studies have shown that mother dolphins whistle their signature tune more in the days before birth.

However, this is the first study to look at how a mother dolphin whistles in the presence of other dolphins, before and after birth.

The researchers studied a dolphin mother at Six Flags Discovery Kingdom in California, who gave birth to a dolphin baby called Mira in 2014.

They recorded 80 hours of sounds from the mother, baby, and other dolphins in the enclosure, during the two months before birth, and two months after birth.

The recordings showed that the mother dolphin began increasing her signature whistle two weeks before birth, and continued to do so for two weeks after birth, before tapering off.




Creds to: https://www.dailymail.co.uk

Extra image from google

Scientists Discover a Mouth-Breathing Dolphin

If you’ve been watching Netflix’s Stranger Things, you know being called a “mouth-breather” is an insult of the highest order. But for one dolphin, being a mouth-breather has likely meant the difference between life and death.

Dolphins don’t normally breathe through their mouths. Instead, they inhale and exhale through the blowhole on the top of their heads. But three years ago, researchers in New Zealand noticed the strangest thing—a single Hector’s dolphin willfully ignoring millions of years of evolution, and instead gasping out of its big, toothy mouth. And this story gets even weirder if you know anything about dolphin anatomy.

Unlike humans, a dolphin’s larynx, which carries air to the lungs, and esophagus, which carries food to the stomach, do not usually share an opening. In other words, dolphins don’t have to worry about something “going down the wrong pipe.” But the two systems aren’t totally separated. The dolphin’s larynx actually punches straight through its esophagus.

This arrangement could actually be a problem for dolphins when they’re trying to eat a particularly large fish, says Stephen Dawson, a marine biologist at the University of Otago in New Zealand, and lead author of a paper published last week describing the mouth-breather. But this quirk of physiology also enables this dolphin’s particular workaround.

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In their normal physiology, shown above, air flows between a dolphin’s lungs and its blowhole. In the mouth-breathing dolphin, the scientists suspect that the larynx disconnects from its normal pathway at the epiglottic spout, and instead creates an opening to the mouth. Adapted from an illustration by Stephen Dawson

In dolphins, the larynx is not a solid tube connecting the blowhole to the lungs. Instead, a dolphin’s airway is made of multiple interlocking sections of cartilage. At the end of one of these sections is the epiglottic spout, which sits where the larynx passes through the esophagus. Normally, the epiglottic spout is held in place by a strong muscle. But in this mouth-breathing Hector’s dolphin, the scientists suspect that every time it breathes, it withdraws this spout so that the lungs connect to the mouth, rather than the blowhole.

Dawson and his coauthors can’t say for sure why the dolphin does this, but they have a few ideas. The most likely scenario seems to be some sort of quirk of the muscles that control the blowhole, since it remains shut tight even when the dolphin surfaces. This could be an injury, abscess, tumor, or other obstruction that prevents the blowhole from opening properly. It’s also possible the muscles where the esophagus closes around the larynx have become injured or infected, or that a foreign object has found its way elsewhere into the respiratory system.

Whatever the cause, the same dolphin has been spotted performing this behavior for three years, apparently without ill effects.

Dawson says he’s long-suspected dolphins have some way of moving their larynx to create more room. “But the published literature states, and the prevailing view among marine mammalogists was, that this was impossible,” he says.

That is, until ole Mouth-breathy McMouthface showed up.

“The behavior is a bit surprising since it has not been observed or reported previously,” says Ted Cranford, a marine biologist at the San Diego State University who was not involved in the new research.

Cranford studies evolution in dolphins, particularly as it relates to biosonar, and he said that, anatomically speaking, it checks out.

“It is clear that there is nothing that prevents these animals from using this new pathway,” said Cranford. “We should all keep in mind that behavioral plasticity probably has more scope for variation than we might expect.”

In other words, there’s no telling what an animal might be capable of when survival’s on the line. Mouth-breathing in a dolphin—why not?



creds to: https://www.hakaimagazine.com

Surfer goes to head-to-head with pod of dolphins as he takes on gigantic Australian waves… and loses

  • Trent Sherborne was catching waves at his local beach in Kalbarri, Western Australia
  • Photographer Matt Hutton was lining up his last shot on the shore when a dolphin suddenly leaped from the ocean
  • What he captured is an incredibly rare picture of man and mammal sharing the same wave.

When surfer Trent Sherbourne zipped up his wetsuit, grabbed his board and headed down to the secluded beach he was probably hoping to have the waves to himself.

So, imagine his surprise when he found himself sharing the surf with a pod of dolphins who jumped out of the water right in front of him.

But even more incredible is that the moment was captured back on land by a self-taught photographer who was lining up his last shot of the day while experimenting with a new lens.

This stunning picture was capture by Matt Hutton who was just lining up the last shot of the day

Dolphins are known to share waves with humans but it is extremely rare for them to breach the surface and even rarer for the moment to be captured on film

Matt Hutton, 31, had been taking pictures of Trent when the local surfer was completely upstaged by dolphin racing him down the wave, before losing out to the speedy sea-mammal.

Amateur snapper Matt was travelling from Perth to his home in Wickham, Western Australia, in order to add pictures to his portfolio when he decided to stop in the small town of Kalbarri.

After asking locals for information he was told of a few good spots to go and take pictures of surfers but was advised that dolphin sightings were rare.

Losing out: Trent’s surfing was completely eclipsed by the stunts of the camera-shy dolphins who shared the surf with him that day

What he captured is the incredibly rare moment a dolphin breached the surface while sharing a wave with a surfer. While the intelligent animals are known to swim with humans, surfing with them is rare and even then, they stay underwater most of the time.

Matt added: ‘It really is a very rare shot and I was so lucky to have been at the right place and right time and in regards to the dolphin and the surfer, Trent said he knew it was him in the photo as it’s not every day you get to eyeball a Dolphin, so it was pretty close!’

‘I have had so many people write kind emails, messages, comments etc and it has been a very humbling experience, it is simply the highlight of my small photography career.

‘A few people think its photoshopped but I can assure you they’re not!’

However, one surfer who fell foul of the usually friendly sea creatures was Troy Robinson, 43, whose arm was broken after clashing with a dolphin in July.

Robinson found himself surrounded by ten of the animals while paddling out to sea, and it quickly became apparent that there was not enough space for all of them on the same wave.

As he ducked and dived through the tangle he was suddenly hit, torpedo-like, by one of the animals which knocked him clean off his board and left him in immense pain.

The impact was so hard he had to have a plate inserted into his left forearm and it also punched a hole into his surfboard.

However, he later joked that it would be a good story to tell his grandchildren, adding that it was ‘better than it being a shark.’



Source: https://www.dailymail.co.uk/

Bottle Nose Dolphin Adopts Whale Calf of Another Species


From a small inflatable boat in the Rangiroa atoll in French Polynesia, Pamela Carzon got her first glimpse of the “strange” trio of marine mammals she’d been told about: a bottlenose dolphin mother (Tursiops truncatus), her seven-month-old calf, and another young cetacean that was slightly smaller and looked to be not a bottlenose dolphin at all, but a melon-headed whale (Peponocephala electra). 

It was April 2015, and Carzon and a colleague at the Marine Mammal Study Group of French Polynesia, a nongovernmental organization dedicated to whale and dolphin conservation, were out for the NGO’s annual photo-ID survey, very much hoping to find animals that a former collaborator had seen while diving in the region the previous November. “[T]he sea was very calm, and there were many dolphins around,” Carzon, also a PhD student at the Centre for Island Research and Environmental Observatory (CRIOBE) in French Polynesia and the École Pratique des Hautes Études in Paris, recalls in an email to The Scientist. “It took us maybe two minutes to spot them: the dark calf was easy to spot among the bottlenose dolphins.”

DOLPHIN ADOPTION: A female bottlenose dolphin in the South Pacific has been sighted with both her own calf and another young cetacean identified as a melon-headed whale.

The mother, dubbed ID#TP25 by the researchers, was known to tolerate divers and boats, and that April day she approached the inflatable with both calves. Carzon grabbed her underwater camera and slipped into the water. “I was able to get good underwater footage and to sex both calves,” she says. ID#TP25’s natural calf was a female; the second calf was male. “I also noticed that both were ‘gently’ pushing each other [in order] to remain under the adult female’s abdomen” in so-called infant position. Continued observation over the following months revealed that the dolphin mom was nursing the foreign calf, whose species ID remains to be confirmed with genetic testing, and otherwise treated him as one of her own.

Carzon had been studying the bottle-nose dolphin community inhabiting the northern part of Rangiroa atoll for a decade and knew that the cetaceans had a history of bringing young animals of other species into their group. In 1996, researchers observed a newborn spinner dolphin (Stenella longirostrisswimming in the slipstream of an adult male bottlenose—a behavior known as echelon swimming and a common interaction between mothers and calves. Scientists also regularly spotted a juvenile spinner dolphin over the next two years, often with a particular adult female bottlenose, Carzon says, although it’s not clear whether it was the same individual they saw as a new born. Then, in November 1998, a new born melon-headed whale spent a few weeks in the area and was filmed swimming in echelon position with the same female bottlenose that had associated with the young spinner dolphin.

More recently, another adult female bottlenose in the same community has twice been seen with young of a different species. In January 2011, she was spotted with a neonate spinner dolphin for a few days, and in February 2018, she was photographed with a new born Fraser’s dolphin (Lagenodelphis hosei), which swam alongside her in echelon position. With such behaviours apparently relatively common within this social group, ID#TP25 may have picked up a thing or two from her conspecific companions, speculates Carzon. “The evidence that bottlenose dolphins are capable of imitation is very strong,” she says. “[S]ocially transmitted ideas or practices from cultural models may have influenced [ID#TP25’s] behaviour.

The adoption was stable, lasting more than two years.

As is the case with most animal adoptions in the wild, how the mother bottlenose came to acquire the melon-headed whale calf is unknown. The calf’s natural mother may have died, or the bottlenose dolphin group may have “kidnapped” it, a behavior that was once observed in a dolphin group in the Bay of Gibraltar, Carzon notes. Whatever scenario landed the outside calf in the care of dolphin ID#TP25, the adoption was stable, lasting more than two years. ID#TP25’s naturalcalf disappeared by early 2016, suggesting it died or weaned early, possibly joining another social group.

There is only one other published case of intraspecies adoption by animals in the wild: for about 14 months in the early 2000s, researchers documented the integration of an infant marmoset (Callithrix jacchus) into a group of capuchin monkeys (Cebus libidinosus) in woodland savanna of central Brazil. A female monkey that the researchers had thought was pregnant but who perhaps lost her own baby cared for the infant marmoset, carrying it on her back and appearing to nurse it. “It was amazing because when she appeared, she was tiny tiny tiny,” says Patrícia Izar, a primate ethologist at the University of São Paulo in Brazil who observed the adoption. “She was really a new born, and she survived.” Izar says she was particularly astonished because she knew that some groups of capuchin monkeys eat young marmosets. Care for the young animal was eventually assumed by another female capuchin, and all group members appeared to tolerate the marmoset’s presence.

As for why intraspecies adoptions do—rarely—occur, wildlife conservation professor Robert Young of the University of Salford in the UK suggests that animals may not recognize that they’re caring for young of another species. In the case of the dolphins, the presumed melon-headed whale is similar in size to the adoptive mother’s own bottlenose dolphin calf, and the dolphins have not evolved a strong ability to differentiate their own young from those of another species. “There’s good reason to think it’s just an identification problem,” says Young, who says he has observed a handful of intraspecies adoptions among black-fronted titi monkeys (Callicebus nigrifrons) in Brazil.

The high levels of oxytocin coursing through mammalian mothers’ bodies and the abundance of resources are also likely to be relevant factors. Indeed, in the case of the capuchin group that took in a marmoset baby, Izar and her colleagues had been providing coconuts to study the animals’ use of stones to crack the fruit open, meaning that the monkeys had plenty of food to eat, and so looking after additional young might have been less costly. Interspecies adoptions are also much more common among domestic and captive animals, for whom food is often plentiful, than they are in the wild, Young notes. “If you’ve got a lactating female dog, you can just about get it to rear any other mammal.”

Documented cases of interspecies adoption among the Rangiroa dolphins and Brazilian monkeys “shows that it’s not impossible,” says Izar. “I think that in time we will have other cases in the wild.”



creds to: https://www.the-scientist.com/

Dolphins can learn from peers how to use shells as tools

The marine mammal learns how to hunt from mom, but not always, a study suggests

For some bottlenose dolphins, finding a meal may be about who you know.

Dolphins often learn how to hunt from their mothers. But when it comes to at least one foraging trick, Indo-Pacific bottlenose dolphins in Western Australia’s Shark Bay pick up the behavior from their peers, researchers argue in a report published online June 25 in Current Biology.

While previous studies have suggested that dolphins learn from peers, this study is the first to quantify the importance of social networks over other factors, says Sonja Wild, a behavioral ecologist at the University of Konstanz in Germany.

Cetaceans — dolphins, whales and porpoises — are known for using clever strategies to round up meals. Humpback whales (Megaptera novaeangliae) off Alaska sometimes use their fins and circular bubble nets to catch fish (SN: 10/15/19). At Shark Bay, Indo-Pacific bottlenose dolphins (Tursiops aduncus) use sea sponges to protect their beaks while rooting for food on the seafloor, a strategy the animals learn from their mothers (SN: 6/8/05).

These Shark Bay dolphins also use a more unusual tool-based foraging method called shelling.  A dolphin will trap underwater prey in a large sea snail shell, poke its beak into the shell’s opening, lift the shell above the water’s surface and shake the contents into its mouth.

“It is pretty mind-blowing,” says Wild, who studied these dolphins as a graduate student at the University of Leeds in England. This brief behavior appears to be rare: From 2007 to 2018, Wild and colleagues documented 42 shelling events by 19 individual dolphins out of 5,278 dolphin group encounters in the western gulf of Shark Bay.

The researchers analyzed the behavior of 310 dolphins, including 15 shellers, that had been seen at least 11 times. The dolphins’ network of social interactions explained shelling’s spread better than other factors, including genetic relatedness and the amount of environmental overlap between dolphins. Wild likens the proliferation of this behavior to the spread of a virus. “Just by spending time with each other, [dolphins] are more likely to transmit those behaviors,” she says. The researchers estimate that 57 percent of the dolphins that shell learned the skill via social transmission, rather than on their own.

But the researchers may be premature in dismissing environmental and maternal factors, says Janet Mann, a biologist at Georgetown University in Washington, D.C., who also studies dolphin behavior at Shark Bay. The environment affects where shelling can occur. “Those shells are found in particular habitats, and animals who overlap in those habitats would have access to those shells, but also bump into each other more often,” she says. A dolphin’s shelling behavior could also have been influenced during the tens of thousands of hours the animal spent as a youngster watching its mother.

“Dolphins are smart: They watch each other and see what others do,” she says.



Creds: https://www.sciencenews.org/

Discover the History of Dolphin Show

This practice goes back to the nineteenth century when in 1860 a pair of belugas whales (Delphinapterus leucas) were held in the Museum of New York. Although Belugas are not precisely dolphins, the event marked a before and after in the dolphinarium industry. Several years passed until in 1938 the Marine Studios opened a dolphinarium in Florida, with the business model as we know today, this is, the one in which an audience pay to see dolphins doing tricks, and at that time they began with a bottlenose dolphin (Tursiops truncatus).

Marine Studios of Florida, later became Marineland and it has the title of being the first dolphinarium in the world. In 2011 the Georgia Aquarium purchased the park.

When this park opened, people realized that dolphins were able to learn tricks and perform stunts if trained, so this created a whole new industry that grew over time, and many other dolphinariums opened to the public. By 1970, there were about 36 dolphinariums in the United Kingdom alone.

Keeping dolphins in captivity is a practice not approved by conservationists and animal rights protectors.

It is important to say that captive dolphins are not only in dolphinariums and water parks to amuse people who pay to see a show. Sometimes dolphins are there for the purpose of being studied or protected if they are in danger of extinction.




Creds: https://www.dolphins-world.com/

Indo-Pacific bottle-nose dolphin

The Indo-Pacific bottlenose dolphin (Tursiops aduncus) is a species of bottlenose dolphin. This dolphin grows to 2.6 m (8.5 ft) long, and weighs up to 230 kg (510 lb).[3] It lives in the waters around India, northern Australia, South China, the Red Sea, and the eastern coast of Africa. Its back is dark grey and its belly is lighter grey or nearly white with grey spots.

Until 1998, all bottlenose dolphins were considered members of the single species T. Truncatus. In that year, the Indo-Pacific bottlenose dolphin was recognized as a separate species. The Indo-Pacific bottlenose dolphin is generally smaller than the common bottlenose dolphin, has a proportionately longer rostrum, and has spots on its belly and lower sides. It also has more teeth than the common bottlenose dolphin — 23 to 29 teeth on each side of each jaw compared to 21 to 24 for the common bottlenose dolphin.[6] Some evidence shows the Indo-Pacific bottlenose dolphin may actually be more closely related to certain dolphin species in the genera Stenella and Delphinus, especially the Atlantic spotted dolphin (S. frontalis), than it is to the common bottlenose dolphin.

Much of the old scientific data in the field combine data about the Indo-Pacific bottlenose dolphin and the common bottlenose dolphin into a single group, making it effectively useless in determining the structural differences between the two species. The IUCN lists the Indo-Pacific bottlenose dolphin as “near threatened” in their Red List of endangered species.

Behaviour

Indo-Pacific bottlenose dolphins live in groups that can number in the hundreds, but groups of five to 15 dolphins are most common. In some parts of their range, they associate with the common bottlenose dolphin and other dolphin species, such as the humpback dolphin.

The peak mating and calving seasons are in the spring and summer, although mating and calving occur throughout the year in some regions. Gestation period is about 12 months. Calves are between 0.84 and 1.5 m (2.8 and 4.9 ft) long, and weigh between 9 and 21 kg (20 and 46 lb). The calves are weaned between 1.5 and 2.0 years, but can remain with their mothers for up to 5 years. The interbirth interval for females is typically 4 to 6 years.

In some parts of its range, this dolphin is subject to predation by sharks; its lifespan is more than 40 years.

Indo-Pacific bottlenose dolphins located in Shark Bay, Australia, are thought to have a symbiotic relationship with sponges by doing what is called “sponging”. A dolphin breaks a marine sponge off the sea floor and wears it over its rostrum, apparently to probe substrates for fish, possibly as a tool, or simply for play.

The first report and footage of spontaneous ejaculation in an aquatic mammal was recorded in a wild Indo-Pacific bottlenose dolphin near Mikura Island, Japan, in 2012.

A tribe of Austral indigenous people on the Mornington Island have been communicating with wild dolphins for millennia. They are said to have “a medicine man who calls the dolphins and “speaks” to them telepathically. By these communications he assures that the tribes’ fortunes and happiness are maintained.”



Source: WKPD

Like humans, beluga whales form social networks beyond family ties


Beluga whales

Study first to uncover the role kinship plays in complex groupings and relationships of beluga whales spanning 10 locations across the Arctic

A groundbreaking study using molecular genetic techniques and field studies brings together decades of research into the complex relationships among beluga whales (Delphinapterus leucas) that spans 10 locations across the Arctic from Alaska to Canada and Russia to Norway. The behavior of these highly gregarious whales, which include sophisticated vocal repertoires, suggest that this marine mammal lives in complex societies. Like killer whales (Orcinus orca) and African elephants (Loxodonta Africana), belugas were thought to form social bonds around females that primarily comprise closely related individuals from the same maternal lineage. However, this hypothesis had not been formally tested.

The study, led by Florida Atlantic University’s Harbor Branch Oceanographic Institute, is the first to analyze the relationship between group behaviors, group type, group dynamics, and kinship in beluga whales. Findings, just published in Scientific Reports, reveal several unexpected results. Not only do beluga whales regularly interact with close kin, including close maternal kin, they also frequently associate with more distantly related and unrelated individuals.

Findings indicate that evolutionary explanations for group living and cooperation in beluga whales must expand beyond strict inclusive fitness arguments to include other evolutionary mechanisms. Belugas likely form multi-scale societies from mother-calf dyads to entire communities. From these perspectives, beluga communities have similarities to human societies where social networks, support structures, cooperation and cultures involve interactions between kin and non-kin. Given their long lifespan (approximately 70 years) and tendency to remain within their natal community, these findings reveal that beluga whales may form long-term affiliations with unrelated as well as related individuals.

“This research will improve our understanding of why some species are social, how individuals learn from group members and how animal cultures emerge,” said Greg O’Corry-Crowe, Ph.D., lead author and a research professor at FAU’s Harbor Branch. “It also has implications for traditional explanations based on matrilineal care for a very rare life-history trait in nature, menopause, which has only been documented in a handful of mammals, including beluga whales and humans.”

Researchers found that belugas formed a limited number of group types, from mother-calf dyads to adult male groups, and from mixed-age groups to large herds. These same group types were consistently observed across population and habitats. Furthermore, certain behaviors were associated with group type, and group membership was found to often be dynamic.

“Unlike killer and pilot whales, and like some human societies, beluga whales don’t solely or even primarily interact and associate with close kin. Across a wide variety of habitats and among both migratory and resident populations, they form communities of individuals of all ages and both sexes that regularly number in the hundreds and possibly the thousands,” said O’Corry-Crowe. “It may be that their highly developed vocal communication enables them to remain in regular acoustic contact with close relatives even when not associating together.”

Beluga whale groupings (beyond mother-calf dyads) were not usually organized around close maternal relatives. The smaller social groups, as well as the larger herds, routinely comprised multiple matrilines. Even where group members shared the same mtDNA lineage, microsatellite analysis often revealed that they were not closely related, and many genealogical links among group members involved paternal rather than maternal relatives. These results differ from earlier predictions that belugas have a matrilineal social system of closely associating female relatives. They also differ from the association behavior of the larger toothed whales that informed those predictions. In ‘resident’ killer whales, for example, both males and females form groups with close maternal kin where they remain for their entire lives.

“Beluga whales exhibit a wide range of grouping patterns from small groups of two to 10 individuals to large herds of 2,000 or more, from apparently single sex and age-class pods to mixed-age and sex groupings, and from brief associations to multi-year affiliations,” said O’Corry-Crowe. “This variation suggests a fission-fusion society where group composition and size are context-specific, but it may also reflect a more rigid multi-level society comprised of stable social units that regularly coalesce and separate. The role kinship plays in these groupings has been largely unknown.”

For the study, researchers used field observations, mtDNA profiling, and multi-locus genotyping of beluga whales to address fundamental questions about beluga group structure, and patterns of kinship and behavior, which provide new insights into the evolution and ecology of social structure in this Arctic whale.

The study was conducted at 10 locations, in different habitats, across the species’ range, spanning from small, resident groups (Yakutat Bay) and populations (Cook Inlet) in subarctic Alaska to larger, migratory populations in the Alaskan (Kasegaluk Lagoon, Kotzebue Sound, Norton Sound), Canadian (Cunningham Inlet, Mackenzie Delta, Husky Lakes) and Russian (Gulf of Anadyr) Arctic to a small, insular population in the Norwegian High Arctic (Svalbard).

“This new understanding of why individuals may form social groups, even with non-relatives, will hopefully promote new research on what constitutes species resilience and how species like the beluga whale can respond to emerging threats including climate change,” said O’Corry-Crowe.



Source: https://www.sciencedaily.com/

5 Facts About the Amazon Pink River Dolphin

Dolphins are one of the most loved marine animals, though most people only get to see the species that live in the ocean. For Valentine’s Day, we decided to do a little research on one of the most unique species: The Amazon pink river dolphin. There’s a lot to love! And if you’d like to make the ocean your Valentine this year, check out Project AWARE® to let them know how deep your love of the ocean is. By donating or sharing photos, you can help protect this dolphin and all the other wonderful marine life on our planet.

They come in many shades of pink (and grey).

The Amazon River dolphin is famous for its pink colour, but many don’t know that it comes in a large number of shades. The dolphins start off grey when they’re young and slowly turn pink as they get older. Their final colour can be influenced by their behaviuor, capillary placement, diet, and exposure to sunlight. The dolphins can be anywhere from mostly grey with some pink spots, to almost flamingo pink. And when the dolphins get excited, they can flush bright pink, similar to humans blushing.

They have the largest bodies and brains of any freshwater dolphin.

Out of the five freshwater species, the pink river dolphin comes out on top. Measuring at up to 9 feet/2.7 meters long, 400 pounds/181 kilograms, and living up to 30 years old, these animals are massive. They also have unusually large brains, with 40% more brain capacity than humans.

They are more solitary than other dolphins.

The pink river dolphin is often seen alone or in small groups of 2-4 individuals. In some food-rich areas or at the mouths of the rivers they can be found in larger groups, but it’s less common. Despite living in small groups, they’re still incredibly curious and outgoing animals, and frequently interact with humans.

They are incredibly agile.

Pink river dolphins have unfused vertebrae in their neck, unlike other dolphins. This means that they can turn their head 180 degrees, allowing them to manoeuvre around tree trunks, rocks, and other obstacles found in their murky river environments. They can also swim forward with one flipper while paddling backwards with the other, letting them turn with more precision. And they’re frequently seen swimming upside down, possibly to help them see the bottom of the river better.

There are tons of mythology surrounding them.

This dolphin is the subject of many South American legends. One story claim that during the night, the dolphins morph into handsome men to seduce the women of the village. Other claims that if you go swimming alone, the dolphins may whisk you away to a magical underwater city. It was frequently considered bad luck to harm them, and even worse luck to eat them. Their status as a semi-magical being may have helped protect the species by encouraging humans to treat them well and preserve them.



cred to: https://blog.padi.com/