How grandmothers help young killer whales survive

Posted on December 10, 2019 by petrel41

This December 2018 video says about itself:

Inside the killer whale matriarchy – Darren Croft

Pods of killer whales inhabit the waters of every major ocean on Earth. Each family is able to survive thanks mainly to one member, its most knowledgeable hunter: the grandmother. These matriarchs can live 80 years or more and their expertise can mean the difference between life and death for their families. Darren Croft details the lives of killer whales and the dangers facing their survival.

Read more here.

From the University of York in England:

Killer whale grandmothers boost survival of calves

Post-menopausal killer whale grandmothers improve the chances of survival for their grand-calves

December 9, 2019

Post-menopausal killer whale grandmothers improve the chances of survival for their grand-calves, new research has found.

The study found that grandmothers who were no longer able to reproduce had the biggest beneficial impact on the survival chances of their grand-offspring. This may be because grandmothers without calves of their own are free to focus time and resources on the latest generation, the researchers suggest.

The research team also found that grandmothers had a particularly important role in times of food scarcity, as the impact on a calf of losing a post-menopausal grandmother was highest in years when salmon was scarce.

Previous research has shown that post-reproductive female killer whales are the most knowledgeable and provide an important leadership role for the group when foraging in salmon grounds.

These benefits to the group may help to solve the long-standing mystery of why the menopause has evolved in some species of whales and in humans, the authors of the study say.

Senior author of the study, Dr Dan Franks from the Department of Biology, at the University of York, said: “The study suggests that breeding grandmothers are not able to provide the same level of support as grandmothers who no longer breed. This means that the evolution of menopause has increased a grandmother’s capacity to help her grand-offspring.

“The death of a post-menopausal grandmother can have important repercussions for her family group, and this could prove to be an important consideration when assessing the future of these populations. As salmon populations continue to decline, grandmothers are likely to become even more important in these killer whale populations.”

The study involved an international research team from the Universities of York and Exeter (UK), the Centre for Whale Research (USA) and Fisheries and Oceans Canada.

The scientists analysed 36 years of data gathered by the Center for Whale Research and Fisheries and Oceans Canada on two populations of resident killer whales. The populations (which include several pods, made up of multiple family groups) live off the North West Pacific Coast of Canada and the US and feed on Chinook salmon.

In resident killer whales, both sons and daughters stay with their mothers for life, but they mate with individuals from a different family group. Male killer whales typically have a shorter lifespan than females with many not surviving beyond 30 years. Females usually stop reproducing in their 30s-40s, but just like humans they can live for many decades following menopause.

Lead author, Dr Stuart Nattrass, from the University of York, added: “The findings help to explain factors that are driving the whales’ survival and reproductive success, which is essential information given that the Southern Resident killer whales — one of the whale populations under study — is listed as endangered and at risk of extinction.

“We suspect when breeding grandmothers are supporting their own calves, their movement and activity patterns are constrained and they are not able to provide support and leadership in the same way as post-menopausal females. Also, grandmothers with their own calves will be busy caring for their own calves, and be able to invest less in their grand-offspring, compared to post-menopausal grandmothers.

We are currently conducting observational studies with drones to directly study helping behaviour between family members in these killer whales.”

Co-author of the study, Prof Darren Croft from the University of Exeter, said “The menopause has only evolved in humans, killer whales and three other species of toothed whales and understanding why females of these species stop reproduction well before the end of life is a long-standing evolutionary puzzle.

“Our new findings show that just as in humans, grandmothers that have gone through menopause are better able to help their grand offspring and these benefits to the family group can help explain why menopause has evolved in killer whales just as it has in humans.”

Orcas in Norway, video

Posted on August 14, 2018 by petrel41

This 9 August 2018 video says about itself:

Orcas Co-Exist With Norway’s Arctic Fishermen

From The Shadows: The symbiotic relationship between Atlantic orcas and the fishermen of Norway is unique. Following this story, underwater photographer Jacques de Vos captures the first footage of the whales feeding at night.

In Northern Norway herring abounds, attracting orcas in their hundreds. Having learnt that escaped herring from the fishermen’s nets are easy prey, the whales can hear the fishing boats pumping their catch from as far as 18km away.

“Sometimes it’s kind of like we help each other”, says professional fisherman Borre Hansen, as orcas circle around his boat. Ensuring that no orcas are captured in his nets “is the biggest challenge” he faces. Filming these animals for the first time at night, Jacques is able to capture their secretive underwater world, noticing their playful and inquisitive behaviour. “This was as much a social ‘get together’ as it was about the feeding”, he marvels.

Ice-trapped orcas saved in Russia

Posted on April 28, 2016 by petrel41

This video from Russia says about itself:

19 April 2016

After an eight-hour-long operation rescuers freed three orcas, including one pup, which had got trapped in ice in the Sea of Okhotsk, Sakhalin, on Tuesday.

1,000 dolphins flee killer whales, video

Posted on April 20, 2016 by petrel41

This video from California in the USA says about itself:

Killer Whales Ambush A Pod of 1,000 Dolphins

14 April 2016

This was an incredible encounter. I just happened to be in the right spot at the right time. It’s very rare that everything comes together and we’re able to document these types of encounters. We know it happens regularly with the common dolphins. But there’s rarely someone there with their video camera focused and waiting for it to happen. Incredible morning on The Monterey Bay for me.

1970s killer whale still alive

Posted on April 1, 2016 by petrel41

This video from the USA says about itself:

29 April 2013

A couple vacationing in Mexico encountered a number of killer whales swimming alongside their boat during a trip.

From the BBC, with video there:

1970s killer whale Dopey Dick spotted off Scotland

3 hours ago

Scientists studying Scotland’s killer whales have made a remarkable discovery.

They have identified a whale which hit the headlines in the 1970s after swimming up the River Foyle in Northern Ireland.

Back then, he was dubbed “Dopey Dick”.

Today, he’s known as Comet… and is still believed to be alive and well.

BBC Scotland‘s environment correspondent, David Miller, reports.

Orcas in the North Sea, video

Posted on October 19, 2015 by petrel41

This video says about itself:

11 October 2015

Ship in North Sea surrounded by Killer Whales.

Older female killer whales become pod leaders

Posted on March 6, 2015 by petrel41

This 2014 video says about itself:

In this intriguing talk, Scott Gass discusses the social structure of killer whales and their superb communication skills when it comes to hunting and protecting their young. Their brand of teamwork is tremendously applicable beyond the ocean.

From the Los Angeles Times in the USA:

Menopausal whales lead the group, study says

By Melissa Healy

Sharelines

Mystery solved (maybe): Some females live beyond their reproductive years because their wisdom benefits kin

Menopause: an evolutionary mystery unique to humans, killer whales and short-finned pilot whales

Female killer whales can live past 90. Males rarely survive after 50

What does an ocean-going titaness do after she has the lost the ability to bear young?

Well, for starters, she goes on living–sometimes past the ripe old age of 90, while male killer whales over 50 are dying off in droves. Throughout the animal kingdom, that is unusual enough.

But the menopausal female killer whale does more than survive, says a new study: She “leans in,” becoming an influential leader of younger killer whales, honing the survival skills of her progeny–and their progeny–unencumbered by direct childcare duties of her own.

Quite the opposite of being a burden to her kind, her post-menopausal leadership role seems to make the older female killer whale her species’ evolutionary ace in the hole.

Published in the journal Current Biology, the new research finds that among killer whales, females beyond their reproductive years become habitual leaders of collective movement–generally foraging movement–within their pods. Their position “on point” becomes particularly prominent in lean years, when salmon–the mainstay of the killer whales’ diet–is scarce.

The new findings offer the first evidence that in certain species and under specific circumstances, females who live well beyond their reproductive years “act as repositories of ecological knowledge.”

That helps solve an enduring mystery among biologists: Why–in humans and in two species of toothed whales only–would individuals who no longer propagate their genes continue to survive?

The authors of the study are marine mammal researchers from the universities of York and Exeter in Great Britain and the Center for Whale Research in Washington state. To glean their findings, they analyzed 751 hours of video taken of Southern resident killer whales during annual salmon migrations off the coast of British Columbia and Washington.

The videos were taken over a period of nine years. They captured the movements of pods of killer whales whose populations have been identified and tracked since 1976. That allowed the researchers to determine the age and relatedness of the 102 creatures whose movements they analyzed.

Such detail also allowed the authors to speculate on why post-menopausal survival is so very rare. If post-reproductive females can be such an evolutionary boon for their kin, why do they not survive to serve that function across many species?

Some have suggested that for humans, at least, the post-menopausal survival of women is merely an artifact of better medical care.

Not so, new research–including the killer whales study–suggests. The answer, the authors of this study wrote, may lie in different kinship patterns. Among killer whales, generations of males and females stay together throughout their lives, foraging as a group. As a female ages, her level of genetic relatedness to members of her pod increases.

“Menopause will only evolve,” they wrote, “when inclusive fitness benefits outweigh the costs of terminating reproduction.”

In short, an older female’s continued value to the group may be a function not only of her accumulated knowledge about the whereabouts of food, shelter and predators, but also of her genetic stake in the group’s survival.

That was the case, too, in hunter-gatherer human societies, the authors note. As human societies evolved, women reaching sexual maturity tended to leave the group. As her sons and their many mates and children populated her group, an aging woman’s “relatedness” to that group tended to grow.

In contrast, among other long-lived mammals, sons move off as they reach sexual maturity. So a female becomes less related to the “pod” she stays with as she become older. Under those circumstances, the authors write, she may have sufficient ecological wisdom but not a sufficient level of “relatedness” to her group to ensure her survival beyond the years of reproduction.

George Harrison Beatle tree killed by beetles

Whaling conference in Slovenia, 15 September

Posted on September 12, 2014 by petrel41

This video is called Killer Whales | Deadly But Social and Smart | Documentary.

From Wildlife Extra:

International Whaling Commission to meet in Slovenia on 15 September

The 65th meeting of the International Whaling Commission (IWC) will begin on 15 September in Portoroz, Slovenia.

Pro-conservation countries and organisations are once again preparing to take on Japan and other pro-whaling nations.

The fight will be over the integrity of the global commercial whaling moratorium that has spared tens of thousands of whales from the harpoon since 1982.

Top priorities for organisations such the Humane Society International (HIS) and the International Fund for Animal Welfare (IFAW) include urging whale-friendly governments to increase pressure for stronger protection for whales and turn back efforts to dilute the worldwide commercial whaling moratorium.

Encouragement will also be given to the IWC Commissioners to take all necessary steps to prevent Japan from further whaling in light of the International Court of Justice’s March 2014 judgment that Japan’s Antarctic whaling did not qualify as scientific research and thus undermined the moratorium.

There is also opposition to Japan’s attempts to create a new category of coastal whaling and Greenland’s proposal to expand aboriginal (subsistence) whaling, both of which would allow commercial sale of whale meat and similarly threaten to undermine the moratorium.

HSI Vice President Kitty Block said: “This year we intend to press all of the nations whose citizens care about whales to exert strong leadership in halting the spread of new whaling proposals.

“We will challenge IWC Commissioners to adopt an agenda that extends beyond whaling to the broader range of threats that imperil whales throughout our oceans.”

103-year-old orca still swimming

Posted on May 13, 2014 by petrel41

This video is called Amazing Orca Killer Whales In The Wild [Full Nature Wildlife Documentary].

From Wildlife Extra:

An orca called Granny swims into the record books

Just in time for Canada’s Mother’s Day last Sunday an orca named J2 – more commonly known as Granny – arrived in the waters between Point Roberts in Washington State, USA, and East Point on Saturna Island in British Columbia, reports The Province newspaper. This was not unusual as J-Pod – the name researchers have given this group of orcas – would normally be expected in the area. What did excite Captain Simon Pidcock of Ocean EcoVentures in Cowichan Bay was the continuing appearance of Granny because she is believed to be 103 years old. She is the world’s oldest known orca and has lived far in excess of the average lifespan of 60 to 80 years for a wild animal.

There was no doubt the orca was Granny, according to Pidcock. He recognises the senior cetacean by her saddle patch, a distinctive white patch each whale has behind its dorsal fin. “They’re like our fingerprints,” he said.

Granny is also recognisable because of a half-moon-shaped notch on the trailing side of her dorsal fin.

Granny is one of the southern resident group of orcas that inhabit the coastal waters from Haida Gwaii, on the north coast of British Columbia, to Northern California for about eight months of the year. Michael Harris, executive director of Pacific Whale Watch Association, which has members in both the US and Canada, said J-Pod had been spotted off the Russian River in Northern California just over a week before.

“The thing I found really interesting is that she’s in the shape to travel, to make the trek she just did with J-Pod,” said Harris. “That’s 800 miles in not even eight days. It’s amazing.”

She appears healthy because of the lack of a “peanut head,” which Pidcock said is a divot-like depression around the animal’s blow hole which appears when they are malnourished. Her endurance and healthy appearance may come from feasting on recent big chinook salmon runs near the Columbia River.

Granny’s birth date of 1911 is an extrapolation by researchers based on her offspring.

She currently has a great-grandchild travelling in J-Pod. Pidcock said researchers also determine age based on the size of the whales, and Granny’s current bulk can be compared to photographic images taken of her in the late 1930s and early 1940s.The oldest orcas in captivity are both about 50 years old, according to the Pacific Whale Watch Association, and belong to the northern and southern resident groups that travel through the Pacific Northwest.

Entangled orca saved from drowning by other pod members: here.

Killer whales, new research

Posted on December 6, 2013 by petrel41

This video is called BBC Natural World: The Woman Who Swims With Killer Whales.

From Wildlife Extra:

Killer whales found to eavesdrop on prey

December 2013: UK Scientists have found evidence that marine-mammal-eating killer whales rely on acoustic clues to locate their prey.

While biologists had evidence that the whales do not echolocate while hunting, due to the excellent hearing of the seals, porpoises and other animals the whales hunt, they were still unsure exactly how the animals do find their prey in the murky northern waters off the west coast of North America.

However, a two-year study by Volker Deecke, a researcher at the Centre for Wildlife Conservation at the University of Cumbria, UK has revealed that killer whales can successfully locate prey even in near-complete darkness. Deecke notes that this new evidence of night-time hunting rules out visual cues as the only means of prey detection.

“We now suspect that mammal-eating killer whales are primarily eavesdropping on sounds generated by their prey to find food,” he said.

Deecke and his colleagues traveled to Alaska to conduct the study, analysing huge quantities of data gathered from acoustic recording tags placed on 13 killer whales. The tags, which are about the size of a cell phone, were attached to the whales with four suction cups and could stay on for up to 16 hours.

The tags’ accelerometers, compass, depth sensor, and hydrophone recorded data on the animals’ movements and any sounds it heard or made. Deecke and his colleagues were able to identify predation events by the characteristic sound of a whale dispatching its prey with a hit from its tail fluke.

Deecke said of one unfortunate seal’s demise: “As soon as we put one of the tags on, it started to record seal roars, which are part of the display that male harbor seals use to attract females. Over the next half hour the roars got louder and louder, then there are a sequence of three quite loud roars that suggest the seal is within a few hundred meters of the killer whale. Twenty-seven seconds later there are the sounds of a predation event, and then no more roars.”

Deecke notes that such a story is compelling but does not provide direct evidence that killer whales are tuning in to the sounds of their prey. Going forward, he hopes to use playback experiments to test killer whales’ responses to recorded seal roars and porpoise echolocation clicks.