Bowhead whales: jazz artists of the deep whose calls rival birdsong

Bowheads serenade each other off Greenland with a vast repertoire of improvised jazz-like song, study says

Agence France-Presse

Wed 4 Apr 2018 07.38 BSTFirst published on Wed 4 Apr 2018 02.50 BST

How do bowhead whales in the unbroken darkness of the Arctic’s polar winter keep busy during breeding season?

They sing, of course.

From late autumn to early spring, off the east coast of Greenland, some 200 bowheads, hunted to the edge of extinction, serenade each other with compositions from a vast repertoire of song, according to a study published on Wednesday.

“It was astonishing,” said the lead author, Kate Stafford, an oceanographer at the University of Washington’s Applied Physics Laboratory in Seattle, who eavesdropped on these subaquatic concerts.

“Bowhead whales were singing loudly, from November until April” – non-stop, 24/7 – “and they were singing many, many different songs.”

Stafford and three colleagues counted 184 distinct melodies over a three-year period, which may make bowheads one of the most prolific composers in the animal kingdom.

“The diversity and inter-annual variability in songs of bowhead whales in this study are rivalled only by a few species of songbirds,” the study found.

Unlike mating calls, songs are complex musical phrases that are not genetically hard-wired but must be learned.

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Bowhead whales come to Cumberland Sound in Nunavut to exfoliate

Date:  November 22, 2017

Source:  University of British Columbia

Summary:

Aerial drone footage of bowhead whales in Canada's Arctic has revealed that the large mammals molt and use rocks to rub off dead skin.

The footage provides one answer to the mystery of why whales return to Cumberland Sound, Nunavut, every summer, and helps explain some unusual behavior that has been noted historically by Inuit and commercial whalers living and working in the area.

"This was an incidental observation," said Sarah Fortune, a PhD student at UBC's Institute for the Oceans and Fisheries and lead author of a new study based on the findings. "We were there to document their prey and feeding behavior, but we noticed some strange behavior near the shore."

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Baleen hormones increase understanding of bowhead whale reproduction

Date:

January 4, 2015

Source:

Society for Integrative and Comparative Biology (SICB)

Summary:

Wild animals provide a unique challenge for physiologists because they are difficult to capture and monitor in their natural habitats. As a result, scientists are increasingly learning about organisms by extracting steroid hormones out of keratinized tissues. This includes hormones such as testosterone, progesterone, and cortisol that are deposited in feathers, human hair, and reptile claws as these tissues grow. A onetime capture and removal of a single sample can provide a scientist with a record of fluctuating amounts of hormone in the body over the growth period of the collected sample. This technique provides a wealth of information about an animal, including its reproductive history. Development of this method is now underway to monitor the reproduction of one of the largest organisms on earth, the bowhead whale.

Continued ...

Ice Age bowhead whales' survival surprises scientists

By Michelle Warwicker, BBC Nature

Ancient DNA shows that bowhead whales bucked the trend to survive the last Ice Age, say scientists.

The demise of cold-adapted land mammals such as mammoths has been linked to rising temperatures around 11,000 years ago.

But researchers were surprised to find a contrasting population boom for whales living off the coast of Britain.

Their study is also the first to discover that the ocean giants lived in the southern North Sea.

Dr Andy Foote from the Natural History Museum of Denmark, based at the University of Copenhagen co-authored the paper published in the journal Nature Communications.

"Based on all previous studies using ancient DNA to estimate the population size... it seems the trend was for cold-adapted species either [to] go extinct or decline in numbers at the end of the Ice Age as the temperature increased," said Dr Foote.

Arctic Britain

But while the fate of now-extinct land-based Ice Age animals is well documented, little has been known about how marine animals were affected by the rapid temperature warming.

Bowhead whales today are found in Arctic seas and rely on sea ice where they feed on tiny crustaceans.

The research team wanted to find out how the whales fared during the rapid climate change of the Pleistocene-Holocene epoch transition when the essential sea ice retreated from their North Sea habitat.

Scientists analysed ancient DNA of partly-fossilised whale remains found in waters between Britain and Holland and around Denmark and Sweden.

They were able to use the data to create a habitat prediction model and build a picture of the whales' past movements and probability of survival.

Read on:  http://www.bbc.co.uk/nature/22027533

Whales' Foraging Strategies Revealed by New Technology

Jan. 9, 2013 — Marine biologists are beginning to understand the varied diving and foraging strategies of filter-feeding whales by analyzing data from multisensor tags attached to the animals with suction cups. Such tags, in combination with other techniques such as echolocation, are providing a wealth of fine detail about how the world's largest creatures find and trap their prey.

Recent studies on the behavior of baleen whales -- which filter small fish or invertebrate animals from seawater -- are described in the February issue of BioScience. Jeremy A. Goldbogen of the Cascadia Research Collective in Olympia, Washington, and his colleagues point out that tags can report not only the depth but also the acceleration of the animal carrying them, which reveals information on its pitch and rolling motion. Together with special software, this can allow foraging dives to be visualized in three dimensions, along with the timing. Studying whale behavior is logistically challenging, as it may be necessary to coordinate the actions of several research vessels and large research teams. Yet despite the difficulties, patterns are becoming clear.

Right whales and bowhead whales have a very different feeding strategy from rorquals -- the group that includes the biggest animal on earth, the blue whale. Right and bowhead whales filter-feed by swimming relatively slowly through prey patches, a mode called continuous ram feeding. This keeps their energy expenditure low and makes possible dives of 10 minutes or longer, but means they miss out on prey able to take evasive action. Rorquals, in contrast, make high-speed lunges at prey patches that enable them to catch elusive species. They must then pause to filter water engulfed in their large mouths, however, and they have to surface more often to breathe than continuous ram feeders. The new tools available mean researchers can study the efficiency of diving and foraging in different whales and relate it to the availability of prey of different types. Because whales are considered keystone predators that structure oceanic food webs, such insights will shed important light on ocean ecology.

http://www.sciencedaily.com/releases/2013/01/130109110606.htm

Bowhead whales cross from Atlantic to Pacific regularly

First range-wide study of bowhead whale genetics finds much genetic diversity lost during age of commercial whaling

October 2012. Scientists from the Wildlife Conservation Society, the American Museum of Natural History, City University of New York, and other organizations have published the first range-wide genetic analysis of the bowhead whale using hundreds of samples from both modern populations and archaeological sites used by indigenous Arctic hunters thousands of years ago.

A newly published study by the Wildlife Conservation Society, the American Museum of Natural History, and other groups represents the first range-wide genetic analysis, using both modern-day tissue samples and historical artifacts of the bowhead whale, a species at home among the ice floes of the Arctic. This individual was photographed off Point Barrow, Alaska. Reaching up to 65 feet in length and up to 100 tons in weight, the bowhead whale is a baleen whale that lives in Arctic and sub-Arctic waters. The bowhead gets its name from its enormous arched head, which it occasionally uses to break through ice up to 60 centimetres thick in order to breathe.

The species widely hunted for centuries by commercial whalers, who prized the species for its long baleen (used in corsets and other items) and its thick blubber (the thickest of any species of whale). The bowhead whale may also be among the most long-lived mammal species. In 2007, aboriginal whalers on the Alaskan coast landed a whale carrying a valuable clue about the animal’s probable age. The whalers discovered a harpoon point manufactured in the 1890s embedded in the whale’s blubber, indicating the animal may have survived an encounter with whalers more than one hundred years ago.

Ancient DNA samples
In addition to using DNA samples collected from whales over the past 20 years, the team collected genetic samples from ancient specimens -extracted from old vessels, toys, and housing material made from baleen-preserved in pre-European settlements in the Canadian Arctic. The study attempts to shed light on the impacts of sea ice and commercial whaling on this threatened but now recovering species. The study appears in the most recent edition of Ecology and Evolution.

"Our study represents the first genetic analysis of bowheads across their entire range," said Elizabeth Alter, the study's lead author and now a professor at City University of New York. "The study also illustrates the value of ancient DNA in answering questions about the impact of changing climate and human exploitation on genetic diversity in bowhead whales."

Continued:  http://www.wildlifeextra.com/go/news/bowhead-migration.html

Bowhead Whales: Ancient DNA Sheds Light On Arctic Whale Mysteries

ScienceDaily (Oct. 19, 2012) — Scientists from the Wildlife Conservation Society, the American Museum of Natural History, City University of New York, and other organizations have published the first range-wide genetic analysis of the bowhead whale using hundreds of samples from both modern populations and archaeological sites used by indigenous Arctic hunters thousands of years ago.

In addition to using DNA samples collected from whales over the past 20 years, the team collected genetic samples from ancient specimens -- extracted from old vessels, toys, and housing material made from baleen -- preserved in pre-European settlements in the Canadian Arctic. The study attempts to shed light on the impacts of sea ice and commercial whaling on this threatened but now recovering species. The study appears in the most recent edition of Ecology and Evolution.

"Our study represents the first genetic analysis of bowheads across their entire range," said Elizabeth Alter, the study's lead author and now a professor at City University of New York. 

"The study also illustrates the value of ancient DNA in answering questions about the impact of changing climate and human exploitation on genetic diversity in bowhead whales."

Read on:  http://www.sciencedaily.com/releases/2012/10/121019130502.htm

Elusive Bowhead whales revealed by undersea microphones

Critically endangered whales sing like birds; new recordings hint at rebound

August 2012. When a University of Washington researcher listened to the audio picked up by a recording device that spent a year in the icy waters off the east coast of Greenland, she was stunned at what she heard: whales singing a remarkable variety of songs nearly constantly for five wintertime months.

Kate Stafford, an oceanographer with UW's Applied Physics Lab, set out to find if any endangered bowhead whales passed through the Fram Strait, an inhospitable, ice-covered stretch of sea between Greenland and the northern islands of Norway. Only around 40 sightings of bowhead whales, which were hunted almost to extinction, have been reported there since the 1970s.

Stafford and colleagues put two hydrophones, or underwater microphones, on moorings attached to the seafloor in Fram Strait, leaving them there for as long as the batteries would last: nearly a year. Since the population of bowhead whales likely to pass through was thought to number in the tens, they didn't anticipate much interesting data.

Gobsmacked by results
"We hoped to record a few little grunts and moans," Stafford said. "We were not expecting to get five months of straight singing."

Not only did they record singing nearly every hour of the day and night, they picked up more than 60 unique songs.

The variety of tunes was so surprising that the researchers compared the whales' song catalog to that of birds.

"Whether individual singers display one, multiple or even all call types, the size of the song repertoire for... bowheads in 2008-2009 is remarkable and more closely approaches that of songbirds than other... whales," they wrote in the report.

Read on:  http://www.wildlifeextra.com/go/news/bowhead-singing.html

Critically Endangered Whales Sing Like Birds; New Recordings Hint at Rebound

ScienceDaily (July 31, 2012) — When a University of Washington researcher listened to the audio picked up by a recording device that spent a year in the icy waters off the east coast of Greenland, she was stunned at what she heard: whales singing a remarkable variety of songs nearly constantly for five wintertime months.

Kate Stafford, an oceanographer with UW's Applied Physics Lab, set out to find if any endangered bowhead whales passed through the Fram Strait, an inhospitable, ice-covered stretch of sea between Greenland and the northern islands of Norway. Only around 40 sightings of bowhead whales, which were hunted almost to extinction, have been reported there since the 1970s.

Stafford and colleagues put two hydrophones, or underwater microphones, on moorings attached to the seafloor in Fram Strait, leaving them there for as long as the batteries would last: nearly a year. Since the population of bowhead whales likely to pass through was thought to number in the tens, they didn't anticipate much interesting data.


Continued:  http://www.sciencedaily.com/releases/2012/07/120731123248.htm

Whales take Northwest Passage as Arctic sea-ice melts

Bowhead whales, the giants of the Arctic, are using the Northwest Passage to move across the top of the Americas.

Skeletons, DNA samples and harpoon heads have all suggested that bowhead populations living on each side of the continent did meet and mingle.

Now, research published in the journal Biology Letters has used satellite tags to provide confirmation.

The work may provide insights into the development of Arctic cultures in which bowhead hunting plays a central role.

Mads Peter Heide-Jorgensen from the Greenland Institute of Natural Resources led a team that has satellite-tagged more than 100 bowheads over the last decade - much of the work funded by oil and gas companies interested in the Arctic's new mineral wealth.

Last August, as the Arctic sea ice neared its annual minimum, the satellite data told them that one whale from the Greenland side and one from the Alaskan side had arrived in pretty much the same area, north of the Canadian mainland.

They spent about 10 days circling in the same patch of water before heading back to their respective home ranges.

This is the first time such mingling has been seen directly, although there is plenty of circumstantial evidence that it has happened sporadically in the past.

Bowhead skeletons are found on elevated beaches through the Canadian archipelago. In 19th Century Alaska, whales were caught containing tips of harpoons that had been thrown by whalers in the Atlantic.

Passage may have been easier in the last four summers than in preceding decades, as the Arctic ice has shrunk to a smaller size than at any time in the satellite record.

"I'm pretty sure that the low sea ice in the summer has triggered this migration through this area," Dr Heide-Jorgensen told BBC News.

"I'm pretty sure that when it occurred in the past, when we got all these skulls on the beach, that was during a warm period.

"During any climatic period, there could have been years with less ice in the Northwest Passage; and I'm pretty sure the bowheads can find cracks [in the ice] that are too small to show up on satellite images."

Whaling route

The other fascinating line of evidence for bowhead migration along northern Canada lies in the human societies that depend on the whales, where communities are structured around the process of whaling.

The best known example today are the Inupiat of Alaska.

They are descended from the Thule culture, which appears to have emerged in Alaska about 1,000 years ago.

Thule people spread across Canada to Greenland in the three centuries following.

They ate meat and blubber from the bowhead, built houses using their bones and burned their oil.

Given their dependence on the single species, could they have made the migration without access to the whales?

Anne Jensen, an archaeologist who has lived in the northern Alaskan town of Barrow for many years and is a leading authority on the Thule people, said the routes taken by the two whales last year passed close by sites that date the Thule expansion.

"This supports the idea that the expansion was connected to whaling," she told BBC News.

"People were moving - presumably after having done some small-group exploring that is archaeologically invisible - to places where they knew whales went, perhaps in a period when the ice cover was reduced for some reason.

"Certainly, they were not settling in places where whales weren't available at that point.

"Since the Thule seem to have been able to hunt whales from the ice at leads, it doesn't mean that there was an ice-free Northwest Passage - just one that bowheads could get through, with enough leads for hunters to see and catch the whales."

Of all the great whales, the bowheads are the best adapted to life in the harsh Arctic environment, with a domed bony head that can force a way through relatively thin sheets of ice, and a thick layer of blubber.

"They have their lunch package on them - they can move for months without eating because they have blubber almost half a metre thick, so so they can move through the Northwest Passage without eating," said Dr Heide-Jorgensen.

Genetic evidence also suggests that in periods past, bowheads also moved along the northern coast of Siberia.

They do not have a set migration pattern, unlike some other whale species - which raises questions about how they may adapt in future, if the projected declines in summer Arctic sea ice materialise.

"I'm sure they will be going all over the area when there's open water," said Dr Heide-Jorgensen.

"They're capable of moving relatively long distances in a short period of time, and they can venture into areas where we haven't seen them for a very long time - so I'm sure they will use the open water if the ice disappears."

The one question mark would be over their food supply, with major changes in Arctic sea ice likely to disrupt food webs that include the swarms of copepods (tiny crustaceans) that are the key ingredient of their diet.
By Richard Black Environment correspondent, BBC News
http://www.bbc.co.uk/news/science-environment-14976344