Baleen whale evolution, new research in New Zealand


This video is called Humpback whales feeding on krill – Deep into the Wild – BBC. It says about itselF:

26 July 2010

Nick Baker crosses some of the world’s most treacherous seas as his mission to get close to some of the wildest animals on Earth takes him to Antarctica. Despite the cold, these oceans are rich with marine life as the mighty humpback whale demonstrates as it gorges itself on krill.

From the University of Otago in New Zealand:

Otago research details 40 million-year-old family tree

Wednesday, 15 April 2015, 3:11 pm

Otago research details 40 million-year-old family tree of baleen whales

New University of Otago research is providing the most comprehensive picture of the evolutionary history of baleen whales, which are not only the largest animals ever to live on earth, but also among the most unusual.

Most other mammals feed on plants or grab a single prey animal at a time, but baleen whales are famous for their gigantic mouths and their ability to gulp and filter an enormous volume of water and food.

In a paper appearing in the UK journal Royal Society Open Science, Otago Geology PhD graduate Dr Felix Marx and Professor Ewan Fordyce present a comprehensive family tree of living and extinct baleen whales stretching back nearly 40 million years.

The pair says that similar family trees have been constructed before, but theirs is by far the largest and, crucially, the first to be directly calibrated using many dated fossils.

The research shows which whales are related and exactly how long ago every branch of the tree—whether extinct or still alive—first arose.

This new family tree allows the researchers to estimate: (1) how many species of baleen whale have existed, (2) similarities and differences between different lineages in terms of overall body shape, and (3) how fast baleen whales evolved at any chosen time over the last 40 million years.

“We find that the earliest baleen whales underwent an adaptive radiation, or sudden ‘evolutionary burst’, similar to that of ‘Darwin’s finches’ on the Galapagos Islands,” says Professor Fordyce.

Dr Marx adds that this early phase of whale evolution coincided with a period of global cooling. At the same time, the Southern Ocean opened, and gave rise to a strong, circum-Antarctic current that today provides many of the nutrients sustaining the modern global ocean.

The researchers found that during their early history, whales branched out into many different lineages, each with a unique body shape and feeding strategy.

“Rather surprisingly, many of these early whales were quite unlike their modern descendants: Although some had baleen, others had well-developed teeth and actively hunted for much bigger prey than is taken by modern species,” says Professor Fordyce.

Yet, after a few million years of co-existence, the toothed ‘baleen’ whales disappeared, leaving behind only their filter-feeding cousins, he says.

That extinction occurred between 30 and 23 million years ago and was about the time that the circum-Antarctic current reached its full strength, providing more nutrients that made filter feeding a more viable option.

The researchers say that the toothed ‘baleen’ whales disappeared perhaps because of increasing competition from other newly evolved toothed marine mammals, such as dolphins and seals.

They found that filter-feeding whales remained successful and diverse until about 3 million years ago, when the number of lineages suddenly crashed.

“This decline was driven mainly by the disappearance of small species of baleen whale, which left behind only the giants—ranging from 6 to as much as 30 metres—that plough the ocean today,” says Dr Marx.

He says the disappearance of small whales likely resulted from the onset of the ice ages, which altered the distribution of available food, caused shallow water habitats to shift or sometimes disappear, and created a need for long-distance migration between polar feeding grounds and equatorial breeding grounds.

“This behaviour—long distance-migration—is still one of the hallmarks of all baleen whales alive today,” notes Professor Fordyce.

See also here. And here.

Penguins and taste, new research


Thuis video is called Funny and cute penguin videos compilation.

From the Australian Broadcasting Corporation:

Poor taste penguins lack umami gene

Rachel Sullivan

Tuesday, 17 February 2015

Penguins can’t appreciate the delicate flavours of the seafood they catch thanks to a lack of taste.

New research published today in Current Biology reveals that penguins don’t have the genes that encode three of the five basic tastes – sweet, bitter, and umami (a savoury flavour), although they are genetically capable of detecting salty and sour tastes.

The study, led by Dr Huabin Zhao from Wuhan University, looked at the recently sequenced genomes of Adelie penguins (Pygoscelis adeliae) and emperor penguins (Aptenodytes forsteri) and 14 other bird species.

They found that while many other birds, such as chickens, finches and Amazon parrots have also lost the ability to taste sweet flavours, unlike penguins they are still able to detect bitter and umami tastes.

“Our results strongly suggest that the umami and bitter tastes were lost in the common ancestor of all penguins, whereas the sweet taste was lost earlier,” explains study co-author Dr Jianzhi Zhang from the University of Michigan.

He says it’s a puzzling finding.

“Penguins eat fish, so you would guess that they need the umami receptor genes, but for some reason they don’t have them.”

Adding to the puzzle is that taste is a powerful indicator of whether a potential food item is good enough to eat.

“In general, a sour taste helps detect spoiled food and bitter taste helps detect toxic food,” Zhang says. “Presumably, penguins cannot use taste to detect toxins … but we don’t know if penguins have other means of detecting toxins.”

Temperature sensitivity

Zhang says that while the research team doesn’t yet have a definitive answer to why penguins are so lacking in taste, they do have some ideas.

Penguins evolved in the chilly Antarctic, and the taste receptors for sweet, umami and bitter tastes (but not salty or sour tastes) are inactive at lower temperatures. It is likely that since they wouldn’t have worked anyway their loss along the evolutionary pathway would have had minimal impact.

Many species of penguins have since spread out into warmer climates. However, Zhang says “if ancestral penguins had lost the receptor genes for the three tastes while in the Antarctic, the genes and tastes cannot be regained even when some migrated away.”

In addition, anatomical studies have shown that penguin tongues seem to lack taste receptors – even for salty and sour flavours. Instead they are covered in stiff, horny bristles designed to help catch and hold their slippery prey, which they then swallow whole, so they may not have much interest in how their food tastes anyway.

But Zhang says he is not sure that penguins completely lack taste buds pointing to the possibility that they yet might be found in the tissues of the pharanx or elsewhere in the palate.

Sweet exception

Interestingly, in nectar-loving hummingbirds that have also lost the genes encoding sweet receptors, the umami receptor has been repurposed to detect the sweet tastes of the food source they depend on.

Zhang says that a similar repurposing hasn’t happened in penguins.

“The sweet and umami receptors have a common ancestry and are similar in structure so it is possible for the hummingbird umami receptor to be repurposed to detect sweet,” he says.

“However, the sour and salty receptors are structurally completely different from sweet and umami receptors: There is no way that they can be repurposed to sense sweet or umami.”

Where to see penguins: around the world in 17 species. Mike Unwin reveals where to see penguins, from Australia to South Africa and Patagonia: here.

SCIENTISTS FIND SIXTH ‘TASTE’ Fat now joins the ranks of sour, sweet, salty, umami and bitter. [WaPo]

South Georgia pipit comeback


This video says about itself:

Dreaming of the South Georgia Pipit

3 August 2011

Lindblad Expeditions-National Geographic guests on the search for the only songbird to live below the Antarctic convergence.

From Wildlife Extra:

Rare pipits return following rat eradication on South Georgia

The world’s most southerly song bird, the South Georgia Pipit, is fighting back from extinction thanks to work carried out by an 18-strong international team to eradicate rats from its island home in Antarctica.

Just as the final phase of the world’s largest rodent eradication project was being undertaken by UK charity, the South Georgia Heritage Trust (SGHT), news came that a nest of five South Georgia Pipit chicks had been found in an area previously overrun by rats.

The South Georgia Pipit is only found on South Georgia and its numbers had been decimated by the invasive rat populations on the island. Its survival as a species was under threat before the eradication work began.

The discovery of the pipit nest was made at Schlieper Bay near the western end of the island by a former member of the rat eradication team, Sally Poncet, an expert on South Georgia’s wildlife and this year a recipient of the Polar Medal in recognition of service to the United Kingdom in the field of polar research.

Poncet was a member of what has been nicknamed Team Rat during its Phase 1 operations. She discovered the nest while on a Cheesemans’ Ecology Safaris expedition (in collaboration with the Government of South Georgia) to survey Wandering Albatrosses.

Alison Neil, Chief Executive of South Georgia Heritage Trust says, “The discovery of pipit chicks is thrilling news and shows the rapid beneficial effect of the Habitat Restoration Project on this threatened species.

“People had spotted pipits exhibiting breeding behaviour following the baiting work, but this is the first firm proof that they are nesting in areas from which they were previously excluded by rodents.

“Pipits cannot breed when rats are present, so this discovery is confirmation that birds are quickly responding to their absence.

“We are confident that when South Georgia is once again free of rodents, it will regain its former status as home to the greatest concentration of seabirds in the world.”

South Georgia is one of the world’s last great wilderness areas and amongst the wildlife on the island are 90 per cent of the world’s Antarctic fur seals and half the world’s elephant seals.

Four species of penguin nest on the island, including King Penguins with around 400,000 breeding pairs. The island’s birdlife includes albatross, skuas and petrels, as well as the endemic South Georgia Pipit, and the South Georgia Pintail.

However, although the wildlife is impressive, it is a shadow of the numbers Captain Cook encountered when he discovered and named South Georgia in 1775.

Rats and mice, arriving in the ships of sealers and whalers, have spread over much of the island, predating on the eggs and chicks of many of the native birds.

The aim of SGHT’s project is to eradicate these invasive rodents and allow millions of birds to reclaim their ancestral home.

A successful trial phase in 2011 was followed by a second phase conducted in 2013. The results have been signs of rodents having been eliminated from almost two-thirds of South Georgia.

Phase 3 began on 18 January. The challenge is to complete the baiting of the entire island during the brief sub-Antarctic summer months and this will be followed by two further years of monitoring by the South Georgia Heritage Trust and the South Georgia Government.

Assuming no signs of rodents have been discovered by 2017, South Georgia will be declared free of rodents for the first time since humans first came to the island.

Rare birds return to remote South Georgia island after successful rat eradication programme: here.

Fish under Antarctic ice discovery


This video is called Antarctic Fish.

From Smart News blog in the USA today:

Fish Live Under Antarctica’s Ice Shelf, Where It Seems They Shouldn’t Survive

Biologists expected the seafloor under a glacier to be nearly barren, until life swam into view

By Marissa Fessenden

SMITHSONIAN.COM

This month, a National Science Foundation-funded expedition began drilling through the Whillans Ice Stream, a glacier that flows from the West Antarctic Ice Shelf to the Ross Ice Shelf. The team wanted to see how the ice was faring and responding to climate change, so they drilled to the glacier’s grounding zone — where it leaves bedrock and meets the sea.

At that zone, the sea bottom looks bare and “rocky, like a lunar surface,” glacial geologist Ross Powell told Douglas Fox for Scientific American. They sent a little underwater vehicle called Deep-SCINI down the borehole to investigate. Its cameras would capture images of the rocks and sediment down on the sea floor. The researchers took sediment cores and seawater samples, which betrayed only the presence of a few microbes — no sign of crustaceans or other life normally found at the bottom of the sea.

This wasn’t a surprise: Under 2,428 feet of ice and 528 miles from the edge of the ice shelf, the site is far from any hint of sunlight, the energy source that typically powers marine food webs. So the next thing they found was shocking.

The ROV had paused while technicians adjusted some controls (it was the bot’s maiden voyage) when they saw something through the down-looking camera. Fox writes:

A graceful, undulating shadow glided across its view, tapered front to back like an exclamation point—the shadow cast by a bulb-eyed fish. Then people saw the creature casting that shadow: bluish-brownish-pinkish, as long as a butter knife, its internal organs showing through its translucent body.

It was a fish. About 20 to 30 fish visited the ROV that day, perhaps attracted to light. And that wasn’t all. Two other kinds of fish, shrimp-like crustaceans and few other invertebrates were also spotted.

“I’ve worked in this area for my whole career,” Ross says. “You get the picture of these areas having very little food, being desolate, not supporting much life.”

The food web down there is still unknown. “Food is in short supply and any energy gained is hard-won,” says Brent Christner, a microbiologist from Louisiana State University. “This is a tough place to live.” Without sunlight, the scant microbes there might be relying on chemical energy — minerals delivered by the moving ice above, currents traveling long distances or seeping up from sediments. “The lack of mud dwellers might indicate that animals living this far under the ice shelf must be mobile enough to follow intermittent food sources from place to place,” writes Fox.

Answering where food comes from is just the beginning of a long list of questions for this chilly, dark underwater community. But for now, the discovery proves yet again that life can eek out in the most remote, unexpected places.

Japanese whaling stops, temporarily


This video is called Close Encounter with Minke Whale in Antarctica.

From Wildlife Extra:

Reduced Japanese whaling fleet departs to conduct scientific studies

A smaller than usual Japanese whaling fleet recently left port in Shimonoseki to carry out research in the Antarctic – but no whales will be harpooned after the World Court ruled last year that Japan’s ‘scientific’ whaling in the Southern Ocean was illegal.

Japan’s Fisheries Agency announced that a reduced number of boats will instead head to the Antarctic to carry out sighting surveys, biopsy work and photo identification of whales led by the country’s Institute of Cetacean Research.

Two catcher boats, without their harpoons, departed first and will be joined by Japan’s factory ship, the Nisshin Maru, which sets off on 16 January, for the non-lethal research which is expected to last until 28 March.

An International Court of Justice (ICJ) ruling in March 2014 ensured that for the first season in more than a century, whales in the Southern hemisphere were not be hunted for commercial purposes.

However, despite its initial vow to abide by the ICJ decision, and current moves to carry out non-lethal research, in November last year the Japanese government revealed details of a new proposal, called NEWREP-A, which would see 333 minke whales harpooned in the name of science in the Southern Ocean from later this year. Conservation organisations have urged Japan to withdraw this proposal.

Patrick Ramage, Global Whale Programme Director for the International Fund for Animal Welfare, says: “While we congratulate Japan on its shift towards humane, non-lethal research on whales and welcome the fact that no whales will be slaughtered in the Southern Ocean this season, sadly Japan has not discarded its harpoons for good.

“Japan’s new whaling plan fails utterly to meet the standard established by the World Court or to live up to the earlier rhetoric of Japanese officials. Japan needs to acknowledge that its cruel and unnecessary whaling must stop once and for all.”

Japan’s new whaling plans are set to be examined by the Scientific Committee of the International Whaling Commission (IWC) when it meets in San Diego in the US in May. The IWC strongly backed the ICJ ruling when member countries met in Slovenia in September.

Antarctic gentoo penguins, video


The Cornell Lab of Ornithologyy in the USA writes about this 4 December 2014 video:

December is just about the warmest time of year for a Gentoo Penguin, and time for them to get busy raising chicks amid the rock and ice of Antarctica and its islands. Watch this video and enjoy a penguin‘s eye view of a breeding colony on the Antarctic Peninsula.

Stay Tuned: After the holidays, join us for two special live-streamed video conversations with scientists at a penguin colony in Antarctica. They’re scheduled for Jan. 29 and Feb. 3 (weather depending). Bookmark this link, and we’ll have more details for you in January.

Antarctic colossal squid examined in New Zealand


This video from New Zealand says about itself:

Scientists latch on to colossal squid

Huge specimen caught in Antarctic waters by New Zealand fishing crew is one of few ever examined

16 September 2014

The live stream begins at 06:57: here.

Te Papa has a new colossal squid!

Watch live online as specialists in squid biology from Te Papa and Auckland University of Technology undertake research on this rare find. This colossal squid and the specimen already on display at Te Papa are the only two of their kind caught intact – ever! Large colossal squid specimens in good condition are rarely available to scientists, so this latest example has caused great excitement.

Ask our squid scientists:

Email sciencelive@tepapa.govt.nz with your questions for our squid scientists, or add them in the comments area below. We’ll answer them during the live show.

For regular updates and the latest on the colossal squid, follow:

Colossal squid blogs: www.blog.tepapa.govt.nz/category/colossa­l-squid

See also here.