Cambrian prehistoric predator evolution, new research


This video says about itself:

26 March 2014

T[amisiocaris]. borealis, an ancient predator, probably used its spiny appendages to sweep through the water for prey and then bring it into its mouth, as these animations show. Credit: Martin Stein. Read more here.

From Wildlife Extra:

Large ocean predators evolved into gentle giants 520 million years ago

April 2014: Large marine creatures that roamed the Earth’s oceans more than 520 million years ago have been found to filter food from the water in a similar way to today’s blue whales and evolved into a gentle sea giant from a large marine predator that feasted on large prey, say scientists.

Newly discovered fossils from North Greenland showed that these ancient giant marine animals used bizarre facial appendages to trawl for nekton and plankton from the seas.

The North Greenland fossil, called Tamisiocaris, was a member of the iconic anomalocarids group of early marine animals which roamed the Cambrian and later Ordovician oceans. They swam using a set of flaps down either side of the body and probably captured large prey with specialised grasping appendages in the front of the mouth.

The team demonstrates that the Tamisiocaris had evolved into a suspension feeder by modifying its grasping appendages into a filtering apparatus that could be swept like a net through the water trapping small crustaceans and other organisms as tiny as half a millimetre in size.

The research, funded by the Agouron Institute, Carlsberg Foundation and Geocenter Denmark, was led by the University of Bristol and also included researchers at Durham University, the University of Bath and the University of Copenhagen.

As well as shedding light on the evolution of the Tamisiocaris, the researchers said their discovery also showed how productive the Cambrian period was and how vastly different species of anomalocarids evolved at that time. It also provides further clues into the ecosystems that existed hundreds of millions of years ago, they said.

Study lead author Dr Jakob Vinther, a lecturer in macroevolution at the University of Bristol, said: “The fact that large, free-swimming suspension feeders roamed the oceans tells us a lot about the ecosystem.

“Feeding on the smallest particles by filtering them out of the water while actively swimming around requires a lot of energy – and therefore lots of food.”

In order to fully understand how an anomalocarid could have fed, Dr Martin Stein from the University of Copenhagen, Denmark, created a 3D computer animation of the feeding appendage to explore the range of movements it could have made.

Dr Stein said: “Tamisiocaris would have been a sweep net feeder, collecting particles in the fine mesh formed when it curled its appendage up against its mouth.

“This is a rare instance when you can actually say something concrete about the feeding ecology of these types of ancient creatures with some confidence.”

The research about this was published here.

April 2014: An international team of researchers from the US, China and the UK have discovered the earliest known cardiovascular system in fossilised remains of an extinct marine shrimp that lived over 520 million years ago. The finding sheds new light on the evolution of the body in the animal kingdom and shows that even the earliest creatures had internal systems that strongly resemble those found in their modern descendants: here.

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Greenland ‘Grand Canyon’ discovery under ice


This video from the USA is called Greenland Rocks, for Geologists.

From Reuters:

Giant Canyon Found Entombed under Greenland Ice

A vast and previously unmapped gorge 800 meters (half a mile) deep has been found under ice in Greenland, comparable in size to parts of the Grand Canyon in the United States, scientists said.

By Environment Correspondent Alister Doyle

OSLO – A vast and previously unmapped gorge 800 meters (half a mile) deep has been found under ice in Greenland, comparable in size to parts of the Grand Canyon in the United States, scientists said.

Other studies have also revealed a rift valley entombed in Antarctica‘s ice in 2012 that scientists said may be speeding the flow of ice towards the sea, and a jagged “ghost range” of mountains buried in Antarctica in 2009 similar to the Alps.

“It’s remarkable to find something like this when many people believe the surface of the Earth is so well mapped,” lead author Jonathan Bamber, of the University of Bristol in England, said of the canyon described in Friday’s edition of the journal Science.

“On land, Google Street View has photographed just about every building in every major city,” he told Reuters of the study, using ice-penetrating radar and carried out with colleagues in Canada and Italy.

The canyon is 750 km (470 miles) long in central and north Greenland and comparable in scale to parts of the Grand Canyon that is twice as deep – 1.6 km – at its deepest, they wrote. The Greenland canyon is buried under about 2 km of ice.

About as long as the Rhone river in France and Switzerland, the ravine was probably cut by an ancient river that eroded rocks as it flowed north before temperatures cooled and ice blanketed Greenland 3.5 million years ago, they wrote.

The gorge probably still plays a role in draining some meltwater from beneath the ice sheet.

ICE FLOWS

The scientists used airborne data collected mainly by NASA and by scientists in Britain and Germany to piece together maps of the canyon. At some frequencies, ice is transparent to radio waves that bounce off the bedrock.

Bamber said the gorge would help scientists refine models of how Greenland’s ice sheet slowly flows downhill but was unlikely to affect understanding of how global warming is melting ice.

“I don’t think it’s particularly influential” in determining the rate of ice flow, echoed David Vaughan of the British Antarctic Survey. He said the canyon was so deep under the ice that it was unlikely to be affected by any warming trend for many decades.

Vaughan led a four-year international study called ice2sea, which said in May that world sea levels could rise by between 16.5 and 69 cm (6-27 inches) with moderate global warming by 2100, partly because of a thaw of Greenland and Antarctica.

He told Reuters a few blanks remain on the map, including two areas of east Antarctica that scientists jokingly dub the “Poles of Ignorance”.

(Reporting by Alister Doyle; Editing by Alistair Lyon)

Northern light video


, who made this video, writes:

More details about the “making of” on newswatch.nationalgeographic.com/2013/06/18/how-a-stunning-aurora-video-was-made/.

The soft light of the arctic regions attracted me magically so that I decided to dedicate a project to it. Around the polar circle light occupies a very important role, especially in winter. During the freezing months the sun creeps only along the horizon providing thus long hours of this tender twilight that occurs before sunrise and after sunset. But the nights are even longer and then another special light brights up the sky: the aurora borealis. In this film I wanted to show how individual the northern lights are: they may dance very fast in a frenetic rhythm or explode in a red-purple firework or they may just glow greenish over the starry sky vaguely distinguishable by the human eye. Every night there is a different night show – if the polar lights appear as they use to be very shy divas.

As a non resident of the Arctic regions it was very difficult for me to hunt the northern lights. I travelled different times to the distant regions at the polar circle. It was not easy enduring the freezing temperatures and the darkness and sleeping in the tent or in the car when the harsh wind was shaking it too strong. But after a year I had the incredible luck to gather enough video material for this film project. Especially on my last trip to Tromsö in february 2013 I experienced incredible beautiful aurora borealis.

The footage was captured in Greenland, Norway (on the Lofoten islands and in the Troms region), Iceland and Finland.

The surreal atmosphere of the landscapes is emphasized thanks to the wonderful music of the talented and creative composer Pablo Garmón vimeo.com/pablojgarmon.

Visitors from Greenland and Togo, welcome!


About three months ago, I wrote a blog post about from which countries visitors had come to my blog, and about which countries were unrepresented so far.

Among those countries with no visits then were Togo in Africa; and Greenland.

This video is called Wild Greenland – home of musk oxen and arctic char.

This morning, WordPress stats say that the first ever visitor from Greenland has arrived. Yeseque, welcome!

This video is called Discover Togo.

Also, there have been two visits from Togo. Not today; I am not sure when. Bienvenu, welcome!

Bowhead whales songs’ discovery


This video is called Bowhead Whale Song.

From Wildlife Extra:

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.

Fram Strait

They have yet to learn why the whales sang so consistently last year. Scientists believe that bowhead whale song comes from males during mating season. In most other kinds of whales, individuals either sing the same song their whole lives or all members of a population sing the season’s same popular tune. If bowheads are like the former, that would mean more than 60 males were in the Fram Strait. If the population is evenly split between males and females, there could have been more than 100 whales — far more than anyone thought comprised this population.

With further study, the scientists instead could discover that individual bowhead whales have a repertoire of songs that they sing during a season. That would be equally interesting because it would make the bowheads the only known whales to sing a variety of songs in the same season. The findings also hint at the possibility of a rebound in bowhead whales.

“If this is a breeding ground, it would be spectacular,” said Stafford. “For such a critically endangered species, it’s really important to know that there’s a reproductively active portion of the population.”

In addition, since the whales are difficult to study given their year-round residence in the Arctic, virtually nothing was known about where they spend their winters. The research offers a clue about the whales’ migration path.

Just a few Bowhead whale populations left

Only a handful of bowhead whale populations remain. The largest historic population, which includes the individuals studied for this report, once possibly numbered more than 30,000 members but was hunted to near-extinction from the 1600s through the 1800s. Commercial whaling reduced bowhead whale populations in other regions as well; combined, the four remaining populations are thought to number fewer than 10,000 members.

Bowhead whales are massive creatures. They grow to over 60 feet long, may live to 200 years old and can weigh 200,000 pounds. They use their huge skulls to break through ice as thick as 1.5 feet.

Bowhead whale song is unique in that the whales appear to sing with “two voices,” simultaneously producing high- and low-frequency sounds. The whales sometimes repeat the same tune for hours at a time.

2000+ hours of recording

Stafford and her colleagues deployed the two hydrophones 60 miles apart. They made 2,144 hours of simultaneous recordings from September 2008 through July 2009. In order to conserve battery power and take recordings for a longer period of time, the hydrophones worked for nine minutes out of every half hour.

The hydrophone in the west, covered in dense ice and in colder water, picked up far more singing than the one in the east, where there was spotty ice coverage and warmer water. The greatest frequency of song occurred in the darkest, coldest period.

“It’s clear there’s a habitat preference,” Stafford said. The thick canopy of ice may provide better acoustics than the loose pack ice and therefore might be favoured by singing whales, she said.

“As Arctic sea ice declines, there may be some places like this that are important to protect in order to preserve a breeding ground for the bowhead whales,” Stafford said.

To answer new questions that the data opens up – including how many whales make up this North Atlantic population – Stafford hopes to do additional study.

Co-authors of the paper include Sue Moore and Catherine Berchok from the National Oceanic and Atmospheric Administration; Øystein Wiig of the University of Oslo; Christian Lydersen, Edmond Hansen and Kit M. Kovacs from the Norwegian Polar Institute; and Dirk Kalmbach with the Alfred Wegener Institute of Polar and Marine Research in Germany. The research was funded by NOAA and supported by the Norwegian Polar Institute and the Alfred Wegener Institute.

A paper detailing their discoveries appears Tuesday (July 31) as the feature article in Endangered Species Research and is openly accessible online.

Greenland lemmings, good for sanderlings


This video is called Zackenberg • Greenland.

Translated from the blog of Dutch biologists doing sanderling research near Zackenberg, Greenland; where there are are more lemmings this summer than usually:

All five [Arctic] fox dens in the research area are occupied and there are little foxes inside. In one den even seven baby foxes, a record. The long-tailed skuas also respond to the food bonanza this year, we have already found 11 nests and each of those contain two eggs, where only one egg per year is usual for these predatory gulls. We have also seen many long-tailed skuas tearing lemmings to pieces.

Good season

It promises to be a very good season with so many lemmings and, as a consequence, little predation of sanderling clutches.

This is a video in Dutch about ringing sanderlings in Greenland.

The surface of the Greenland ice shelf had a flash melting from July 8 to July 12. About 97 percent of the country experienced surface thawing, increasing from 40 percent over the span of four days. The last time such an event occurred was in 1889: here.

Greenland loses ice in fits and starts: here.

Everything You Need to Know About Arctic Sea Ice Melt, in One 10-Second Animated Gif: here.

Greenland sanderlings and muskoxen


This is a video of sanderlings and turnstones looking for food in the ice.

Translated from the blog of Jeroen Reneerkens and Stefan Sand, Dutch biologists now doing research about sanderlings in the Zackenberg area in north-east Greenland; where there is more snow now than usually in summer there:

These large amounts of snow have resulted this winter in many musk oxen dying. They were starving because they could not reach the plants which they feed on through the snow and ice. In the first week we found many carcasses, often eaten by arctic foxes and sometimes there we saw also ravens flying away.

Only near the research station there are quite a few snow-free places, and researchers, present there since the end of May have told me that sanderlings in the first weeks of June were present regularly between the wooden barracks of the station. Even a mating was observed from the window of one of the barracks, involving a bird which had been color ringed by me earlier.