Last woolly mammoths, 4,000 years ago


This August 2014 video from London, England says about itself:

The last of the mammoths | Natural History Museum

Why did the woolly mammoth go extinct? Museum mammoths expert Professor Adrian Lister discusses what his research reveals about the cause. Find out more about Museum research into the last major extinction of large mammals.

From the University of Helsinki in Finland:

The last mammoths died on a remote island

October 7, 2019

The last woolly mammoths lived on Wrangel Island in the Arctic Ocean; they died out 4,000 years ago within a very short time. An international research team from the Universities of Helsinki and Tübingen and the Russian Academy of Sciences has now reconstructed the scenario that could have led to the mammoths‘ extinction. The researchers believe a combination of isolated habitat and extreme weather events, and even the spread of prehistoric man may have sealed the ancient giants’ fate. The study has been published in the latest edition of Quaternary Science Reviews.

During the last ice age — some 100,000 to 15,000 years ago — mammoths were widespread in the northern hemisphere from Spain to Alaska. Due to the global warming that began 15,000 years ago, their habitat in Northern Siberia and Alaska shrank. On Wrangel Island, some mammoths were cut off from the mainland by rising sea levels; that population survived another 7000 years.

The team of researchers from Finland, Germany and Russia examined the isotope compositions of carbon, nitrogen, sulfur and strontium from a large set of mammoth bones and teeth from Northern Siberia, Alaska, the Yukon, and Wrangel Island, ranging from 40,000 to 4,000 years in age. The aim was to document possible changes in the diet of the mammoths and their habitat and find evidence of a disturbance in their environment. The results showed that Wrangel Island mammoths’ collagen carbon and nitrogen isotope compositions did not shift as the climate warmed up some 10,000 years ago. The values remained unchanged until the mammoths disappeared, seemingly from the midst of stable, favorable living conditions.

This result contrasts with the findings on woolly mammoths from the Ukrainian-Russian plains, which died out 15,000 years ago, and on the mammoths of St. Paul Island in Alaska, who disappeared 5,600 years ago. In both cases, the last representatives of these populations showed significant changes in their isotopic composition, indicating changes in their environment shortly before they became locally extinct.

Earlier aDNA studies indicate that the Wrangel Island mammoths suffered mutations affecting their fat metabolism. In this study, the team found an intriguing difference between the Wrangel Island mammoths and their ice age Siberian predecessors: the carbonate carbon isotope values indicated a difference in the fats and carbohydrates in the populations’ diets. “We think this reflects the tendency of Siberian mammoths to rely on their reserves of fat to survive through the extremely harsh ice age winters, while Wrangel mammoths, living in milder conditions, simply didn’t need to,” says Dr. Laura Arppe from the Finnish Museum of Natural History Luomus, University of Helsinki, who led the team of researchers. The bones also contained levels of sulfur and strontium that suggested the weathering of bedrock intensified toward the end of the mammoth population’s existence. This may have affected the quality of the mammoths’ drinking water.

Why then did the last woolly mammoths disappear so suddenly? The researchers suspect that they died out due to short-term events. Extreme weather such as a rain-on-snow, i.e. an icing event could have covered the ground in a thick layer of ice, preventing the animals from finding enough food. That could have led to a dramatic population decline and eventually to extinction. “It’s easy to imagine that the population, perhaps already weakened by genetic deterioration and drinking water quality issues could have succumbed after something like an extreme weather event,” says professor Hervé Bocherens from the Senckenberg Center for Human Evolution and Palaeoenvironment at the University of Tübingen, a co-author of the study.

Another possible factor could have been the spread of humans. The earliest archaeological evidence of humans on Wrangel Island dates to just a few hundred years after the most recent mammoth bone. The chance of finding evidence that humans hunted Wrangel Island mammoths is very small. Yet a human contribution to the extinction cannot be ruled out.

The study shows how isolated small populations of large mammals are particularly at risk of extinction due to extreme environmental influences and human behavior. An important takeaway from this is that we can help preserve species by protecting the populations that are not isolated from one another.

Elephants, extinct and living, size comparison video


This 19 August 2019 video says about itself:

In this video we will compare the size of different elephants and mammoths, ranging from the living African bush elephant and Indian elephant to the extinct mammoths, from woolly mammoth to Palaeoloxodon namadicus.

See also here.

Elephant family in Kenya video


This 12 April 2019 video from Kenya about elephants says about itself:

Look at who our team spotted recently while out collecting data in Samburu National Reserve – Monsoon and her adorable calf! This little guy was seen suckling while in the company of his aunties – Hurricane and Tempest – and his cousin who is seen here pushing his way around. Monsoon, the matriarch of the Storms 2 herd, amazed researchers last year when she gave birth again for the first time in nine years to this feisty youngster. Footage: Tanya Onserio.

Donald Trump’s revenge on bald eagles


This 18 August 2019 video from the USA says about itself:

Trump Takes Revenge After Bald Eagle Attack

Trump takes revenge on animals after a bald eagle attack. John Iadarola breaks it down on The Damage Report.

“Mother Nature has it figured out. She’s designed a master scheme that connects plants and animals, all working in concert to keep every living thing in balance. Imagine a stack of dominoes—knock down one of them, and the rest will tumble. The same can happen in nature.

This is especially evident in places like central Africa and in South American tropical rainforests where certain animals—from the world’s largest to its smallest—help keep trees safe and healthy, which is critical as trees absorb vast amounts of planet-warming carbon pollution.

Recent research warns that losing the creatures that nurture trees puts forests in danger. This, by extension, is helping to accelerate dangerous climate change.

In central Africa, for example, elephants eat fast-growing trees, making room for those that grow more slowly. The slow-growing trees—with their very dense wood—store more carbon than their thinner, faster-developing counterparts. Without elephants, more carbon would accumulate in the atmosphere, worsening climate change, according to a new study that used computer models to project what could happen if elephant populations continue to dwindle or become extinct.”

Read more here.

Baby elephants, BBC video


This 27 July 2019 video says about itself:

Baby Elephants are So Clumsy! | First Year on Earth | BBC Earth

Newborn elephants are the biggest babies on earth, in more ways than one.

The findings, published in the September issue of Ecology Letters, indicate how elephants employ a diverse array of strategies that they adjust based on ecological changes. In particular, poaching causes elephants to switch their movements. The study results indicate that landscape conservation efforts should consider the needs of the different tactics elephants display: here.

South African dung beetles, new research


This 2007 video says about itself:

African Dung Beetle | National Geographic

Sacred to ancient Egyptians, these beetles recycle – of all things – dung.

From the University of Würzburg in Germany:

How dung beetles know where to roll their dung balls

June 25, 2019

Summary: When the South African dung beetle rolls its dung ball through the savannah, it must know the way as precisely as possible. Scientists have now discovered that it does not orient itself solely on the position of the sun.

The South African dung beetle Scarabaeus lamarcki has — to put it mildly — an interesting technique to ensure its offspring a good start in life. When the animal, which is only a few centimetres tall, encounters elephant dung, for example, it forms small balls out of it which it then rolls away in a randomly chosen direction. After a while, the beetle stuffs the dung into underground passages, which serve as its breeding chamber; where it then lays its eggs.

How the dung beetle finds its way from the elephant dung pile to the underground passages: This is what Dr. Basil el Jundi is interested in. The neurobiologist heads an Emmy Noether Junior Research Group at the Biocentre of Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, and investigates the navigational ability of insects.

Together with scientists from Sweden and South Africa, he has now discovered that the dung beetle — contrary to previous assumptions — does not only orient itself on the position of the sun when navigating, but also includes information about wind direction in its route planning. The researchers have published their new findings in the current issue of the journal PNAS — Proceedings of the National Academy of Sciences.

On a straight line away from the dung heap

“South African dung beetles must roll their dung ball away from the dung pile as quickly as possible to prevent the ball from being stolen by other beetles,” explains el Jundi. To ensure that they actually get out of the dangerous area as quickly as possible, the beetles roll the ball away from the dung pile along a straight line. In order to keep their course, they use celestial cues as orientation references — for example, the position of the sun. However, it was not yet clear how the beetles find their way when the sun provides no useful information, for example when it is noon.

Basil el Jundi and his team can now answer this question: “We have discovered that dung beetles use the wind for orientation in addition to the sky.” The animals perceive the corresponding signals via their antennae. The necessary information is provided by high wind speeds, which occur in the African savannah especially around noon, when orientation by the sun becomes difficult.

The combination of the systems increases precision

However, to produce an efficient and robust “compass”, the animals must combine and harmonize the wind information with the other celestial signals. This is the only way to ensure that they find their way, even in a sudden calm, by flexibly switching back to the solar compass as the main orientation signal. As the researchers were able to show, this combination of different orientation systems not only makes it easier for the beetle to find its way, but it also increases the precision of the beetle compass.

For their study, the scientists worked within a laboratory arena in which they were able to simulate and control the position of the sun and the wind direction to precisely record their effects on beetle navigation. Their experiments not only show that the beetles set the wind directional information relative to the position of the sun. “We could also show that the beetles were able to transfer the directional information, which they have set with the sun as their only reference, to the wind compass,” says el Jundi. This shows that both the wind compass and the solar compass in the beetle brain “access” the same spatial memory network and therefore communicate with each other.

A highly plastic neuronal machinery

Thus, the recently published study shows that dung beetles use a much more dynamic compass than science has previously thought possible. The access to different sensory modalities enables the animals to navigate at any time with highest precision. Their abilities clearly exceed human abilities — even though they are equipped with a brain that is smaller than a grain of rice. In addition, the results confirm that an insect brain is not a “static substrate”, but a piece of a “highly plastic neuronal machinery that can adapt to its environment in a perfect way”, as the scientists write.