This video shows two beavers washing their fur.
René Sluimer made the video in the Rhoonse Grienden nature reserve in the Netherlands.
This 2011 video says about itself:
The European beaver (Castor fiber) was hunted almost to extinction, both for fur and for castoreum, a secretion of its scent gland believed to have medicinal properties. However, the beaver is now being re-introduced throughout Europe. Several thousand live on the Elbe, the Rhône and in parts of Scandinavia. In northeast Poland there is a thriving community of Castor fiber. They have been reintroduced in Bavaria and The Netherlands and are tending to spread to new locations.
Translated from the Dutch ARK Natuurontwikkeling conservationists, 7 February 2016:
After more than two hundred years of absence about twenty years ago beavers emerged spontaneously in Limburg province. These were some individuals from Germany. Their number was too small, and mutual distance too large to form a viable population within the foreseeable future. Therefore thirty beavers were freed in the region between 2002 and 2004. There was enough habitat by river restoration and nature reserve management in the Meuse Valley. Meanwhile beavers live, with numbers estimated at five hundred animals, in nearly the whole of Limburg. In wet, wooded nature beavers play a key role.
This video says about itself:
Shared noses: Extinct wildebeest relative was remarkably dinosaur-like
5 February 2016
From the Christian Science Monitor in the USA:
Weird convergence: Extinct wildebeest cousin and dinosaur shared noses
Scientists discover two unrelated, extinct animals had the same strange nose.
By Eva Botkin-Kowacki, Staff writer February 5, 2016
You might not expect to find many similarities between a mammal and a reptile, particularly if they lived millions of years apart. But scientists have found that two such extinct beasts share a rare, distinctive facial feature.
An extinct relative of the wildebeest and a duck-billed dinosaur both had bizarre crests on their heads. But it wasn’t the protruding bump that has most intrigued scientists, it’s what they found beneath.
The bony crest is hollow, forming a trumpet-shaped nasal passage unlike any seen outside these two species. No other animal, living or dead, has been found with such a feature.
“We have an animal that its skeleton looks a lot like a wildebeest – it’s actually very closely related to modern wildebeests – but its face looks a lot more like something you would see if you went way back in time to the Cretaceous and looked at hadrosaur dinosaurs,” study lead author Haley O’Brien tells The Christian Science Monitor in an interview.
Rusingoryx atopocranion, the mammal, lived about 65 thousand years ago, during the late Pleistocene, while Lambeosaurine hadrosaurs, the dinosaur, lived closer to 65 million years ago, during the late Cretaceous – and yet both animals evolved the same strange nose.
And not only do their nasal passages look alike, she said, the feature also appears to develop the same way as the animals grow up from juveniles to adults, as a variety of fossils display.
“When I first saw the complete skulls, I was blown away,” vertebrate paleontologist David C. Evans, who was not part of the study, writes in an email to the Monitor. “The resemblance between Rusingoryx and some hollow-crested dinosaurs in the form of their nasal structures is truly striking, and there are clear parallels in how they evolved and grew. Both groups elongated their noses to such a degree that they evolved highly domed skulls to house their nasal passages on top of their heads, above their eyes.”
Different origins, same result
“It’s probably one of the best examples of convergence in large animals that I’ve seen in a long time,” Ali Nabavizadeh, a researcher in evolutionary biology and anatomy at the University of Chicago, who was not involved in the study, tells the Monitor.
One was a mammal and the other a reptile, and millions of years elapsed between their tenure on Earth, but still, these animals developed the same adaptation.
Convergent evolution occurs when two species along different lineages independently evolve the same, or similar, features for the same function. One example is how insects, birds, and bats can all fly.
Convergence typically occurs when different species face the same ecological pressures. So what did Rusingoryx and the hadrosaurs have in common?
Both animals were herbivores and lived in herds. Rusingoryx was a ruminant and hadrosaurs have been called the cows of the Cretaceous, but the similarities, besides the shared nose, stop there.
Rusingoryx lived on the savanna, a dry wide open plain, while Lambeosaurine hadrosaurs were thought to have lived in a tropical rainforest.
Understanding this mysterious convergence might hinge on the purpose that these strange nasal passages served.
Without looking inside the animals’ skulls, the crest might appear to be simply for visual display or some other external use.
“We have known for decades that visual display and physical combat have strongly shaped skull evolution in many groups of animals with elaborate horns and crests,” Dr. Evans says. But the long, trumpet-shaped interior suggests a more complex purpose.
The hollow cavity, part of the respiratory tract, loops up over the animal’s head and seems to connect to the vocal tract.
To determine the purpose behind this strange nose, scientists focused on the mammal’s living cousins, wildebeests and antelopes. While researchers can look at their soft tissue for clues, all that’s left of the dinosaurs is bone.
The unusual nose could have helped the animals smell, bugle, or even regulate their temperature, Evans says. “The case for vocalization as the primary function of the nasal dome in Rusingoryx is by far the most convincing, as the authors advocate.”
The Rusingoryx are very social, says Ms. O’Brien. “They live in herds and they use a lot of vocal signals to communicate. When we looked into the function of what this skull type might be doing in Rusingoryx, we really couldn’t prescribe a function outside of that social vocalization.”
“There are obviously a lot of things that animals do with their faces,” she says. “But we don’t think that this crazy nasal dome would have really changed those more normal functions for this animal. We think that it was using the nasal crest to modify the way that it’s producing these vocalizations and communicating.”
That makes sense, says Thomas E. Williamson, curator of paleontology at the New Mexico Museum of Natural History and Science, who was not part of the study.
“When you have any kind of a tubing, it becomes naturally resonant,” he explains. “So the idea that it’s being used somehow to amplify certain frequencies of sound, it will do that,”
Not your average moo
O’Brien and her colleagues suggest that Rusingoryx, and perhaps the dinosaurs by extension, used this bizarre nasal dome to communicate at frequencies other animals cannot hear. This is called infrasound, and animals like elephants and cassowaries use it to communicate under the radar.
That’s possible, says Dr. Nabavizadeh. “If you have a very gregarious group of animals and they’re in a big arid, open environment, as these bovids are, then you are under the selective pressure to start to create more lower bellowing sounds that are possibly outside of the hearing range of carnivores, so they can communicate without being found in big open environments.”
But the environment doesn’t preclude the dinosaurs from needing this ability too, says Dr. Williamson. “Infrasound … is able to travel over great distances and open areas and in closed environments. It pretty much goes everywhere,” he says. And cassowaries, the living birds thought to communicate in infrasound, live in dense tropical rainforests.
This video, from Kruger National Park in South Africa, says about itself:
1 February 2016
This video is dedicated to Roger Gower, a man who was killed this week, while protecting our precious wildlife. With all the horrible poaching of rhinos that is currently happening, we thought we would cheer everyone up with a video that will make you feel overloaded with cuteness.
Video by: Simone
From Science News:
Removing worn-out cells makes mice live longer and prosper
Antiaging treatment shows promise for lengthening life span
By Tina Hesman Saey
1:00pm, February 3, 2016
Killing worn-out cells helps middle-aged mice live longer, healthier lives, a new study suggests.
Removing those worn-out or “senescent” cells increased the median life span of mice from 24 to 27 percent over that of rodents in which senescent cells built up normally with age, Mayo Clinic researchers report online February 3 in Nature. Clearing senescent cells also improved heart and kidney function, the researchers found.
If the results hold up in people, they could lead to an entirely new way to treat aging, says gerontology and cancer researcher Norman Sharpless at the University of North Carolina School of Medicine in Chapel Hill. Most prospective antiaging treatments would require people to take a drug for decades. Periodically zapping senescent cells might temporarily turn back the clock and improve health for people who are already aging, he says. “If this paper is right, I believe it will be one of the most important aging papers ever,” Sharpless says.
Senescent cells are ones that have ceased to divide and do their usual jobs. Instead, they hunker down and pump out inflammatory chemicals that may damage surrounding tissues and promote further aging. “They’re zombie cells,” says Steven Austad, a biogerontologist at the University of Alabama at Birmingham. ”They’ve outlived their usefulness. They’re bad.”
Cancer biologist Jan van Deursen of the Mayo Clinic in Rochester, Minn., and colleagues devised the strategy for eliminating senescent cells by making the cells commit suicide. A protein called p16 builds up in senescent cells, the researchers had previously discovered. The team hooked up a gene for a protein that causes cells to kill themselves to DNA that helps turn on p16 production, so that whenever p16 was made the suicide protein was also made.
The suicide protein needs a partner chemical to actually kill cells, though. Once mice were a year old — 40 to 60 years old in human terms — the researchers started injecting them with the partner chemical. Mice got injections about every three days for six months. Mice that got the cell-suicide cocktail were compared with genetically engineered mice that were injected with a placebo mix.
Senescent cells were easier to kill in some organs than others, the researchers found. Colon and liver senescent cells weren’t killed, for instance. But age-related declines in the function of organs in which the treatment worked — eyes, fat, heart and kidney —were slowed.
Genetic engineering and regular shots would not be feasible for use in people, but several companies are developing drugs that might clear the zombie cells from humans, Austad says. Some side effects to the treatment in mice also would be important to consider if those drugs are ever used in people. Senescent cells have previously been shown to be needed for wound healing, and mice that got the killing cocktail couldn’t repair wounds as well as those that didn’t get the treatment. Once treatment stopped, the mice were able to heal normally again. That result suggests that people undergoing senescent-cell therapy might need to stop temporarily to heal wounds from surgery or accidents.
Previously, the researchers had killed senescent cells in mice with a mutation that caused them to age prematurely (SN: 12/3/11, p. 11). Removing the worn-out cells helped the prematurely old mice live longer, but other researchers weren’t convinced that the results applied to normal aging. “It’s great when you find something that helps prevent premature aging, but there’s always this nagging doubt,” says Judith Campisi, a researcher at the Buck Institute for Research on Aging in Novato, Calif. It’s gratifying that the treatment works to extend life and health in normally aging animals, she says.
Campisi also studies the effect of senescent cells on aging, but doesn’t think the cells are entirely to blame for the ills of old age. “We don’t believe senescence is the only thing that drives aging,” she says. “That would be stupid. If this were the magic bullet, Jan’s mice would live forever, but they don’t.”
This video from the USA says about itself:
3 February 2016
Will this jaguar ever find a mate? The US-Mexican border wall started by George W Bush which damages wildlife will make that problematic. One should hope Donald Trump’s plan for a still bigger wall will never become reality.
Wildlife Extra writes about this video:
Drone footage captures rare sight of endangered blue whale mother and calf
“Filming this endangered blue whale and her calf with a drone was unbelievable,” drone pilot Gavin Garrison said in a statement.
“Spotting a blue whale from the deck of the Steve Irwin is a thrill, but being able to film the biggest animals on the planet from the air is truly awe-inspiring.”
Blue whales occur worldwide including Arctic and Antarctic waters, and are famously the largest animals known to ever live, with a maximum length of 32 metres and a weight of up to 181,437 kilograms.
The calves are eight metres long and weigh four tonnes at birth, and wean off their mothers after seven to eight months once reaching 15 metres in length.
Sea Shepherd did not estimate the size of the pair encountered by the Steve Irwin.
The species has been classified as endangered on the International Union for Conservation of Nature (IUCN) red list of threatened species since 1986.
However, the IUCN recommends listing the Antarctic subspecies separately as critically endangered due to the size of population loss over the past century.
The last population census used by the IUCN lists the Antarctic population at about 1,700 in 1996 and growing at 7.3 per cent every year.
The IWC granted protection to blue whales by 1966 before the total whaling ban in 1986, and says that despite continued whaling by Iceland, Norway, Japan and the Russian Federation, no blue whales have been recorded deliberately caught since 1978.
The World Wide Fund for Nature estimates the total global population at between 10,000 and 25,000.