For thousands of years, humans have used names to communicate with one another. We also give names to animals, especially ones we love, such as pets. Until now there has been little evidence of animals naming one another, but a new study suggests that elephants use specific noises to identify other elephants.

A few animals, including parrots and dolphins, have been known to use sounds that are similar to names. Each dolphin invents a signature whistle that is unique to it, and other members of its species communicate with it by simulating this special call. The new study, led by Michael Pardo of Colorado State University, shows that wild African elephants use names in a way that is not just copying sounds and is much closer to the way humans use names.   

For the study, the researchers recorded 625 sounds made by wild African elephants in Kenya that they called "rumbles (隆隆声)”. This is the most common type of call produced by elephants, and it can travel long distances-as far as 3. 7 miles. It takes place at a very low frequency, which means humans can't hear it.

The researchers analyzed the sounds using computers and found that certain rumbles were directed at specific elephants to get their attention They found that all the elephants in the herd used the identical call to get a particular elephant's attention -these calls were not just nicknames used by one of the elephant's friends. Also. unlike the way dolphins communicate. the rumbles were not just imitations of the elephant they were trying to communicate with.

The researchers then played back some of the recorded rumbles to the elephants. They found that elephants responded more to their own name than to other calls. coming toward it more quickly or calling back faster. Cartlin O'Connell-Rodwell, an elephant expert, said, "The study shows that elephants can still keep in touch with one another even across a large area. "She told Live Science, "The rumbles ere magical, which allow them to spread out much further and still have very close tabs（密切关注） on individuals. "

For the first time, scientists have created baby mice from two males.

“It’s a very clever strategy,” said Diana Laird, a stem cell and reproductive expert at the University of California, San Francisco, who was not involved in the research. “It’s an important step in both stem cell and reproductive biology.”

Scientists described their work in a study published Wednesday in the journal Nature. First, they took skin cells from the tails of male mice and transformed them into “induced pluripotent stem cells,” which can develop into many different types of cells or tissues. Then, through a process that involved growing them and treating them with a drug, they converted male mouse stem cells into female cells and produced functional egg cells. Finally, they fertilized those eggs and implanted the embryos into female mice. About 1% of the embryos — 7 out of 630 – grew into live mouse pups.

The pups appeared to grow normally and were able to become parents themselves in the usual way, research leader Katsuhiko Hayashi of Kyushu University and Osaka University in Japan told fellow scientists at the Third International Summit on Human Genome Editing last week.

In a commentary published alongside the Nature study, Laird and her colleague, Jonathan Bayerl, said the work “opens up new avenues in reproductive biology and fertility research“ for animals and people. Down the road, for example, it might be possible to reproduce endangered mammals from a single male.

But they raised several cautions. The most notable one? The technique is extremely inefficient. They said it’s unclear why only a tiny fraction of the embryos placed into surrogate mice survived; the reasons could be technical or biological. They also stressed that it’s still too early to know if the protocol would work in human stem cells at all.

Three years ago, Nikki Robinson found a little raccoon (浣熊) by the road. She saved him and after a bunch of attempts at taking him to wildlife centers and vets, Nikki was disappointed in the lack of help. However, her mother Linda had experience in raising raccoons and after a little persuasion, took the little creature in.

They named him Little Hands and fell in love with the trash panda. Linda and Nikki fed him, raised him, and eventually let him go. To their surprise, Little Hands kept coming back, sometimes after a few days, sometimes a few months. He would come back and ask for hugs, food, and just love.

Little Hands was taken care of by Linda. He was released onto her large property and was allowed to come and go as he pleased. He was very fearful of any human or animal that he didn’t grow up with, but would come back to visit them most nights. Linda would leave food out for him every night and sit outside on the porch swing before bed, waiting for his visit. The first thing he would do is that he would climb over to Linda on the swing, sit beside her, and want pats from her.

“Little Hands stayed with us for about two and a half months before he was fully released into the wild. He has always been a calm, peaceful raccoon, very loving and compassionate, even as he matured. But still wild enough he thrives on his own,” Nikki said.

People asked Nikki what their reaction was when Little Hands returned to them. “Pure joy. And every time he came back it was a more and more joyous occasion especially because he wanted our attention as well as our food.”

At last, Nikki said: “Be kind. We share the planet with so many creatures that need to be respected. They are capable of complex social systems and emotions.”