Dolphins are universally regarded as some of the cleverest creatures in the world. In captivity (圈养), they can be trained to complete complex tasks such as jumping through hoops and somersaulting through the air.

But their intelligence doesn’t stop there. In a recent study of cetaceans (鲸目动物)—a group of animals that includes dolphins and whales—researchers created a list of intelligent behaviors observed in 90 different cetacean species, reported the Guardian. For example, the smartest cetaceans hunt in groups, share knowledge through mimicry (模仿) and even care for each other’s children. Some even consider their behavior to be human-like.

“There is the saying that ‘it takes a village to raise a child’ seems to be true for both whales and humans,” Michael Muthukrishna of the London School of Economics, co-author of the study, told the Guardian.

However, cetaceans don’t just use their brain power for survival. The study suggests that dolphins might even gossip. That’s because some species greet each other with specific whistles, just as humans greet each other by name, the Guardian reported. Sometimes, a group of dolphins whistles the “name” of a dolphin that isn’t there. Could they be speaking about their “friend” behind its back?

For the researchers, dolphin small talk is a big deal. As they found that the most social cetaceans also have the largest brains, they argue that cetacean intelligence developed to meet the demands of complex social groups.

Known as the “cultural brain hypothesis (假设),” it had only been used to explain the intelligence of humans and other primates (灵长目动物). The new study aimed to find a common pathway for the evolution of intelligence among biologically different species.

“It is interesting to think that whale and human brains are different in their structure but have brought us to the same patterns in behavior,” Luke Rendell, a biologist at the University of St Andrews, told the Guardian.

Indeed, we still have a lot to learn about our intelligent ocean-dwelling neighbors. “We don’t have to look at other planets to look for aliens,” Muthukrishna told the Guardian, “because we know that underwater there are these amazing species with so many parallels to us in their complex behaviors.”

Old dogs may not have an easy time learning new tricks, but it’s not a problem for cockatoos (凤头鹦鹉). In fact, researchers believe they teach one another. In Sydney, Australia, these birds have learned to lift the lids of rubbish bins. Then they can enjoy the treats inside. At first only birds in a few suburbs of Sydney could do the trick. But nearly two years later, the technique had spread to birds in 44 suburbs. Cockatoos proved to be smart birds and good learners.

Cockatoos are some of the most fascinating birds in the world. Members of the parrot family, they live in Australia and parts of Southeast Asia. Their striking good looks, intelligence and social nature make them popular pets.

One of the most distinctive features of cockatoos is the crest (羽冠) of feathers on their heads. The birds can raise or lower these feathers at will. If it is excited or scared, a cockatoo will raise its crest to show its emotions.

Cockatoos have powerful beaks (喙) that they use to open seeds and nuts—or rubbish bin lids. They are also versed in using tools. In the wild, some cockatoos use sticks to get insects out of tree bark. Others use small stones to crack open hard-shelled nuts.

Cockatoos are also very social. In the wild, they form large flocks of up to several hundred individuals. They make different sounds to communicate with one another. They engage in playful behaviours such as dancing and cleaning each other’s feathers.

As pets, the birds can form strong bonds with their owners and be entertaining companions. But cockatoos can be challenging pets to keep. They require a lot of attention and social interaction. If they don’t get it, they can become bored and destroy things. Cockatoos live long lives—around 70 years—making keeping one a serious responsibility.

Rather than committing to caring for one at home, enjoy the birds in the wild. Who knows what trick they will learn next!

As a species,ginkgo(银杏）trees, which enjoy a reputation as "The Tree that Time Forgor", have existed relatively unchanged for 200 million years.While scientists have revealed the mysteries of the tree's long life, it won't help humans soon.

Scientists in China examined the genetic component of very young ginkgo trees,comparing samples between several hundred and a thousand years old.【小题1】The scientists also found that, unlike other plants, ginkgo genes with regard to aging do not automatically become active at a certain stage in their life cycle.【小题2】This explains why old ginkgo trees produce as many seeds as young ones and how they continue to grow wide for as long as they live.

Furthermore,ginkgo trees are born with protective biochemical characteristics,in the form of hormones, antioxidants, and bactericides.【小题3】Also, they have evolved adaptations that enable them to resist pests and climate extremes.

【小题4】Over time,weather and other factors limit upright growth and cause leaves to die.Yet,even as this aging occurs, the cell-reproducing system of the gingko tree remains active, maintaining healthy growth.Growth typically starts slowing down after 200 years, but the trees remain healthy.Each year, they renew their parts, adding new wood,leaves, roots, and reproductive organs.In theory,gingko trees should live forever.【小题5】