For many animals, an island can be a great place to live. Water all around keeps big predators away. But islands have their own dangers. Food and water are limited. A storm or volcano can easily wipe out a whole population or change the land in big ways. If a predator (like cats or rats) does arrive, there’s no escape. These challenges can cause island animals to evolve (进化) quite differently from their mainland ancestors (祖先). So, islands around the world are home to rare species found nowhere else.

The Galápagos are a group of small volcanic islands in the Pacific Ocean, 600 miles (966km) west of Ecuador. When these islands first erupted (喷发) from the sea, they were empty of life. Over time, plant seeds blew or drifted there. Birds arrived, bringing more seeds. Tortoises and iguanas (鬣蜥) floated over on logs.

When scientist Charles Darwin visited the Galápagos in 1835, he noticed something interesting. Many of the islands had similar animals—iguanas, land tortoises, small birds. But these animals were a bit different on each island. On one island, birds called finches had long, narrow beaks —right for catching bugs. But on the next island, the finches had short, strong beaks. That island had more seeds, and fewer bugs. Each type of finch had a beak that matched the most common food on its island. He found similar differences in the tortoises and iguanas.

After thinking about this for many years, Darwin’s observations led him to a startling new idea. He realized that each family of animals probably shared a common ancestor—the original birds or turtles who flew or drifted there. Gradually, as they spread to different islands, the young with traits that best suited the food on that island did better. But since each island was different, the birds or turtles on each island evolved slightly different traits. He called this idea “natural selection”.

Darwin’s idea explained more than just the Galápagos. It also explains why islands are so often home to unusual animals. Islands separate animals from others of their kind and present them with new challenges. Those animals that do best on an island many not be the same ones who did best on the mainland. So over time, they become different.

【推荐2】Born at the Beijing Zoo, China’s giant panda Yaya was taken to the Memphis Zoo in Tennessee, the United States in 2003 for a research project. In December 2022, the Memphis Zoo announced (宣布) that it would return Yaya to China. After finishing her 20-year loan period (租借期), China’s giant panda Yaya finally returned home from the US on April 27, 2023.

In January, visitors in the Memphis Zoo found that Yaya became bony, making many Chinese and animal lovers abroad worried about her health and life quality at the Memphis Zoo. China prepared to welcome back Yaya and experts from the Beijing Zoo arrived in the US in March to learn about her habits and feeding situation from the zoo staff members. Foreign Ministry spokesman Wang Wenbin said that the quarantine (检疫) and feeding places for Yaya were ready along with her feeding plans and medical care.

The news that Yaya is coming back to China has cheered up millions of Chinese people. By April 9, a topic about Yaya had received 250 million views. “Come home soon, YaYa. I’ll go to see you in the zoo even if I have to queue all day long!” an Internet user commented (评论) on Sina Weibo.

On April 27, Yaya arrived in Shanghai. Groups of people rushed to the airport to welcome Yaya. During the quarantine in Shanghai, the zoo prepared enough bamboo and foods for Yaya. Experts and carers took care of her 24 hours a day there. Yaya’s health was in stable (稳定的) condition. After finishing the quarantine, Yaya was safely transported to the Beijing Zoo on May 29. The giant panda, Yaya will spend her late years there and won’t meet the public recently.

【推荐3】Climate change (气候变化) has brought a serious warning to the living areas of the Siberian crane, increasing the need to better protect the birds and their migratory channels (迁徙路径), an expert said.

The Siberian crane breeds (繁殖) in northeast Siberia in Russia and flies to Poyang Lake for the winter in East China’s Jiangxi Province. About 95 percent of the birds spend the season in Poyang.

Qian Fawen, a research professor from the National Bird Banding Center of China, said that Poyang’s water levels decide whether it is suitable for the birds to live there. However, climate change has made the levels change often. “In some years, the lake experiences floods; in others, it experiences droughts. Both of these situations create food shortages in the cranes’ living area,” he said.

The Siberian crane is listed as seriously endangered on the International Union for Conservation of Nature Red List. “We need to protect their living area, which is mainly wetland, so that we can protect them,” Qian said.

In the recently announced National Action Plan for the Protection of Bird Migration Channels (2021-35), 1, 140 places in China were considered as important breeding grounds, wintering grounds and staying stops, including Poyang and the Yellow River wetland in Ningxia. The plan said that the government should watch and count the number of migratory birds and pay farmers for losses caused by the birds.

Since China joined the Ramsar Convention on Wetlands in 1992, it has designated (指定) 202,600 hectares of wetland as Wetlands of International Importance. They store and clean water, keep all kinds of living things, help store floods and prevent droughts. According to a plan announced by the central government in October, by 2025, China will have protected 55 percent of its wetlands.

After the Wetlands Protection Law, the nation’s first law to protect wetlands, was introduced on June 1, 2022, complete protection was strengthened. The law clearly explained what the government should do and introduced strict punishment for people who destroy wetland areas. It limits building at important national wetlands and it doesn’t allow harmful activities, including using them as farmlands, leaving wastewater everywhere, harvesting and fishing too much.

Key nature reserve management offices in China have reported more birds wintering in the nation’s wetlands, including some new rare kinds. ▲

【推荐3】Day by day, you are not a child any more. You become a stronger adult (成年人) as time goes by. But do you know what happens inside your body when you are growing up?

An adult has 206 bones (骨头), but a baby is born with around 99 more bones than an adult. Many of the bones are mainly made of cartilage (软骨). As a person grows, the cartilage in his or her body grows, too. Over time, most of it slowly turns into hard bones with the help of calcium (钙). This is called ossification (骨化). Ossification usually finishes when you are more than twenty. At that point, your bones are as big as they’ll ever be. Then your bones will grow much slower, or even stop growing.

Many of you want to grow tall, but do you know how you can grow tall before your bones stop growing? Here is some helpful advice for you.

•Pay attention to what you are eating. Have a lot of fruit and vegetables every day. Fruit and vegetables are rich in vitamins (维他命) and have little fat. Drink milk every day. Kids need calcium to have strong bones, and milk is rich in it.

•Have enough sleep. As we all know, sleep is very important to us. If we don’t have enough sleep at night, we may lose the chance of growing taller.

•Enjoy the sunshine. People can get vitamin D from sunshine. It can help our bones grow better.