The Amazon rainforest is a noisy place, with many different animals competing to make themselves heard, But who has won the corn petition? The male white bellbird may be the loudest bird on Earth.

According to a new study, the bird's all is twice as loud as the screaming piha (尖声伞鸟) The bellbird’s call is at least nine decibels (分贝) (dB) louder than that of the piha, and can reach 125 dB. That similar to what you'd hear standing next to speakers at a rock concert. Jeff Podos, an American biologist, and his teas published paper in the journal Current Biology. But they didn't set out to find the world’s loudest bird, Co-author Cohn-Haft brought a specimen (标本) of a male white bell bird back for his museum after a research trip.

Coin-Haft found male white bell bird had thick abdominal muscle (腹部的肌肉)―leading him to believe this had something to do with their loud calls, Discovering no one had published a study about bell birds, the team set out into the rainforest to record the sounds of male pihas and bell birds, female’s (雌鸟) don’t have loud voice at all.

They divided their calls into three types; the male pihas’call. The male bell birds’Type 1 song―which is quieter and longer and the male bell birds’Type 2 song, which is louder and shorter. The pihas calls proved to be the softest, and the typed bell bird calls the loudest. There’s a reason the Type 2 song is so simple and lasts for a very short time―reaching such high decibels takes n lot of strength.

The study finds the male may have developed this behavior to attract female. The louder birds are probably filter. It’s likely female use the loudness to judge the male, probably preferring louder male,

People are social creatures and we depend on our relationships with others for our health and happiness. While we can individually make efforts toward slow living, finally we need the support of others and community organizations to be successful. Slow Cities meet this need. Like Slow Food, the Slow Cities movement started in Italy. Its organization is known as Cittaslow, which has spread to about 30 other countries throughout the world since 1999.

Cittaslow has set up 50 goals and principles, which supports communities as they protect the environment and build upon their own special qualities reflecting their historical roots as well as their strong desire or ambition for the future. This is not about nostalgia and following tradition closely; rather it is a call to refuse the forces of the same types that result in every place looking and feeling like every other place. By gathering together with others who share the same opinions or interests, we can start to include new projects to further improve the quality of life in our communities by using our imagination.

The basic part of Slow Cities is the idea that our health and happiness partly depend upon a healthy connection to the people and place where we live. The growing Sunday Parkways movement is just one great example of an activity that combines many of the well-being goals for cities in a fun, healthy, and family-oriented way. The Cittaslow website is designed as a place where ideas like these can be explored and exchanged.

The Slow Cities movement is not just about improving the quality of life of the citizens; it also encourages communities to develop their friendly and generous behavior towards guests, offering them an organized event, for example, a concert, a sporting event so that visitors can go through what is different and special about the area, really learning about the local culture. Slow Cities invite people to slow down so that they can see and connect with the rich diversity of the world where they live as well as the diversity of the world around them.

Spider webs are made from silk. And silk is made from something scientists call “proteins”. Proteins are special chemicals made by a living thing like an animal or a plant. You have lots of them in your body. Your hair and your nails are made of proteins (they are both made by a protein called “keratin”). Insects and spiders make silk in a special part of their bodies called a gland (腺), and use their legs to pull it out of their bodies. This is called spinning. Most species of spider have more than one kind of silk gland. Each one has different strength and stretchiness and is used for a specific purpose such as web frame, or covering eggs. The strength and stretchiness of silk depends on the way the spider’s body arranges the silk proteins.

We don’t usually notice just how strong they can be because they are amazingly thin. But the strongest silk, such as silk from a golden orb spider, is actually stronger than steel. Even more amazing, it is about 50 times as light. Actually, spider silk is a bit like a cross between steel and rubber. Even with the help of complicated machines and chemicals, humans still don’t know how to make a material this strong, stretchy, and light. Spiders are still the champions at this.

In fact, silk-making animals include crickets, glow-worms, ants, bees, etc. Some of these make silk to protect themselves. Crickets, for example, use silk to sew leaves together to build a nest. Some use silk for hunting, such as spiders and even glow-worms, which use sticky silk to capture flying animals they’d like to eat.

Studies about spider webs could pave the way for creating new materials that could be used in medicine and engineering. But synthetic (人工合成的) spider silk has been difficult to create. In the meantime, researchers hope their work will help us unreel one of the toughest materials of the natural world.