4 . Everyone wants to be nice to their own pets! Here are a few tips.

Feed them not too little, but not too much either. You have to tell the difference between the times they’re hungry and the times they’re just trying to get food. Clean their food and drink bowls at least once a day.     1    You wouldn’t eat off the same plate for one whole week or drink out of the same glass for a month!

    2    Pets want as much of your attention as possible, dogs especially. In general, admit your pets’ existence; even say “Hi, how are you doing?” Clearly they won’t understand what you’re saying, but it shows that you care for them.

Take dogs on walks. Most dogs don’t like to be kept in a house all day long.     3    They can also meet other dogs this way. Dogs like the company of other dogs.

Take them to the vet regularly. Your pet may not like it.     4    Reward it once in a while and he will be happy with what he gets.

If you had to take your dog to the hospital, he might be afraid of riding in cars.     5    Your dog will finally realize that not all car rides end at the hospital.

5 . Dogs, more so than almost any other domestic pets, are desperate for human eye contact.     1    and according to a new study, that pull on the heartstrings might be exactly why dogs can give us those looks at all.

    2     Studying the two animals is a bit like cracking open a four-legged time capsule. A paper published in the Proceedings of the National Academy of Sciences found that dogs’ faces are structured for complex expression in a way that wolves’ aren’t.

For the study, a team looked at two muscles (the RAOL and LAOM muscles) that work together to widen and open a dog’s eyes, causing them to appear bigger and more lovely, which we read as distinctly humanlike. The muscles for two short, straight lines, which connect the ring of muscle around a dog’s eye to either end of the brow above.     3     Therefore, they concluded that the origin of these complex facial expressions is after dogs splitting from wolves. Research has also shown that when dogs work these muscles, humans respond more positively. This isn’t simply a coincidental love story, in which the eyes of two species just so happen to meet across a crowded planet.     4     

For a species to change quickly, a pretty powerful force must be acting on it.     5     .We connect more deeply with animals capable of making humanlike facial movements, so dogs have evolved to look like our own human babies to be selected for adoption.

6 . Wildlife Crossing Bridges

The Wildlife Bridge

In 2018, Utah built a wildlife bridge over the busy highway 1-80. A 4.8-kilometer fence was created to help guide animals to the bridge. Normally, animals take a long time to discover and begin using wildlife bridges, so experts didn’t expect the bridge to get much traffic for several years. But recently, they’ve discovered many different kinds of animals are beginning to move by using the bridge.

The Rope Bridge

On China’s Hainan Island in 2015, scientists created a bridge for Hainan gibbons that are the world’s most endangered primates and normally cross the forest by swinging high in the trees. But after a 2014 typhoon, landslides caused huge gaps in the forest, which were forcing the gibbons to make dangerous jumps. Scientists created a simple and cheap rope bridge, which settled the problem.

The Eco-Bridge

In Uttarakhand state in India, the forest department has built a special "eco-bridge" , made from all-natural materials. It’s 27.5 meters long and runs over one of the busiest highways in the area. Though the bridge is high in the trees, forest department workers hope the bridge will help smaller animals on the ground, too. Already, the bridge has gotten a lot of attention on the Internet, with many people taking photos in front of it every day.

The Park Bridge

The Phil Hardberger Park lies in San Antonio, Texas, and recently it has opened what they say is the largest wildlife bridge in the US. This bridge, unlike the others mentioned here, was built for use by both animals and humans. The park says they have already seen deer using the bridge.

7 . Just like humans, birds too rely on sound to communicate. However, they do not have a “language” in the true sense of the word and instead produce a variety of sounds to convey different emotions.

Often, birds recognize their mates(or young) by sound rather than sight. Hungry young birds use begging calls to let their mothers know it is feeding time. Alarm calls, flight calls and warning calls are other sounds made frequently by adults.

A new study shows that songbirds rehearse(排演) their songs even in their sleep. The activity in the brain of the birds when asleep is similar to the brain activity when the birds were awake and singing. The team used tiny recording devices to measure the activity of individual brain cells in four songbirds both when they were singing and when they were asleep.

Apparently the bird stores a song after hearing it, and then rehearses it later in its sleep. Scientists now believe the birds “dream of songs and tunes” to help them master the fine art of singing and that sleep plays a key role in the learning process!

Many songbirds learn to sing listening to adult birds of the same species. However, if separated from the adults, the young birds develop sounds which are hard to understand instead of normal song patterns. Researchers carried out an experiment in which a male bullfinch (灰雀) was raised by a female canary(金丝雀). The bullfinch soon learned the canary’s song and when it was later mated to a female bullfinch, Mr.Bullfinch taught his children the canary’s songs.

Last year, a British survey of London’s songbirds showed that the city’s birds are losing their tunes. Birds could hardly hear one another, over the traffic noise; as a result, instead of copying the sweet notes of the adults, young birds were copying the sounds they heard most often, namely car horns and beeping cellphones!

8 . Tracking wildlife is a tough job. Take the case of a one-eared leopard named Pavarotti.

Kasim Rafiq, a wildlife biologist at Liverpool John Moores University. “So I used to get up at the crack of dawn, follow his tracks and try and find him. So one day, I went out, and I was looking for him. And his tracks took me off road through this woodland area...and...”

Before he knew it, the wheel of his Land Rover was stuck in a deep hole. He wasted several hours getting it out. And then, on the way back to camp, he came across some local tour guides and their safari (观赏野兽的旅行) guests, who’d had way better luck spotting Pavarotti. “Basically, they laughed and they talked to me that they’d seen him that morning.”

Rafiq then realized that tourist wildlife sightings might be an untapped source of information about wild animals.

So he and his team worked with a safari lodge in Botswana to analyze 25,000 tourist photographs of wildlife. They compared those data to the estimates they made with traditional wildlife biology methods.

It turned out that the estimates from tourists’ photos were just as good as those gleaned (四处搜集) from traditional methods. And the tourists were actually the only ones to see elusive (难以捉摸的) leopards — the researchers would have missed the cats without the citizen science data. The results are in the journal Current Biology.

The idea is not to put wildlife researchers out of a job. “The reality is there are so many interesting things we still have to find out about these large carnivores (食肉动物) and so many conservation (保护) projects that need to be carried out that we don’t have the time or resources to do them all.” And tourist photos might help make sure that all the local carnivores are spotted.

Thanks for listening for Scientific American-60-Second Science. I’m Christopher Intagliata.

9 . On a break from his studies in the MIT Media Lab,Anirudh Sharma traveled home to Mumbai, India. While there, he noticed that throughout the day his T-shirts were gradually gathering something that looked like dirt."I realized this was air pollution，or sooty（像煤一样）particulate matter (PM)，made of black particles released from exhaust（尾气）of vehicles，" Sharma says. "This is a major health issue."Soot consists of tiny black particles, about 2.5 micrometers or smaller, made carbon produced by incomplete burning of fossil fuels.

Back at MIT,Sharma set out to help solve this air-pollution issue. After years of research and development, Sharma’s startup Graviky Labs has developed technology that attaches to exhaust systems of diesel generators（柴油发电机）to collect particulate matter.Scientists at Graviky then turn it into ink, called Air-Ink, for artists around the world. So far, the startup has collected I.6 billion micrograms of particulate matter.More than 200 gallons of Air-Ink have been harvested for a growing community of more than 1,000 artists, from Bangalore to Boston, Shanghai,and London.

Posted all over Graviky Lab's Facebook page today are photos of art made from the Air-Ink and pant, including street wall paintings, body art and clothing prints.At first, there was still no specific application for the ink. Then the startup decided to find new ways to further spread its mission.It chose to do so through art."Art helps us raise awareness about where the ink and paint comes from. Air pollution knows no borders. Our ink sends a message that pollution is one of the resources in our world that's the hardest to collect and use.But it can be done,"Sharma says.

10 . Splash (落水声)! Did you hear that? Can you guess what it is? Can you figure it out? If you guessed the ocean, then you’re correct! I believe that my organization, Reef Check, is the most worthy of receiving the Chocolate Heart money. Do you want to know why? Well, soon you’ll find out.

First of all, Reef Check needs the money to repair and clean coral reefs (珊瑚礁) which are home to millions of sea animals. Reef Check hopes to educate the public about the value of reef ecosystems (生态系统) and the danger that sea animals and plants are facing. Based in Los Angeles, Reef Check has volunteer teams in more than 90 countries, making community volunteers, businesses, universities, and other non-profit organizations work together. It works to create a worldwide network of volunteer teams trained in Reef Check’s scientific methods that survey coral and rocky reefs and report on reef health. Also, Reef Check takes action to protect remaining ancient reefs and repair reefs in danger worldwide.

For example, imagine you are a poor sea animal, whose home just got destroyed or wasn’t clean. What would you do? What could you do? Nothing much, really. But that’s exactly Reef Check’s job! To clean and protect these homes for many sea animals!

Furthermore, in 1997, Reef Check carried out the first-ever survey of coral reef health that provided scientific evidence that our coral reefs were in danger because of overfishing, illegal fishing, and pollution. The results surprised many biologists who had not realized the seriousness of human influence on reefs. In August 2002, Reef Check presented its report, The Global Coral Reef Crisis - Trends and Solutions, at the World Summit in South Africa. The report warned that there was no reef in the world that remained untouched by human influence, such as overfishing, pollution, and climate change.

In short, everyone should have a home including animals from the sea. So don’t leave them out! Be generous and give them a home!