【推荐1】In the 1980s, millions of western monarchs gathered in trees from northern California down to western Mexico. Now, their wintering sites are mostly on California’s central coast.

Western monarch butterflies travel south from the Pacific Northwest to California each winter. They return to the same places and even the same trees, where they gather. The monarchs usually arrive in California at the beginning of November. They spread across the country once warmer weather arrives in March.

The western monarch butterfly population has decreased by more than 99 percent since the 1980s. Another monarch population on the eastern side of the Rocky Mountains travels from southern Canada and the northeastern US to spend the winter in western Mexico. Scientists estimate the monarch population in the eastern US has fallen about 80 percent since the mid-1990s.

Monarchs from across the West migrate (迁徙) yearly to about 100 wintering sites along central California’s Pacific coast. One of the best-known wintering places is the Monarch Grove Sanctuary in the city of Pacific Grove.

Pacific Grove, California, known as “Butterfly Town, USA”, has worked for years to help the decreasing monarch population. The city holds a parade to celebrate the butterflies every October. It also bans human interference with the monarchs. The crime carries a $ 1,000 fine.

In 2020, no monarchs appeared in Pacific Grove. But in 2021, an early count found that more than 13,000 of the insects had moved in.

Scientists do not know why the population increased in 2021. But Jepsen, director of Endangered Species at Xerces Society, said it is likely a combination of reasons, including better conditions on their breeding grounds. The non-profit science group Xerces Society carries out the official study every year. Volunteer counters have reported the presence of as many as 50,000 monarchs in the last few weeks.

Monarch butterflies lack legal protection that could keep their territory from being destroyed. Last year, the butterflies were denied federal protection. But the insects are now among the candidates for listing under the federal Endangered Species Act.

【推荐3】If you can potty-train(坐便训练) a child, you can potty-train a cow. At least, that was the theory a group of researchers in Germany decided to test. Farmed cattle produce roughly 66—88 pounds of waste and 8 gallons of urine(尿) each day and are free to relieve themselves where they please. However, the spread of their waste into the soil can have negative effects on the environment.

A team of scientists from FBN and FLI in Germany and the University of Auckland in New Zealand began to potty-train the little cows, in the process they called “MooLoo training”. In the first phase of training, the cattle were put in a closed public toilet. And whenever they urinated, they were given a reward. “Once they were allowed outside, the little cows would go in the toilet to get their reward, but they soon learned that there’s only a reward if they urinate.” FBN’s Neele Dirksen, first author of the study, told CNN.

To encourage little cows to use the toilets, researchers also came up with a punishment. “We first used in-ear headphones and we played a very unpleasant sound whenever they urinated outside,” said Langbein. “We thought this would punish the animals, but they didn’t care. Ultimately, a splash(溅泼) of water on them worked well as a gentle punishment.” The little cows were trained for 45 minutes every other day. And after 10 training days, the team managed to successfully train 11 out of the 16 little cows involved in the experiment, which was more than they had expected.

The results showed that little cows performed at a similar level to children when learning to potty-train, and did better than very young children. “It is possible to potty-train little cows,” Langbein said, “I hope that in a few years all cows will go to a toilet.”

【推荐1】Calculated every year by Global Footprint Network（GFN），Earth Overshoot Day（地球生态超载日）is the day when human has used up all the natural resources—produce,meat,fish,water and wood.This means we use up them ahead of time before the end of the year.

It is just like spending your entire years' money by August and then borrow money from friends,knowing fully well you cannot pay back. GFN says the same thing happens in the case of the earth."Because we give out more carbon dioxide into the atmosphere than our oceans and forests can take in,and we harvest forests more quickly than they can regrow,"he said.

In a perfect world,we should only spend what we have.This means Earth Overshoot Day would fll on 31 December or perhaps in the following year. Unfortunately,the day has been climbing up quickly since 2014 when it fell on 19 August.In 2015,it was 13 August,and this year, the earliest so far—8 August!

According to GFN,Australia tops the list,with the United States coming in a close second.If the world's population started to live like either of these countries,we would need more resources to meet our needs.

Fortunately,experts say the situation isn't as bad as it sounds. Many countries have already taken measures to reduce carbon emissions（释放）by using wind or solar energy.People can also help by eating less meat, walking, cycling or taking public transportation,as well adopting the three Rs: Reduce,Reuse&Recycle.If we work together,we can help push back Earth Overshoot Day to December 31 or even beyond.