3 . Raccoons are arguably the most successful urban carnivore (食肉动物) in North America. They maintain large populations in most U.S. cities and are certainly just as common in Chicago, though actual population estimates are unknown. Almost anyone who has spent time outdoors at night has likely seen one, and they are quite difficult to confuse with anything else — their fat bodies, and mask-like facial markings, make them quite distinctive, and even perhaps charming.

A typical urban raccoon is able to eat virtually anything. Their diet includes earthworms, carrion, plant matter, cat food, and all kind of discarded human food waste. Raccoons are probably the most advanced wildlife which can dive our dustbins. Their paws (爪子) are quite dexterous and enable them to access closed garbage dustbins. Raccoons are also capable climbers and can be found on the top of fences and in trees. While they are typically solitary, they are willing to tolerate crowds of other raccoons if high quality food resources are present. They give birth once and sometimes twice a year in late spring and make use of a wide variety of den (巢穴) sites, including hollow trees, chimneys, etc. Because they make dens in a variety of human structures, raccoons can be a source of human-wildlife conflict, through direct confrontation with humans, property damage caused by their activities, and, perhaps most critically, through the transmission of disease. Leptospirosis, canine distemper, raccoon roundworm, and rabies are the most important zoonotic (人畜共患的) diseases carried by raccoons. Rabies in particular has had a massive effect on raccoon populations and caused a public health attention, to the point where use of vaccine have been attempted in some cities.

In most cases where raccoons are reported by the public, no management action is necessary. Large packs of raccoons, such as those often sighted along the lakeshore path, likely suggest a large artificial food source, such as people deliberately feeding raccoons on unchecked garbage. These large gatherings present a high disease risk and people should be strongly discouraged from feeding raccoons or leaving food outside for them. In cases where there is evidence of disease, individual raccoons will need to be trapped and killed.

A Mammoth Project

A US company called Colossal has raised 11 million dollars to bring mammoths (猛犸象) back from extinction. Mammoths died out about 3,700 years ago but their bodies are sometimes     1     in ice. This allows scientists to     2     their DNA, which could hold the key to bringing mammoths back to life.

A team of scientists at Colossal plan to use information from mammoth     3     to edit the DNA of Asian elephants — their closest living relatives. The team will focus on DNA that is linked to bushy hair and other     4     for cold weather. These were what helped mammoths survive on the Arctic steppe — ancient chilly grasslands. By adding this DNA to egg cells from Asian elephants, they hope to create an elephant-mammoth mix, which could develop into a baby either inside a living Indian elephant or in a(n)     5     organ.

Colossal hopes that the first set of calves could be born this way in six years. “We want something that is     6     equivalent to the mammoth, that will enjoy its time at - 40°C and do all the things that elephants and mammoths do, in particular knocking down trees,” said Church, the founder of Colossal. It’s hoped that the destructive habits of the hybrids (杂交种) could help restore areas of Arctic steppe that have been     7     by trees since mammoths became extinct. That can help keep the world cooler.

Arctic grasslands     8     more heat from the Sun than forests and can absorb more of the gases released by human activity. However, not everyone agrees with the     9    . Professor Adrian says the extinction of mammoths had little to do with the     10     of steppe grasslands. He points out that it would take thousands of mammoths to have an effect on the environment.

7 . Laura walked towards the man. “It is terribly cold,” she said.

“Colder than ever,” the man said. “Now tell me what you want.” He stared at Laura for a few seconds and then grinned, “Maybe you’d like to come inside and warm up.”

“No. No, I don’t want to come in.” She took a deep breath. “I just wanted to know if you’re interested in selling your dog.”

“That worthless mutt?” The man pointed to a dog in the yard and laughed for a few seconds, then suddenly stopped. “I was just joking about the worthless part. He’s a pretty good dog. Yeah. I might be interested.”

“Well, he’s the kind of dog I’m looking for. And it doesn’t seem like you’re too fond of him. I mean he’s tied up outside. I don’t see any food or water.”

“You just wait a minute. I take good care of that dog. The guy I got him from said he was a trained guard dog. The trouble is, the stupid thing doesn’t even bark when strangers come around. But then I guess that wouldn’t matter to you. You’re probably just looking for a pet, huh?”

“Yeah. Well, here’s your chance to get rid of him. I’ll give you twenty dollars.”

“You expect me to sell a purebred guard dog for twenty dollars?” the man snorted (哼着鼻子说). “Fifty dollars. That’s my price. You bring me fifty dollars, honey, and you got yourself a dog.” He smiled. “Sure you don’t want to come in?”

Laura shook her head. “I’ll be back with the money.” Breakfast forgotten, she searched for and found a cash machine four blocks away. I can’t afford this, she thought as she punched the numbers into the machine. The dog will need a vet, and where am I going to get the money for that? Her fears wore off as she pictured the dog, curled up, not outside on the cold, hard ground, but in front of a glowing fireplace. Blue ceramic bowls filled with food and water sat in the corner of the kitchen, and she saw him, head held high, matching her stride on their daily walk.

With the money in her purse, she hurried back to the man’s house.

9 . The population of rare Atlantic puffins in Maine, US, took a hit this year, as the number of chicks to survive a tough summer collapsed. The state's coastal bays and the Gulf of Maine are among the fastest warming large water bodies on the planet, making the puffins' fate a test-case for how climate change could disrupt marine ecosystems worldwide.

The little clown-colored birds faced a complex of challenges: nests were flooded by some of the heaviest rains in a hundred years, exposing chicks to cold and predators. It was tough for young puffins, who were being brought up in caves along the island's shores. And their parents had a hard time finding herring (鲱鱼) and other North Atlantic prey they usually dive for, which scientists think may have swum to cooler waters too deep or far-off for the birds. The adult puffins flew farther than usual to find food. Scientists say this limited their time to keep baby puffins warm in their nests. They did find and bring to the nests a lot of butterfish, but the thing is that butterfish are too big for young puffins to swallow.

The director of the National Audubon Society's Seabird Institute, Don Lyons, says puffins provide a unique window on global warming, on how even small shifts in the range or timing of any one species' occurrence can influence the fate of many others. "Working with puffins in Maine, we're seeing the harbingers (预兆) of climate change every day," he said. "I tend to think of puffins as a group of researchers. They're going out and sampling our marine ecosystem all summer, many times a day. And the way we learn from them is watching what fish they bring back and how well they are able to raise baby coffins. ... They're really telling us to be concerned, you know, to pay attention."

Lyons says that with good management of herring and other fisheries that the puffins depend on, the birds should be able to hang on. Puffins can live up to 30 years and this means it won’t be too terrible if they meet only a bad year. He adds, though, that their future in Maine may depend on just how often those bad years keep rolling in.