HEFEI- Three Dalmatian pelicans (卷羽鹈鹕), or Pelecanus crispus, were spotted at Chaohu Lake for the first time, the fifth    1    (large) freshwater lake in the country.

The rare birds    2     (photograph) on Wednesday by a local biological resources survey team and two birdwatchers.     3    number of Dalmatian pelicans, a national first class protected species, is quite small in China.    4    , it is rare to see three of    5    (they) at the same time, according to Yu Lei, a bird expert on the local biological resources survey team.

“This wading bird, which feeds on fish, has a high level of alertness and requires a good    6    (live) environment. The fishing ban in the lake and the improved environment are reasons behind the    7    (appear) of these pelicans,” said Yu, adding that they migrated here    8    (spend) the winter.

More than 80 birds, such as little swans and cormorants, were also spotted on Wednesday at the lake. Hefei City,     9    the lake is located,    10    (take) a number of measures to strengthen the protection of 10 major wetlands around Chaohu Lake in recent years, including banning fishing, land reclamation and waste dumping in the protected zones.

3 . The African penguin is expected to go extinct in the wild in just over a decade, given its current population decline. The main reason is a lack of food caused by disturbance to ocean conditions from global heating and competition from the commercial fishing industry. According to a study, scientists have identified a possible additional cause, one that is an entirely new threat and that further prevents the penguins from finding food: noise pollution from marine (海洋的) ships in a bay.

Since 2016, a new shipping practice has started at Algoa Bay. The bay offers ship-to-ship refueling for ships anchored offshore. Since the start of this practice, marine traffic in the bay has doubled. The number of bulk carriers (散货船) pulling into the bay has increased by ten times as much. Thus the noise levels in the area had doubled and the population of penguins has dropped sharply. High noise levels affect the ability of marine animals to find food, communicate or navigate properly.

Researchers used data from ship identification tools to estimate underwater noise from passing ships. They also attached underwater microphones and accelerometers (感应器) to some of the penguins. Recording the noise will tell researchers what the penguins are hearing, if they’re talking while hunting, if they’re changing their movements in response to noise, and if the noise is drowning out their hunting conversations. This will allow researchers to determine whether the sound disturbance is a direct cause of the penguins’ ongoing difficulties in finding sufficient food.

The study is the first to explore the effects of ocean traffic noise pollution on seabirds and the consequences of offshore shipping activities on underwater noise levels. Experts are considering proposing various global best-practice approaches to reduce some of the impacts of noise pollution, such as policies that limit the number and size of ships allowed into a bay of this kind. “We also need more scientific monitoring of noise, before these measures are put in place and afterward, so that we have a proper understanding of what works.” a researcher said.

4 . The swan is a large, beautiful bird with a long neck, big white wings and wide feet. It is a great flyer because of its strong wings. It is also a good swimmer, swimming quickly and nicely through the water. But on dry land, it’s a different story—the swan’s heavy body and slow walk make it look a bit funny!

Swans live anywhere there is fresh water, like lakes and slow-moving rivers. They eat water plants and small fish. Swans are very territorial (地盘性的), which means that they protect their homes against any strangers. When swans want to look strong, they stand up tall, show their long necks and open their big wings while letting out big noises.

In spring, swans make a nest (巢) of tree leaves near the water. They often use the same nest year after year, repairing it when egg laying time comes round. The mother swan lays between five and eight eggs in the nest, and then sits on them to keep them warm and safe until about a month later, cygnets are born. Sometimes the father swan will take the first—born cygnets out onto the water while the mother stays to look after the other eggs. The cygnets are looked after by both parents, who will fight other animals, people or even boats if they think their cygnets are in danger!

8 . When you think of wolves（狼）, you probably imagine groups of them howling （尖声蒙叫）into the cold night sky. However, very little is known about their movements in the summer. A research team led by Dr. Thomas Gable from the University of Minnesota decided to make a study. They created the Voyageurs Wolf Project.

As the weather warms up and spring arrives, wolf babies are born. They are too small to hunt, but they have a very large need to feed. The routine（生活习惯） of the wolves changes. They begin to hunt alone. This means they are unable to kill the larger animals. Instead, they look for beavers（海狸） and young deer—much smaller than the animals they hunt in the Winter.

Dr. Gable’s team found it difficult to discover the wolves in the summer. The wolves live in thick forests at this time. What’s more, because they hunt smaller animals, no large bones are left behind, so it is hard to know where the wolves are. Caught wolves were fitted with GPS and cameras before being sent back into the wild. The locations（位置） of the wolves were then sent to the Voyageurs team every 20 minutes, 72 times a day for several months.

It was discovered that the wolves were skillful in their hunt for smaller animals. They would find a place where beavers visited. There, they would wait patiently for up to twelve hours for a beaver to appear. What’s more, the wolves would consider the wind direction. They would place themselves in such a way that their smell would be blown away from the beaver. From the information sent to the Voyageurs team, they were able to see the location where each wolf was waiting for smaller animals. They would visit later and try to work out how the wolves had hunted smaller animals. Because some of the wolves had cameras on them, they were able to see how the wolves attacked. They discovered that the wolves were able to hunt for fish—something that had never been seen before.

9 . The panda bear may be one of the world's cutest animals, but it also has one of the world's grossest habits：They like to spread horse dung（粪便） on their necks and faces and roll around in it to cover their entire bodies. Now, researchers say they have an explanation for these dung baths. The horse dung contains something that might help the animals deal with colder temperatures .

To get to the bottom of things, researchers analyzed 38 instances of dung rolling recorded by cameras at the reserve. The bears tended to roll in horse dung less than 10 days old. The dung contained natural compounds（化合物），called BCP and BCPO，that are scarce in older dung, say the scientists .

The team then added these compounds to the hay（草料） of pandas and found the animals favored the hay treated with these compounds. What's more, the pandas tended to roll in horse dung in colder weather, at temperatures between−5℃and 15°C. Could BCP and BCPO help keep the giant pandas warm?

As giant pandas are a national treasure for China, there are strict limitations on conducting research on these protected animals, so the team turned to mice. Covering mice in a BCP-BCPO solution boosted the animals' cold tolerance, the authors report. Treated mice more readily walked on colder surfaces. The researchers discovered BCP-BCPO blocks receptors that sense cold.

“Although it's not concrete proof, the authors provided solid evidence to explain the unique behavior,”Fan Yang, a biophysicist at the Zhejiang University School of Medicine, wrote in an email.“The same receptors are present in many animals. So it is possible that using natural compounds to manage body temperature may actually be a general strategy widely adopted by other animals.”

Staying warm in the winter can be challenging for pandas,   notes Zejun Zhang, an ecologist at China West Normal University ,because their low-calorie diet of bamboo makes it hard to store extra fat. It's possible, the authors say, that pandas have used horse dung in this way for thousands of years.