Another panda has died after being released(放走) into the wild, putting Chengdu Research Base of Giant Panda Breeding under criticism.

Hesheng, a panda, died in September 2016, two months after being released into the wild in Southwest China’s Sichuan Province, Chengdu Panda Base announced. The announcement caused a great deal of opposition on the Internet. Many online users questioned whether the panda reintroduction(重返旧栖息地) program was protecting or killing pandas.

However, experts in the field of pandas have not given up. Wild giant pandas live in six highly separated mountain systems in China, leading to frequent inbreeding(近亲交配) and increasing the risk of extinction. “We release pandas into the wild to live, mate and give birth in an attempt to make the species’ genetic pool different,” said Zhang Hemin, director of the China Conservation and Research Center for the Giant Panda.

A staff member from Chengdu Panda Base said releasing pandas back into the wild was a complicated process involving many unexpected changes and even failures. The accidental death of Hesheng has put the base under a lot of pressure, because Hesheng, the male panda, died of a disease after being attacked by unknown animals after being released for only two months.

China has released eight pandas into the wild since the reintroduction program began in 2006. Five have survived. In addition to Hesheng, Xiang Xiang, the first panda released into the wild, died of fighting with wild pandas for food and land about a year later. Xue Xue, the fourth released panda, died of illness a month after being released.

There are several steps that must be completed before release can be declared a success. Releasing is just the beginning. The reintroduced pandas need to survive for at least one year to prove that they can feed themselves.

Findings of an international team of researchers from Japan and China suggest that geese might have been the first poultry species to have been domesticated (驯养) by humans—as far back as 7,000 years ago.

Scientists have long held different opinions on the history of the domestication of birds, with a belief that it was chickens that were the first to be domesticated. In 2014, Chinese researchers reported ancient DNA taken from the earliest archaeological chicken bone discovery in China, suggesting chickens were domesticated in northern China as early as 10,000 years ago.

But the researchers behind the latest findings say that the 2014 study lacks firm evidence. In the new study, the team unearthed the archaeological site of Tianluoshan, a 7,000-year-old rice cultivation village in the lower Yangtze River valley in what is today known as East China’s Zhejiang province. They found a total of 232 goose bones at the site. The inhabitants of the village were hunter-gatherers.

The researchers used multiple approaches to study the bones, and found evidence of domestication.

Four bones were from goslings (幼鹅) ranging from eight to 16 weeks old, suggesting they hatched near the site. Geese were domesticated from wild geese. These migratory birds fly to northern Siberia to breed (繁殖) after the spring and then fly south for the winter, according to researchers from the Zhejiang Provincial Institute of Cultural Relics and Archaeology. They said the goslings were too young to have flown in from elsewhere. At the time, Tianluoshan did not have the conditions to be a natural breeding place for wild geese, so it follows that the goslings were born after domestication.

The researchers also analyzed the chemical makeup of adult goose bones, which contained evidence of the water they drank. Their analysis indicated that the adult geese also seemed to have been locally bred, for they were all roughly the same size. Carbon dating also showed that the bones belonged to geese that lived about 7,000 years ago.

Researchers say ancient DNA analysis is required in further studies to investigate which species were bred to become local geese populations.

As waterfowl (水鸟) seasons unfold each year across North America, the question “Where are the ducks?” unavoidably arises somewhere. While that seems like a straightforward, easy question, the answer is actually very complex. There are many factors that influence distribution of waterfowl in fall and winter.

Most waterfowl hunters understand the effect weather has on waterfowl migration (迁徙). Except for the few species that are hardwired for more dependable long-distance migrations, such as blue-winged teal (水鸭), waterfowl are adapted to migrating only as far as is necessary for them to find food and places to rest. Waterfowl like to wander at places without freezing temperatures and snow to cover food sources. It is advantageous for them to reduce risk of death from migration. Some birds that arrive earliest on breeding areas have access to the best regions, which results in a higher probability of nesting successfully.

Snow and ice cover and their influence on waterfowl migration are easy to understand to most duck hunters. However, what may be less understood is the trend toward warmer winters. If current climate trends continue in North America, northern regions will have less frequent ice and snow cover in future winters. So waterfowl that are adapted to staying as close to breeding areas are likely to be influenced, meaning significantly delayed fall migrations and shorter periods on southern areas.

In the past 200 years the landscapes that are most important to waterfowl have suffered huge habitat loss, with some states losing more than 90 percent of wetlands, and nearly all losing over 50 percent. Perhaps the most discouraging loss of wetlands important to wintering waterfowl has been in coastal Louisiana, where more than 40 percent of the states, approximately 3 million acres of wetlands have disappeared over the past several decades.

Changes in the number of wetlands and the trend toward warmer winters are likely enabling waterfowl to winter farther north or, at least, delaying fall migration. Unsurprisingly across most of the eastern United States’ many waterfowl hunters saw reduced harvest as a result.