TIANJIN - An endangered species of bird grabbed headlines in Chinese media over the past week not because of its elegant beauty, but because 20 died of poisoning in northern China.

Poachers poisoned the wild birds within a wetland nature reserve in North China's Tianjin municipality. Their actions left 20 Oriental white storks dead and 13 others sickened, triggering public outcry for intensified protection of wild animals and harsher punishments for those behind the deaths of the storks.

The birds, no more than 3,000 of which remain in the wild worldwide, were stopping at the city's Beidagang Wetland Nature Reserve along their migratory route from Northeast China to central Poyang Lake.

Sources with the reserve management committee have confirmed that the birds, as well as other species, were found poisoned on November 11 after an amateur photographer spotted the dead body of a stork.

Volunteers and workers from the Tianjin Wild Animal Rescue and Training Center carried out rescue work, retrieving 13 poisoned birds and 20 corpses.

White storks are set free after rescue in Tianjin on Nov 21, 2012. Thirteen poisoned white cranes were saved by a wildlife protection institute in Tianjin before they were set free. Another 20 died from the poisoning. [Photo/Asianewsphoto]

Since being treated in the center, the 13 poisoned birds have made complete recoveries and are ready to be released on Wednesday morning, according to Dai Yuanming, director of the center.

Dai said the birds have been banded for further tracking and research.

Police said the water in the wetland was confirmed to have contained carbofuran, also known as furadan, one of the most toxic carbamate pesticides.

Local authorities are diluting the tainted water and looking for the sources of the pesticide. It is believed that the birds were poisoned by poachers who sell the rare birds to restaurants where wildfowls are sold illegally.

Though hunting and trading endangered animals are both banned in China, a large bird like the Oriental white stock can fetch about 200 yuan (about $32) on the black market, while a swan can garner up to 1,000 yuan.

Local authorities have since stepped up protection measures at the reserve, and a 50,000 yuan reward has been offered for clues on the whereabouts of the poachers.

The poisoning of the wild birds has triggered angry outbursts directed at poachers, as well as outcry for intensified wild animal protection.

"What a cruel and greedy slaughter! The storks are just like travellers on their way home, but now they will never have a chance to get back on their way," "xianyubujiaoao" wrote on Sina Weibo, a popular Twitter-like microblogging platform.

"No trading, no poaching! The true murderers behind wild animal poaching are those greedy gluttons who devour almost everything," wrote Weibo user "linxiaohaidechuntian."

Xue Manzi, a famous Chinese angel investor and an active Weibo user, also asked the public not to eat wildfowls or other wild animals and urged authorities to intensify their crackdown on the illegal industrial chain of poaching, including restaurants that sell endangered animals.