Police in northern China investigating the deaths of hundreds of wild swans, which are believed to have been poisoned at a lake by poachers, have offered a reward of 100,000 yuan (HK$114,000) for information leading to the arrest of the culprits, mainland media reports.
Some 233 swans and 26 mallards were discovered dead at the lake in Zhenglan Banner, an area in Xilin Gol League, Inner Mongolia, the Beijing Youth Daily reported.
Test results have revealed traces of a highly toxic pesticide in the birds, the report said.
Swans are prized and have special significance in ethnic Mongolian culture and are a protected species in China.
The forest public security bureau received reports last Wednesday about the incident and are now investigating.
An elderly couple visiting the lake alerted the authorities, a herdsman was quoted as saying.
Photographs of the dead wild birds have circulated on social media since Sunday, sparking a huge reaction among internet users.
The size of the reward showed the death of so many birds was considered to be “extremely significant” and had had a “serious impact” on society, an official at the security bureau was quoted as saying in a report by news website Thepaper.cn on Wednesday.
The official also said that a special squad had been set up to investigate the matter.
Police have widened the scope of their inquiries by visiting more herdsmen living near to the scene of the crime, the report said.
Herdsmen have previously reported poachers in the area, with some saying that they had heard gunshots during the past six months.
No gun wounds were spotted on the bodies of the swans believed to have died from poisoning, some herdsmen were quoted as saying.
They also said that other swans might have been killed and removed by the poachers already.
Poaching first emerged more than 10 years ago, with some residents in the area even finding mobile phones discarded by poachers in the past, the report said.
Swans usually survived on a diet of algae, but in recent years they had begun to get used to feeding on corn, an expert was quoted as saying in the report.
The expert said the suspected poachers could have taken advantage of this change in the swans’ diet by using poisoned corn to kill the birds.
Poaching has long been a serious problem in China, with the increasingly rich middle classes prepared to pay ever higher prices for animal products from endangered or protected species, including ivory, tiger bones and furs.