Jin Deqiang, an official in charge of wild life protection affairs at the Forestry Bureau of Guangyuan city, on Thursday said the bird was spotted on March 10 on the Dongxi river shoreline, Xinhua news agency reported.
"A villager said he had seen an 'odd' shaped bird. When we arrived, the bird looked unwell, and could not stand, but there was no visible wound," he said.
It died a few hours later, likely due to some sort of disease, he added.
The bird might have been separated from its flock during movement from north to south.
According to Birdlife International, white-eared night herons are known to live in southern China and northern Vietnam, but are hard to track.