The popular cage-bird is listed as endangered by the International Union for the Conservation of Nature (IUCN) and a protected species by the Indonesian environment and forestry ministry.

Officials found the huge cache of birds in eight cages on Friday, including 140 that died, at a port on Flores island in eastern Indonesia, Joko Waluyo, an official at a provincial conservation agency, told reporters Sunday.

The birds were due to be taken by ferry to Surabaya, a city in the east of Indonesia's main island Java.

"The alleged perpetrator, who has not yet been found, brought Javan white-eye birds in 8 bird cages. The number of birds that were attempted to be transported was 1,260, 140 of which were found dead," said Joko.

The surviving white-eye birds were released back into the wild.

"The release aims to save all secured (birds), increase the population in nature, and raise public awareness," he said.

Under Indonesian law, poaching or trading of protected species is punishable up to 15 years in prison.

Indonesia's illegal trade in wildlife along with habitat loss has driven numerous endangered species, from the Sumatran elephant to the orangutan, to the brink of extinction.