Crossbreeding a threat in Milky Stork conservation

A Milky Stork (photo: Eddy Lee Kam Pang)

An NUS team of researchers, led by NUS Biological Sciences Assistant Professor Frank Rheindt, has discovered that the conservation of Milky Storks — an endangered white plumaged stork species native to Southeast Asia — could be threatened by crossbreeding with their more widespread cousins — the Painted Storks.

“Apart from habitat loss and fragmentation, extinction through hybridisation is one of the major threats to endangered species. Our study is the first to provide an estimation of the population genomic status of the endangered Milky Stork in Singapore, and the findings can contribute to the design of effective solutions for conservation management of the globally endangered species,” said Asst Prof Rheindt.

The research team analysed tissue samples of 46 storks from both captive and wild environments in Singapore. Their results showed that the genomic composition of more than half of the sampled storks had been affected by genetic infiltration from the Painted Storks, indicating that due to their small populations, the globally endangered species could eventually be absorbed into the genome of the more widespread species.

To prevent this from happening, and to avoid the possibility of using genetically admixed individuals for conservation breeding or reintroduction into the wild, the research team recommended that hybrid storks in bird parks, zoos and the Singapore wild should be identified and isolated from pure Milky Storks to prevent crossbreeding, with thorough genetic analysis conducted on individual storks to ensure their purity in any planned breeding programmes or releases. Additionally, the team suggested a strict removal of hybrids from the wild and a release of genetically pure Milky Storks, which is necessary for the continued survival of the species.

See press release.