Ecologists at the School of Biological Sciences of The University of Hong Kong (HKU) have made discoveries that could transform the conservation of two iconic cockatoo species: the Sulphur-crested Cockatoo and the critically endangered Yellow-crested Cockatoo. According to HKU, there are only about 2,000 Yellow-crested Cockatoos remaining in the wild. Researchers note that no whole-genome research had been conducted on either of these birds before this work. Until now, the two species were identified by their subtle morphological differences.
The HKU team conducted two studies, published in leading journals Molecular Biology and Evolution and Molecular Ecology. Researchers say the results will be highly influential in guiding future conservation efforts.
One highlight of the research is the reconfirmation of the Triton Cockatoo as a distinct species, after more than a century of being grouped with the Sulphur-crested Cockatoo. Scientists reveal that the Triton Cockatoo occurs across most of New Guinea, while the Sulphur-crested Cockatoo is restricted largely to Australia and a small portion of southern New Guinea. HKU points out that this newly clarified distribution has major conservation implications in areas where both species exist. Programs led by the Indonesian government and NGOs aim to reintroduce surrendered pet birds into the wild on the western part of New Guinea to counter ongoing threats.
Dr. Arthur Sands, an expert on cockatoos from the School of Biological Sciences at HKU and main author of the study in Molecular Biology and Evolution, explained the risks of mixing species during reintroduction. “Introducing the wrong species in the wrong place could jeopardise their long-term survival in the wild through hybridisation or competition between the Triton Cockatoo and the Sulphur-crested Cockatoo, potentially even disrupting ecosystems in the long term,” he said. Dr. Sands stressed that such reintroduction programs must incorporate genetic data moving forward to avoid this.
Because the Triton Cockatoo is recognized as a separate species, HKU indicates that global legislation, including the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), may now require updates. The recognition may also require new levels of protection due to the split.
The other HKU study, published in Molecular Ecology, focused on the critically endangered Yellow-crested Cockatoo, which lives in Indonesia and East Timor. The team used DNA from 100-year-old museum specimens to learn about genetic differences among subspecies of this species. This approach, known as “museomics,” offers important insights without disturbing the few remaining birds in the wild.
The research identified three genetically distinct groups of the Yellow-crested Cockatoo across the Wallacean region, which simplifies the earlier classification of seven subspecies. Scientists observe that one of these previously recognized subspecies may not be as distinct as believed. They also note questions about an isolated population found on a remote Indonesian island, especially given that cockatoos generally do not migrate over long distances.
Dr. Astrid Andersson, who led this study, said, “One of the benefits of museomics is the ability to examine genetic data from taxa that are extinct, rare or inaccessible. In this case, it provides valuable information to inform conservation efforts, such as translocation, genetic rescue and breeding—steps that are crucial to avoid global extinction of C. sulphurea.”
Professor Juha Merilä, Associate Director (Ecology & Biodiversity Research Groups) and Chair Professor of the School of Biological Sciences at HKU, added, “Accurate identification of evolutionarily significant units and species is essential for the effective management and conservation of rare and threatened species. Our research highlights the genetic diversity within and among these iconic cockatoo species and underscores the importance of incorporating genetic data into conservation planning.”
This article was written in collaboration with generative AI company Alchemiq