Researchers at The University of Hong Kong’s School of Biological Sciences have made groundbreaking discoveries that could significantly enhance conservation efforts for two notable species of cockatoos: the Sulphur-crested and the critically endangered Yellow-crested cockatoos, which are down to just 2,000 individuals left in the wild.
Until recently, whole-genome studies had not been performed on either species, which were differentiated solely based on minor physical traits. Two pioneering studies conducted by the team have revealed new genetic information that transforms our understanding of these species and brings renewed hope for their survival amidst serious threats like habitat destruction and illegal trapping. The results, published in the journals Molecular Biology and Evolution and Molecular Ecology, will play a crucial role in shaping future conservation strategies.
Triton Cockatoo Recognized as a Separate Species After Over a Century
While it was previously thought that the Triton Cockatoo (Cacatua triton) and the Sulphur-crested Cockatoo (Cacatua galerita) were the same species due to their similar appearances and overlapping habitats in Australia and New Guinea, genomic analysis from the study in Molecular Biology and Evolution has confirmed that they are actually separate species. The Triton Cockatoo is predominantly found in New Guinea, whereas the Sulphur-crested Cockatoo is confined only to Australia and a small part of southern New Guinea.
This revelation carries significant implications for conservation efforts, especially in New Guinea where both species are present, and where initiatives led by the Indonesian government and NGOs aim to restore surrendered pet birds to the wild. These efforts are crucial in combating the impacts of climate change, land use changes, and poaching.
Dr. Arthur SANDS, a cockatoo expert from SBS and the principal author of the Molecular Biology and Evolution study, underlined the importance of this finding. He stated, “Introducing the wrong species to the wrong environment could threaten their long-term survival in the wild due to hybridization or competition between the Triton and Sulphur-crested Cockatoos, potentially disrupting ecosystems in the long run.” He emphasized the need for future reintroduction programs to include genetic data to prevent such issues. Acknowledging the Triton Cockatoo as a distinct species now necessitates updates to international laws, including the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which aims to protect these and other parrot species, potentially leading to increased protection due to this classification change.
The second study, published in Molecular Ecology, examined the critically endangered Yellow-crested Cockatoo (Cacatua sulphurea), which is native to Indonesia and East Timor. By analyzing DNA from century-old museum specimens, researchers looked into the genetic variety within subspecies. This method, known as ‘museomics’, involves studying DNA from preserved specimens in museums throughout the USA and Europe. It enables scientists to gather essential biological data without disturbing the endangered populations still living in the wild.
The research identified three genetically unique groups across the Wallacean region, a biogeographical area between the Asian and Australian continental shelves, and simplified the previous classification from seven to three subspecies. It appears that the C. s. citrinocristata subspecies may not be as distinct as formerly believed, raising questions about how the isolated C. s. abbotti population ended up on a distant Indonesian island, especially considering that cockatoos are not renowned for long migrations. These findings redefine the genetic landscape of the Yellow-crested Cockatoo and provide new perspectives on its evolution and distribution.
Dr. Astrid Andersson, who directed the study in Molecular Ecology, noted that “museomics allows us to analyze genetic information from species that are extinct, rare, or difficult to access. This information can greatly aid conservation efforts such as translocation, genetic rescue, and breeding – steps vital to preventing the global extinction of C. sulphurea.”
Professor Juha Merila, Associate Director of the Ecology & Biodiversity Research Groups and Chair Professor at SBS, who oversees the research team that includes Drs. Sands and Andersson, remarked, “Accurate identification of evolutionarily significant units and species is crucial for the effective management and conservation of endangered species. Our research reveals the genetic diversity within and among these iconic cockatoo species and highlights the necessity of integrating genetic data into conservation planning.”
