Assessing the Genetic Health and Conservation Value of an Introduced Urban Population of a Critically Endangered...

Non-native species can be introduced to novel environments such as cities via wildlife trade. These populations may have conservation value-particularly if they are of a species threatened in its native range. Genetic tools can help assess the fitness of introduced populations by indicating if they are (1) suffering the consequences typically associated with small, isolated populations derived from few founders (e.g., inbreeding, low genetic diversity) or (2) they demonstrate gene flow indicative of mixed-origin founders, successful breeding, and/or continual introductions of conspecifics. Such data can inform management interventions in the ex-situ environment and highlight potential contributions of introduced populations to native-range conservation. We examined multiple metrics of genetic health of a non-native population of ca. 200 critically endangered Yellow-crested Cockatoos (Cacatua sulphurea)-native to the eastern Indonesian archipelago-introduced to Hong Kong (HK) from the 1960s. We sequenced whole genomes and mitochondrial DNA of HK cockatoos and compared them to native-range C. sulphurea, Sulphur-crested Cockatoos (C. galerita) from Australia, and representatives from five additional wild parrot populations. Results indicate HK's cockatoos may have as yet evaded the severe negative genetic consequences of small, isolated populations, and currently have N _e and nucleotide diversity comparable to other wild parrot populations. Their genetic characteristics conform to those of young, mixed-origin, non-native populations: high individual-level variance in relatedness and inbreeding/outbreeding, and influences of admixture. Given that C. sulphurea subspecies exhibit very low genetic distances, HK's city cockatoos are worthy of further examination as a potential genetic reservoir and rescue source for C. sulphurea.