DISCUSSION
We explored the population genomic status of the critically endangered King Island scrubtit in the context of its mainland congener - the Tasmanian scrubtit, using a genome-wide SNP dataset developed with samples collected from across their contemporary distribution. We also provide the first sequenced and assembled long-read genome for the family Acanthizidae. We show that the scrubtit population is structured into four genetic clusters, with additional substructuring of the King Island scrubtit population when analysed independently. Genomic diversity is lower and inbreeding coefficients are higher in the King Island scrubtit than in the Tasmanian scrubtit. Crown baldness was present in over 50% of King Island scrubtits, but none of the 55 Tasmanian scrubtits. Baldness was not linked to particularly low levels of multi-locus heterozygosity in King Island scrubtits, but was significantly associated with six candidate SNPs. Below, we discuss the implications of these results for research and genetic management requirements of the King Island scrubtit.