UCLA

Species across the globe are faced with unprecedented pressures due to human impacts. In what is now recognized as the Sixth Mass Extinction, habitat loss and climate change have driven many populations to and over the brink of extinction. Drawing from recent advances in genomic sequencing and analyses, I aimed to facilitate the conservation and recovery of two declining species, the Tricolored Blackbird (Agelaius tricolor) and the Western Burrowing Owl (Athene cunicularius hypugaea). I analyzed population structure and genetic diversity in both species, the former with both reduced representation and whole genome sequencing and the latter with low coverage, whole genome data. For the Tricolored Blackbird, I found no indications of population structure in the species, an important finding for conservation as this indicates there is neither a need for individual management units for the species nor a concern about barriers to gene flow. Burrowing Owls are more complicated in having both resident and migratory breeding groups. I found genetic structure was linked to the migratory phenotype, with residents being highly structured and migrants having no structure. Furthermore, I found indications of high inbreeding in resident breeding populations. Using numerous metrics of environmental variation, I found significant genetic differences between residents and migrants. Among those regions of the genome most differentiated and correlating with environmental differences, genes associated with the processing of fats, or lipophagy, were found to be significantly more represented. Revisiting Tricolored Blackbirds with whole genome data, I found indications that perhaps the population is not in complete panmixia as previously indicated by reduced representation data analyses, but that any restrictions to gene flow are indeed low. Further, the higher resolution dataset detected that the recent known decline of the species is apparent in changes in effective population size over time. My work provided essential information for conservation efforts for both species and should be a foundation for continuing genomics research on these and other species of conservation concern as well.