Master of Science
Environment and Sustainability
Habitat loss and climate change have caused declines in species diversity and abundance globally, including in butterflies which are important components of many ecosystems. Reintroductions are increasingly used to reverse diversity loss but are most effective when informed using genetics. I developed 24 microsatellites and characterized genetic structure and diversity of the endangered Mottled Duskywing (Erynnis martialis) in Ontario and neighbouring provinces and states. These were used to inform a planned reintroduction in Ontario. Populations had moderate levels of genetic diversity, however all but the largest populations may be subject to appreciable levels of genetic drift. Populations more than 8 km apart appear to be isolated from each other. My work forms part of a larger effort to achieve the overall recovery of the species in Ontario. Tools I developed may be used to inform future reintroductions of the species, and to monitor status of introduced and extant populations.
Summary for Lay Audience
A growing human population and associated climate changes and habitat losses have led to declines in species across the globe, with some researchers calling this the sixth mass extinction event. Worldwide declines in insect species threaten a “catastrophic collapse of nature’s ecosystems”. Butterfly species are facing one of the largest of these declines. Butterflies are important as they provide ecological services and are important indicators of environmental health. Re-introducing species to areas where they once occurred is increasingly being used as a strategy for recovering at-risk populations. Many early reintroductions of butterfly species were largely unsuccessful due to a lack of background research and rigorous protocols. The Mottled Duskywing (Erynnis martialis) is a medium-sized, brown butterfly listed as Endangered in Ontario, and reintroductions to formerly occupied locations have begun as part of the species Recovery Plan. I developed and used genetic tools to determine metrics of diversity within and among Mottled Duskywing populations in Ontario and nearby locations. Genetic diversity is an indicator of population health; the more variability there is among individuals of a population, the more likely that a population will be able to survive in a changing environment. Populations had moderate amounts of diversity and differed from one another. However, populations within 8 km of one another were not differentiated. These results have informed a reintroduction of the species to Pinery Provincial Park through the selection of the source population based on the levels of genetic diversity in the populations. Moving forward in the recovery goals, the tools I developed can be used to inform future reintroductions through the selection of other potential source populations and selection of females used in captive rearing programs. Additionally, they can be used to assess the genetic status of both remnant and reintroduced populations.
Kroeze, Shayla, "Using conservation genetics to inform reintroduction of the endangered Mottled Duskywing (Erynnis martialis)" (2022). Electronic Thesis and Dissertation Repository. 8513.