Monarch butterflies (Danaus plexippus) are best-known from their North American range but more recently have also become established on nearly every Pacific island chain. Because of their geographic isolation, these island populations of monarch butterflies provide ideal ?natural experiments? for addressing ecological and evolutionary questions about the monarch butterfly. This project will focus on museum specimens and live-caught monarchs from Australia?where populations of migratory and non-migratory monarchs co-occur?and will be in collaboration with Dr. Myron Zalucki (University of Queensland), the world?s foremost expert on Pacific island monarchs. Results from this research will contribute to a better understanding of (1) the genes and environmental cues that govern monarch migration, (2) how migratory and non-migratory monarchs may differ in their morphology, behavior, and interactions with parasites and (3) the strategies employed by milkweed host plants to cope with monarch herbivory. This information will contribute to strategies for protecting North American monarchs, which are currently being petitioned for federally protected status.

Oceanic islands have long served as valuable natural laboratories for understanding evolutionary processes over both contemporary and long-term time scales. Monarch butterflies on Pacific islands provide replicated natural experiments for investigating transitions from migratory to non-migratory status as well independent re-associations with their milkweed host plants. For this project, I will focus on Australian monarchs (both museum specimens and live-caught individuals) and their milkweed host plants. This will enable me to answer questions about (1) the short-term evolution of monarch wing morphology and antennal circadian rhythm expression in relation to migratory status, (2) the prevalence and virulence of the protozoan parasite Ophryocystis elektroschirrha, and (3) the evolution of resistance and/or tolerance traits in novel milkweed host plants. The results of this research will contribute to a greater understanding of the basic biology of the monarch butterfly and potentially aid in its conservation.

This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.

National Science Foundation (NSF)
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Anne Emig
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Freedman Micah G
United States
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