This article discusses the work of Dana Statterfield, a doctoral student at the Odum School of Ecology at the University of Georgia, who studies human effects on migratory behavior.
In summary: Butterfly populations have declined by more than 90 percent, hitting a record low last year. Causing this decline is the removal of wild milkweed which are being replaced by the planting of corn and soybeans. Adding to the issue is the planting of an exotic species called tropical milkweed which may lead to unseasonal breeding, putting monarchs at higher risk of disease and reproductive failure. Nonstop breeding on the same plants can unleash a devastating parasite called OE, Ophryocystis elektroscirrha, which causes inability to fly or early death. Her study focuses on whether migrant butterfly’s pick up parasites as they pass through winter-breeding colonies and if they start breeding at these locations. This is a major issue because in an already reduced population disease could be catastrophic.