Milkweed is the sole food plant for the larvae of monarch butterflies – no milkweed, no monarchs. Restoration of milkweed occurs at two scales. First, which portion of the breeding range should we focus on to enhance milkweed abundance? Here, we use techniques such as stable isotopes and population models to identify the natal origin and areas of productivity for monarchs across different portions of the annual cycle to identify which geographic regions are the most important for milkweed restoration. Second, on a local scale, which land use areas are the best candidates for increasing milkweed quantity and quality? Modern roadside management uses frequent mowing to enhance aesthetics and ensure public safety along roadways. Mowing can restrict the establishment of vegetation communities of perennials like milkweed which are slow to mature and reproduce. Our work used field manipulations to enhance milkweed quantity and quality in road, rail and utility right-of-ways to maximize population viability of monarch butterflies and milkweeds while ensuring that public safety is not compromised. This same approach could be applied to enhance pollinating insects in these environments.

Example publications

• Flockhart, DTT, TG Martin & DR Norris. 2012. Experimental examination of intraspecific density-dependent competition during the breeding period in Monarch butterflies (Danaus plexippus). PLoS ONE 7(9):e45080.