Yosemite and Tioga Pass Area

Monarch Butterfly (Danaus plexippus) nectaring on Purple milkweed (Asclepias cordifolia). Overwintering populations of D. plexippus are found in Mexico, California, along the Gulf coast, year-round in Florida, and in Arizona. Habitat requirements change during migration. During the fall migration, butterflies must have access to nectar-producing plants. During the spring migration, butterflies must have access to larval food plants and nectar plants. All the species of milkweed provide both nectar and larval food plants.