I was excited to see a flutter of wings on one of my milkweed plants outside the window. I’ve been expanding the milkweed patches in my yard for years, hoping a monarch butterfly mother will choose my yard for her babies. But this is good, too. A western tiger swallowtail. This butterfly is feeding on the flower nectar. It won’t lay eggs on the milkweed plant like monarchs will.
They’re as big as monarchs. But monarchs are orange. And there haven’t been many confirmed sightings in our area yet. Only three. Check the report here.
Some of the swallowtails have crescents of blue at the edges of their wings. Those are the females.
The monarchs that migrate to Idaho come from California. The general population is much smaller than the monarch migration from Mexico that heads to spots east of the Rockies for reproduction. We also do not have as many people dedicated to submitting data in the West.