This is what millions of monarch butterflies look like. Last week Center staff traveled to the Monarch Butterfly Biosphere Reserve near Mexico City to witness eastern monarch butterflies during their annual overwintering. Most of the world's monarchs are currently at the reserve. They’re stirring now with the spring warmth, and in March they'll begin one of planet's great migrations. The number of monarchs at the reserve right now is astounding – a sight that brings people to tears. The just-rel