Two Fall Migration Flyways

Sightings of overnight roosts contributed by citizen scientists have revealed that the monarchs follow two distinct flyways as they travel to Mexico, an Eastern Flyway and a Central Flyway. Only one flyway appears to lead directly to Mexico. The eastern flyway lagged behind the central flyway roosts in timing, suggesting that monarchs traveling in the eastern flyway have a reduced chance of making it to the Mexico wintering sites.