What does fall migration look like?

Dr. Calvert watches monarchs as they arrive at their winter home in Mexico.

Go outside, lie down on your back, and simply look up at the sky!

  • Watch for monarchs traveling in a southerly direction, undergoing "directional flight." ("Directional flight" means the butterflies are not moving randomly; they are clearly working to move in a southerly direction.)
  • Monarchs don't migrate far using "flapping flight." It takes too much energy! On sunny days, watch for monarchs spiraling upward in tight circles, lifted effortlessly by thermals. Then watch them glide downward toward the south. (Read this description of a monarch soaring in a thermal, and a field trip in the sky to experience a thermal.)
  • Watch for monarchs gliding with the wind on days when the wind is northerly. The monarchs may be traveling very high! (Read this description of a watching high-flying monarchs with binoculars.)
  • Monarchs migrate alone, but on big migration days you may see many at one time. On a single day you may see tens, hundreds or even thousands flying overhead!

Where Can Migrating Monarchs Be Seen?

  • Where the largest numbers of monarchs breed: Migrating monarchs can be seen anywhere in the monarch's breeding range. However, over half of all monarchs breed in the Midwest's "corn belt" in most years, so the migration is the strongest there during migration.
  • Where the migration route approaches Mexico: Millions and millions of monarchs funnel through Texas on their way to Mexico, so the greatest concentrations of monarchs are seen in that state. Nearby states have strong migrations as well.
  • Where geographic features concentrate the monarchs: The geography of shorelines and peninsulas concentrate the monarchs' flight. This is because monarchs avoid over-water crossings unless the wind is right. The coastlines of the Great Lakes, the Atlantic Ocean and the Gulf of Mexico are excellent places to observe migration.

How Can I Study Migrating Monarchs?

  • Calculate the Migration Rate!

    Monarchs per hour or monarchs per minute

    Make Your Observations on a Regular Basis: If possible, try to put aside 10-15 minutes each day, at the same time each day. With a stopwatch, keep track of the time you begin and end your observations, and tally of the number of monarchs you see.
  • Quantify your observations by calculating the migration rate. Please report the rate as either monarchs per hour (or monarchs per minute). This standard helps people compare one observation to the next.
  • Example: 20-minute daily observation period
  • Shawnee, Kansas
  • Fairfield, Ohio
  • Joplin, Missouri