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
|