Track Monarch Butterfly Migration
Weekly Monarch Migration News Updates Resume August 2021
Our weekly monarch news updates will resume this month.
What To Report
Now that the summer breeding season is coming to a close, the fall migration monitoring begins. Here is a rundown on what to report:
- Monarch Adult Sighted – Please report all monarch adults (ie. butterflies, not eggs or larvae) that you see, whether or not you think they are migrating south. Reports should reflect the number of monarchs you observe at a single location. In your comments, tell us more about your observation. Were the monarchs exhibiting directional flight? How many adult monarch butterflies did you observe at this one location? How did you estimate the number of monarch observed? Please submit photos when you can.
- Monarch Egg Sighted – Once a week if possible. Please submit photos when you can. Please let us know milkweed species if known.
- Monarch Larva Sighted – Once a week if possible. Please submit photos when you can. Please let us know milkweed species if known.
- Monarch Other Observations – Once a week if possible. Please submit photos when you can. Other observations could include mating, laying eggs, nectaring (please let us know plant species observed if known), basking in the sun, and deceased monarch.
- Milkweed Sighted – Once a week if possible. Please submit photos when you can. Please let us know milkweed species if known.
- Monarch Peak Migration — Monarch Fall migration is spectacular and also unpredictable. People often report seeing large numbers of monarchs flying in a clear “directional” flight, or seeing “hundreds of butterflies” nectaring in a field of flowers fueling up for the long flight. If you witness what seems to be a large number of monarchs for your area (i.e. dozens, hundreds), please report this sighting under PEAK Migration. For reported numbers to be meaningful, please let us know the length of time you spent counting monarchs.
- Monarch Roosts-- Migrating monarchs cluster together in trees at night, forming what is called a roost. A roost may have a handful of butterflies or more than you can count. Fall roost reports should reflect the number of monarchs observed within a roost for a single night. In your comments, let us know when the roost formed, how you estimated the number of monarchs roosting, and other information (such as nearby nectar sources, species of tree(s) in roost, and whether the monarchs are shielded from the wind in their location).
Letters From The Field Monarch Butterfly Biosphere Reserve
For news of the western monarch population, Ms. Gail Morris will begin her weekly posts mid-August. Catch up on her previous news updates: Western Monarch News Archive.
If you missed the posts from Dr. Ellen Sharp, Ms. Anna Moreno, Mr. Pato Moreno, and Ms. Estela Romero this past winter, now is the time to catch up on your reading. These posts provide rich stories from the monarch sanctuaries in the States of Michoacán and Mexico, in central Mexico.
For reports from Cerro Pelon Monarch Butterfly Sanctuary written by Dr. Ellen Sharp, Ms. Anna Moreno, and Mr. Pato Moreno, please refer to:
- Letters From The Field: Archive Collection: Dr. Ellen Sharp
- Letters From The Field: Archive Collection: Ms. Anna Moreno
- Letters From The Field: Archive Collection: Mr. Pato Moreno
For Ms. Romero’s reports from Sierra Chincua and El Rosario Sanctuaries please refer to: