The museum at La Brea Tar Pits and the William S. Hart museum will remain closed until further notice. Advanced tickets are required for entry to NHM’s Spider Pavilion, and are now available online. See NHMLAC's response to coronavirus (COVID-19).

Follow the Butterflies

Help us count butterflies!

Close up of Painted Lady Butterfly

Every year, painted lady butterflies migrate north from Mexico and inland from the deserts, seeking their food, succulent green plants. As things dry up throughout their range, the butterflies move on, looking for greener pastures. Eventually, the butterflies (or at least their descendants) make it up to the northern states and Canada, to breed and multiply while the summer lasts, and finally make their way south in a much less visible migration that stays at higher elevations in the mountains. 

Image of a Painted Lady Butterfly
Vanessa cardui

Although this happens every year, we have remarkably little data here at the museum about the duration of the event, when exactly it occurs, and how many butterflies there are compared to other years. We thought it would be fun to begin collecting this information in collaboration with the public, since we are all at home. I enlisted my neighbor’s two kids, Sofia and Jackson Caldwell, to help me, and for the last few days we have been counting. Every day around noon we watch for 10 minutes and count all the painted ladies that cross the street in front of our houses. The painted ladies are easy to recognize because they are flying strongly in one direction—no fluttering around like other butterflies. The direction they are going is another thing to record—ours are all flying west, but that can vary by location. 

two kids, a boy and girl, sit on a low wall
Sofia and Jackson Caldwell join Brian Brown for butterfly spotting
Brian Brown

Would you like to join us and help out this scientific project? We have a data form you can fill out here; please record every day until the migration stops in your area.

We need your help to better understand their migration patterns.

Tips: 

  • It is best to conduct the timed count around noon as butterflies like the warm weather. 

  • We are looking for as much data as possible, so if you can keep counting day after day, that is great! 

  • Stop collecting data when the migration stops in your area (i.e., when no butterflies are seen after three sunny days of observation).

Helping out is easy.  Follow these 9 steps:

1) Gather your materials (data sheet, pen/pencil, timing device, compass—you can use the timer and compass on your phone).

2) Download & print your data sheet.

3) Go outside and find a nice safe place to sit (remember to follow orders of your local governments and to employ social distancing—staying six feet away from those that don't live in your household).

4) Start your timer (make note of time) and begin counting the number of painted lady butterflies you see flying past you.

5) Tally each butterfly on your paper as they fly past you.

6) End after 10 minutes (make note of time).

7) Make a note of which direction the butterflies were flying.

8) Make a note of any other butterflies you saw during the 10 minutes.

9) Upload your data using our Google form.

Note: if you are able to get any images of painted lady butterflies before or after your count, please be sure to add them to our painted lady migration project on iNaturalist.