Where do monarch butterflies go in the winter?

Some flutter down to Southern California, gathering en masse in a eucalyptus grove in the small city of Goleta. If you’re there are the right time of year, you can catch a peek of the winged creatures huddled in enormous clumps in the Goleta Monarch Butterfly Grove.

The Goleta Grove, also called Ellwood Main, is a great place to observe these lovely insects, since it’s small enough that the viewing station allows you to get relatively close up. However, it’s still a good idea to bring binoculars. At first, the clusters will just seem like clumps of dead leaves, but as the sun’s rays warm things up, you’ll start to see a flicker of movement.

Although eucalyptus trees are not native to California, monarch butterflies have favored them as winter hideouts ever since people started planting them in the area. The warmest part of the day, between 12:30 and 2pm, generally hosts the most activity, and the best months to visit the grove are November through February, with December being peak season. 

The peak population varies each year, and sadly, the monarch population has been in serious decline for many years, resulting in smaller and smaller migratory clusters to marvel upon at the Goleta Grove. One factor in their current decline is a parasite called Ophryocystis elektroscirrha, or OE, which has been causing birth defects. Loss of habitat and food resources have also contributed to the problem; monarchs only lay their eggs on milkweed, the sole food of the caterpillars will eat, which makes them highly dependent on what is available in a given region. Planting a variety of native milkweed where you live is one way that you can give the monarchs a little support. 

Update, July 2017: The trails and groves are closed, due to a terrible drought, which has resulted in dead dangerous trees and declining monarch population. As of February 2018, they are still closed indefinitely.