Just above the ground at Monarch Butterfly Grove in Pismo Beach are wind anemometers that are collecting data to better understand how wind moves within the grove.
This study is part of the Western Monarch Overwintering Science Initiative, which is working toward monarch conservation.
Kyle Nessen, a graduate student from Cal Poly, San Luis Obispo, is leading the first phase of the Western Monarch Overwintering Science Initiative’s Forest Structure & Cluster Location Project.
Nessen and his colleagues are exploring how to aid Western monarch conservation by studying what overwintering monarchs need to thrive, where and when the butterflies move, and how to better support overwintering through forest management.
The wind anemometers hanging amongst the trees record the average and maximum wind speeds every minute within the grove.
“The goal here is to actually collect real-world numbers of how wind dynamics are occurring in this grove, and then in the Spring I’ll come back and I’ll fly a LiDAR at this grove, recreate this habitat in the computer in 3D and then simulate the same wind events that happened during this season and see how well my computer numbers agree with the actual numbers,” said Nessen.
The wind anemometers will show where the weakest locations are within the grove and the data will recommend if more trees need to be planted.
“What this will give us is a tool to experiment and play with planting designs, so that we can be really confident that the tree recommendations we’re putting forward are actually going to be effective in 20 to 30 years,” said Nessen.
According to the Xerces Society, over 60 overwintering sites along the Pacific Coast have been lost to development over the last several decades.
Nessen says active management of the grove is necessary to help recover and restore the habitat.
“Large hundred-foot eucalyptus generally is what we see monarchs prefer, and the decisions we make today we won’t really see the benefit of for 10, 15, 20 years when they become mature,” said Nessen. “It’s really important for us to make the best possible decisions now so that these groves can be useful to monarchs for many decades to come.”
The Xerces Society also says that Western monarch overwintering numbers have declined more than 90% since the 1980s.
Some visitors hope it can be reversed.
“To know that it's decreasing," said Sierra Williams, a visitor from Fresno. "Definitely makes me sad."
“Yeah," said one San Luis Obispo resident. "Super bad."
Nessen also says the group is conducting a second project at Vandenberg Space Force Base where modified infrared cameras and wind sensors will be used to track monarch cluster locations and movement over the season.
