Day 7: Santa Cruz Overwintering Sites

We started the day early at Natural Bridges State Park in Santa Cruz to join the local folks in the official Thanksgiving monarch count. Martha Nitzberg, a ranger at Natural Bridges, coordinated the effort and we were pleased that Paul Cherubini joined us. We climbed down the boardwalk where at one time 120,000 monarchs created an orange canopy in the eucalyptus trees. But today there were hardly any to be seen. We took a moment to learn the process of how to count: each of us would count the monarchs in each cluster then we would compare numbers and reach a consensus. Loners and flyers would be counted separately. At first we saw only 436 monarchs in 6 small clusters in the middle of the grove facing east. But then some hikers told us about more on the west side of the thicket, where none of us “experts” expected them. Paul explained that the storm on Friday likely blew some of monarchs from their eastern orientation to move to this side to protect themselves from the intense wind. The clusters there were larger and denser. We updated the census to 1,254 monarchs at this site, better than our first numbers, but considerably lower than last year’s count of 3,500. We also learned that because of the storm we might find monarchs in unusual places.

We jumped in our cars and drove to our next stop, Lighthouse Fields. Almost all the monarchs were clustering on a single Monterey Cypress in the center of the grove facing south. We had the incredible good fortune of running into John Dayton, a renowned professor at San Jose State and a monarch specialist who has personally monitored the California overwintering sites for over 20 years. His explanations easily revealed the depth of his knowledge that tapped into our own desire to learn more about these fascinating insects and their behavior. We could talk with him all day, but we had to move forward with the count!

From outside the rope fence, our estimate was 1,700 monarchs. But we had a wide variation in numbers. Martha asked John Dayton for his estimate: 4,000. Then we discovered an explanation for the discrepancy – the storm had moved the monarchs here, too! Under the authority of the uniformed park ranger we hopped the fence and from our improved vantage point we could see several densely packed clusters on the same tree not visible from the outside. Our unofficial count more than doubled. Although the final official numbers for this site are not yet available, everything seems to indicate they will far surpass last year’s 2,607.

We talked to Paul about this interesting increase of monarchs at Lighthouse Fields when most of the oth

er Western sites have declining numbers. Much of the increase could be due to the improving habitat conditions for the area. More trees have been planted offering more wind protection.

We had a fun discovery back at our cars. Paul noticed a monarch caterpillar on a nearby milkweed, and we found two more, an unusual find for so late in the season.

It was time to begin our trip back to the LA area, but we stopped to see one more site. At Moran Lake the monarchs rested on eucalyptus trees in loose clusters in a broad area. The clusters were lower than the previous sites and the grove and canopy was larger with an opening for the morning sun. As much as we wanted to continue participating in the count, we knew we had to leave. What a great morning with fun people to share our love of monarchs!